1. Vitamin D in youth with Type 1 diabetes: prevalence of insufficiency and association with insulin resistance in the SEARCH Nutrition Ancillary Study.
- Author
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The, N. S., Crandell, J. L., Lawrence, J. M., King, I. B., Dabelea, D., Marcovina, S. M., D'Agostino, R. B., Norris, J. M., Pihoker, C., and Mayer‐Davis, E. J.
- Subjects
VITAMIN D deficiency ,ACADEMIC medical centers ,ANALYSIS of variance ,CONFIDENCE intervals ,INSULIN resistance ,NUTRITION ,TYPE 1 diabetes ,VITAMIN D ,HLA-B27 antigen ,DATA analysis ,CROSS-sectional method ,DIAGNOSIS - Abstract
Aims To determine the prevalence of plasma vitamin D (25-dihydroxyvitamin D) insufficiency in individuals with Type 1 diabetes and to determine the cross-sectional and longitudinal associations of plasma vitamin D with insulin resistance. Methods Participants from the SEARCH for Diabetes in Youth Study [ n = 1426; mean age 11.2 years ( sd 3.9)] had physician-diagnosed Type 1 diabetes [diabetes duration mean 10.2 months ( sd 6.5)] with data available at baseline and follow-up (approximately 12 and 24 months after baseline). Insulin resistance was estimated using a validated equation. Cross-sectional and longitudinal multivariate logistic regression models were used to determine the association of plasma vitamin D with insulin resistance, adjusting for potential confounders. Results Forty-nine per cent of individuals had plasma vitamin D < 50 nmol/l and 26% were insulin resistant. In cross-sectional multivariate analyses, participants who had higher plasma vitamin D (65 nmol/l) had lower odds of prevalent insulin resistance than participants with lower plasma vitamin D (25 nmol/l) (odds ratio 0.70, 95% CI 0.57-0.85). This association was attenuated after additional adjustment for BMI z-score, which could be a confounder or a mediator (odds ratio 0.81, 95% CI 0.64-1.03). In longitudinal multivariate analyses, individuals with higher plasma vitamin D at baseline had lower odds of incident insulin resistance, but this was not significant (odds ratio 0.85, 95% CI 0.63-1.14). Conclusions Vitamin D insufficiency is common in individuals with Type 1 diabetes and may increase risk for insulin resistance. Additional prospective studies are needed to determine the association between plasma vitamin D and insulin resistance, and to further examine the role of adiposity on this association. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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