Context Vitamin D deficiency is associated with cardio-metabolic and diabetes-related complications in those with type 2 diabetes mellitus (T2DM). This deficiency is also much more prevalent in Mexican-Americans compared to non-Hispanic Whites. Information about the causes of the observed vitamin D deficiency disparity in subjects with T2DM has not been reported using NHANES' assay-adjusted serum 25(OH)D measurements.
Objectives The objective of this study was to estimate the disparity of vitamin D deficiency, measured with serum 25(OH)D levels, between Mexican-Americans and non-Hispanic Whites with type 2 diabetes mellitus.
Design, Setting, and Participants Data was obtained from NHANES, a stratified, multi-stage and nationally representative survey conducted across the US on the non-institutionalized population. Analysis was restricted to adults aged 18-85, who were of Mexican-American and non-Hispanic White ethnicity (n=292, 483; total n=775), and were diagnosed with T2DM. T2DM was defined by age of diagnoses (>30 years of age) or if currently taking hypoglycemics. All statistical analyses were conducted to take into account the weighting for the multi-stage, combined survey cycles.
Outcome The outcome of interest was vitamin D deficiency, defined as serum 25(OH)D levels <15 ng/mL and any disparity in deficiency between Mexican-Americans and non-Hispanic whites with T2DM.
Results In those with T2DM, vitamin D deficiency was much more prevalent in Mexican-Americans compared to non-Hispanic whites, a disparity also seen in the crude logistic regression model (38.7% vs. 20.0%, p<0.0001; OR 2.51, 95% CI 1.66-3.79). Adjusting for potential confounders, such as supplement use, demographics, behavioral risk factors, cardiovascular-related risk factors (41% attenuation), and diabetes medication type (46% attenuation), resulted in attenuation of the crude OR, with the latter two, resulting in the greatest attenuations.
Conclusion The observed vitamin D deficiency disparity between Mexican-Americans and non-Hispanic whites with T2DM was greatly attenuated by potential confounders, highlighting further disparities in the occurrence of the risk factors that inflate the true deficiency. Future studies should explore the nature of these observed confounders and how to address them in order to reduce the overall risk of vitamin D deficiency, which can complicate skeletal as well as non-skeletal effects in those with T2DM.
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About this Master's Thesis
|Committee Chair / Thesis Advisor|
|Disparity of Vitamin D Deficiency between Mexican-Americans and Non-Hispanic Whites with Type 2 Diabetes Mellitus, NHANES 2001-2006 ()||2018-08-28||