Higher Offspring Birth Weight Predicts the Metabolic Syndrome in Mothers but Not Fathers 8 Years After Delivery the Pune Children’S Study Chittaranjan S
Total Page:16
File Type:pdf, Size:1020Kb
Higher Offspring Birth Weight Predicts the Metabolic Syndrome in Mothers but Not Fathers 8 Years After Delivery The Pune Children’s Study Chittaranjan S. Yajnik,1 Charu V. Joglekar,1 Anand N. Pandit,2 Ashish R. Bavdekar,2 Swati A. Bapat,2 Sheila A. Bhave,2 Samantha D. Leary,3 and Caroline H.D. Fall3 In Europid populations, low birth weight of offspring predicts insulin resistance in the mother and cardiovas- cular disease in both parents. We investigated the asso- here is growing interest in the association be- ciation between birth weight of offspring and obesity tween size at birth and the risk of diabetes and and cardiovascular risk in the parents of 477 8-year-old cardiovascular disease in later life (1). Size at children born at the King Edward Memorial Hospital, Tbirth reflects intrauterine growth, which is deter- Pune, India. Eight years after the birth of the child, mined by intrauterine environment as well as genetic of heavier babies factors. Diabetes is more common in those who are small (459 ؍ mothers (33 years of age, n were taller and more obese (BMI, fat mass, and waist or large at birth (2,3). Studies that show an inverse relation circumference, all P < 0.001) than mothers of lighter between birth weight and insulin resistance syndrome babies. Increasing offspring birth weight predicted (metabolic syndrome) have been interpreted to mean that higher homeostasis model assessment for insulin resis- “fetal undernutrition” is the causative factor (the “thrifty tance (P < 0.01) and metabolic syndrome in mothers phenotype” hypothesis) (4). The “fetal insulin hypothesis” (P < 0.001) (adjusted for offspring sex and birth order, offers an alternative genetic explanation for the relation- maternal age, and socioeconomic status) but not hyper- ship (5). Davey-Smith et al. (6) have explored another ؍ glycemia. Fathers (39 years of age, n 398) of heavier aspect of this relationship. They showed that offspring low babies were taller and heavier, independent of maternal birth weight is associated with increased cardiovascular size (P < 0.01, both), but were not more insulin resis- risk in parents (6–8), increased maternal insulin resis- tant. Unlike other reports, lower offspring birth weight tance during late adulthood (9), and diabetes in fathers did not predict insulin resistance in fathers. Thus, urban Indian parents have a higher risk of being obese 8 years (10). They favor a genetic explanation for their findings. after delivery of a heavier child. Mothers but not fathers On the other hand, large babies born to mothers with of heavier babies also have a higher risk of being insulin gestational diabetes mellitus (GDM) have an increased resistant and developing the metabolic syndrome. Our risk of diabetes (11,12), and mothers also have an in- findings highlight the need for a better understanding of creased risk of diabetes (13). Maternal insulin resistance the relation between fetal growth and future health during (late) gestation is an important mechanism to before contemplating public health interventions to divert nutrients (glucose, amino acids, and triglycerides/ improve fetal growth. Diabetes 52:2090–2096, 2003 fatty acids) to the fetus to promote growth (14). Offspring birth weight could be used as a useful surrogate for maternal metabolism in pregnancy. In recent years there has been a growing recognition that pregnant metabolic state and events provide a window into future maternal risk of disease (15). In the Pune Children’s Study, we investigated the deter- minants of insulin resistance in 8-year-old urban children (16). At the same time, we measured body size, insulin From the 1Diabetes Unit, King Edward Memorial Hospital and Research Centre, Pune, India; the 2Department of Pediatrics, King Edward Memorial resistance, and other cardiovascular risk factors in their Hospital and Research Centre, Pune, India; and the 3Medical Research parents. We report the relationship between the child’s Council, Environmental Epidemiology Unit, Southampton, U.K. birth weight and parental measurements. Address correspondence and reprint requests to Dr. C.S. Yajnik, Director, Diabetes Unit, King Edward Memorial Hospital and Research Centre, Pune, India 400 011. E-mail: [email protected]. Received for publication 6 November 2002 and accepted in revised form12 RESEARCH DESIGN AND METHODS May 2003. Details of our methods have been reported previously (16). Of 477 families, 6 CHD, coronary heart disease; GDM, gestational diabetes mellitus; HOMA, homeostasis model assessment; HOMA-IR, HOMA for insulin resistance; IGT, mothers and 12 fathers had died, and 459 (nonpregnant) mothers and 398 impaired glucose tolerance; OGTT, oral glucose tolerance test; SES, socio- fathers agreed to be studied. Standardized anthropometric measurements economic status; WHR, waist-to-hip ratio. were made by one of two trained observers. Fat mass was calculated from © 2003 by the American Diabetes Association. four skinfold-thickness measurements using Durnin’s formula (17). Blood 2090 DIABETES, VOL. 52, AUGUST 2003 CS YAJNIK AND ASSOCIATES TABLE 1 Anthropometric and biochemical measurements in parents of 8-year-old children Mothers Fathers n 456 398 Age (years) 33 (30–35) 39 (36–42) Anthropometry Height (cm) 153.0 (150.0–157.0) 165.8 (162.3–170.3) Weight (kg) 52.0 (44.5–59.8) 63.0 (55.8–70.0) BMI (kg/m2) 22.1 (18.9–25.3) 22.8 (20.7–25.4) WHR 0.76 (0.71–0.81) 0.91 (0.86–0.94) Body fat (%) 33.6 (27.6–37.6) 25.3 (21.3–28.2) Glucose-insulin Fasting plasma glucose (mmol/l) 4.8 (4.4–5.4) 5.0 (4.4–5.6) 30-min plasma glucose (mmol/l) 7.8 (6.7–8.8) 8.2 (6.9–9.3) 120-min plasma glucose (OGTT) (mmol/l) 5.5 (4.7–6.7) 6.1 (5.0–7.7) Fasting plasma insulin (pmol/l) 34.0 (22.0–50.0) 35.0 (21.0–51.0) 30-min plasma insulin (pmol/l) 199.0 (123.0–308.5) 195.0 (103.5–319.0) 120-min plasma insulin (pmol/l) 176.5 (102.7–308.2) 214.0 (107.0–425.0) Plasma split 32-33 insulin (pmol/l) 6.3 (3.9–9.8) 12.0 (7.6–22.0) Plasma proinsulin (pmol/l) 4.1 (3.0–5.8) 7.8 (4.9–13.0) HOMA-IR 1.42 (0.96–2.13) 1.94 (1.15–3.10) Lipids Total cholesterol (mmol/l) 3.8 (3.3–4.4) 4.2 (3.6–5.0) HDL cholesterol (mmol/l) 1.0 (0.8–1.2) 0.9 (0.7–1.1) Triglycerides (mmol/l) 0.8 (0.6–1.2) 1.2 (0.9–1.9) Blood pressure Systolic (mmHg) 120 (113–127) 129 (122–137) Diastolic (mmHg) 71 (65–78) 77 (71–84) Data are median (interquartile range). pressure was measured using a digital automated device (Dinamap; Criticon, RESULTS Tampa, FL) after 10-min rest in the supine position. The mean birth weights of the children were 2.8 kg (boys) A 75-g anhydrous oral glucose tolerance test (OGTT) was performed on subjects not on antidiabetic treatment. Three venous blood samples (fasting and 2.6 kg (girls). Their birth weight distribution was and at 30 and 120 min after oral glucose) were collected for measurement of similar to that for all babies born in the hospital during the plasma glucose and insulin concentrations. Plasma cholesterol, HDL choles- same time period. There was no significant difference in terol, triglycerides, proinsulin, and 32-33 split proinsulin were measured in the birth weight of children whose parents were studied or not fasting sample by standard methods. Insulin resistance was calculated using studied. Birth weight increased with the birth order of the the homeostasis model assessment (HOMA) (18), and the 30-min insulin Ͻ  child (P 0.001), but was not related to the SES of the increment was used as an estimate of -cell function (19). Metabolic syn- ϭ drome was defined following World Health Organization guidelines (20), family (P 0.42). except that the BMI cutoff point for obesity was 25 kg/m2 rather than 30 kg/m2 Parents. Table 1 shows the characteristics of the parents. because of the recent recognition of a need to revise BMI criteria for Asian Tables 2 and 3 show maternal and paternal size and populations (21). Those in the highest quartile of HOMA for insulin resistance cardiovascular risk factors by thirds of their child’s birth (HOMA-IR) were diagnosed as insulin resistant. Metabolic syndrome was weight. diagnosed if a subject had a fasting plasma glucose concentration Ն6.1 mmol/l or a 120-min concentration Ն7.8 mmol/l and/or were insulin resistant and in Mothers. One mother was known to be diabetic before addition had two or more of the following: 1) BMI Ն25 kg/m2 and/or waist-hip pregnancy and died 5 years after delivery. Her child and ratio Ն0.90 for men and Ն0.85 for women, 2) plasma triglyceride concentra- his father are excluded from the analysis. tion Ն1.7 mmol/l and/or HDL cholesterol Ͻ0.9 mmol/l for men and Ͻ1.0 The OGTT was not routinely performed during preg- mmol/l for women, and 3) blood pressure Ն140/90 mmHg. nancy, but 13 mothers were diagnosed as having GDM by Socioeconomic status (SES) was assessed using the Kuppuswamy score the treating obstetrician on clinical indications; none of (22), a standardized scoring system based on a questionnaire asking for details of occupation, education, income, and size and type of housing. Each aspect them were on antidiabetic treatment at the time of this is separately scored, and the scores are added to get a total socioeconomic study.