Association Of Birth Weight, Inflammation And Variables Of The Metabolic Syndrome In Mexican American Girls Aged 6-11 Years

摘要

Background: Few studies have examined the association of birth weight, inflammation, and components of the metabolic syndrome in representative samples of total populations of minority children.Objective: To evaluate the association of waist-to-hip ratio (WHR), sum of skinfold thickness (SSF), glycated hemoglobin percent and other components of the metabolic syndrome with birth weight (BW) in Mexican American girls.Design: Cross-sectional survey of a large national sample, the Third National Health and Nutrition Examination Survey.Participants: Mexican American girls aged 6-11 years (N=475).Measurements: Body circumferences, skinfold thickness, body mass index, glycated hemoglobin percent, serum lipid concentrations, blood pressure, C-reactive protein (CRP) and parent-reported BW.Results: BW showed no significant independent associations with WHR or other indices of body fat distribution. SSF was elevated in the upper two quintiles of BW (p<0.05). BW was not significantly associated with glycated hemoglobin %. CRP was lowest in the top BW quintile but p for trend was 0.07. Conclusion: In a population group with high prevalence of obesity, diabetes and insulin resistance as adults, BW was not strongly or consistently associated with inflammation or components of the metabolic syndrome in girls. Introduction Low weight at birth has been shown to be a risk factor for cardiovascular disease, non-insulin dependent diabetes and the metabolic syndrome in adults (1, 2). Inflammation has also been associated with cardiovascular risk in adults (3). Few studies have examined the relationship of birth weight (BW) and insulin resistance or abdominal body fat distribution, blood pressure, serum triglycerides and HDL cholesterol, components of the metabolic syndrome, or with inflammation in representative samples of Mexican American children despite the relationship postulated for these variables with atherosclerosis and diabetes, major public health problems in Mexican American adults (1,2,3,4,5,6). In English children aged 10-11 years, fasting and post-load serum insulin levels were inversely associated with BW only after adjusting for current height and ponderal index (7). BW was not associated with central obesity or other components of the metabolic syndrome except blood pressure. In US children aged 7-12, independent associations of BW with subscapular-to-triceps ratio (SFR) and body mass index (BMI), were reported (8). Well established are associations of body circumference measures and skinfold measures of body fat distribution and fatness with insulin sensitivity, non-insulin dependent diabetes, and other cardiovascular risk factors of the metabolic syndrome (4,9, 10). Mechanisms have been advanced to explain the associations of low BW with atherosclerosis and diabetes (1, 2, 7, 8). Since adverse patterns of blood lipids and atherosclerosis itself begin in childhood, studies of population and individual differences in the early onset and progression through adolescence of possible initiating risk factors are important (9, 11,12,13,14). Tracking of blood lipids, obesity, and body fat distribution over long periods has been demonstrated (14,15,16,17). In order to test the hypothesis that obesity, circumference and skinfold indices of body fat distribution, components of the metabolic syndrome, and inflammation are significantly associated with BW in girls independent of gender, ethnicity, or age, data from the Third National Health and Nutrition Examination Survey (NHANES III) were examined. Mexican Americans were selected for study because of the reported higher prevalence of obesity, diabetes, and insulin resistance compared to non-Hispanic whites or blacks (18, 19). The results of these analyses will show that BW was not strongly or consistently associated with inflammation or components of the metabolic syndrome in children. Methods Subjects. The Third National Health and Nutrition Examination Survey (NHANES III) was conducted in