Are waist circumference and body mass index independently associated with severity of knee osteoarthritis in elderly Kuwaiti populations?

ABSTRACT

Osteoarthritis [OA] of the knee is one of the major causes of pain and physical disability. Obesity is perhaps the strongest modifiable risk factor for the progression of the disease. The study aimed at exploring the associations between the severity of knee osteoarthritis [OA], and body mass index [BMI], and waist circumference [WC] as two putative parameter of obesity. The study design is a cross sectional one, in which 110 patients with idiopathic symptomatic knee OA were classified using Health Assessment questionnaire [HAQ] score into row groups mild/moderate [48 patients] and severe [62 cases]. A pre-designed questionnaire included personal data, anthropometric measurements and results of clinical and radiological examination. Basic univariate analyses were followed by multiple logistic regression analysis. Of the risk factors examined, obesity was the only significant determinant of progression of knee OA [OR = 48.8, 95% CI 2.9-90.2], while female gender and presence of Heberden's nodes showed border line statistical significance [OR = 1.5, 95% CI 1.0 - 2.2 and OR = 1.4, 95% CI 1.0 - 1.9 respectively]. Weight, BMI and WC were significantly correlated with HAQ severity score of OA. Obesity is the strongest modifiable risk factor for the severity of osteoarthritis. Weight loss may reduce the risk of progression of OA of the knee, BMI and waist WC can be used as clinical measures and predictors of the severity of knee OA