Vitamin D, adiposity, and calcified atherosclerotic plaque in African-Americans

Abstract

Context: Inverse associations are reported between circulating 25-hydroxyvitamin D and visceral adiposity. The effects of vitamin D levels on atherosclerosis are unknown. Objective: The objective of this study was to test for relationships between vitamin D, adiposity, bone density, and atherosclerosis in African-Americans. Design: Circulating 25-hydroxyvitamin D, 1,25 dihydroxyvitamin D, intact PTH, C-reactive protein and computed tomography-derived calcified atherosclerotic plaque (CP), bone density, and fat volumes were measured. Setting: Examinations were performed at a single outpatient general clinical research center visit. Subjects: Three hundred forty African-Americans with type 2 diabetes were evaluated. Mean±SD age was 55.6 ± 9.6 yr, diabetes duration 10.6 ± 8.3 yr, glomerular filtration rate 1.6 ± 0.5 ml/sec, body mass index 35.6 ± 8.7 kg/m2, and 25-hydroxyvitamin D concentration 50.4 ± 30.5 nmol/liter. Main Outcome Measure: Biomarkers were tested for association with pericardial, visceral, im, and sc adipose tissues; thoracic and lumbar vertebral bone density; and aorta, coronary, and carotid artery CP. Results: Adjusting for age, gender, body mass index, glycosylated hemoglobin, and glomerular filtration rate, 25-hydroxyvitamin D was negatively associated with visceral adiposity (P = 0.009) and positively associated with carotid artery CP and aorta CP (P =0.013 and 0.014, respectively) but not with coronary artery CP or bone density. Conclusions: We confirmed an inverse association between vitamin D and visceral adiposity in African-Americans with diabetes. In addition, positive associations exist between 25-hydroxyvitamin D and aorta and carotid artery CP in African-Americans. The effects of supplementing vitamin D to raise the serum 25-hydroxyvitamin D level on atherosclerosis in African-Americans are unknown. Prospective trials are needed to determine the cardiovascular effects of supplemental vitamin D in this ethnic group. Copyright © 2010 by The Endocrine Society.