Effectiveness of lifestyle interventions on obstructive sleep apnea (OSA): systematic review and meta-analysis

Background: Obstructive sleep apnea (OSA) is a common sleep disorder associated with several adverse health outcomes. Given the close association between OSA and obesity, lifestyle and dietary interventions are commonly recommended to patients, but the evidence for their impact on OSA has not been systematically examined. Objectives: To conduct a systematic review and meta-analysis to assess the impact of weight loss through diet and physical activity on measures of OSA: apnea-hypopnea index (AHI) and oxygen desaturation index of 4% (ODI4). Methods: A systematic search was performed to identify publications using Medline (1948-2011 week 40), EMBASE (from 1988-2011 week 40), and CINAHL (from 1982-2011 week 40). The inverse variance method was used to weight studies and the random effects model was used to analyze data. Results: Seven randomized controlled trials (519 participants) showed that weight reduction programs were associated with a decrease in AHI (-6.04 events/h [95% confdence interval -11.18, -0.90]) with substantial heterogeneity between studies (I² = 86%). Nine uncontrolled before-after studies (250 participants) showed a signifcant decrease in AHI (-12.26 events/h [95% confdence interval -18.51, -6.02]). Four uncontrolled beforeafter studies (97 participants) with ODI4 as outcome also showed a signifcant decrease in ODI4 (-18.91 episodes/h [95% confdence interval -23.40, -14.43]). Conclusions: Published evidence suggests that weight loss through lifestyle and dietary interventions results in improvements in obstructive sleep apnea parameters, but is insuffcient to normalize them. The changes in obstructive sleep apnea parameters could, however, be clinically relevant in some patients by reducing obstructive sleep apnea severity. These promising preliminary results need confrmation through larger randomized studies including more intensive weight loss approaches.