The association between vitamin K status and knee osteoarthritis features in older adults: the Health, Aging and Body Composition Study

Authors: SHEA, KYLA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; KRITCHEVSKY, STEPHEN - Wake Forest University; HSU, FANG-CHI - Wake Forest University; NEVITT, MICHAEL - University Of California; BOOTH, SARAH - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; KWOH, CHIAN - University Of Arizona; MCALINDON, TIMOTHY - Tufts University; VERMEER, CEES - Maastricht University; DRUMMEN, NADJA - Maastricht University; HARRIS, TAMARA - National Institute On Aging (NIA, NIH); WOMACK, CATHERINE - University Of Tennessee; LOESER, RICHARD - University Of North Carolina

Submitted to: Osteoarthritis and Cartilage
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/2014
Publication Date: 3/1/2015
Citation: Shea, K., Kritchevsky, S., Hsu, F., Nevitt, M., Booth, S.L., Kwoh, C.K., McAlindon, T.E., Vermeer, C., Drummen, N., Harris, T.B., Womack, C., Loeser, R.F. 2015. The association between vitamin K status and knee osteoarthritis features in older adults: the Health, Aging and Body Composition Study. Osteoarthritis and Cartilage. 23:370-378. https://doi.org/10.1016/j.joca.2014.12.008.

Interpretive Summary: We investigated whether vitamin K nutritional status in older men and women was associated with changes in bone and cartilage that are characteristic of knee osteoarthritis. Knee osteoarthritis was assessed using magnetic resonance imaging (MRI.) Vitamin K status was measured in blood samples using two biomarkers. Matrix gla protein is a measure of vitamin K function in cartilage and bone. Concentrations of uncarboxylated matrix gla protein increase when vitamin K status is low. We found individuals with very low circulating vitamin K concentrations were more likely to have worsening of cartilage and meniscus damage over three years. However, the concentration of uncarboxylated matrix gla protein in blood was not associated with any feature of knee osteoarthritis progression. Future studies are needed to understand the mechanisms underlying vitamin K's role in osteoarthritis.

Technical Abstract: Background: Vitamin K-dependent proteins, including the mineralization inhibitor matrix-gla protein (MGP), are found in joint tissues including cartilage and bone. Previous studies suggest low vitamin K status is associated with higher osteoarthritis (OA) prevalence and incidence. Objective: To clarify what joint tissues vitamin K is relevant to in OA, we investigated the cross-sectional and longitudinal association between vitamin K status and knee OA structural features measured using MRI. Methods: Plasma phylloquinone (PK, vitamin K1) and dephosphorylated-uncarboxylated MGP ((dp)ucMGP) were measured in 791 older community-dwelling adults who had bilateral knee MRIs (mean +/- SD age = 74 +/- 3y; 67% female). The adjusted odds ratios (and 95% confidence intervals) [OR(95%CI)] for presence and progression of knee OA features according to vitamin K status were calculated using marginal models with generalized estimating equations, adjusted for age, sex, BMI, triglycerides and other pertinent confounders. Results: Longitudinally, participants with very low plasma PK (<0.2nM) were more likely to have articular cartilage and meniscus damage progression after 3 years [OR(95%CIs): 1.7(1.0-3.0), 2.6(1.3-5.2) respectively] compared to sufficient PK (=1.0nM). Higher plasma (dp)ucMGP (reflective of lower vitamin K status) was associated with higher odds of meniscus damage, osteophytes, bone marrow lesions, and subarticular cysts cross-sectionally [ORs(95%CIs) comparing highest to lowest quartile: 1.6(1.1-2.3); 1.7(1.1-2.5); 1.9(1.3-2.8); 1.5(1.0-2.1), respectively]. Conclusion: Community-dwelling men and women with very low plasma PK were more likely to have progression of articular cartilage and meniscus damage. Plasma (dp)ucMGP was associated with presence of knee OA features but not progression. Future studies are needed to clarify mechanisms underlying vitamin Ks role in OA.