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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #203222
Title: Low Levels of Vitamin D and Worsening of Knee OA: Results from Two Longitudinal Studies

Author
item FELSON, DAVID - BOSTON UNIVERSITY
item NIU, JINGBO - BOSTON UNIVERSITY
item CLANCY, MARGARET - BOSTON UNIVERSITY
item ALIABADI, PIRAN - RADIOLOGY, BAND WOMEN'S
item SACK, BURTON - BOSTON UNIVERSITY
item GUERMAZI, ALI - SYNARC, INC.
item HUNTER, DAVID - BOSTON UNIVERSITY
item AMIN, SHREYASEE - MAYO CLINIC
item ROGERS, GAIL - HNRCA AT TUFTS
item Booth, Sarah

Submitted to: Arthritis and Rheumatism
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/11/2006
Publication Date: 12/28/2006
Citation: Felson, D.T., Niu, J., Clancy, M., Aliabadi, P., Sack, B., Guermazi, A., Hunter, D.J., Amin, S., Rogers, G., Booth, S.L. 2006. Low Levels of Vitamin D and Worsening of Knee OA: Results from Two Longitudinal Studies. Arthritis and Rheumatism. 56(1): 129-136.

Interpretive Summary: Vitamin D deficiency has been associated with an increased risk of symptoms joint space narrowing or cartilage loss in osteoarthritis (OA). We measured vitamin D concentrations in subjects from two studies, the Framingham Osteoarthritis Study and the Boston Osteoarthritis of the Knee Study (BOKS). In the first study, subjects obtained knee x-rays in 1992-5 and again in 2002-4; blood was drawn for measurement of vitamin D status in 1996-2000. In the second, subjects with knee OA had x-rays of both knees and MRI’s of the more symptomatic knee at baseline, 15 and 30 months. Blood was drawn at all visits for measurement of vitamin D, and baseline specimen was used when available. In both studies, we defined x-ray worsening based on joint space loss in the knee. In BOKS, we also evaluated cartilage loss. In the Framingham Study, 715 subjects had a mean vitamin D concentrations of 20ng/ml and 20.3% of the knees showed OA worsening with most knees having no evidence of OA at baseline. In BOKS, 211 subjects with OA had a mean vitamin D concentrations of 20ng/ml with 23.6% of knees showing OA worsening. We found no association of 25-OH D levels with OA worsening as determined by x-rays in either cohort. In conclusion, vitamin D status is unrelated to the risk of knee osteoarthritis.

Technical Abstract: Objective: To confirm reports that 25-hydroxyvitamin D (25-OH D) deficiency is associated with an increased risk of joint space narrowing or cartilage loss in osteoarthritis (OA). Methods: We measured 25-OH D levels in subjects from two longitudinal cohort studies, the Framingham Osteoarthritis Study and the Boston Osteoarthritis of the Knee Study (BOKS). In the first, subjects obtained weight bearing AP and lateral knee radiographs in 1992-5 and again in 2002-4 (mean interval 9 years); blood was drawn for measurement of vitamin D status in 1996-2000. In the second, subjects with symptomatic knee OA participating in a natural history study had fluoroscopically positioned semiflexed PA and lateral x-rays of both knees and MRI’s of the more symptomatic knee at baseline, 15 and 30 months. Blood was drawn at all visits, and baseline specimen was used when available. In both studies, we defined x-ray worsening based on joint space loss in the tibiofemoral joint on either AP/PA or lateral weight bearing views using a semiquantitative scale (worsening defined as increase by >=1 on 0-3 scale). In BOKS, we evaluated cartilage loss semiquantitatively using the WORMS scale. In both studies, 25-OH D levels were measured by RIA (Diasorin). Analyses focused on whether vitamin D levels [defined 1) in tertiles or 2) as deficient (25-OH D <20ng/ml) vs. non-deficient] predicted worsening of OA using logistic regression analysis adjusted for age, body mass index, gender and baseline OA level. Results: In the Framingham Study, 715 subjects had a mean 25-OH D level of 20ng/ml and 20.3% of the knees showed worsening with most knees having no evidence of OA at baseline. In BOKS, 211 subjects with OA had a mean 25-OH D level of 20ng/ml with 23.6% of knees showing radiographic worsening. We found no association of 25-OH D levels with radiographic worsening in either cohort and confidence limits for analyses of vitamin D deficiency were narrow, suggesting that results were not based on insufficient power. In fact, the risk of worsening was slightly but non-significantly lower in persons with low levels of vitamin D than persons with higher levels. In BOKS, vitamin D levels were unrelated to cartilage loss on MRI. Conclusion: Vitamin D status is unrelated to the risk of joint space or cartilage loss in knee osteoarthritis.