Trends in height, weight, BMI, skinfolds, and measures of overweight and obesity from 1979 through 1999 among American Indian Youth: The Akwesasne Mohawk.

BACKGROUND/OBJECTIVES: Information on recent changes in overweight, obesity, and adiposity among American Indians is scarce. To assess changes in size and adiposity among American Indian youth, data from two samples of Akwesasne Mohawk youth, were compared. SUBJECTS/METHODS: Both project 1, conducted in 1979 (n = 75) and Project 2, conducted between 1996 and 1999 (n = 206), sampled youth 10-14 years of age from the Akwesasne Mohawk Reservation (aka St. Regis) that borders New York state, and Ontario and Quebec provinces. Heights, weights, and skinfold thicknesses were converted to z-scores using CDC reference values. BMI status was calculated in terms of WHO age-specific cutoffs and CDC cutoffs. RESULTS: z-Scores for heights differed little between projects. The between-project difference in weight z-score is twice the between-project z-score difference for height. Differences among males are larger and more often significant. Triceps and subscapular skinfold thickness are significantly greater in Project 2. The rate of overweight and obesity combined, increased 3.3-fold. In multiple regression analyses with sex, height, and age in the model, project is a significant predictor of weight and skinfolds. CONCLUSIONS: Weight and adiposity have increased substantially from 1979 to 1996-99. Overweight and obesity became significantly more common. Given the increase in adiposity, these youth may be facing significant health risks as adults in terms of cardiovascular disease, cancer, and type II diabetes unless weight and adiposity is reduced.

Persistent organic pollutants as predictors of increased FSH:LH ratio in naturally cycling, reproductive age women.

Although several recent studies suggest endocrine disrupting compounds, such as polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p', DDE), and hexachlorobenzene (HCB), target different organs and systems in the body, their impact on female reproductive function in humans is not well characterized. We seek to determine the relationship between several known endocrine disrupting compounds and a marker of ovarian responsivity, the FSH:LH ratio (higher ratio indicates less ovarian responsivity). For this analysis, 169 naturally cycling women between 21 and 38 years of age completed interviews and had their blood drawn on day 3 of their menstrual cycle for analyses of toxicants, gonadal sex hormones (E2 and P4), and gonadotropins (FSH and LH). PCB congeners were classified into five groups based on their environmental persistence, distribution in human tissue, and toxicological action, reflecting the structure, mechanism, and known biological activity of individual PCB congeners. For every unit (ppb) increase in the level of the estrogenic PCB group, there was a 5-fold greater risk of a FSH:LH ratio ≥ 2, controlling for individual differences in age, percent body fat, cycle day 3 estradiol levels, parity, alcohol use and cigarette smoking in the past year (exp[ß] = 5; p = ≤0.01). PCB congeners identified as estrogenic were analyzed individually, and, of the 19 potentially estrogenic congeners, five were significantly, and positively related to an increased FSH:LH ratio. Four of these congeners are non-persistent, easily volatilize in the environment, and are easily metabolized, and hence, are indicative of very recent or current exposure. p,p'-DDE and HCB were not associated with FSH:LH ratio. We find a clinical indicator of ovarian responsivity, FSH:LH ratio, is associated with a specific group of estrogenic PCBs. These congeners may become airborne when they volatilize from dredged PCB-contaminated soil or from indoor PCB-containing window caulk and sealants in older buildings leading to inhalation exposure. PCB exposure, particularly to non-persistent, estrogenic congeners, may pose an unrecognized threat to female fecundity within the general population.

Maternal-infant interaction as an influence on infant adiposity.

OBJECTIVES: The aim of this research is to identify whether specific aspects of the early life psychosocial environment such as quality of home and maternal-infant interaction are associated with increased infant adiposity, in a disadvantaged population in the United States. METHODS: Data on 121 mother-infant pairs from the Albany Pregnancy and Infancy Lead Study were analyzed using three multiple linear regression models with subscapular skinfold thickness (SST), triceps skinfold thickness (TST), and weight z-scores at 12 months of age as outcome variables. Maternal-infant interaction was indexed by the Nursing Child Assessment Teaching Scales (NCATS) and home environment quality was indexed by the Home Observation for Measurement of the Environment (HOME). RESULTS: In models including infant birth weight, cigarette use in second trimester, infant caloric intake at 9-12 months, size at birth for gestational age, infant sex, and mother's prepregnancy BMI, specific subscales of NCATs predicted infant adiposity z-scores. Poorer mother's response to infant distress was associated with greater SST ( ß = -0.20, P = .02), TST ( ß = -0.19, P = .04), and weight ( ß = -0.14, P = .05). Better maternal sensitivity to infant cues was associated with larger SST ( ß = 0.25, P < .01), while mother's poorer social-emotional growth fostering predicted greater SST ( ß = -0.23, P < .01) and weight ( ß = -0.16, P = .03). Better scores on HOME Organization of the Environment were associated with greater SST ( ß = 0.34, P = .02) and TST ( ß = 0.33, P = .04). CONCLUSIONS: Emotionally relevant aspects of the maternal-infant interaction predicted infant adiposity, though in different directions. This indicates that the psychosocial environment, through maternal behavior, may influence infant adiposity. However, the general home environment was not consistently related to infant adiposity.

Unequal adaptive value of changing cigarette use during pregnancy for heavy, moderate, and light smokers.

To determine the effects of changes in maternal cigarette use during pregnancy on birthweight, a sample of Caucasian births free of major malformations (n = 9,943) was examined. Births were stratified by level of maternal smoking in the first trimester and subdivided according to whether the mother continued at the same level, reduced, or quit by the second trimester. Birthweights were adjusted statistically for extraneous variables. As expected, second and third trimester cigarette use was associated with birthweight, but so too was cigarette use during the first trimester, and the effect of quitting varied significantly with the level of first trimester smoking. Among moderate and light smokers, who comprise the majority of smokers, quitting before the second trimester is associated with heavier infants. However, infants of heavy smokers who quit by the second trimester did not weigh significantly more than infants of mothers who continued to smoke heavily throughout pregnancy, and weighed significantly less than infants of nonsmokers or other smokers who quit. Thus, quitting by the end of the first trimester may not completely negate the effect of heavy first trimester smoking, and the adaptive value of qutting is unequal among different levels of first trimester smoking. Further research on prenatal growth should take cigarette smoking in all trimesters into account. © 1994 Wiley-Liss, Inc.