Does Scoliosis Affect Sleep Breathing?

Abstract

Objective: Scoliosis, especially thoracic curves, causes poor pulmonary function. As a result, scoliosis may impair sleep breathing. The literature regarding the relationship between scoliosis and sleep breathing is sparse.

Methods: Fifty-seven patients with adolescent idiopathic scoliosis or congenital scoliosis and 25 healthy control subjects were included. The wrist sleep monitors was used. Sleep breathing was evaluated with the following parameters: 1) Respiratory Disorders Index (pRDI), indicating mean respiratory events per hour of sleep including apnea, hypoxia, and respiratory effort-related arousal; 2) Apnea and Hypopnea Index (pAHI), expressing the number of apnea and hypopnea events per hour of sleep; and 3) mean and minimal oxygen saturation (Sao₂) during sleep.

Results: No differences in age, sex distribution, and body mass index were found between the two groups. Patients with scoliosis had statistically significant higher pRDI (median, 10.10 vs. 8.65; P = 0.039) and pAHI (median, 1.60 vs. 0.72; P = 0.029) scores than the control group. The minimal SaO₂ value in patients with scoliosis was lower (median, 93% vs. 94%, respectively; P = 0.005), whereas no difference was found in the mean SaO₂ value during sleep. In patients with scoliosis, pAHI scores were higher when lying on the convex side of the thoracic curve compared with the concave side (2.34 vs. 2.28, respectively; P = 0.044), whereas no such difference was observed in the control group.

Conclusions: Patients with scoliosis have more respiratory events of apnea and hypopnea during sleep than the control group. The minimal SaO₂ value in patients with scoliosis is lower than the normal population. Sleeping on the convex side of the thoracic curve results in higher pAHI scores than on the concave side.

Keywords: Hypopnea; Scoliosis; Sleep apnea; Sleep-disordered breathing; Thoracic cage deformity.