Association Between Sleep and Obesity in African Americans in the Jackson Heart Study.

BACKGROUND

In the United States, data from the National Health and Nutrition Examination Survey suggest that 68% of adults are overweight and obese. Obesity has been shown in previous cross-sectional and longitudinal studies to be influenced by short sleep duration, which can lead to unregulated appetite, excessive eating during awake time, and decreased energy expenditure.

OBJECTIVE

To examine the associations among sleep duration, sleep quality, body mass index (BMI), and waist circumference (WC) in African Americans.

METHODS

The sample included participants in the Jackson Heart Study. During a clinic visit, the sleep habits of participants were recorded via a sleep history questionnaire, and BMI and WC measurements were also recorded. Multivariate analysis was used to examine the associations among sleep duration, sleep quality, general obesity (measured by BMI), and abdominal obesity (measured by WC).

RESULTS

The authors studied participants who provided data for the variables of interest (N=3778; 1363 men and 2415 women). Of all participants, 3317 (87.8%) were overweight, and 2149 (56.9%) were obese. The mean (SD) BMI was 32.1 (7.2) kg/m2, and the mean (SD) WC was 103.3 (16.0) cm. Mean sleep duration was 6.3 (1.4) hours for men and 6.4 (1.5) hours for women. Among the men, a significant negative relationship was found between sleep duration and body composition: longer sleep was associated with lower BMI levels but negatively associated with WC in men (β=-1.06; P<.01)]. Sleep quality was positively associated with WC in men (β=1.20; P<.01) and women (β=0.61; P<.05).

CONCLUSIONS

This study's findings highlight the high rate of overweight and obesity among participants in the Jackson Heart Study. About one-fourth of the participants described themselves as enjoying ideal health. In men, longer sleep duration was associated with lower BMI levels and lower WC; in both men and women, good sleep quality was associated with lower WC. However, more research is needed to examine sleep and body composition as risk factors for disease development in African Americans.