The effects of resistance exercise on obstructive sleep apnea severity and body water content in older adults: A randomized controlled trial.

Objectives/background: The prevalence of obstructive sleep apnea (OSA) in people over 70 years can reach up to 95%. Aerobic or combined exercise programs have been shown to impact positively on OSA severity. Resistance training changes leg fluid retention. We hypothesized that through this mechanism it may have an impact on the OSA severity in older adults.

Patients/methods: We evaluated changes in the respiratory event index (REI) of older adults with moderate-severe obstructive sleep apnea in a randomized, masked, controlled, parallel group trial. Participants between the age of 65 and 80 years with REI between 20 and 50 events/hour were assigned randomly to 12 weeks of resistance training or healthy life-style recommendations. Change in REI was the primary outcome. Muscle thickness, maximum strength, and physical function were secondary outcomes and body mass index (BMI) and body water content were assessed as mediators.

Results: Twenty-three subjects were included, 57% men, aged 71 ± 5 years, randomized to training (n = 12) and control intervention (n = 11). The baseline REI in the training and control groups were 30 ± 7/h and 29 ± 9/h; at follow-up, the delta REI were -3.6/hour (95% confidence interval -0.7 to -5.4) and 6.7/hour (5.2-8.6), respectively, with significant time × group interaction that remained significant after adjusting the generalized estimating equations model for delta BMI and delta body water content.

Conclusions: Twelve weeks of resistance training in older adults significantly changed the respiratory event index and was well tolerated. Changes in body water content were slight but cannot be dismissed as contributing to REI reduction.