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OBJECTIVE:: This study was conducted to examine the influence of insulin resistance on weight change in postmenopausal women of various ethnic groups. SUBJECTS:: Data were obtained from 3389 women (60% White, 20% Black, 12% Hispanic, and 8% Asian/Pacific Islander), ages 50-79, enrolled in either the Women's Health Initiative Clinical trial or Observational Study, whose blood samples were selected randomly from the full cohort of 161?809 women for analyses. MEASUREMENTS:: Glucose, insulin, and lipids were measured on fasting serum samples drawn at baseline and after 3?y of follow-up. Weight, height, waist circumference, and blood pressure were measured. Physical activity and energy intake were assessed via questionnaire. Insulin resistance was estimated using the HOMA (homeostasis model) calculation. RESULTS:: Average age was 62?y, average BMI (body mass index) was 27.4?kg/m2, and average weight change was a gain of 0.4?kg in 3?y. In a multivariate analysis, insulin resistance and insulin concentrations were independent predictors of increases in weight in White women (P=0.002 and 0.004, respectively) and in the combined group (P=0.027 and 0.039). For the whole group, after adjustment for other covariates, those in the highest quartile of insulin resistance gained 0.4?kg in 3?y, whereas those in the lowest quartile lost 0.06?kg. Similar trends were found for insulin resistance and weight gain in Hispanic and Asian/Pacific Islander women, but they did not reach statistical significance. In Black women, no relation was seen between either insulin or insulin resistance and weight change. A significant interaction between obesity and insulin resistance was observed (P=0.002 for White women and 0.032 for the whole group), so that there is weight gain with increasing insulin resistance in the leaner women, but weight loss with increasing insulin resistance in the most obese. CONCLUSION:: Insulin resistance appears to be a predictor of weight gain in postmenopausal women, except for the most obese women. The effect is more pronounced in women who have a lower BMI, and the effect was not seen in the Black women who as a group had a higher BMI.International Journal of Obesity (2004) 28, 1039-1047. doi:10.1038/sj.ijo.0802645 [ABSTRACT FROM AUTHOR]

Diabetes increases the risk of cardiovascular disease (CVD). Only part of this excess risk is explained by diabetes-associated hypertension, obesity, and lipid disorders. Poor glycaemic control may help explain the residual CVD risk. The aim of this study was to determine whether variations in glycaemic control are associated with CVD risk in diabetic individuals. We examined longitudinal data from the Strong Heart Study, a population-based study of CVD and its risk factors among American Indians (a population with a high prevalence of diabetes). Diabetes was defined using the 1998 World Health Organization criteria: fasting plasma glucose ≥ 126 mg/dl or 2-h plasma glucose ≥ 200 mg/dl. American Diabetes Association guidelines for glycaemic control were used: good, A1c < 7%; fair, 7–7.9%; and poor, ≥ 8%. The analysis was based on data from diabetic individuals with no CVD at baseline. During 9 years of follow-up, 494 of the 2011 diabetic participants developed CVD. Although Cox multivariate regression modelling showed dose–response effects of glycaemic control on overall CVD and coronary heart disease (CHD) incidence, the relationships were weakened when adjusted for confounding variables. Kaplan–Meier analysis, however, showed that diabetic individuals with poor baseline glycaemic control had significantly increased proportions of overall CVD and CHD ( P = 0.001) during the 9 years of follow-up, compared with those who had good or fair control. These findings highlight the importance of risk factors, such as high blood pressure and dyslipidaemia, in increasing CVD risk in those with diabetes. Diabet. Med. (2004) [ABSTRACT FROM AUTHOR]

OBJECTIVE: To examine the hypothesis linking measures of obesity including body mass index (BMI), waist circumference (waist) and percentage body fat to coronary heart disease (CHD) prevalence and its risk factors in American Indians. DESIGN: The Strong Heart Study assesses the prevalence of CHD and its risk factors in American Indians in Arizona, Oklahoma and South/North Dakota. Participants underwent a physical examination and an electrocardiogram; anthropometric and blood pressure measurements were taken, as were measurements of glucose, lipoproteins, fibrinogen, insulin, hemoglobin A[sub 1c] and urinary albumin. PARTICIPANTS: Data were available for 4549 men and women between 45 and 74 y of age. MEASUREMENTS: Obesity, measured using body mass index, waist circumference and percentage body fat, was correlated with prevalent CHD and its risk factors. RESULTS: More than 75% of participants were overweight (BMI > 25 kg/m²). Measures of obesity were greater in women than in men, in younger than in older participants, and in participants with diabetes than in nondiabetic participants. CHD risk factors were associated with measures of obesity but, except for insulin concentration, changes in metabolic variables with increasing obesity were small. Associations were not stronger with waist than with BMI. The prevalence of CHD in those whose BMI and/or waist measurements lay in the lowest and highest quintiles, by gender and diabetic status, was similar. CONCLUSIONS: Although CHD risk factors are associated with obesity in American Indians, distribution of obesity (ie waist) is no more closely related to risk factors than is generalized obesity (ie BMI), and changes in CHD risk factors with obesity were small. Thus, the relations among obesity, body fat distribution and CHD risk may differ in this population. [ABSTRACT FROM AUTHOR]