Publication:

Is the radiological stage of knee osteoarthritis associated with the risk of obstructive sleep apnea or insomnia severity?

Background Aim was to investigate the relationship between knee osteoarthritis severity and obstructive sleep apnea risk and insomnia severity

Methods A total of 127 patients with knee osteoarthritis were included in this prospective cross-sectional study. The relationship between Kellgren-Lawrence classification, Western Ontario and McMaster University Osteoarthritis Index score, Berlin questionnaire score, Insomnia Severity Index score, age, sex, and body-mass index was evaluated with univariate and multivariate analyses.

Results The mean age of the radiological stage 1 group was significantly lower compared to the other group (p<0.001). 84.3% of all patients were female, and there was no significant sex difference between the groups (p=0.327). The median WOMAC scores of the stage 2, 3 and 4 groups were significantly higher than that of the stage 1 group (p<0.001). The median WOMAC pain subscore of the stage 3 and 4 groups were significantly higher than that of the stage 2 and the stage 1 group (p<0.001). Multiple logistic regression analysis revealed that high BMI (p=0.005) was the only factor independently associated with greater OSA risk. Multiple linear regression analysis revealed that sex (p=0.008) and WOMAC score (p=0.001) were independently associated with greater insomnia severity.

Conclusions In multivariable analysis, high BMI was determined as the only independent risk factor associated with higher OSA likelihood, while advanced age and high WOMAC total score were determined as independent risk factors for greater insomnia severity. The WOMAC score can be used to predict the severity of osteoarthritis and insomnia, and could be valuable for management.