Neighbourhood socioeconomic status and cross-sectional associations with obesity and urinary biomarkers of diet among New York City adults: the heart follow-up study

OBJECTIVE: To determine whether neighbourhood socioeconomic status (SES) is associated with body mass index (BMI), waist circumference (WC) and biomarkers of diet (urinary sodium and potassium excretion). DESIGN: A cross-sectional study. SETTING: The data reported were from the 2010 Heart Follow-up Study, a population-based representative survey of 1645 adults. PARTICIPANTS: Community-dwelling diverse residents of New York City nested within 128 neighbourhoods (zip codes). PRIMARY AND SECONDARY OUTCOME MEASURES: BMI (kg/m(2)) and WC (inches) were measured during in-home visits, and 24-hour urine sample was collected to measure biomarkers of diet: sodium (mg/day) and potassium (mg/day), with high sodium and low potassium indicative of worse diet quality. RESULTS: After adjusting for individual-level characteristics using multilevel linear regressions, low versus high neighbourhood SES tertile was associated with 1.83 kg/m(2) higher BMI (95% CI 0.41 to 3.98) and 251 mg/day lower potassium excretion (95% CI −409 to 93) among women only, with no associations among men (P values for neighbourhood SES by sex interactions <0.05). CONCLUSION: Our results suggest that women may be particularly vulnerable to the effects of a socioeconomically disadvantaged neighbourhood. Future neighbourhood research should explore sex differences, as these can inform tailored interventions. TRIAL REGISTRATION NUMBER: NCT01889589; Results.