Abstract
Objective.To clarify the association of knee osteoarthritis (KOA) with overweight (OW), hypertension (HTN), dyslipidemia (DL), and impaired glucose tolerance (IGT), which are components of metabolic syndrome (MS), in a Japanese population.
Methods.We enrolled 1690 participants (596 men, 1094 women) from the large-scale cohort study Research on Osteoarthritis Against Disability (ROAD), begun in 2005 to clarify epidemiologic features of OA in Japan. KOA was evaluated by the Kellgren-Lawrence grade, minimum joint space width (MJSW), minimum joint space area (JSA), and osteophyte area (OPA). OW, HTN, DL, and IGT were assessed using standard criteria.
Results.The prevalence of KOA in the total population in the age groups ≤ 39, 40–49, 50–59, 60–69, 70–79, and ≥ 80 years was 2.2%, 10.7%, 28.2%, 50.8%, 69.0%, and 80.5%, respectively. Logistic regression analyses after adjustment for age, sex, regional difference, smoking habit, alcohol consumption, physical activities, regular exercise, and history of knee injuries revealed that the OR of KOA significantly increased according to the number of MS components present (1 component: OR 1.21, 95% CI 0.88–1.68, p = 0.237; 2 components: OR 1.89, 95% CI 1.33–2.70, p < 0.001; 3 or more components: OR 2.72, 95% CI 1.77–4.18; p < 0.001). The number of MS components was inversely related to medial MSJW (ß = −0.148, R2 = 0.21, p < 0.001), medial JSA (women only; ß = −0.096, R2 = 0.18, p = 0.001), and positively related to OPA (ß = 0.12, R2 = 0.11, p < 0.001).
Conclusion.The accumulation of MS components is significantly related to presence of KOA. MS prevention may be useful to reduce cardiovascular disease and KOA risk.
Footnotes
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Supported by Grants-in-Aid for Scientific Research B20390182 (N. Yoshimura), C20591737 (T. Akune), C20591774 (S. Muraki), and the Young Scientists A18689031 (H. Oka). Collaborating research with NSF 08033011-00262 (Director, N. Yoshimura) from the Ministry of Education, Culture, Sports, Science and Technology, and H17-Men-eki-009 (Director, K. Nakamura), H18-Choujyu-037 (Director, T. Nakamura), and H20-Choujyu-009 (Director, N. Yoshimura) from the Ministry of Health, Labour and Welfare in Japan. This study was also supported by grants from the Japan Osteoporosis Society (N. Yoshimura), Nakatomi Foundation (N. Yoshimura), and research aid from the Japanese Orthopaedic Association (Director, H. Kawaguchi).
- Accepted for publication December 21, 2010.