Metabolic syndrome, radiographic osteoarthritis progression and chronic pain of the knee among men and women from the general population: The Rotterdam study.

Objective: Although a relationship between osteoarthritis and components of metabolic syndrome (MetS) has been suggested, most of the results have been cross-sectional. We, therefore, aimed to investigate the sex-specific longitudinal association of (components of) MetS with progression of radiographic osteoarthritis and chronic pain in the knee joints in a large prospective cohort.

Method: In the large population-based Rotterdam study of up to 6,138 individuals, median follow-up time 5.7 (IQR 5.5) years, we examined the relation between MetS and its components (abdominal obesity, high triglycerides, low high-density lipoprotein, elevated blood pressure, and type 2 diabetes) with the progression of osteoarthritis using generalized estimating equations, generalized linear models and competing risk analysis. Analyses were stratified for sex. Covariates adjusted for: age, smoking, alcohol use, education, sub-cohort, baseline K/L grade, months between radiographs and BMI.

Results: The presence of MetS (37.6 % in men, 39 % in women) and elevated blood pressure was associated with an increased risk of knee osteoarthritis progression in both men and women. MetS was associated with an increased risk of incident chronic knee pain (CKP) in men. In addition, abdominal obesity and high triglycerides showed higher riskfor incidence of CKP in men,but not in women. The associations were attenuated and no longer significant after BMI-adjustment, except for the association of MetS and high triglycerides with incidence of CKP in men that stayed significant (OR 1.04, 95 %CI 1.00-1.07 for MetS and OR 1.04, 95 %CI 1.01-1.07 for high triglycerides).

Conclusion: Metabolic syndrome and individual metabolic components, such as abdominal obesity and elevated blood pressure, were associated with radiographic progression of knee OA in both men and women, but not independent of BMI. Metabolic syndrome and high triglycerides were associated with incidence of CKP only in men.