|Chaganti, R Krishna - University Of California|
|Tolstykh, Irina - University Of California|
|Javaid, Muhammad - University Of California|
|Neogi, Tuhina - Boston University|
|Torner, James - University Of Iowa|
|Curtis, Jeffrey - University Of Alabama|
|Jacques, Paul - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|Felson, David - Boston University|
|Lane, Nancy - University Of California|
|Nevitt, Michael - University Of California|
Submitted to: Osteoarthritis and Cartilage
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2013
Publication Date: 10/2/2013
Citation: Chaganti, R., Tolstykh, I., Javaid, M.K., Neogi, T., Torner, J., Curtis, J., Jacques, P., Felson, D., Lane, N.E., Nevitt, M.C. 2013. High plasma levels of vitamin C and E are associated with incident radiographic knee osteoarthritis. Osteoarthritis and Cartilage. 22(2):190-196.
Interpretive Summary: Antioxidants have been investigated for their beneficial effects in protecting against the development of several chronic diseases. Vitamins C and E both have antioxidant properties and have been investigated for their potential to prevent cardiovascular disease, cancer, and to protect joints and prevent the development and progression of osteoarthritis (OA). However, studies examining the association between these vitamins and OA have shown mixed results. For example, some studies have shown an association between vitamin C intake and reduced OA progression, but the same was not observed for vitamin E. One study in animals indicated that vitamin C worsened the severity of OA. Many of these previously conducted studies have measured vitamin C and E intake from food frequency questionnaires (FFQs) in which individuals are asked to report the types and quantity of foods that they typically consume. It is believed that vitamin C and E levels in the blood better reflect the amounts consumed than intake measured from FFQs. Thus, in this study, we examined the association between vitamin C and E in the blood with development of OA in the knee over a 30 month period. We used data from the Multicenter OA Study, which examined approximately 3,000 individuals over the age of 50 years at high risk of OA. Participants with the highest vitamin C levels in the blood had a higher incidence of OA compared to those with the lowest vitamin C levels. Similarly, participants with the highest vitamin E levels had a higher incidence of OA compared to those with the lowest vitamin E levels. Our results suggest that higher intakes of vitamins C and/or E do not help to protect against the development of OA in the knee. Future research should examine the role of antioxidant intake in OA development and why, in particular, higher levels of vitamin C and E were associated with OA in our study.
Technical Abstract: Previous studies suggest that the antioxidants vitamins C and E may protect against development of knee osteoarthritis (OA). We examined the association of circulating levels of vitamin C and E with incident whole knee radiographic OA (WKROA). We performed a nested case-control study of incident WKROA in MOST, a cohort of 3,026 men and women aged 50-79 years with, or at high risk of, knee OA. Incident cases were knees without either tibiofemoral (TF) or patellofemoral (PF) OA at baseline that developed TF and/or PF OA by 30-month follow-up. Two control knees per case were selected from those eligible for WKROA that did not develop it. Vitamin C and E (alpha-tocopherol) assays were done on baseline supernatant plasma (PCA) and serum samples, respectively. We examined the association of gender-specific tertiles of vitamin C and E with incident WKROA using logistic regression with GEE, adjusting for age, gender, and obesity. Subjects without WKROA at baseline who were in the highest tertile of vitamin C had a higher incidence of WKROA [adjusted OR = 2.20 (95% CI: 1.12-4.33); P-value = 0.021], with similar results for the highest tertile of vitamin E [adjusted OR = 1.89 (1.02-3.50); P-value = 0.042], compared to those in the lowest tertiles. P-values for the trend of vitamin C and E tertiles and incident WKROA were 0.019 and 0.030, respectively. Higher levels of circulating vitamin C and E did not provide protection against incident radiographic knee OA, and may be associated with an increased risk of knee OA.