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Not All Elderly People Benefit From Vitamin D Supplementation with Respect to Physical Function: Results From the Osteoporotic Fractures in Men Study, Hong Kong
Author(s) -
Chan Ruth,
Chan Dicken,
Woo Jean,
Ohlsson Claes,
Mellström Dan,
Kwok Timothy,
Leung Ping Chung
Publication year - 2012
Publication title -
journal of the american geriatrics society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.992
H-Index - 232
eISSN - 1532-5415
pISSN - 0002-8614
DOI - 10.1111/j.1532-5415.2011.03789.x
Subject(s) - medicine , confounding , interquartile range , vitamin d and neurology , body mass index , prospective cohort study , cross sectional study , gerontology , national health and nutrition examination survey , vitamin d deficiency , demography , cohort , physical therapy , population , environmental health , pathology , sociology
Objectives To examine vitamin D status and its association with physical performance and muscle mass in older C hinese men. Design Cross‐sectional and prospective cohort study design. Setting H ong K ong, People's of Republic of C hina. Participants Nine hundred thirty‐nine community‐dwelling men aged 65 and older for cross‐sectional analysis and 714 for longitudinal analysis. Measurements Baseline serum 25‐hydroxyvitamin D (25 OHD ) was measured using a competitive radioimmunoassay kit. Baseline and 4‐year physical performance measures (grip strength, 6‐m walking speed, step length in a 6‐m walk, time to complete five chair stands) were measured, and appendicular skeletal muscle mass ( ASM ) was assessed using dual‐energy X ‐ray absorptiometry. Data were collected for confounding factors: demographic, number of diseases, smoking, alcohol use, body mass index, physical activity, diet, season of blood sampling, and serum parathyroid hormone ( PTH ) level. Multivariate regression analyses were performed with adjustments for confounding factors. Results Mean ± standard deviation serum 25 OHD level of this sample of C hinese community‐dwelling older men who had a high level of baseline physical function was 77.9 ± 20.5 nmol/L; 94.1% of participants had serum 25 OHD levels of 50 nmol/L or greater. Median (interquartile range) serum PTH level was 4.1 pmol/L (3.1–5.5 pmol/L). After adjustment for potential confounding factors, serum 25 OHD levels were not associated with baseline or 4‐year change in physical performance measures and ASM . Conclusion In C hinese older men who are vitamin D replete and have a high level of baseline physical function, vitamin D may not have an important role in physical function and muscle mass.