Association of sleep-disordered breathing and wound healing in patients with diabetic foot ulcers

Study Objectives: Sleep-disordered breathing (SDB) is prevalent and associated with an increased risk of morbidity and mortality. However, whether SDB has an adverse impact on wound healing in patients with diabetic foot ulcers (DFUs) is uncertain. The purpose of this study was to investigate the association of SDB with wound healing in patients with DFUs. Methods: A total of 167 patients with DFUs were enrolled between July 2013 and June 2019 atWest China Hospital (Chengdu, China) to assess the association of SDB with wound healing, ulcer recurrence, and all-cause mortality. Results: Whereas there was no significant association between apnea-hypopnea index (AHI) and wound healing, total sleep time (per hour: Hazard ratio [HR], 1.15; 95%confidence interval [CI], 1.01-1.30; P =.029), sleep efficiency (per 10%: HR, 1.20; 95%CI, 1.04-1.37; P =.012), and wakefulness after sleep onset (per 30 minutes: HR, 0.89; 95% CI, 0.82-0.97; P =.008) were associated with wound healing. Total sleep time (per hour: Odds ratio, 0.71; 95%CI, 0.51-0.97; P =.035) and sleep efficiency (per 10%: Odds ratio, 0.68; 95%CI, 0.47-0.97; P =.033) were also associated with ulcer recurrence. Mean oxygen saturation (per 3%: HR, 0.68; 95% CI, 0.49-0.94; P = .021) and percentage of sleep time with oxygen saturation < 90% (per 10%: HR, 1.25; 95% CI, 1.03-1.53; P = .026) were significantly associated with mortality. Conclusions: SDB is highly prevalent in patients with DFUs but its severity, as conventionally measured by AHI, is not associated with wound healing. Sleep fragmentation and hypoxemia are stronger predictors of poor wound healing, high ulcer recurrence, and increased risk of death in patients with DFUs.