1. Vitamin D insufficiency and abnormal hemoglobin a1c in black and white older persons.
- Author
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Kositsawat J, Kuchel GA, Tooze JA, Houston DK, Cauley JA, Kritchevsky SB, Strotmeyer ES, Kanaya AM, Harris TB, Johnson KC, and Barry LC
- Subjects
- Aged, Biomarkers blood, Body Mass Index, Diabetes Mellitus, Type 2 complications, Diabetes Mellitus, Type 2 diagnosis, Female, Humans, Independent Living, Longitudinal Studies, Male, Medicare statistics & numerical data, Pennsylvania epidemiology, Predictive Value of Tests, Sensitivity and Specificity, Tennessee epidemiology, United States, Vitamin D blood, Vitamin D Deficiency complications, Vitamin D Deficiency diagnosis, Black or African American statistics & numerical data, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 ethnology, Glycated Hemoglobin metabolism, Vitamin D analogs & derivatives, Vitamin D Deficiency blood, Vitamin D Deficiency ethnology, White People statistics & numerical data
- Abstract
Background: Although vitamin D has been mechanistically linked to insulin secretion and sensitivity, it remains unclear whether low 25-hydroxyvitamin D levels confer an increased risk of impaired glucose metabolism. We evaluated the relationship between vitamin D insufficiency (25-hydroxyvitamin D < 20ng/mL) and abnormal hemoglobin A1c (A1c) (≥6.5%) in community-dwelling older persons and examined whether this relationship differed according to race., Methods: Participants were 2,193 persons of age 70-79 years at Year 1 (52% women; 37% black) in the Health, Aging, and Body Composition study who had clinic visits at Years 2 and 4. Logistic regression analyses, adjusted for potential confounders, were used to evaluate the association between vitamin D insufficiency and abnormal A1c 2 years later. Interaction of race and vitamin D insufficiency was tested., Results: A total of 665 (30%) and 301 (14%) of the participants had vitamin D insufficiency at Year 2 and abnormal A1c at Year 4, respectively. After controlling for demographics, other potential confounders, and diabetes status at Year 4 (n = 477 diabetics), we found that vitamin D insufficiency was associated with an increased likelihood of having abnormal A1c (odds ratio = 1.56; 95% CI: 1.03-2.37). We also found that this relationship persisted among the 1,765 participants without diabetes in Year 2 (odds ratio = 2.33; 95% CI: 1.00-5.40). Findings did not differ by race., Conclusions: Vitamin D insufficiency was associated with abnormal A1c levels among black and white older persons independent of diabetes status. Future studies are needed to establish the temporal relationship between vitamin D and A1c in diverse samples of older persons., (© The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2015
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