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Not a simple fat-soluble vitamin: changes in serum 25-(OH)D levels are predicted by adiposity and adipocytokines in older adults

Citation

Ding, C and Parameswaran, V and Blizzard, L and Burgess, J and Jones, G, Not a simple fat-soluble vitamin: changes in serum 25-(OH)D levels are predicted by adiposity and adipocytokines in older adults, Journal of Internal Medicine, 268, (5) pp. 501-510. ISSN 0954-6820 (2010) [Refereed Article]


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Copyright Statement

The definitive published version is available online at: http://interscience.wiley.com

Official URL: http://interscience.wiley.com

DOI: doi:10.1111/j.1365-2796.2010.02267.x

Abstract

Objective. To determine the associations between body adiposity and change in serum 25-(OH)D levels over 2.6 years, and if these associations are mediated by metabolic andinflammatory factors in older adults. Methods. This is a longitudinal study of 859 randomly selected subjects (mean 62 years, range 5180, 49% women). Serum 25-hydroxyvitamin D [25-(OH)D] was assessed by radioimmunoassay at baseline and 2.6 years later. Baseline serumlevel of leptinwas assessed by radioimmunoassay and interleukin (IL)-6 by a chemiluminescent immunoassay in the first 183 subjects. Results. In multivariable analyses, body mass index, trunk fat percentage and waist-to-hip ratio were significant predictors of increased incident vitamin D deficiency [a 25-(OH)D < 50 nmol L)1 at follow-up when 50 nmol L)1 at baseline] and decreased recovery of vitamin D deficiency [a 25-(OH)D 50 nmol L)1 at follow-up when < 50 nmol L)1 at baseline]. Change in 25-(OH)D levels per annum was also independently predicted by baseline leptin (b: )0.09⁄unit, 95% CI: )0.17, )0.03), IL-6 (b: )0.68⁄ quartile, 95% CI: )1.35, )0.02) and total cholesterol ⁄ high-density lipoprotein (HDL) ratio (b: )0.51, 95% CI: )0.88, )0.14). The associations between body adiposity measures and change in 25- (OH)D completely disappeared after adjustment for leptin, diminished after adjustment for IL-6, but remained unchanged after adjustment for total cholesterol ⁄HDL ratio. All associations were independent of season and sun exposure. Conclusions.Bodyfat isnot simplyapassive reservoir for 25-(OH)D. In addition to season and sun exposure, 25-(OH)D levels appear to be determined by metabolic and, to a lesser extent, inflammatory factors, and these appear to mediate the effects of adiposity onchange in25-(OH)D.

Item Details

Item Type:Refereed Article
Keywords:adiposity, interleukin-6, leptin, lipids, vitamin D deficiency
Research Division:Medical and Health Sciences
Research Group:Clinical Sciences
Research Field:Endocrinology
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Endocrine Organs and Diseases (excl. Diabetes)
Author:Ding, C (Professor Chang-Hai Ding)
Author:Blizzard, L (Professor Leigh Blizzard)
Author:Burgess, J (Professor John Burgess)
Author:Jones, G (Professor Graeme Jones)
ID Code:65402
Year Published:2010
Web of Science® Times Cited:31
Deposited By:Menzies Institute for Medical Research
Deposited On:2010-11-11
Last Modified:2011-05-02
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