The impact of obstructive sleep apnea syndrome severity on physical performance and mental health. The use of SF-36 questionnaire in sleep apnea.

Statistical analysis revealed that in patients with respiratory disturbance index (RDI) ≥ 15, (n = 115), RDI was independently associated with lower performance in role limitations due to physical problems (p = 0.005). Additionally, RDI was the only factor associated with decreased vitality (p = 0.014) and mental health scores (p = 0.047). In the same patient subgroup, body mass index (BMI) and age were associated with poorer scores in physical functioning (p < 0.001 and p = 0.003, respectively). BMI was an independent clinical predictor of worse scores in bodily pain (p = 0.006) general health (p = 0.006), social functioning (p = 0.025) and role limitations due to emotional problems (p = 0.004).