Behavioral Sleep Interventions and Cardiovascular Risk Factors: Systematic Review and Meta-analysis of Randomized Controlled Trials.

Background/objectives: Chronic sleep disturbance has been consistently associated with cardiovascular disease. We sought to determine whether behavioral interventions to improve sleep have been associated with improvements in 4 common cardiovascular disease risk factors: hypertension, diabetes mellitus (DM), obesity, and smoking.

Methods: Randomized controlled trials evaluating the prospective effect of behavioral sleep interventions on ( a ) blood pressure in participants with hypertension/prehypertension, ( b ) glycemic control in participants with DM/pre-DM, ( c ) anthropometrics in participants who were overweight/obese, and ( d ) smoking status in smokers were eligible. Where feasible, we undertook random-effects meta-analyses of standardized mean differences in cardiovascular disease risk factor change.

Results: Overall, 3 trials met the inclusion criteria for blood pressure, 4 for glycemic control, 9 for overweight/obesity, and 2 for smoking. On meta-analysis, interventions with sleep as the sole behavioral target were associated with a significant reduction in hemoglobin A 1c % (-0.84; 95% confidence interval [CI], -1.34 to -0.34), but not a significant reduction in systolic blood pressure (-0.18; 95% CI, -0.55 to 0.20) versus controls. In addition, any interventions with sleep as a behavioral target were associated with significant reductions in hemoglobin A 1c % (-0.71; 95% CI, -1.01 to -0.42) and weight (-0.78; 95% CI, -1.11 to -0.45), but not systolic blood pressure (-0.72; 95% CI, -1.82 to 0.37). Trials evaluating smoking status were not amenable to meta-analysis.

Conclusion: Behavioral interventions to improve sleep were associated with improved glycemic control in patients with DM. It is also possible that these interventions improve weight in individuals who were overweight/obese. A low number of trials and small sample sizes indicate that further large, well-designed randomized controlled trials of interventions are warranted.