Effects of obstructive sleep apnoea treatment on cardiovascular and sleep health in bed partners: the sleep partners clinical trial.

BACKGROUND: It remains unclear whether obstructive sleep apnoea (OSA) and its treatment influence cardiovascular and sleep health in bed partners. METHODS: In this placebo-controlled trial, patients with moderate/severe OSA who had bed partners were randomly assigned to receive continuous positive airway pressure (CPAP) or placebo (nasal strips). At baseline and after 3 months, the bed partners underwent clinical evaluation, endothelial function (flow-mediated dilation, FMD), 24-hour ambulatory blood pressure (BP) monitoring, sleep questionnaires and 1-week wrist actigraphy. RESULTS: A total of 63 couples were recruited (34 patients randomised to CPAP and 29 to nasal strips). At baseline, bed partners showed impaired FMD and a higher frequency of long sleep latency, fragmented sleep, short sleep duration and poor sleep quality. Mean adherence to CPAP and nasal strips in OSA patients was 5.7±1.7 hours and 93.1%±12.6%, respectively. Compared with placebo, bed partners of patients assigned to CPAP did not change FMD (Δ: -0.94% (6.03%; 2.24%) vs Δ: -3.27% (-6.50%; 1.76%), p=0.67). However, significant differences were observed for 24-hour systolic BP (CPAP: -0.85±5.22 mm Hg; placebo: +3.14±8.00 mm Hg; p=0.03), daytime systolic BP (CPAP: -1.2±5.5 mm Hg; placebo: +3.8±8.8 mm Hg; p=0.01) and night-time heart rate (CPAP: -3±6 bpm; placebo: +2±7 bpm; p=0.01). They improved sleep quality (p=0.02), decreased daytime sleepiness (p=0.01), time awake after sleep onset (CPAP: -4.71±20.32 min; placebo: +7.36±17.51 min; p=0.002) and number of awakenings (CPAP: -0.97±9.42; placebo: +2.83±9.14; p=0.02). In a stratified analysis by CPAP adherence, endothelial function in bed partners was preserved with optimal use (≥6 hours/night), but worsened with lower adherence (p=0.03). CONCLUSIONS: OSA treatment did not improve endothelial function in bed partners but prevented BP increases, alongside improvements in sleep quality, daytime sleepiness and sleep fragmentation. TRIAL REGISTRATION NUMBER: NCT03011294.