title: The association between vitamin K status and knee osteoarthritis features in older adults: the Health, Aging and Body Composition Study.
abstract: BACKGROUND
  Vitamin K-dependent (VKD) 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 magnetic resonance imaging (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 ± 3 y; 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 (GEEs), adjusted for age, sex, body mass index (BMI), triglycerides and other pertinent confounders.
  
  
  RESULTS
  Longitudinally, participants with very low plasma PK (<0.2 nM) 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 (≥ 1.0 nM). 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].
  
  
  CONCLUSIONS
  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.
authors.affiliation: USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA. Electronic address: kyla.shea@tufts.edu.
authors.forename: M K
authors.initials: MK
authors.lastname: Shea
authors.affiliation: Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Kritchevsky
authors.affiliation: Department of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: F-C
authors.initials: FC
authors.lastname: Hsu
authors.affiliation: Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Nevitt
authors.affiliation: USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Booth
authors.affiliation: Division of Rheumatology, University of Arizona, Tucson, AZ, USA.
authors.forename: C K
authors.initials: CK
authors.lastname: Kwoh
authors.affiliation: Division of Rheumatology, Tufts Medical Center, Boston, MA, USA.
authors.forename: T E
authors.initials: TE
authors.lastname: McAlindon
authors.affiliation: VitaK, Maastricht, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Vermeer
authors.affiliation: VitaK, Maastricht, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Drummen
authors.affiliation: Laboratory of Epidemiology and Population Sciences, National Institute on Aging, USA.
authors.forename: T B
authors.initials: TB
authors.lastname: Harris
authors.affiliation: Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: C
authors.initials: C
authors.lastname: Womack
authors.affiliation: Division of Rheumatology, Allergy and Immunology, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: R F
authors.initials: RF
authors.lastname: Loeser
mesh_terms: D000368:Aged; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002358:Cartilage, Articular / Q000473:pathology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003653:Decarboxylation; D018450:Disease Progression; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology*; D016017:Odds Ratio; D020370:Osteoarthritis, Knee / Q000453:epidemiology / Q000378:metabolism* / Q000473:pathology; D054850:Osteophyte / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology; D010766:Phosphorylation; D010837:Vitamin K 1 / Q000378:metabolism*; D014813:Vitamin K Deficiency / Q000453:epidemiology / Q000378:metabolism*; D000097568:Matrix Gla Protein
chemical_list: D002135:Calcium-Binding Proteins; D016326:Extracellular Matrix Proteins; D010837:Vitamin K 1; D000097568:Matrix Gla Protein
keywords: Epidemiology; Matrix gla protein; Nutrition; Osteoarthritis; Phylloquinone; Vitamin K