Esmee Koeckhoven1, Marike van der Leeden2, Leo D Roorda1, Natasja M van Schoor1, Paul Lips1, Arjan de Zwart1, Joost Dekker1, Martin van der Esch1, Willem F Lems1. 1. From the Amsterdam Rehabilitation Research Center/Reade; Department of Rehabilitation Medicine, and EMGO Institute for Health and Care Research, and Department of Epidemiology and Biostatistics, and Department of Psychiatry, VU University Medical Center; Reade, Department of Rheumatology, Amsterdam, the Netherlands.E. Koeckhoven, MSc, Amsterdam Rehabilitation Research Center/Reade; M. van der Leeden, PhD, Amsterdam Rehabilitation Research Center/Reade, and Department of Rehabilitation Medicine, and EMGO Institute for Health and Care Research, VU University Medical Center; L.D. Roorda, PhD, Amsterdam Rehabilitation Research Center/Reade; N.M. van Schoor, PhD, EMGO Institute for Health and Care Research, and Department of Epidemiology and Biostatistics, VU University Medical Center; P. Lips, PhD, Department of Internal Medicine/Endocrinology, VU University Medical Center; A. de Zwart, MSc, Amsterdam Rehabilitation Research Center/Reade; J. Dekker, PhD, Department of Rehabilitation Medicine, and EMGO Institute for Health and Care Research, and Department of Psychiatry, VU University Medical Center; M. van der Esch, PhD, Amsterdam Rehabilitation Research Center/Reade; W.F. Lems, PhD, Department of Rheumatology, VU University Medical Center, and Amsterdam Rehabilitation Research Center/Reade. 2. From the Amsterdam Rehabilitation Research Center/Reade; Department of Rehabilitation Medicine, and EMGO Institute for Health and Care Research, and Department of Epidemiology and Biostatistics, and Department of Psychiatry, VU University Medical Center; Reade, Department of Rheumatology, Amsterdam, the Netherlands.E. Koeckhoven, MSc, Amsterdam Rehabilitation Research Center/Reade; M. van der Leeden, PhD, Amsterdam Rehabilitation Research Center/Reade, and Department of Rehabilitation Medicine, and EMGO Institute for Health and Care Research, VU University Medical Center; L.D. Roorda, PhD, Amsterdam Rehabilitation Research Center/Reade; N.M. van Schoor, PhD, EMGO Institute for Health and Care Research, and Department of Epidemiology and Biostatistics, VU University Medical Center; P. Lips, PhD, Department of Internal Medicine/Endocrinology, VU University Medical Center; A. de Zwart, MSc, Amsterdam Rehabilitation Research Center/Reade; J. Dekker, PhD, Department of Rehabilitation Medicine, and EMGO Institute for Health and Care Research, and Department of Psychiatry, VU University Medical Center; M. van der Esch, PhD, Amsterdam Rehabilitation Research Center/Reade; W.F. Lems, PhD, Department of Rheumatology, VU University Medical Center, and Amsterdam Rehabilitation Research Center/Reade. m.vd.leeden@reade.nl.
Abstract
OBJECTIVE: Vitamin D deficiency, which is common among elderly people, has been linked to muscle weakness. In patients with knee osteoarthritis (OA), the association between muscle strength and serum 25-hydroxy Vitamin D [25(OH)D] level has not been studied comprehensively. The aim of our study was to examine the association between serum 25(OH)D level and muscle strength in patients with knee OA. METHODS: Data of the Amsterdam Osteoarthritis cohort from 319 participants with knee OA were used in a cross-sectional study. Serum 25(OH)D level (nmol/l) was measured by a competitive electrochemiluminescence method. Muscle strength (nm/kg) of the upper leg was measured isokinetically. Univariable and multivariable linear regression analyses were used to calculate the association between serum 25(OH)D level and muscle strength. RESULTS: Serum 25(OH)D level was significantly associated with muscle strength (B = 0.036, 95% CI 0.017-0.054, p < 0.001), adjusted for season of blood collection. After adding body mass index (BMI) to the model, this association was no longer significant (B = 0.011, 95% CI -0.007 to 0.029, p = 0.214). Alcohol consumption, number of comorbidities, and sex were subsequently added and changed the model slightly. Without BMI, this model showed a significant association between serum 25(OH)D level and muscle strength (B = 0.029, 95% CI 0.014-0.043, p < 0.001). CONCLUSION: The observed association between a low serum 25(OH)D level and muscle weakness in patients with knee OA is attenuated by BMI. Further studies are needed to explain the associations among Vitamin D level, muscle strength, and adiposity in patients with knee OA.
OBJECTIVE:Vitamin D deficiency, which is common among elderly people, has been linked to muscle weakness. In patients with knee osteoarthritis (OA), the association between muscle strength and serum 25-hydroxy Vitamin D [25(OH)D] level has not been studied comprehensively. The aim of our study was to examine the association between serum 25(OH)D level and muscle strength in patients with knee OA. METHODS: Data of the Amsterdam Osteoarthritis cohort from 319 participants with knee OA were used in a cross-sectional study. Serum 25(OH)D level (nmol/l) was measured by a competitive electrochemiluminescence method. Muscle strength (nm/kg) of the upper leg was measured isokinetically. Univariable and multivariable linear regression analyses were used to calculate the association between serum 25(OH)D level and muscle strength. RESULTS: Serum 25(OH)D level was significantly associated with muscle strength (B = 0.036, 95% CI 0.017-0.054, p < 0.001), adjusted for season of blood collection. After adding body mass index (BMI) to the model, this association was no longer significant (B = 0.011, 95% CI -0.007 to 0.029, p = 0.214). Alcohol consumption, number of comorbidities, and sex were subsequently added and changed the model slightly. Without BMI, this model showed a significant association between serum 25(OH)D level and muscle strength (B = 0.029, 95% CI 0.014-0.043, p < 0.001). CONCLUSION: The observed association between a low serum 25(OH)D level and muscle weakness in patients with knee OA is attenuated by BMI. Further studies are needed to explain the associations among Vitamin D level, muscle strength, and adiposity in patients with knee OA.
Entities:
Keywords:
BODY MASS INDEX; MUSCLE STRENGTH; OSTEOARTHRITIS; VITAMIN D