Associations of Metabolic Syndrome and Its Components with the Risk of Incident Knee Osteoarthritis Leading to Hospitalization: A 32-Year Follow-up Study.

OBJECTIVES: To examine whether metabolic syndrome or its individual components predict the risk of incident knee osteoarthritis (OA) in a prospective cohort study during a 32-year follow-up period. DESIGN: The cohort consisted of 6274 participants of the Mini-Finland Health Survey, who were free from knee OA and insulin-treated diabetes at baseline. Information on the baseline characteristics, including metabolic syndrome components, hypertension, elevated fasting glucose, elevated triglycerides, reduced high-density lipoprotein, and central obesity were collected during a health examination. We drew information on the incidence of clinical knee OA from the national Care Register for Health Care. Of the participants, 459 developed incident knee OA. In our full model, age, gender, body mass index, history of physical workload, smoking history, knee complaint, and previous injury of the knee were entered as potential confounding factors. RESULTS: Having metabolic syndrome at baseline was not associated with an increased risk of incident knee OA. In the full model, the hazard ratio for incident knee OA for those with metabolic syndrome was 0.76 (95% confidence interval [0.56, 1.01]). The number of metabolic syndrome components or any individual component did not predict an increased risk of knee OA. Of the components, elevated plasma fasting glucose was associated with a reduced risk of incident knee OA (hazard ratio 0.71, 95% confidence interval [0.55, 0.91]). CONCLUSIONS: Our findings do not support the hypothesis that metabolic syndrome or its components increase the risk of incident knee OA. In fact, elevated fasting glucose levels seemed to predict a reduced risk.

Dietary magnesium intake, serum high sensitivity C-reactive protein and the risk of incident knee osteoarthritis leading to hospitalization-A cohort study of 4,953 Finns.

OBJECTIVES: To study whether low dietary magnesium (Mg) intake and serum high sensitivity C-reactive protein (hs-CRP) predict the development of clinical knee osteoarthritis (OA). METHODS: The cohort consisted of 4,953 participants of a national health examination survey who were free of knee and hip OA at baseline. Information on the incidence of knee OA leading to hospitalization was drawn from the National Care Register for Health Care. During the follow-up of 10 years, 123 participants developed incident knee OA. Dietary magnesium intake was assessed on the basis of a food frequency questionnaire from the preceding year. We used Cox's proportional hazards model to estimate the strength of the association between the tertiles of dietary Mg intake and incident knee OA, adjusted for baseline age, gender, energy intake, BMI, history of physical workload, leisure time physical activity, injuries, knee complaints, the use of Mg supplements, and serum hs-CRP levels. RESULTS: At baseline, dietary Mg intake was inversely associated with serum hs-CRP even after adjustment for all the potential confounding factors. During the follow-up, the adjusted hazard ratios (with their 95% confidence intervals) for incident knee OA in dietary Mg intake tertiles were 1.00, 1.28 (0.78-2.10), and 1.38 (0.73-2.62); the p value for trend was 0.31. Serum hs-CRP level at baseline did not predict incident knee OA. CONCLUSIONS: The results do not support the hypothesis that low dietary Mg intake contributes to the development of clinical knee OA, although Mg intake is inversely associated with serum hs-CRP level.

Serum 25-hydroxyvitamin D and the risk of knee and hip osteoarthritis leading to hospitalization: a cohort study of 5274 Finns.

OBJECTIVE: The aim of this study was to investigate whether low levels of serum 25-hydroxyvitamin D [25(OH)D] predicts the development of knee or hip OA. METHODS: The cohort consisted of 5274 participants in a national health examination survey who had no knee or hip OA at baseline. Information about the incidence of OA was drawn from the National Health Care Register. During the follow-up of 10 years (50 134 person-years), 127 subjects developed incident, physician-diagnosed OA in the knee and 45 in the hip joint. The information on covariates, including age, sex, education, BMI, work load, leisure time physical activity, smoking history, knee or hip complaint during the past month and previous injuries, was gathered at baseline. Serum 25(OH)D concentrations were determined from baseline serum samples. RESULTS: After adjustment for age and gender, serum 25(OH)D showed statistically significant associations with known risk factors for OA except injuries. In the fully adjusted model, low serum 25(OH)D concentration did not predict increased incidence of knee and hip OA. CONCLUSION: The results do not support the hypothesis that low levels of serum 25(OH)D contribute to the development of knee or hip OA.