AN OVERVIEW of OBESITY and DIABETES in the DIVERSE POPULATIONS of the PACIFIC May Okihiro, MD

AN OVERVIEW OF OBESITY AND DIABETES IN THE DIVERSE POPULATIONS OF THE PACIFIC

Background: Pacific Islanders (PI) have some May Okihiro, MD; Rosanne Harrigan, EdD, MS, APRN-Rx of the highest prevalence of obesity and type 2 diabetes in the world. Data related to PI are often reported as though the group is an INTRODUCTION prevalence of obesity and obesity-related aggregate; however, PI are a group of very diverse peoples. illnesses underscore the importance of The obesity epidemic is a significant understanding the problem of obesity, Objective: To explore the obesity problem in global public health issue. In the United its correlates and precursors, and the PI by: 1) characterizing the major ethnic States, the prevalence of overweight in health disparities experienced by Pacific groups in the Pacific; 2) describing the most children six to 19 years of age has Island peoples. recent US census data on PI and their recent immigration patterns; and 3) synthesizing the tripled in the last 20 years. Among There are several issues complicating literature on obesity in PI and type 2 diabetes adults, 65.1% are either overweight or our understanding of the health issues mellitus. obese; 30.4% are obese, and 4.1% and health disparities experienced by are extremely obese.1,2 Worldwide Pacific Island peoples. The first is the Methods: Census information and anthropo- there are more than one billion people term itself - Pacific Islanders. Data logic resources on the Pacific Islands and its peoples were obtained through an Internet who are overweight and one third of related to the health status of PI, 3 search. Literature on obesity, diabetes, and these are clinically obese. Closely including reports on the prevalence of body composition in PI were obtained through following this increase in obesity has obesity and diabetes are often presented a systematic analysis of citations listed on been a sharp rise in the prevalence of as though this group is an aggregate. Medline. type 2 diabetes, the most common Such aggregation implicitly homoge-

Results: Pacific Islanders (PI) are diverse chronic disease associated with obesity. nizes these related but diverse people people, culturally, biologically, and linguisti- In 2002, 6%–8% of US adults had and creates an obstacle in itself to 4 cally. Polynesians and some Micronesians have diabetes. Pacific Islanders (PI) have understanding correlates of complex a very high prevalence of obesity and diabetes. some of the highest reported prevalence health issues such as obesity. Melanesians are among the most diverse of obesity and type 2 diabetes in the Another issue is that health data on ethnic groups in the world. Body mass index 5,6 (BMI) cut-point values for Polynesians may be world. PI is sparse. Many obesity studies on PI inaccurate. Pacific Islanders (PI) make up were conducted years ago and have not a small but increasing portion of the been updated. In addition, some Pacific Conclusions and Recommendations: The US population. Increasing numbers of Island groups, such as islanders of cause of obesity and diabetes in PI is unclear. PI are migrating to the United States as Nauru, have been studied extensively Some factors involved are related to urbanization and migration. Obesity research should well as to New Zealand and Australia. while others, such as the Melanesians, distinguish between island ethnicities and not According to the 2002 US Census have received little attention. aggregate all PI together. Research is needed to update, of the total US population of The overall aim of this review is to define body fat distribution of Polynesians in 288.4 million, 942,000 people reported explore the problem of obesity and relationship to obesity co-morbidities, to de- that they were Native Hawaiian or other diabetes in Pacific Island peoples. The termine normal growth of Polynesian children, 7 to determine the relationship between growth PI, an increase of 4% in just 2 years. three main objectives to achieve this are: abnormalities and adult obesity, and to de- The 2001 New Zealand Census re- 1) to characterize the major ethnic termine the impact of immigration on PI. (Ethn vealed that, of the total New Zealand groups in the Pacific within the three Dis. 2005;15 [suppl 5]:S5-71–S5-80) population of 3.7 million, 6.2% or geographic areas of Polynesia, Micro- 231,798 people reported being PI.8 nesia, and Melanesia; 2) to describe the Key Words: Diabetes, Ethnicity, Obesity, Pacific Islander Increasing PI out-migration, increased Pacific Island countries most closely modernization and urbanization of associated with the United States in Pacific Island countries, and the high the context of their current political relationship with the United States, the most recent US Census data, and the Address correspondence and reprint immigration patterns to the United From the Department of Pediatrics requests to May Okihiro, MD; Assistant States; and 3) to synthesize the literature (MO), Department of Complementary and Professor of Pediatrics; University of Ha- on obesity and type 2 diabetes mellitus Alternative Medicine (RH), University of waii, John A. Burns School of Medicine; Hawaii, John A. Burns School of Medicine; 651 Ilalo St; Honolulu, HI 96813; 808-235- in PI. The emphasis will be on Poly- Waianae Coast Comprehensive Health 9501; 808-692-1247; okihirom001@ nesians, including Native Hawaiians, Center (MO), Honolulu, Hawaii. hawaii.rr.com since many obesity studies on PI include

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Polynesians. Body composition studies on PI will be discussed in order to highlight the controversy about BMI cut-points for obesity in Polynesians.

METHODS

Sample Data were obtained using three methodologies. Census information and anthropologic resources on PI were found through an Internet search using the search terms Pacific Islander, origins, pre-contact, migration, and Cen- sus. Information from reliable and verifiable sources was obtained through Internet web sites. Research literature Fig 1. Oceania, showing the geographic areas of Polynesia, Melanesia and relating to obesity and diabetes was Micronesia. Permission for reprint granted from Kirch PV. On the Road of the found by a Medline search of articles Winds: an Archeological History of the Pacific Islands before European Contact. Los through October 2004. Search terms Angeles, CA: The Regents of the University of California. 2000 used included obesity, overweight, body Analyses Melanesians.10 Although still common- composition, body mass index, diabetes, Search data were entered into a ma- ly used today, these groupings have lost Pacific Islander, Hawaii, Polynesia, trix and analyzed for thematic threads their historical importance as research Micronesia, Melanesia, and ethnic. using constant comparative analyses.9 has shown they obscure important The search was supplemented by man- Themes generated included ethnic genetic, linguistic, and cultural relation- ual searching of references from appro- groups in the Pacific, US-associated ships. The labels provide ‘‘geographical priate papers. Forty-four publications Pacific Islands, Pacific Islanders in the referents’’ but should not be used to were reviewed. United States, obesity in Polynesians, meaningfully subdivide segments of Native Hawaiians, body composition of cultural history. Inclusion and Exclusion Criteria Polynesians, BMI cut-points, Polyne- Studies show that Polynesian culture Studies that could be reviewed in sian children, Micronesian, and Mela- and language derived from a common their entirety were included; however, nesians. Findings related to each of ancestral root over a period of about studies that did not define obesity or these categories are described below. 2,500 years. Research in biological an- type 2 diabetes were excluded. Studies Epidemiologic population surveys con- thropology has supported the homoge- that did not distinguish among Pacific ducted in Pacific Island countries were neity of Polynesian populations; mor- Island ethnic groups were also generally used to identify prevalence of obesity phologic features of Polynesians excluded, since this assumes that differ- and diabetes. including large body size, and genetic ent ethnic groups have similar risks. features such as a characteristic nine- base-pair deletion in the mtDNA, are Methodological and Conceptual CHARACTERIZING THE found in extremely high frequency Issues MAJOR ETHNIC GROUPS IN throughout Polynesia.10 One of the challenges of reviewing THE PACIFIC WITHIN THE The islands of Polynesia are found and comparing this historical database THREE GEOGRAPHIC AREAS within a triangle formed by Hawaii to of articles is the changes in definitions of OF POLYNESIA, the north, New Zealand to the south- overweight, obesity and diabetes in MICRONESIA, AND west, and Easter Island to the southeast adults. The definition of overweight MELANESIA (Figure 1). Ethnographically Polynesia and obesity in children has also can be subdivided into two major changed recently from weight-for- In 1932, the French explorer Du- divisions, Western Polynesia including height percentiles to BMI percentiles mond d’Uruville divided indigenous Tonga, Samoa, Wallis, and Futuna and for age and sex. Definitions for each Pacific Islanders into the three racial Eastern Polynesia including the Cook study have been included. groups: Polynesians, Micronesians, and Islands, the Society Islands (Tahiti), the

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Table 1. Political status of the US Associated Pacific Islands

Country Political Status Capital Administration/Government Status of Citizens American Samoa US Territory Pagopago Administered by US Dept of US Nationals who may become Interior US citizens Guam US Territory Agana Administered by US Dept of US Nationals who may become Interior US citizens Commonwealth of US Commonwealth Saipan Administered by US Dept of US Citizens Northern Marianas Interior Federated States of Independent Pohnpei Self-governing. US relationship May freely migrate to US Micronesia Country outlined in Compact of Free Association Belau (Palau) Independent Koror Self-governing. US relationship May freely migrate to US Country outlined in Compact of Free Association Republic of the Marshall Independent Majuro Self-governing. US relationship May migrate freely to US Islands Country outlined in Compact of Free Association

Marquesas, and the more isolated New Guinea, the Solomon Islands, associated Pacific Islands—American islands of Hawaii, Rapa Nui (Easter), Vanuatu, New Caledonia, Maluku and Samoa and the Micronesian islands of and New Zealand. Archeological re- Fiji (Figure 1). In terms of language, Guam, the Commonwealth of the search has demonstrated that Western biological variation, and culture, the Northern Marianas (CNMI), the Fed- Polynesia was first settled around 1000– Melanesians are ‘‘among the most di- erated States of Micronesia (FSM), 900 BC and was the geographic home- verse and heterogeneous to be found in Belau (formerly known as Palau), and land of Ancestral Polynesians. Subse- any comparably sized geographic space the Republic of the Marshall Islands quent migration led to the settlements on earth.’’10 Because of this, the term (RMI). An understanding of these of Eastern Polynesia.10 Melanesia should be used exclusively to islands’ political history and current The islands of Micronesia are locat- describe a geographic region and should relationships with the United States ed around and north of the equator and not imply ethnic, linguistic, or biologic helps to explain the increase in migra- include the Marianas (Guam, Saipan) uniformity. tion in recent years (Table 1). and Belau (Palau) to the east, the In summary, the commonly used The islands of Samoa are divided Federated States of Micronesia (Pohn- terms Polynesia, Micronesia, and Mel- politically into American Samoa and pei, Yap, Kosrae, and Chuuk) centrally, anesia describe three geographic areas in Samoa, an independent island nation the Marshall Islands to the west and the Pacific populated by many ethnic formerly known as Western Samoa and Nauru and Kiribati to the south groups. Polynesians are ethnically the administered in the past by New (Figure 1). In contrast to Polynesia, most homogeneous. Micronesians are Zealand. As a US territory, American Micronesia does not form a ‘‘monophy- made up of at least three cultural groups Samoa is administered by the US De- letic cultural group.’’ Linguistic and and Melanesians are among the most partment of the Interior. The people of archeological studies have shown that heterogeneous people in the world. American Samoa are US nationals and human settlement in Micronesia prob- may become naturalized citizens. Out- ably involved a three-part sequence. migration has been common and there One group moved from the islands of DESCRIBING THE PACIFIC are now more Samoans living abroad, Southeast Asia to the western Microne- ISLAND COUNTRIES MOST especially in California and Hawaii, sian islands of Palau and the Marianas. CLOSELY ASSOCIATED WITH than in American Samoa. Another group probably migrated from THE UNITED STATES— Of the US-associated islands of the Solomon Island-Vanuatu region to THEIR CURRENT Micronesia, Guam is the largest and, the central-eastern Micronesian islands RELATIONSHIPS WITH THE like American Samoa, is a territory of including Kiribati, Kosrae, Pohnpei, UNITED STATES,US the United States. The native people of and the Marshall Islands and a third CENSUS DATA, AND Guam are known as Chamorros. The group moved to the islands of Yap from RECENT IMMIGRATION islands north of Guam make up the the Bismarck Archipelago of Papua PATTERNS Commonwealth of the Northern Mari- New Guinea.10 anas. Established in 1975, CNMI is The islands of Melanesia, in the The largest PI immigrant groups in administered under the US Department southwestern Pacific, include Papua the United States are from the US- of the Interior with a local governing

Ethnicity & Disease, Volume 15, Autumn 2005 S5-73 PACIFIC ISLANDERS,OBESITY AND DIABETES - Okihiro and Harrigan body and all residents are US citizens. the Midwest. Over half, 58%, of the in (Western) Samoa in 1978 and 1991 The Federated States of Micronesia Pacific Islanders lived in just two states, showed an increase in obesity prevalence (FSM) and the Republic of the Marshall California and Hawaii. The cities with from 1978 to 1991 in all locations but Islands (RMI) were administered by the the largest PI populations were Hono- most notably in the most rural commu- United States after World War II. In lulu, New York, Los Angeles, and San nity of Tuasivi where prevalence in 1986 and 1990, FSM and RMI, re- Diego.12 males increased almost 300% to 39.3% spectively, became newly independent, and in females by 115% to 57.2%. In self-governing nations. FSM and RMI 1991 there were higher levels of obesity governments each signed a Compact of SYNTHESIZING THE in urban vs rural areas; 74% of urban Free Association with the United States LITERATURE ON OBESITY women and 56% of urban men were to provide the citizens with critical AND TYPE 2DIABETES obese. Women tended to be more obese economic development aid and the MELLITUS IN PACIFIC than men; the mean BMI in the urban right to migrate freely to the United ISLANDERS community was 31.8 kg/m2 in men and States, without a passport, in exchange 34.8 kg/m2 in females. Even relatively for defense rights to their waterways and Polynesians young subjects, 25 to 34 years old, were land. In 1994 Belau became in in- Early European explorers first noted obese. More than 50% of women in all dependent nation and ratified its own the striking, large, muscular build of locations and 45% of urban young men Compact with the United States. Since Polynesians in comparison to other were obese.15 independence, large numbers of Micro- Pacific Islanders. Of the Samoans: Diabetes, the best documented con- nesians from FSM, the RMI, and Belau ‘‘The men were a remarkably fine sequence of obesity, is also very preva- have migrated to the United States. looking set of people, and among them lent among Polynesians, especially Migration has increased in recent years, were several above six feet high, with among those who have become more possibly due to changes under the new Herculean proportions.’’ Of the Maori: westernized.16–25 The longitudinal compacts for FSM and RMI that place ‘‘The Zealanders are generally tall and study in (Western) Samoa found a sharp restrictions on the freedom to relocate well built. Men of six feet are not at all rise in the prevalence of diabetes as the to the United States.11 uncommon among them.’’ Another obesity prevalence climbed over the 13- wrote of the New Zealander Maori that year follow up in both rural and urban Pacific Islanders in the United ‘‘the inhabitants are of a fine stature but communities.22 Between 1978 and States their legs are so thick that they appear 1991 diabetes increased in the rural According to the 2000 census, swollen.’’13 community of Poutasi, from 0.1% to 401,000 people identified themselves Polynesians may have always been 5.3% in men. In Tuasivi, the most rural as Native Hawaiian, either alone or in ‘‘big’’ but they have not always been community, prevalence increased from combination with one or more other obese. Several population surveys were 2.3% to 7.0% in men and from 4.4 to races, making Native Hawaiians the conducted from 1978 to 1991 by the 7.5% in women. Age-standardized prev- largest PI group. Samoans were the International Diabetes Institute in Aus- alence was highest in the urban center of second largest group with 133,000 tralia to determine the obesity preva- Apia; 9.5% in men and 13.4% in followed by Chamorros or Guamanians lence in several Pacific Island countries. women. Diabetes increased with age, with 93,000. Combined, Native Ha- These included the Polynesian islands of peaking at 35.4% in women 55 to waiians, Samoans, and Guamanians Samoa, New Caledonia and Wallis 64 years. However, diabetes was also accounted for 74% of all PI in the Island, Cook Islands, Niue, and Tuvalu. seen at younger ages; 5.2% of men and United States. In 2000 there were Adults 25 to 69 years old were surveyed 10.5% of women, ages 35–44 years. 22,971 Micronesians other than Gua- and height and weight measured. Body A more recent survey of the Poly- manians, including 6,650 Marshallese, mass index (BMI) was calculated and nesian country of Tonga conducted 3,469 Belauans, and 2,121 from the obesity defined as a BMI greater than or between 1998 and 2000 showed an FSM states of Chuuk, Pohnpei, Kosrae, equal to 30 kg/m2.14,15 Subjects were overall age-standardized prevalence of and Yap. Thirty-six percent of Native also given a standard 75 gm oral glucose diabetes of 15.1%, 12.2% in men and Hawaiians and other PI were under the tolerance test to determine prevalence of 17.6% in women, of which 80% was age of 18, while only 5% were 65 or diabetes. previously undiagnosed. Standardized older.12 As in many developing countries, for the Segi world population aged 30 In 2000, 73% of PI lived in the population surveys showed the preva- to 64 years, the prevalence of type 2 Western United States, 14% in the lence of obesity increasing with urban- diabetes was 16.0% (13.3–18.6). Obe- South, 7% in the Northeast, and 6% in ization and modernization. The surveys sity was common; 60.3% had a BMI

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Table 2. Body composition studies of Polynesian adults

Author Methods Results Rush EC 199728 Subjects: 42 Caucasian and 40 Polynesian At a fixed %BF, BMI was higher in Polynesians compared with Caucasians. A women BMI of 30 kg/m2 for the Caucasian group corresponded to a BMI of 34 kg/ Measurements: BMI, skin fold thicknesses, m2 for the Polynesians at an equivalent %BF (42%). waist and hip circumference Body Composition: Total body water using oxygen-18 dilution. Swinburn B Subjects: 189 Maoris, 185 Samoans, 241 At higher BMI, Polynesians (Maori and Samoans combined) had significantly 199629 Caucasians higher ratio of LM to FM compared with Caucasians. Polynesians with BMI Measurements: BMI, skin-folds greater than 25 kg/m2 have more FFM and less FM than Caucasians and are Body Comp: BIA and DXA significantly leaner. Swinburn B Subjects: 128 Polynesian Cook Islanders Male and female Polynesians were younger and heavier than Caucasians. At 199930 and 493 Caucasians every level of weight (adjusted for height and age), resistance was lower in Measurements: Weight, height, BMI Polynesians. At every level of BMI the predicted %BF was lower in Body Composition: BIA Polynesians. Craig P 200131 Subjects: 543 Tongans and 393 Caucasians Tongans had significantly higher FFM, elbow width, and lower %BF than Measurements: BMI, waist/hip circumference, Caucasians (Australians). A %BF of 25% at a BMI of 30 kg/m2 in Australian four skinfolds, midarm circumferences, women was equivalent to a %BF of 28.8% at a BMI of 35.1 kg/m2 in Tongan elbow breath. women. A %BF of 25% at a BMI of 30 kg/m2 in Australian men was Body composition: BIA equivalent to a %BF of 27.5% at a BMI of 35.8 kg/m2 in Tongan men. Craig P 200332 Subjects: 56 Tongans and 85 Caucasians Tongan males (BMI, 32.8 6 4.6 kg/m2) were heavier than Caucasian males Measurements: BMI (BMI, 27.1 6 3.7 kg/m2) but differences in TBF, CAF, and A%F were not Body Comp: TBF, CAF, A%F measured by DXA significant. Tongan females (BMI, 34.3 6 5.5 kg/m2) were heavier than Caucasian females (BMI, 26.2 6 6.3 kg/m2) but differences in TBF and A%F were less than expected given the difference in BMI.

%BF5percent body fat; BMI5body mass index (kg/m2); LM5lean mass; FM5fat mass; FFM5fat free mass; TBF5total body fat; CAF5central abdominal fat; A%F5abdominal percent fat; BIA5bioelectrical impedance; DXA5dual energy x-ray absorptiometry.

$30 mg/dl and the average BMI was obese. The percentage of Hawaiian to BMI cut-points accepted by the 32.3 kg/m2.23 ancestry was significantly associated Center for Disease Control (CDC) with increased BMI, waist-to-hip ratio and the World Health Organization Native Hawaiians (WHR), and age; this association per- (WHO). However, the point at which Native Hawaiians, like other Poly- sisted after adjusting for age, leisure Polynesians move from simply being big nesians, also have a very high prevalence time physical activity and total dietary in stature to being overly fat or obese, of obesity and diabetes.5,24–26 Accord- intake. and at risk for obesity-related illness, is ing to the 2003 Hawaii State De- The same study, using the standard unclear. The importance of this point is partment of Health Behavioral Risk world population of Segi, found that the underscored by the acceptance of large Factor Surveillance Survey (BRFSS) age-adjusted prevalence rates of im- size in Polynesian culture. Body com- telephone survey, 32.6% of Hawaiians paired glucose tolerance and type 2 position studies help to define this risk reported they were overweight (BMI 25 diabetes among rural native Hawaiians, by determining the amount of body fat to 30) and 32.9% reported they were ages 30 to 64 years, was 15.5% and for a given BMI, and in some cases, the obese (BMI.30). Of Hawaiians, 20.4%, respectively. This is the highest distribution of body fat. 13.8% reported they had diabetes vs prevalence of diabetes in a Polynesian or Several studies on the body compo- 7.6% prevalence in the general popula- part-Polynesian group reported. Preva- sition of Polynesian adults have con- tion.26 lence of diabetes was significantly higher cluded that BMI criteria for obesity in The Native Hawaiian Health Re- among full Hawaiians compared with Caucasians may not be appropriate for search Project studied 567 rural Native part-Hawaiians (34.1% vs 19.3%).27 Polynesian adults. Studies on Polyne- Hawaiians, 30 years of age and older, sians from Tonga, Samoa, the Cook and found the combined prevalence of Polynesian Ethnicity, Body Islands, and New Zealand (Maoris) overweight (BMI 25–30 kg/m2)and Composition and BMI have shown that Polynesians are obesity (BMI.30 kg/m2) was 81.5%.5 Clearly, large numbers of Polyne- leaner than Caucasians at a given BMI Almost half of participants (49%) were sians are overweight or obese according (Table 2). Body composition studies

Ethnicity & Disease, Volume 15, Autumn 2005 S5-75 PACIFIC ISLANDERS,OBESITY AND DIABETES - Okihiro and Harrigan have not been done in Micronesians or of adult Polynesians has rapidly in- sian children, including Native Hawai- Melanesians. creased over the last 20 to 30 years. This ian children, are taller and heavier, with trend has been accompanied by an a higher BMI, when compared with BMI Cut-Points for Obesity in equally rapid increase in diabetes. accepted US reference standards.41,42 Polynesians Stevens commented, ‘‘Even in groups In order to determine whether BMI Body composition studies have such as Samoans, in which scientific standards are appropriate for PI chil- shown that percent body fat (%BF) evidence may indicate that a higher cut- dren, a few studies have examined the differs between ethnic groups. For the point could be justified, a policy to set relationship between BMI and body same %BF, Polynesians and African a higher BMI cut-point for obesity may composition.43,45 These studies, howev- Americans have a higher BMI compared not gain strong support.’’37 er, did not delineate among the differ- with Caucasians. Other studies have ent Pacific Island ethnic groups. A small found that Asians have a lower BMI for Obesity, Body Composition and BMI study on children five to 14 years of a given body fat percent than Cauca- Cut-Points in Polynesian Children age, using bioelectrical impedance anal- sians.33–34 However, the question as to The question of whether ethnic- ysis (BIA), showed that Maori and whether BMI cut points should be specific cut-points for BMI should be ‘‘Pacific Island’’ girls had lower %BF ethnic-specific remains controversial. applied to children is even less clear. than Caucasian children for a given Stevens points out that obesity cut- Body mass index (BMI) changes BMI.43 points should be based on risk, rather throughout childhood as body fat stores A large study by Tyrell et al con- than %BF.35 Comparisons for risk must change, dropping to a low at about age ducted in New Zealand with .2000 be done carefully for each outcome, 6 and increasing steadily thereafter. In children determined obesity prevalence such as diabetes or hypertension, since the United States experts have recom- among school children using BMI and each may yield a different result. For mended that children with a BMI for %BF by BIA. All PI children except for example, Stevens showed that, for di- age and sex between the 85th and 95th Maoris were grouped together.44,45 abetes, African-American women with percentiles should be considered at risk Obesity prevalence, based on BMI, a BMI of 30 kg/m2 have an equivalent for overweight and that children above varied with ethnicity and was highest risk to that of White women with a BMI the 95 percentile considered overweight. among PI children and Maori children, ranging from 28.0 to 34.5 kg/m2, However studies have suggested that 24.1% and 15.8%, respectively. A small depending on the measured effect (in- BMI cut-points for children may also but statistically significant effect of cidence rate, rate ratio, or rate differ- need to be ethnic specific. A study of ethnicity on this relationship was ence). Stevens also demonstrated that Singapore Chinese, Beijing Chinese, thought to be due to the large number the literature on BMI mortality associa- and Dutch children showed that for of PI children with BMI .30 kg/m2 tions showed no support for a lower the same BMI for age and sex, Singa- but Tyrell et al stated that this should cut-point for obesity in Asians com- pore children had a higher %BF than not justify the use of different BMI pared to Caucasians.36–37 the other children, implying that the percentiles for different ethnicities. Tyr- To address the same issue in Asians, relationship between %BF and BMI can ell’s study also indicated that in popula- WHO convened a panel of experts in differ among ethnicities in children.39 tions, such as PI, with high levels of 2003.38 The panel concluded that, Those who know Polynesian chil- obesity-related disease, accepting higher although Asians tend to have a higher dren also have the general impression BMI values for PI children would be %BF compared with Caucasians, the that they are ‘‘bigger’’ than Caucasian accepting a different level of health. available data does not indicate clear and Asian children. There are a limited These researchers concluded that ethnic- BMI obesity cut-points applicable to all number of studies on normal growth specific BMI percentiles for childhood Asians. A substantial portion of Asians and the overweight prevalence of PI obesity are not appropriate. have risk factors for diabetes and children, including Polynesian children. cardiovascular disease below the WHO A study in the 1980s showed that the Micronesians BMI cut-point of 25 kg/m2. Lowering growth of Samoan children was mark- The prevalence of obesity and di- the value by three units may be edly influenced by westernization.40 abetes in some Micronesians is also very appropriate for Hong Kong Chinese, Samoan children from more rural high.46–48 In Nauru, a small island Indonesians, and Singaporeans but is communities of (Western) Samoa were country now almost completely depen- likely too high for other populations shorter and lighter for height compared dent on imported foods, 70.3% of like the Japanese. with Samoan children from the more Micronesian women are obese (BMI. Thus, while Polynesians may be westernized American Samoa and Ha- 30). In 1987 the mean BMI of males leaner than Caucasians, the mean BMI waii. Studies have shown that Polyne- was 34.2 for males and 34.9 for

S5-76 Ethnicity & Disease, Volume 15, Autumn 2005 PACIFIC ISLANDERS,OBESITY AND DIABETES - Okihiro and Harrigan females.47 In accordance with this high Islanders, have also been affected by Studies relating health risk to eth- level of obesity is an extremely high urbanization and westernization.52,53 nicity are inherently difficult and com- prevalence of diabetes. The prevalence, Few studies on the prevalence of obesity plex. Kaplan and Bennett further note age standardized to Australia, was 37%, and diabetes have been done in Mela- ‘‘the complexity of individual identity, the second highest in the world after the nesia in the last 15 years; however, the lack of clear cut boundaries between American Pima Indians.47 Diabetes was previous studies have shown a rising categories used to capture socially de- previously unknown in Nauru. prevalence of both problems. The 1993 fined constructs of race and ethnicity, A survey of adults on Kosrae, an National Nutrition Survey in Fiji and the lack of consistency across island state in the Federated States of showed 29% of native Fijian women studies and datasets make it difficult to Micronesia, also showed a very high and 11.2% of native Fijian men were write about race/ethnicity with pre- prevalence of obesity and diabetes.48 overweight. Diabetes prevalence was cision.’’ In addition ‘‘the racial/ethnic Like Nauruans, Kosraean lifestyles have 12%, although the survey did not categories commonly used in biomedi- become more sedentary and dependent distinguish between native Fijians and cal sciences and epidemiology are broad on imported Western processed food. Indo-Fijians.54 and overlapping. Individuals do not fit Of 2188 adults surveyed, 29% had In a 1998 WHO report, 2.6% of neatly into these categories, and these a BMI 25–29 kg/m2, 35% had a BMI rural men and 5.1% of rural women in broad groupings can obscure significant 30–34 kg/m2, and 24% had a BMI Vanuatu were obese compared with within-group heterogeneity.’’58 Self- $35 kg/m2. Twelve percent of the 17.9% of urban men and 27.9% of identified ethnicities found in many population had diabetes. In both Nauru urban women.53 Similarly, a 1985 pop- studies often force a person to choose and Kosrae, the risk of diabetes in- ulation survey of the same population one ethnicity when he or she may, in creased with BMI and age. showed a much lower prevalence of fact, be biologically or culturally from There are few obesity studies on diabetes although rural vs urban differ- several ethnicities. western Micronesians, who have differ- encespersisted:1.0%ofruralmen Thus, caution must be taken when ent ethnic origins than central-eastern and 0.9% of rural women had diabetes determining risk and making conclu- Micronesians, such as those from compared with 2.1% of urban men sions about health, especially when Nauru, Kosrae, and the Marshall Is- and 12.1% of urban women. A relying on data that arbitrarily aggregate lands. In addition, little has been survey in the Solomon Islands of people, such as PI. When reaching published about nutritional problems rural and urban Melanesians showed conclusions in a study involving ethnic- and risk factors for adult disease in PI an age standardized rate of impaired ity, researchers should remember that children including Micronesian chil- glucose tolerance plus diabetes of ‘‘a statistically significant association dren. A 1997 study in the Marshall only 0.14% for males and 1.9% for between race or ethnicity and an Islands showed that while 50% of females.55 undesirable health outcome does not men and 60% of women were either by itself establish causality. Health overweight or obese, 35.5% of chil- outcomes usually have multiple causes dren 1–5 years of age and 36.3% DISCUSSION that can be either direct or indirect of children 5–10 years of age were and are often interrelated and interac- stunted. Almost a third of the house- Pacific Islanders are a diverse people tive.’’58 holds had at least one obese adult —culturally, biologically, and linguisti- In the study of obesity, the distinc- and one undernourished child.49 Stud- cally. Although other reviews have tion among PI subgroups is important ies in other populations have suggested addressed obesity in PI, these investiga- since differences in body composition that low birth weight and nutritional tions have not distinguished among the and body size among the island ethni- stunting in early childhood may increase different Pacific Island ethnicities.56,57 cities are integral to both the under- the risk of obesity, even central obesi- Studies relating health risk to ethnicity standing of normal growth of PI ty.50,51 are important, especially in light of children and disease susceptibility of health disparities experienced by PI. PI adults. Some have concluded that Melanesians However, as Kaplan and Bennett note, BMI cut-point values should be specific As stated previously, Melanesia has ‘‘for the discussion of disparities to be for all PI but this is probably not a complex history and thus, caution precise and meaningful, equal attention appropriate since body size and compo- should be taken when making conclu- must be given to the way in which race sition may differ across ethnic sub- sions about epidemiologic and clinic and ethnicity are conceptualized and groups. Studies have shown that Poly- studies from this geographic area. It is described and the rationale for reporting nesians are leaner than Caucasians with clear that Melanesians, like other Pacific racial/ethnic differences.’’58 the same BMI but similar studies have

Ethnicity & Disease, Volume 15, Autumn 2005 S5-77 PACIFIC ISLANDERS,OBESITY AND DIABETES - Okihiro and Harrigan not been done on Micronesians and determine normal growth of Polynesian 3. World Health Organization. Global strategy Melanesians. children and to determine whether on diet, physical activity, and health. Available at: www.who.int. standard growth charts, such as those The literature demonstrates that 4. National Diabetes Fact Sheet. Center for obesity and diabetes are common recommended by the CDC, are appro- Disease Control. Available at: www.cdc.gov. among many PI but the causes remain priate for Polynesian children. Further 5. Grandinetti A, Chang HK, Chen R, Fujimoto unclear. Factors involved are related to research is also needed to assess the WY, Rodriguez BL, Curb JD. Prevalence of the rapidly changing lifestyles associated relationship of growth abnormalities, overweight and central adiposity is associated with percentage of indigenous ancestry among with urbanization and migration. such as stunting, to obesity-related illness native Hawaiians. Int J Obes Relat Metab Sedentary lifestyles, diets higher in and to define other risk factors in Disord. 1999;23(7):733–737. fat and refined sugars, and decreased childhood that increase susceptibility to 6. Hodge AM, Dowse GK, Zimmet PZ. Associ- infant breastfeeding are now common obesity and diabetes in this population. ation of body mass index and waist-hip among Pacific Islanders and have all Research is also needed on island circumference ratio with cardiovascular disease risk factors in Micronesian Nauruans. Int J Obes been associated with obesity and di- populations that have been poorly Relat Metab Disord. 1993;17(7):399–407. 59–61 studied, such as western Micronesians abetes. Theroleofbirthand 7. Native Hawaiians and Other Pacific Islanders childhood factors such as low birth and Melanesians. Research is needed to honored in May. Available at: www.census. weight, stunting, and malnutrition in further determine the impact of urban- gov. the development of obesity remains ization and migration on the health of 8. Pacific Peoples in New Zealand. Available at: unclear. However, studies have shown PI. www.minpac.govt.nz. Finally, until factors associated with 9. Garrard J. Health Sciences Literature Review a relationship between these factors and Made Easy: The Matrix Method. Boston, Mass: obesity and its related illnesses such as obesity and its co-morbidities are fur- Jones and Bartlett Publishers; 1999. diabetes.50,51,62 Finally, the role of ther delineated, research on these prob- 10. Kirch PV. On the Road of the Winds: An genetic susceptibility is unknown. lems should distinguish island groups Archeological History of the Pacific Islands before and not aggregate all PI as one European Contact. Berkeley, Calif: University homogenous group. of California Press; 2000. 11. Grieco EM. The Federated States of CONCLUSIONS AND Micronesia: The ‘‘push’’ to migrate. Migra- RECOMMENDATIONS tion Policy Institute. Available at: www. ACKNOWLEDGMENTS migrationinformation.org. In conclusion, the peoples of the The contents of this article are solely the 12. Grieco EM. The Native Hawaiian and Other responsibility of the authors and do not Pacific are diverse, and obesity and type Pacific Islander Population: 2000. US Census necessarily represent the official views of the Bureau. Available at: www.census.gov. 2 diabetes are common. Polynesians NCRR/NIH or Department of the Interior. 13. Houghton P. The adaptive significance of have been shown to be bigger and leaner We would also like to thank the following Polynesian body form. Ann Hum Biol. than Caucasians. In light of the con- for their support and editorial assistance: 1990;17(1):19–32. flicting implications of inherently large Brian Quinn, Dr. James Davis, associate 14. Hodge AM, Dowse GK, Zimmet PZ, Collins size and high prevalence of obesity- professor, John A. Burns School of Medicine VR. Prevalence and secular trends in obesity in Pacific and Indian Ocean island populations. related illnesses, it is unclear whether (JABSOM), Dr. Kelley Withy, associate professor of Family Practice, JABSOM, Obes Res. 1995;3(suppl 2):77s–87s. BMI cut-points should be specific for and Dr. Nina Etkin, professor of Anthro- 15. Hodge AM, Dowse GK, Toelupe P, Collins Polynesians. However, it is clear that pology, University of Hawaii. VR, Imo T, Zimmet PZ. Dramatic increase in because of the differences in anthro- Supported by the National Center for the prevalence of obesity in Western Samoa over the 13 year period 1978–1991. Int J Obes pologic origins and the lack of research Research Resources, National Institutes of Relat Metab Disord. 1994;18(6):419–428. Health, grant R25 RR019321 and the US on the body composition of Microne- 16. Scragg R, Baker J, Metcalf P, Dryson E. Department of Defense, Pacific Telehealth sians and Melanesians, recommenda- Prevalence of diabetes mellitus and impaired and Technology Hui, contract #1435-04- tions for ethnically specific BMI cut- glucose tolerance in a New Zealand multiracial 03-CT-87084. points should not be generalized to all workforce. NZMedJ. 1991;104(920): PI. 395–397. REFERENCES 17. McGarvey ST. Obesity in Samoans and In order to further understand the 1. Ogden CL, Carroll MD, Flegal KM. Epide- a perspective on its etiology in Polynesians. health risks for Polynesians, research is miologic trends in overweight and obesity. Am J Clin Nutr. 1991;53(6 suppl):1586S– needed to define the distribution of Endocrinol Metab Clin North Am. 2003;32(4): 1594S. body fat in Polynesians as it relates to 741–760, vii. 18. Weinstein S, Sedlak-Weinstein E, Taylor R, obesity co-morbidities, and to deter- 2. Hedley AA, Ogden CL, Johnson CL, Carroll Zimmet P. The high prevalence of impaired MD, Curtin LR, Flegal KM. Prevalence of glucose tolerance and diabetes mellitus in an mine the consequences of sustaining overweight and obesity among US children, isolated Polynesian population, Manihiki, higher BMI over time in Polynesians. adolescents, and adults, 1999–2002. JAMA. Cook Islands. NZMedJ. 1981;94(697): Clearly more research is needed to 2004;291(23):2847–2850. 411–413.

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19. King H, Taylor R, Koteka G, et al. Glucose Tongans. Acta Diabetol. 2003;40(suppl 1): 46. King H, Zimmet P, Raper LR, Balkau B. Risk tolerance in Polynesia. Population-based sur- S282–S285. factors for diabetes in three Pacific popula- veys in Rarotonga and Niue. Med J Aust. 33. Deurenberg P, Deurenberg-Yap M. Differ- tions. Am J Epidemiol. 1984;119(3):396–409. 1986;145(10):505–510. ences in body-composition assumptions across 47. Dowse GK, Zimmet PZ, Finch CF, Collins 20. King H, Rewers M. Global estimates for ethnic groups: practical consequences. Curr VR. Decline in incidence of epidemic glucose prevalence of diabetes mellitus and impaired Opin Clin Nutr Metab Care. 2001;4(5): intolerance in Nauruans: implications for glucose tolerance in adults. WHO Ad Hoc 377–383. the ‘‘thrifty genotype.’’ Am J Epidemiol. Diabetes Reporting Group. Diabetes Care. 34. Deurenberg P, Deurenberg-Yap M, Guricci S. 1991;133(11):1093–1104. 1993;16(1):157–177. Asians are different from Caucasians and from 48. Shmulewitz D, Auerbach SB, Lehner T, et al. 21. Zimmet P, Faaiuso S, Ainuu J, Whitehouse S, each other in their body mass index/body fat Epidemiology and factor analysis of obesity, Milne B, Deboer W. The prevalence of percent relationship. Obes Rev. 2002;3(3): type II diabetes, hypertension, and dyslipide- diabetes in the rural and urban Polynesian 141–146. mia (syndrome X) on the Island of Kosrae, population of Western Samoa. Diabetes. 35. Stevens J. Ethnic-specific cutpoints for obesity Federated States of Micronesia. Hum Hered. 1981;30(1):45–51. vs country-specific guidelines for action. 2001;51(1–2):8–19. 22. Collins VR, Dowse GK, Toelupe PM, et al. Int J Obes Relat Metab Disord. 2003;27(3): 49. Gittelsohn J, Haberle H, Vastine AE, Dyck- Increasing prevalence of NIDDM in the 287–288. man W, Palafox NA. Macro- and microlevel Pacific island population of Western Samoa 36. Stevens J, Truesdale KP. Epidemiology and processes affect food choice and nutritional over a 13-year period. Diabetes Care. consequences of obesity. J Gastrointest Surg. status in the Republic of the Marshall Islands. 1994;17(4):288–296. 2003;7(4):438–442. J Nutr. 2003;133(1):310S–313S. 23. Colagiuri S, Colagiuri R, Na’ati S, Muimui- 37. Stevens J, Juhaeri, Cai J, Jones DW. The 50. Popkin BM, Richards MK, Montiero CA. heata S, Hussain Z, Palu T. The prevalence of effect of decision rules on the choice of a body Stunting is associated with overweight in diabetes in the kingdom of Tonga. Diabetes mass index cutoff for obesity: examples from children of four nations that are undergoing Care. 2002;25(8):1378–1383. African-American and White women. Am J the nutrition transition. J Nutr. 1996;126(12): 24. Beddow R, Arakaki R. Non-insulin depen- Clin Nutr. 2002;75(6):986–992. 3009–3016. dent diabetes mellitus: an epidemic among 38. WHO Expert Consultation. Appropriate 51. Hoffman DJ, Sawaya AL, Verreschi I, Tucker Hawaiians. Hawaii Med J. 1997;56(1):14, body-mass index for Asian populations and KL, Roberts SB. Why are nutritionally stunted 16–17. its implications for policy and intervention children at increased risk of obesity? Studies of 25. Aluli NE. Prevalence of obesity in a Native strategies. Lancet. 2004;363(9403):157–163. metabolic rate and fat oxidation in shantytown Hawaiian population. Am J Clin Nutr. 39. Deurenberg P, Deurenberg-Yap M, Foo LF, children from Sao Paulo, Brazil. Am J Clin 1991;53(6 suppl):1556S–1560S. Schmidt G, Wang J. Differences in body Nutr. 2000;72(3):702–707. 26. Hawaii State Department of Health. 2003 composition between Singapore Chinese, 52. Hughes RG. Diet, food supply, and obesity in State of Hawaii Behavioral Risk Factor Beijing Chinese, and Dutch children. Eur J the Pacific. World Health Organization. Surveillance System. Available at: www. Clin Nutr. 2003;57(3):405–409. Available at: www.wpro.who.int. hawaii.gov. 40. Bindon JR, Zansky SM. Growth patterns of 53. World Health Organization Report. Work- 27. Grandinetti A, Keawe’aimoku Kaholokula J, height and weight among three groups of shop of obesity prevention and control Chang HK, et al. Relationship between plasma Samoan preadolescents. Ann Hum Biol. strategies in the Pacific. World Health Orga- glucose concentrations and Native Hawaiian 1986;13(2):171–178. nization. Available at: www.wpro.who.int. Ancestry: The Native Hawaiian Health Re- 41. Chai D, Kaluhiokalani N, Little J, et al. 54. Vatucawaqa P, Marchesich R, Food and search Project. Int J Obes Relat Metab Disord. Childhood overweight problem in a selected Agriculture Organization, United Nations. 2002;26(6):778–782. school district in Hawaii. Am J Hum Biol. Available at: www.fao.org. 28. Rush EC, Plank LD, Laulu MS, Robinson 2003;15(2):164–177. 55. Eason RJ, Pada J, Wallace R, Henry A, SM. Prediction of percentage body fat from 42. Derrickson J, Tanaka D, Novotny R. Heights Thornton R. Changing patterns of hyperten- anthropometric measurements: comparison of and weights of Head Start preschool children sion, diabetes, obesity, and diet among New Zealand European and Polynesian young in Hawaii. J Am Diet Assoc. 1997;97(12): Melanesians and Micronesians in the Solomon women. Am J Clin Nutr. 1997;66(1):2–7. 1424–1426. Islands. Med J Aust. 1987;146(9):465– 29. Swinburn BA, Craig PL, Daniel R, Dent DP, 43. Rush EC, Plank LD, Davies PS, Watson P, 469, 473. Strauss BJ. Body composition differences Wall CR. Body composition and physical 56. Davis J, Busch J, Hammatt Z, et al. The between Polynesians and Caucasians assessed activity in New Zealand Maori, Pacific and relationship between ethnicity and obesity in by bioelectrical impedance. Int J Obes Relat European children aged 5–14 years. Br J Nutr. Asian and Pacific Islander populations: a liter- Metab Disord. 1996;20(10):889–894. 2003;90(6):1133–1139. ature review. Ethn Dis. 2004;14(1):111–118. 30. Swinburn BA, Ley SJ, Carmichael HE, Plank 44. Tyrrell VJ, Richards GE, Hofman P, Gillies 57. Duncan E, Schofield G, Duncan S, Kolt G, LD. Body size and composition in Polyne- GF, Robinson E, Cutfield WS. Obesity in Rush E. Ethnicity and body fatness in New sians. Int J Obes Relat Metab Disord. Auckland school children: a comparison of the Zealanders. N Z Med J. 2004;117(1195): 1999;23(11):1178–1183. body mass index and percentage body fat as the U913. 31. Craig P, Halavatau V, Comino E, Caterson I. diagnostic criterion. Int J Obes Relat Metab 58. Kaplan JB, Bennett T. Use of race and Differences in body composition between Disord. 2001;25(2):164–169. ethnicity in biomedical publication. JAMA. Tongans and Australians: time to rethink the 45. Tyrrell VJ, Richards G, Hofman P, Gillies GF, 2003;289(20):2709–2716. healthy weight ranges. Int J Obes Relat Metab Robinson E, Cutfield WS. Foot-to-foot bio- 59. Forshee RA, Anderson PA, Storey ML. The Disord. 2001;25(12):1806–1814. electrical impedance analysis: a valuable tool role of beverage consumption, physical activ- 32. Craig P, Samaras K, Freund J, Culton N, for the measurement of body composition in ity, sedentary behavior, and demographics on Halavatau V, Campbell L. BMI inaccurately children. Int J Obes Relat Metab Disord. body mass index of adolescents. Int J Food Sci reflects total body and abdominal fat in 2001;25(2):273–278. Nutr. 2004;55(6):463–478.

Ethnicity & Disease, Volume 15, Autumn 2005 S5-79 PACIFIC ISLANDERS,OBESITY AND DIABETES - Okihiro and Harrigan

60. Schmidt M, Affenito SG, Striegel-Moore R, Pediatr Adolesc Med. 2005;159(7):626– tative review of published evidence. Pediatrics. et al. Fast-food intake and diet quality in 631. 2005;115(5):1367–1377. Black and White girls: the National 61. Owen CG, Martin RM, Whincup PH, Smith 62. Dietz W. Overweight in childhood and Heart, Lung, and Blood Institute GD, Cook DG. Effect of infant feeding on the adolescence. N Engl J Med. 2004;350(9): Growth and Health Study. Arch risk of obesity across the life course: a quanti- 855–857.

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