BACKGROUND & AIMS: Although continuous positive airway pressure (CPAP) is the first-line treatment for obstructive sleep apnea (OSA), lifestyle interventions have also emerged as complementary therapeutic choices. We aimed to explore whether the addition of a weight-loss Mediterranean diet/lifestyle intervention to OSA standard care, i.e. CPAP prescription and brief written healthy lifestyle advice, has an incremental effect on improving OSA severity, over the effect of standard care alone.
METHODS: We designed a parallel, randomized, controlled, superiority clinical trial. Eligible participants were adult, overweight men and women, diagnosed with moderate-to-severe OSA [apnea-hypopnea index (AHI)≥ 15 events/h] through an attended overnight polysomnography. Participants were blindly randomized to a standard care group (SCG, n = 65), a Mediterranean diet group (MDG, n = 62) or a Mediterranean lifestyle group (MLG, n = 60). All three study groups were prescribed with CPAP. The SCG additionally received written healthy lifestyle advice, while intervention arms were subjected to a 6-month behavioral intervention aiming at weight loss and increasing adherence to the Mediterranean diet. The MLG also received counselling on physical activity and sleep habits. Polysomnographic data and OSA symptoms were evaluated pre- and post-intervention.
RESULTS: A total of 187 OSA patients were recruited. Seven patients were excluded post-randomization and 53/180 (29%) were lost to follow-up. No harms from the interventions applied were reported. According to intention-to-treat analysis (n = 180), mean (95% confidence interval) AHI change was -4.2 (-7.4, -1.0) for the SCG, -24.7 (-30.4, -19.1) for the MDG and -27.3 (-33.9, -20.6) for the MLG. Post-intervention age-, sex-, baseline- and CPAP use-adjusted AHI was significantly lower in the MDG and the MLG compared to the SCG (mean difference: -18.0, and -21.2, respectively, both P < 0.001), and the differences remained significant after further adjustment for body-weight change (P = 0.004 and 0.008, respectively). Other respiratory event indices, daytime sleepiness and insomnia were also significantly lower in both intervention arms compared to the SCG (all P < 0.05). The MLG only presented higher percent rapid-eye-movement sleep and lower daytime sleepiness compared to the MDG (both P < 0.05). Results were similar in the per-protocol analysis (n = 127).
CONCLUSIONS: A dietary/lifestyle intervention on top of standard care leads to greater improvements in OSA severity and symptomatology compared to standard care alone. Benefits are evident regardless of CPAP use and weight loss.
TRIAL REGISTRATION: Clinicaltrials.gov NCT02515357, https://clinicaltrials.gov/ct2/show/NCT02515357.
