Association of lung volumes with nocturnal oxygen saturation in obese persons: A possible role for Therapeutic continuous positive airway pressure

We investigated the association among obesity, nocturnal oxygen saturation, and pulmonary function in 31 obese women and 17 obese men scheduled for bariatric surgery who underwent nocturnal polysomnography and pulmonary function testing. Pearson correlation coefficients showed a significant association between expiratory reserve volume percent and average oxygen saturation (P = 0.027), between body mass index and lowest oxygen saturation (P = 0.034), and between body mass index and average oxygen saturation (P = 0.039). The mean age, body mass index, expiratory reserve volume percent, and functional residual capacity percent were not significantly different between obese women and men. The lowest oxygen saturation was 80 ± 10% in obese women and 62 ± 19% in obese men (P = 0.001). The average oxygen saturation was 88 ± 5% in obese women and 83 ± 6% in obese men (P = 0.005) Therapeutic nocturnal continuous positive airway pressure may have a role by improving ventilation-perfusion matching and thereby improving nocturnal oxygen saturation in these patients.