Risk factors for incident symptomatic knee osteoarthritis: A population-based case control study in Lebanon

Objectives To identify risk factors for symptomatic knee osteoarthritis (OA) and explain the geographical disparities in its occurrence. Methods A population-based case control study used data from a national Community Oriented Program for the Control of Rheumatic Diseases (COPCORD) study conducted in Lebanon in 2009. The sample included 59 incident cases of symptomatic knee OA with no past knee injury, knee pain for a period of <12months, and were examined by rheumatologists. One hundred and eighteen randomly sampled population-based controls were frequency matched with cases by age and gender. Results Obesity, overweight and area of residence were significant risk factors for knee OA, after adjusting for type of job, monthly income and family history of joint problems. Conclusion Determinants of symptomatic knee OA in Lebanon may differ by geographical location, potentially reflecting differences in social conditions, biological elements and environmental factors. The geographical differences remained significant even after accounting for investigated factors. Thus, further research is needed to explore other potential determinants, such as living conditions, biomechanical and hormonal factors.