Larsen, S., Horgan, G.W., Mikkelsen, M-L., Palmeira, AL., Scott, S., Duarte, C., Santos, I., Encantado, JE., O'Driscoll, R., Turicchi, J., Michalowska, J., Stubbs, J. and Heitmann, BL.
(To be decided) 44, 1577-1585.
||Background: Several studies have suggested that reduced sleep duration and quality is associated with an increased risk of obesity and related metabolic disorders, but the role of sleep in long-term weight loss maintenance has not been thoroughly explored using prospective data.
Design: A total of 967 participants from the European NoHoW trial, who had achieved a weight loss of ¡Ý5 % and had a BMI of ¡Ý25 kg/m2 prior to losing weight, was included in the present study. Information was available on objectively measured sleep, collected during a 14-days at baseline, 12-month changes in body weight, body fat percentage and metabolic markers (blood pressure, low- and high-density lipoproteins, triglycerides and glycated haemoglobin), as well as potential baseline confounding factors. In addition to sleep duration, sleep duration variability, sleep onset and sleep onset variability was assessed across a 14-day baseline period. Regression models were conducted with sleep related variables as explanatory and subsequent changes in body weight, body fat percentage (primary outcomes) and obesity-related metabolic markers (secondary exploratory outcomes) as response variables.
Results: We found no evidence that sleep duration, sleep duration variability or sleep onset was associated with weight regain or change in body fat percentage. A higher between day variability in sleep onset, assessed using the standard deviation across all nights recorded, was directly associated with weight regain [0.55 kg per hour (95% CI: 0.10, 0.99); P=0.02] and increase in body fat percentage [0.41 % per hour (95% CI: 0.04, 0.78); P=0.03]. Analyses of the secondary outcomes showed that a higher between day variability in sleep duration was associated with an increase in glycated haemoglobin [0.02 % per hour (95% CI: 0.00, 0.05); P=0.04]. Moreover, participants with a sleep onset between 19:00 and 22:00 had the greatest reduction in diastolic blood pressure (P=0.02), but also the most pronounced increase in triglycerides (P=0.03).
Conclusion: Our results suggest that sticking to a consistent bedtime is associated with improved weight loss maintenance. Sleep onset and variability in sleep duration may also be associated with subsequent change in different metabolic markers, but due to multiple-testing the secondary exploratory outcomes should be interpreted cautiously.