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International Journal of Endocrinology
Volume 2014, Article ID 543783, 6 pages
http://dx.doi.org/10.1155/2014/543783
Research Article

Vitamin D Binding Protein Affects the Correlation of 25(OH)D and Frailty in the Older Men

Geriatric Department of the Second Xiang-Ya Hospital, Institute of Aging and Geriatric, Central South University, Changsha, Hunan 410011, China

Received 20 November 2013; Revised 19 February 2014; Accepted 20 March 2014; Published 13 April 2014

Academic Editor: Zhongjian Xie

Copyright © 2014 Yi Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Vitamin D binding protein (DBP) may alter the biologic activity of 25-hydroxyvitamin D [25(OH)D]. The objective of our present study was to determine the joint effect of serum 25(OH)D and DBP on the risk of frailty. Five hundred sixteen male participants aged 70 years or older were recruited in Changsha city and its surrounding area in Hunan province of China. Frailty was defined as the presence of at least three of the five following criteria: weakness, low physical activity, slow walking speed, exhaustion, and weight loss. Multivariate linear regression analysis was performed to assess the relationship between 25(OH)D and DBP levels. Odds ratios (ORs) for frailty were evaluated across quartiles of 25(OH)D and DBP levels, adjusted age, education, and body mass index. The results showed that participants in the lowest quartile of 25(OH)D and the highest quartile of DBP levels, the lowest quartile of 25(OH)D and the lowest quartile of DBP levels, and those in the the lower quartile of 25(OH)D and lowest quartile of DBP levels had significantly higher OR of being frail compared with those in the highest quartile of 25(OH)D and lowest quartile of DBP, with OR of 3.18 (95% CI: 1.46–4.56, ), 2.63 (95% CI: 1.31–3.68, ), and 2.52 (95% CI: 1.22–3.52, ), respectively. The results indicate that the joint effect of serum 25(OH)D and DBP levels is associated with the risk of frailty, and serum DBP levels affects 25(OH)D-frailty relationship in the older men.