Longitudinal associations between sleep and BMI in a low-income, predominantly Black American sample

Abstract

Objective: Black individuals and those experiencing socioeconomic disadvantage are at increased risk for sleep problems and obesity. This study adds to the limited extant literature examining longitudinal associations between objectively measured sleep and changes in body mass index (BMI) in Black Americans.

Design: We focused on individuals with at least 1 observation of sleep and BMI at 1 of 3 study time points (2013, 2016, and 2018). We modeled longitudinal trends in BMI as a function of time, average of each sleep variable across assessments, and within-person deviations in each sleep variable over time.

Setting: Data were collected via interviewer-administered at-home surveys and actigraphy in Pittsburgh, PA.

Participants: Our sample comprised 1115 low-income, primarily Black adults, including 862 women and 253 men.

Measurements: Sleep measures included actigraphy-measured total sleep time, sleep efficiency, and wakefulness after sleep onset, as well as self-reported sleep quality. We also included objectively measured BMI.

Results: In models adjusted for age, gender, and other sociodemographic covariates (eg, income, marital status), there were no significant longitudinal associations between total sleep time, sleep efficiency, wakefulness after sleep onset, or subjective sleep quality and changes in BMI.

Conclusions: This study provides further evidence that, among a sample of low-income Black adults, sleep problems are not longitudinally predictive of BMI. Although ample cross-sectional evidence demonstrates that sleep problems and obesity commonly co-occur, longitudinal evidence is mixed. Better understanding the overlap of sleep and obesity over time may contribute to prevention and intervention efforts.

Keywords: BMI; Longitudinal; Obesity; Sleep.