a1 Faculty of Health Sciences, University of Sydney, Lidcombe, NSW, Australia
a2 Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
a3 Faculty of Veterinary Sciences, University of Sydney, Camperdown, NSW, Australia
a4 Department of Research and Development, George Institute, Beijing, People's Republic of China
a5 Department of Kinesiology, California Polytechnic State University, San Luis Obispo, CA, USA
a6 Bosch Institute, Faculty of Medicine, University of Sydney, Camperdown, NSW, Australia
a7 Division of Epidemiology, Department of Environmental Medicine, NYU School of Medicine, NY, USA
a8 Fred Hutchinson Cancer Research Center in Seattle, Seattle, WA, USA
a9 Marshfield Clinic Research Foundation, Marshfield, WI, USA
a10 Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA
Abstract
Hypovitaminosis D may be associated with diabetes, hypertension and CHD. However, because studies examining the associations of all three chronic conditions with circulating 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D) are limited, we examined these associations in the US Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial (n 2465). Caucasian PLCO participants selected as controls in previous nested case–control studies of 25(OH)D and 1,25(OH)2D were included in this analysis. Diabetes, CHD and hypertension prevalence, risk factors for these conditions and intake of vitamin D and Ca were collected from a baseline questionnaire. Results indicated that serum levels of 25(OH)D were low ( < 50 nmol/l) in 29 % and very low ( < 37 nmol/l) in 11 % of subjects. The prevalence of diabetes, hypertension and CHD was 7, 30 and 10 %, respectively. After adjustment for confounding by sex, geographical location, educational level, smoking history, BMI, physical activity, total dietary energy and vitamin D and Ca intake, only diabetes was significantly associated with lower 25(OH)D and 1,25(OH)2D levels. Caucasians who had 25(OH)D ≥ 80 nmol/l were half as likely to have diabetes (OR 0·5 (95 % CI 0·3, 0·9)) compared with those who had 25(OH)D < 37 nmol/l. Those in the highest quartile of 1,25(OH)2D ( ≥ 103 pmol/l) were less than half as likely to have diabetes (OR 0·3 (95 % CI 0·1, 0·7)) than those in the lowest quartile ( < 72 pmol/l). In conclusion, the independent associations of 25(OH)D and 1,25(OH)2D with diabetes prevalence in a large population are new findings, and thus warrant confirmation in larger, prospective studies.
(Received June 16 2010)
(Revised January 13 2011)
(Accepted February 14 2011)
(Online publication May 17 2011)
Correspondence:
c1 Corresponding author: K. E. Brock, fax +61 2 93519540, email kaye.brock@sydney.edu.au
Footnotes
Abbreviations: 1,25(OH)2D, 1,25-dihydroxyvitamin D; 25(OH)D, 25-hydroxyvitamin D; PA, physical activity