Obstructive sleep apnea is a risk factor for osteoarthritis

Obstructive sleep apnea (OSA) syndrome is closely associated with cardiovascular and metabolic disorders. Recent studies reported that osteoarthritis (OA) is associated with cardiovascular disease as well as inflammation defined as "metabolic disorder". Due to the strong association of metabolic disorders with both OA and OSA, we aimed to investigate the association between severity of OSA and osteoarthritis grade based on X-Ray.

Patients who underwent polysomnography due to suspicion of OSA were recruited in a cross-sectional study. Included patients were grouped according to apnea-hypopnea index (AHI) as mild (AHI between 5 and 14.9), moderately (AHI between 15 and 29.9), and severe OSA (AHI ≥ 30). Patients with AHI p< 5 served as the control group. Kellgren-Lawrence scoring system was used to express OA severity, which was graded as Grade 0, 1, 2, 3 and 4.

One hundred twenty patients were enrolled into the study. Mean age was 52.4 ± 11.5 years and 56% (68/120) of the patients were male. A strong correlation was present between severity of OSA and severity of OA. Among those with Grade 4 OA group (33 patients), all patients had severe OSA and this association was independent from body-mass index. In the Grade 1 OA group, none of the patients had severe OSA (p< 0.05). A positive correlation was also seen between severity of OSA, OA and hs-CRP.

There is a strong association between OSA and OA. OSA might be a novel risk factor for the development OA. Further studies should evaluate the effect of OSA treatment on OA.