Association between weight loss response and sleep among overweight women participating in a weight loss intervention trial

Abstract

Chronic sleep deprivation (< 7 hours of sleep for more than 3 consecutive days), has been associated with higher BMI and weight gain, possibly secondary to elevated serum cortisol levels. Whether weight loss results in a reduction in cortisol levels and/or improved sleep patterns in overweight adults is unknown. We tested this hypothesis in a cohort subsample of overweight women enrolled in a randomized, controlled, multi‐center weight loss intervention trial (n=144). Subjects were assessed at baseline and 6 months for sleep duration and quality, using the self‐reported Pittsburg Sleep Quality Index (PSQI), and a.m. serum cortisol levels. Baseline weight among participants was 91.7 ± 10.0 kg (mean + SD). A significant weight loss of 8.1 ± 5.9 kg was observed at 6 months (p <0.0001). PSQI scores were stable from baseline to 6 months (5.2, 5.3, respectively). Regression analysis suggested a small, statistically significant improvement in PSQI score with weight loss at 6 months (p < 0.015), controlling for baseline age, weight and PSQI score. Cortisol levels were stable and within reference normal limits throughout (13.7 ± 6.1 µg/dL). This preliminary analysis suggests that an average weight loss of 8.1 ± 5.7 kg is associated with improved PSQI scores, though not cortisol levels, among overweight adult women. Funded by a contract with Jenny Craig, Inc. and the University of Arizona Nutritional Sciences Graduate Program.Grant Funding SourceContract with Jenny Craig, Inc. and University of Arizona Graduate Department