RELATIVE WEIGHT AND MORTALITY IN US BLACKS AND WHITES - FINDINGS FROMREPRESENTATIVE NATIONAL-POPULATION SAMPLES

PURPOSE: To examine the impact of relative weight on mortality in blac k and white men and women. METHODS: Two representative national popula tions samples were used: the NHANES-I Epidemiologic Follow-up Study (N HEFS), and the National Health Interview Survey (NHIS). The principal analysis focused on 13,242 participants in the NHEFS and 114,954 in th e NHIS. Minimum mortality was estimated from both categorical analysis and a logistic model. RESULTS: Minimum mortality ranged from a body m ass index (BMI) of 25 to 32 kg/m(2). The model estimated BMI of minimu m mortality for NHEFS was 27.1 (24.8-29.4, 95% CI), 26.8 (24.7-28.9, 9 5% CI), 24.8 (23.8-25.9, 95% CI) and 24.3 (23.2-25.4, 95% CI); for bla ck men, black women, white men and white women, respectively, whereas for NHIS the corresponding values were 30.2 (24.8-35.6, 95% CI) 26.4 ( 24.2-28.7, 95% CI), 27.1 (25.5-28.7, 95% CI), and 25.6 (24.2-27.0, 95% CI). In all groups the shape of the relative risk curve was virtually identical and a broad range of BMI values in the middle of the distri bution was associated with low relative mortality risk. Averaging the results from both surveys, the observed BMI of minimum risk was 3.1 kg /m(2) higher in black men and 1.5 kg/m(2) higher in black women than i n their white counterparts; when adjusted for covariates these differe nces were only of borderline statistical significance, however. CONCLU SIONS: Because of the wide range of BMI values associated with low ris k, and the consistency of the point of the up-turn in risk, group spec ific definitions of optimal values do not appear to be warranted. (C) 1997 Elsevier Science Inc.