A Systematic Review on the Effects of Nonpharmacological Sleep Interventions on Cardiometabolic Risk or Disease Outcomes.

BACKGROUND: Many authors of epidemiological studies have documented the detrimental effects of insufficient or poor sleep on cardiometabolic health. However, little is known about the effects of sleep interventions on the individuals with cardiometabolic risks/diseases. OBJECTIVES: This systematic review aimed to evaluate the mediating effects of nonpharmacological sleep interventions, which were defined as interventions not involving the use of medications or invasive methods to alter sleep, on cardiometabolic outcomes among adults with cardiometabolic risks/diseases. METHODS: A systematic search of randomized controlled trials was conducted in 5 electronic databases from inception to November 2019. The Population, Intervention, Comparison and Outcomes of this review was the effects of nonpharmacological sleep interventions on sleep and cardiometabolic outcomes among the adults with cardiometabolic risks/diseases as compared with any control methods. Two reviewers independently assessed eligibility for inclusion and methodological quality. Narrative analysis was performed when meta-analysis was not appropriate. RESULTS: Nine studies met the inclusion criteria. These studies included exercise-based, sleep hygiene, and cognitive behavioral therapy interventions to improve sleep among adults who are overweight or obese and patients with type 2 diabetes and hypertension. All of the exercise-based interventions were effective in improving sleep, but not to an extent that can positively influence cardiometabolic health. The mediating effects on cardiometabolic risks were more apparent for the sleep hygiene and cognitive behavioral therapy interventions, despite the small number of pilot-scale studies in this area. CONCLUSION: The mediating effects of sleep improvement on cardiometabolic risk/disease control were inconclusive. More research to examine the effect of sleep-related risk-factor modification on cardiovascular health is warranted.