LAUSR

Background Vitamin K could be implicated in structural change of osteoarthritis (OA), but current evidence is limited or conflicting so the association between vitamin K and OA symptoms remains unclear. Objectives This study aims to investigate the association of vitamin K intake with knee symptoms and structural features in people with knee OA. Methods The parent study, Vitamin D Effect on Osteoarthritis (VIDEO) study, was conducted between June 2010 and December 2013 in Tasmania and Victoria, Australia. Knee symptoms were assessed using the Western Ontario and McMaster University Index of osteoarthritis (WOMAC) and a Visual Analogue Scale (VAS) for pain. A validated Food Frequency Questionnaire (FFQ) (developed by the Cancer Council Victoria in Australia) was completed at baseline and used to determine dietary vitamin K intake. Knee Magnetic Resonance Imaging (MRI) scans were obtained according to a standardised protocol using a 1.5 T whole-body MRI unit. Cartilage volume, cartilage defects, bone marrow lesions and effusion volume were measured. The associations between vitamin K intake quartile and changes in clinical or MRI features were analysed using linear regressions. Results 261 participants were included at baseline and 213 completed 2 years of follow-up. There were no significant differences between two equal divisions with high or low level of vitamin K intake in term of baseline characteristics. As table 1 and figure 1 show, higher vitamin K intake quartiles were significantly associated with greater decrease in total WOMAC score and WOMAC function score over 24 months. Similar trends were seen in WOMAC pain score and stiffness score, though not statistically significant. There were no significant associations between baseline vitamin K intake and changes in total cartilage volume, cartilage defects, bone marrow lesions and effusion volume over 24 months.Abstract FRI0525 – Table 1 Associations between vitamin K intake quartile and changes in clinical symptoms over 24 months Value of change, Mean (SD) Multivariable*,β (95% CI) P value P for trend Total WOMAC Score Vitamin K intake quartile 1 −112.9 (327.7) Reference: 0.046 Vitamin K intake quartile 2 −130.0 (482.6) −3.6 (-165.3,158.1) 0.97 Vitamin K intake quartile 3 −270.6 (403.3) −149.8 (-313.8,14.2) 0.07 Vitamin K intake quartile 4 −234.4 (415.5) −122.4 (-281.3,36.5) 0.13 WOMAC Pain Score Vitamin K intake quartile 1 −30.4 (81.8) Reference: 0.33 Vitamin K intake quartile 2 −32.9 (115.5) 3.3 (-37.3,43.8) 0.87 Vitamin K intake quartile 3 −74.8 (103.1) −41.1 (-82.1,–0.22) 0.05 Vitamin K intake quartile 4 −39.7 (107.5) −7.5 (-47.2,32.1) 0.71 WOMAC Function Score Vitamin K intake quartile 1 −71.4 (241.2) Reference: 0.03 Vitamin K intake quartile 2 −82.8 (339.4) −5.7 (-120.3,108.8) 0.92 Vitamin K intake quartile 3 −168.7 (275.2) −94.7 (-210.9,21.5) 0.11 Vitamin K intake quartile 4 −172.5 (301.8) −104.1 (-216.6,8.5) 0.07 *Adjusted for age, sex, BMI and vitamin D intervention group Figure 1 Change in WOMAC score over 24 months among those with different vitamin K intake quartiles Conclusions Higher baseline vitamin K intake was associated with decreased knee symptoms over 24 months in patients with knee OA. These suggest that vitamin K intake may be beneficial for knee OA. Disclosure of Interest None declared