Tufts University, Boston, Massachusetts.
University of North Carolina, Chapel Hill.
Arthritis Care Res (Hoboken). 2018 Aug;70(8):1150-1159. doi: 10.1002/acr.23451. Epub 2018 May 29.
Vitamins K and D are important for the function of vitamin K-dependent proteins in joint tissues. It is unclear whether these nutrients are mutually important to functional outcomes related to knee osteoarthritis (OA). We evaluated the association of vitamin K and D sufficiency with lower-extremity function in the Health, Aging and Body Composition knee OA substudy (Health ABC) and conducted a replication analysis in an independent cohort, the Osteoarthritis Initiative (OAI).
In Health ABC (60% female, mean ± SD age 75 ± 3 years) baseline nutrient status was measured using circulating vitamin K and 25-hydroxyvitamin D (25[OH]D). Lower-extremity function was assessed using the Short Physical Performance Battery (SPPB) and usual 20-meter gait speed. In the OAI (58% female, mean ± SD age 61 ± 9 years), baseline nutrient intake was estimated by food frequency questionnaire. Lower-extremity function was assessed using usual 20-meter gait speed and chair stand completion time. Multivariate mixed models were used to evaluate the association of vitamin K and D status and intake with lower-extremity function over 4-5 years.
Health ABC participants with sufficient plasma vitamin K (≥1.0 nmoles/liter) and serum 25(OH)D (≥50 nmoles/liter) generally had better SPPB scores and faster usual gait speed over followup (P ≤ 0.002). In the OAI, sufficient vitamin K and vitamin D intake combined was associated with overall faster usual gait speed and chair stand completion time over followup (P ≤ 0.029).
Sufficient vitamin K status combined with sufficient vitamin D status was associated with better lower-extremity function in 2 knee OA cohorts. These findings merit confirmation in vitamin K and D co-supplementation trials.
维生素 K 和 D 对于关节组织中维生素 K 依赖性蛋白的功能至关重要。目前尚不清楚这些营养素对于与膝骨关节炎（OA）相关的功能结果是否相互重要。我们评估了维生素 K 和 D 充足与健康、老龄化和身体成分膝关节 OA 亚研究（Health ABC）下肢功能的关系，并在一个独立队列——骨关节炎倡议（OAI）中进行了复制分析。
在 Health ABC（60%为女性，平均年龄 ± 标准差为 75 ± 3 岁）中，使用循环维生素 K 和 25-羟维生素 D（25[OH]D）测量基线营养状况。下肢功能通过短体物理性能电池（SPPB）和通常的 20 米步行速度评估。在 OAI（58%为女性，平均年龄 ± 标准差为 61 ± 9 岁）中，基线营养素摄入量通过食物频率问卷进行评估。下肢功能通过通常的 20 米步行速度和坐立起身时间评估。多元混合模型用于评估 4-5 年内维生素 K 和 D 状况和摄入量与下肢功能的关系。
Health ABC 参与者的血浆维生素 K（≥1.0 纳摩尔/升）和血清 25（OH）D（≥50 纳摩尔/升）充足通常在随访期间具有更好的 SPPB 评分和更快的通常步行速度（P ≤ 0.002）。在 OAI 中，充足的维生素 K 和维生素 D 摄入量相结合与随访期间整体更快的通常步行速度和坐立起身时间相关（P ≤ 0.029）。
在 2 个膝骨关节炎队列中，充足的维生素 K 状态与充足的维生素 D 状态相结合与更好的下肢功能相关。这些发现值得在维生素 K 和 D 联合补充试验中得到证实。
