Short sleep duration preferentially increases abdominal adiposity in adults: preliminary evidence.

Unlabelled: What is already known about this subject •  The evidence that short sleep duration is another determinant of obesity is accumulating. •  Lack of sleep has been reported to constitute a metabolic stressor, with increased cortisol concentrations as the end product. What this study adds •  This is the first study to show that short sleep duration is associated with a preferential increase in abdominal adiposity in adults.

Summary: The aim of this 6-year longitudinal study was to verify whether short sleep duration preferentially increases abdominal adiposity in adults. A total of 276 adults, aged 18-64 years, from the Quebec Family Study were available for this study. Anthropometric measurements (body mass index and waist circumference), self-reported sleep duration and several covariates were assessed. A regression equation derived from the changes in body mass index and waist circumference of normal- and long-duration sleepers (reference category, ≥ 7 h of sleep per night, n = 233) was used to predict the change in waist circumference of short-duration sleepers (≤6 h of sleep per night, n = 43). Additionally, the influence of sleep duration on waist circumference changes was modelled by using linear regression in both sleep duration groups, adjusting for changes in body mass index and other covariates. We observed that measured (actual) changes in waist circumference were significantly greater than predicted changes (mean ± SEM: 3.41 ± 0.53 vs. 2.69 ± 0.51 cm, respectively, P < 0.05), implying that short-duration sleepers had an excess of abdominal fat accumulation over the 6-year follow-up period. After controlling for the changes in total adiposity as measured by body mass index, only short-duration sleepers gained more abdominal adiposity over 6 years. The present study provides evidence that short sleep duration is associated with preferential increases in abdominal adiposity in adults. This finding is of particular concern because abdominal adiposity is correlated with a number of metabolic anomalies.