Trends and Development of Non-Communicable Diseases and Risk Factors in Samoa Over 24 Years Satupaitea Viali
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Trends and Development of Non-Communicable Diseases and Risk Factors in Samoa over 24 years Satupaitea Viali Thesis submitted in fulfilment of the degree of Master of Public Health University of New South Wales April 2009 C RTIFICAT OF ORIGINALITY I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, nor material which to a substantial extent has been accepted for the award of any other degree or diploma at the UNSW or any other educational institution, except where due acknowledgment is made in the thesis. Any contribution made to the research by others, with whom I have worked UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project)s design and or in style, presentation and linguistic expression is acknowledged. Signed: Satupaitea Viali ACKNO(LEDG ) NT This thesis would not have been possible without the assistance from a number of important and valued people who have directly or indirectly assisted and supported me during this time of study. To these people, I owe my gratitude and thanks. I would like to express my sincere gratitude to my supervisor, Professor Stephen Colagiuri for his direction and enthusiatic guidance throughout the course of this research work. His patience, expertise, commitment and constructive criticisms added a lot of value to this thesis. It has been a great learning experience working together with such an ethusiatic person in research. I would also like to thank Associate Professor .uth Colagiuri for the ongoing support, encouragement, and assistance in many ways to maximise my working environment in Sydney. Her commitment and dedication to the Pacific has enabled me to finish this research work. I am also extremely grateful to my friend and statistician, /afruil Huz0ain, for his expertise and assistance in the statistical theory, analysis and application. I would also like to thank the Samoa Ministry of Health, Samoa National Health Services and World Health 1rgani0ation for allowing me to undertake this research work. I thank WH1 for providing financial support for the first half of this thesis. I would like to acknowledge the contribution of Professor Paul /immet and Professor Stephen Mac2arvey to this research work. I would like to acknowledge with sincere gratitude and appreciation the support of my wife 3Sialei Viali4 and kids 3Eliana and /enith Viali4 during this time of study. The many hours of being absent from home during this work is finished. Special thanks to all my relatives and friends who supported me in Sydney during my UNSW campus visits. 6inally and above all, I am forever grateful to 2od for the wisdom, energy and guidance to finish this work, and may His name be glorified. , Glossary of Acronyms A8A American Diabetes Association 9MI 9ody mass index, kg/m; CAP8 Continuous ambulatory peritoneal dialysis CH8 Coronary heart disease CV8 Cardiovascular diseases ES.6 End stage renal failure 6P2 6asting Plasma Glucose H8L High density lipoprotein I86 International Diabetes Federation IH8 Ischaemic Heart Disease L8L Low density lipoprotein mmHg millimeters of mercury mmo/l millimoles per litre MM. Maternal mortality rate M1H Ministry of Health NC8 Non-communicable diseases NI88M Non-insulin dependent diabetes 12TT 1ral glucose tolerance test 1. 1dds ratio S8 Standard deviation TTM Tupua Tamasese Meaole Hospital, National Hospital VL8L Very low density lipoprotein WH. Waist hip ratio WH1 World Health Organi0ation 7 ABSTRACT Non-Communicable 8iseases like diabetes, cardiovascular diseases, cancers and others, have become the ma(or cause of premature death, morbidity and disability in many Pacific countries including Samoa. These are linked by common preventable risk factors like obesity, hypertension, smoking, unhealthy diets and physical inactivity. 19JECTIVES: To determine the trends and development of Non-Communicable diseases and its risk factors in Samoa over the last 7 years using the recently developed diagnostic criteria. .ESEA.CH 8ESI2N AN8 METH18S: This research thesis combines , large surveys that were done in 1978, 1991, and 2002, looking at the trends in the prevalence of diabetes, and the prevalence of the NC8 risk factors such as blood pressure, obesity, cholesterol and smoking. The 3 survey samples were selected randomly from around similar regions 3Urban Upolu, .ural Upolu, and .ural Savaii4 of Samoa in 1978, 1991 and 2002, with a total of 5973 individuals 31978 survey C 14DAE 1991 survey C 17ABE 2002 survey C A B4 available for the thesis analysis. The 1978 and 1991 data sets were secured from Professor P /immet, and the 2002 STEPs survey data set was secured from the Samoa Ministry of Health. The , surveys methodologies, survey procedures, Fuestionnaires and anthropometric measurements were similar though the diagnostic criteria used to measure obesity slightly differ between the surveys. The blood pressure measurements were similar though the diastolic blood pressure measure in 1978 was higher. The 1978 and 1991 surveys used fasting venous blood sampling to measure fasting plasma glucose, and cholesterol levels at the laboratory. 12TT was also used in 1978 and 1991, but not 2002. The 2002 survey used capillary sampling to measure fasting glucose using a glucometer, and cholesterol level using a cholesterol meter. The combined data was then cleaned, standardi0ed and matched with each survey, to make analysis easier. The recent diagnostic criteria were then applied to all the surveys to diagnose diabetes 31999 WH1 8iabetes Criteria4, hypertension 3WH1 1999, JNC-VII 2003, NH6 1999 Hypertension Criteria4, obesity 39MI G30 kg/m;4, and hypercholesterolaemia. The prevalences using the recent diagnostic criteria were then mapped out. 5 .ESULTS: The overall age-standardi0ed prevalence of type 2 diabetes 3known or previously unknown) utili0ing the current 1999 WH1 diagnostic criteria for men and women G20 years of age has increased from 5.4% 3males 4.8%, females 5.9%4 in 1978, to 12.0% 3males 10.9H, females 13.5%4 in 1991, and to 20.1% 3males 17.2H, females ' H4 in 2002. Among the individuals with diabetes in the 3 surveys, more than 60% had previously undiagnosed diabetes. Compared with the 1978 survey, the diabetes prevalence in 002 represents a 4-fold increase over the 24 year period. This has occurred along with increasing obesity, urbani0ation and moderni0ation, aging, cultural changes, and changes in physical activity. There is a high prevalence of non-communicable disease risk factors. The age- standardi0ed prevalence of hypertension defined by the WH1 1999 and JNC-VII 2003 criteria was 47.2% in 1978, 22.5% in 1991, and 24.0% in 2002. The high prevalence of hypertension in 1978 was due to the method used for recording diastolic blood pressure. Hypertension was more common in the urban regions than rural regions in 1978 and 1991 while in 2002, there was no statistical difference between the rates of hypertension between the different regions due to the rise in the prevalence rate of hypertension in rural regions. There is a high prevalence of overweight and obesity in Samoa. Using the WH1 classification for 9MI, there was an increase in obesity 39MI G 30kg/m;4 prevalence in Samoa in the last decade, increasing steeply from 34.9% in 1978 to 51.3H in 1991, and slowing down to an increase to 57.4% in 2002. The prevalence of obesity is significantly higher in females compared with their male counterparts. The overweight prevalence 39MI 25- 9.9kg/m;4 was ,7H in 1978, 31% in 1991 and 29H in 2002. The prevalence of obesity has increased by 65% from 1978 to 2002 with an increase of 7AH from 1978 to 1991, and 12H from 1991 to 2002. Prevalence of obesity is increasing with age and is more of a problem in women than men. It is higher in the urban regions but there has been a faster rise in obesity prevalence in rural regions from 1978 to 2002 as the rural regions become urbani0ed. The prevalence of hypercholesterolaemia 3total cholesterol G 5.2 mmol/l4 was 30.5% in 1978, and this increased to 51.1% in 1991. There was a marked decline of D hypercholesterolaemia in 2002 314.7H4, which may be due to differences in the method of measurement. Although smoking prevalence remains high in Samoa it declined significantly from 7 .4% 1978 to 35.,H 1991 but remained essentially steady at ,8% in 002. There was a significant gender difference in smoking with about 60% of men and 20H of women smoking regularly. C1NCLUSI1N: Samoa is experiencing an increasing problem with Non- Communicable diseases like diabetes and some of its risk factors. 8iabetes prevalence has dramatically increased by 4-fold in the last 24 years. The prevalence of hypertension has stabili0ed around ,H though there was a decrease from 1978. The prevalence of obesity has also increased. Smoking prevalence has slightly increased from 1991 to 2002 with a significant number of the population smoking. Hypercholesterolaemia is more common in 1991 with an apparent decrease in 200 . These findings have important implications for public health efforts and policy developments to contain the epidemic of Non-Communicable diseases in Samoa. A Table of Contents Page Title Page 1 Certificate of Originality 2 Acknowledgement 3 2lossary of Terms 4 Abstract 5 C-APT R 1 INTROD/CTION 16 1.1 Non Communicable Diseases 16 1. About Samoa : The Land and it)s people 19 1.2.1 Geography