Associations among 25-Hydroxyvitamin D, Diet Quality, and Metabolic Disturbance Differ by Adiposity in United States Adults.
J Clin Endocrinol Metab. 2010 May 12. Epub ahead of print
Beydoun MA, Boueiz A, Shroff MR, Beydoun HA, Wang Y, Zonderman AB.
National Institute on Aging (M.A.B., A.B.Z.), National Institutes of Health Intramural Research Program, Baltimore, Maryland 21224; Department of Internal Medicine (A.B.), Johns Hopkins University, School of Medicine, and Center for Human Nutrition (Y.W.), Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205; Department of Epidemiology (M.R.S.), Michigan State University, East Lansing, Michigan 48824; and Graduate Program in Public Health (H.A.B.), Eastern Virginia Medical School, Norfolk, Virginia 23507.
Context: Recent evidence indicates that a higher plasma level of 25-hydroxyvitamin D 25(OH)D is associated with lower adiposity and a reduced number of metabolic disturbances (MetD).
Objectives: We examined associations among dietary quality, 25(OH)D, percent body fat (%BF), and MetD, and a pathway linking them, across central obesity.
Design: This cross-sectional nationally representative study used extensive data from the National Health and Nutrition Examination Surveys of 2001-2004. Participants: U.S. adults aged at least 20 yr were stratified by central obesity (CO) status. Sample sizes ranged from 1943 (all MetD combined) to 7796 (each component).
Main Outcome Measures: %BF was measured using dual-energy x-ray absorptiometry, and MetD was measured with individual continuous nonadiposity outcomes (e.g. fasting plasma glucose) and with a composite count index of binary MetD with prespecified cutoff points (Index I).
Results: A higher 25(OH)D was associated with better dietary quality, lower %BF, and lower number of MetD. These inverse 25(OH)D-%BF and 25(OH)D-MetD associations (i.e. fasting blood glucose, homeostatic model assessment of insulin resistance, C-reactive protein, and Index I) were significantly stronger among the CO(+) group.
Finally, the pathway linking the dairy component of the Healthy Eating Index (HEIdairy) to Index I through 25(OH)D and %BF indicated complete mediation among the CO(-) group, but HEIdairy and 25(OH)D had direct inverse associations with Index I among the CO(+) group.
Conclusions: Due to potential genetic differences between CO(-) and CO(+) groups, empowering U.S. adults with central obesity to make related behavioral changes may be especially effective in improving their vitamin D status and metabolic profile. PMID: 20463091