The Impact of Weight Change on Mortality and Cardiovascular Outcomes in Obstructive Sleep Apnea

Study Objectives Weight is related to the severity of obstructive sleep apnea (OSA), but the impact of weight and its change on prognosis remains unclear. This study aimed to investigate the association between weight, weight change and mortality in participants with OSA. Methods This cohort study investigated participants with OSA from the Sleep Heart Health Study (SHHS). Participants were grouped according to body mass index (BMI) at SHHS1 and the percent difference in body weight between SHHS1 and SHHS2. The weight change patterns were defined as: weight loss (lost ≥2.5%), stable weight (changed <2.5%), and weight gain (gained ≥2.5%). The association between weight, weight change with mortality and cardiovascular outcomes were analyzed. Results Of 1525 participants, with a median age of 65 years at SHHS1, weight was positively correlated with the severity of OSA, but higher risk was seen in lean participants (BMI <25 kg/m2) for all-cause mortality. From SHHS1 to SHHS2, the burden of OSA decreased in the weight loss group and increased in the weight gain group. With a median follow-up of 6.6 years since SHHS2, weight loss increased the risk of all-cause and cardiovascular diseases mortality [hazard ratio (95% CI): 1.370 (1.019, 1.841) and 1.700 (1.024, 2.823)], while weight gain reduced the risk of adverse outcomes, compared to participants with stable weight. Conclusion Among middle-aged and elderly OSA participants, weight loss reduced the burden of OSA, but increased the risk of mortality. For this population, a risk-based approach may be necessary to guide individualized weight management.