Lifecourse socioeconomic position and weight change among blacks: The Pitt County study.

OBJECTIVE: The elevated prevalence of obesity among U.S. blacks has been attributed to low socioeconomic position (SEP), despite inconsistent empirical findings. It is unclear whether low SEP at various lifecourse stages differentially influences adulthood BMI and BMI change. RESEARCH METHODS AND PROCEDURES: Among 1167 black adults in the Pitt County Study, we examined independent cross-sectional and longitudinal associations between SEP, measured in childhood and adulthood, and BMI and 13-year BMI change. Low vs. high childhood SEP was measured by parental occupation and childhood household deprivation; low vs. high adulthood SEP was assessed by employment status, education, and occupation. Using childhood and adulthood SEP, four lifecourse SEP categories were created: low-low, low-high, high-low, high-high.
RESULTS: We found no consistent associations between SEP and BMI or BMI change among men. Among women, we observed the expected inverse association between SEP and BMI at baseline. In multivariable-adjusted analyses, socioeconomically advantaged women demonstrated larger 13-year increases in BMI: skilled vs. unskilled parental occupation (6.1 vs. 4.8 kg/m2, p = 0.04); college-educated vs. < high school (6.2 vs. 4.5 kg/m2, p = 0.04); white-collar vs. blue-collar job (5.8 vs. 4.8 kg/m2, p = 0.05); and high-high vs. low-low lifecourse SEP (6.5 vs. 4.6 kg/m2, p = 0.02). DISCUSSION: For women in this black cohort, lower SEP predicted earlier onset of obesity; however, low SEP was less predictive of BMI increases over time. Our findings demonstrate complex patterns of association between SEP and BMI change among black women.