El impacto de la pérdida de peso en los endotipos fisiológicos asociados con la apnea obstructiva del sueño

Weight-loss improves upper airway collapsibility in people with obstructive sleep apnea (OSA). However, it is unclear how weight-loss affects the other physiological traits (i.e. endotypes) associated with OSA (loop gain, arousal threshold, and muscle compensation).

What is the effect of metabolic bariatric surgery on the OSA endotypes and are the baseline endotypes associated with improvements in OSA severity?

and Methods: Using non-invasive methods, the OSA endotypes were measured in 43 patients before and after (∼6-18 months) metabolic bariatric surgery during an overnight clinical polysomnogram. OSA endotypes were also measured using gold standard physiological techniques (i.e. CPAP-dial down method) in a subset of patients (n=10). Generalized linear mixed-effects models were used to evaluate the effect on outcome variables.

Metabolic bariatric surgery was associated with improvements in AHI (50.7±26.8 vs. 24.6±19.2 events/hr, p<0.001), body mass index (42.1±5.5 vs. 32.8±4.5 kg/m², p<0.001), upper airway collapsibility (67.0±21.4 vs. 72.8±16.2 %V_eupnea, p=0.011) and loop gain (0.65±0.19 vs. 0.58±0.19, p=0.011). Weight-loss also reduced arousal threshold (149.7±28.6 vs. 142.6±30.1, %V_eupnea, p=0.011). Gold standard measures showed changes consistent with non-invasively derived endotypes. A greater improvement in airway collapsibility was associated with a greater reduction in AHI (B=-0.62, 95%CI [-0.97 to -0.27], P=0.002, R²=0.23) and greater decreases in arousal threshold were associated with larger improvements in AHI (B=0.63, 95%CI [0.33-0.92], p<0.001, R²=0.29). Multivariable models controlling for baseline AHI found those with less-collapsible upper airways and low loop gain at baseline may be more likely to see improvements in their OSA severity post-surgery.

Metabolic bariatric surgery is associated with improvements in weight, AHI, upper airway collapsibility and loop gain and may be particularly effective for those with mild upper airway collapsibility and low loop gain.