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Prevalence of Vitamin D Deficiency and Association with Glycemic Control in Patients with Type 2 Diabetes Mellitus: A Retrospective Analysis« Back to Volume 26, Issue 1, September 2010 - Table of Contents From ENDO 2010 The Endocrine Society Annual Meeting, San Diego, June 19-22, 2010 Hypovitaminosis D has long been suspected to be a risk factor for glucose intolerance. Several reports have suggested an active role of vitamin D (Vit D) in the functional regulation of pancreatic beta cells. Hypovitaminosis D may be an independent risk factor for type 2 diabetes mellitus (T2DM) and metabolic syndrome. The authors estimated the prevalence of 25 (OH) Vit D deficiency in T2DM and the association of Vit D level with HbA1c. They performed a retrospective continuous chart review of 124 patients with T2DM seen at the endocrine outpatient clinic from 2003 to 2008. The data included: age, race, HbA1c, Vit D, PTH level, family history of T2DM, and calcium intake. Vit D levels were divided into 4 quartiles: normal (Vit D >32 ng/dL), mild deficiency (Vit D >25-32 ng/dL), moderate deficiency (Vit D 14-25 ng/dL), and severe deficiency (Vit D <14 ng/dL). SPSS software was used to apply T-test, ANOVA and Chi-square tests for analysis of data. A total of 113 T2DM patients (91.1%) were found to be Vit D deficient (35.5% severe, 38.7% moderate, 16.9% mild). Serum Vit D level was inversely related to HbA1c (Pearson correlation -0.208, P=0.029). Mean HbA1c was higher in patients with severe Vit D deficiency when compared with patients with normal Vit D (7.1% vs 8.18%, P=0.065). Only 90 of 124 patients had their race documented in the medical record (54 White, 33 Black, 3 Asian). The mean HbA1c was higher in Blacks than in Whites (8.59% vs 7.0%, P <0.05), but the mean Vit D level was lower (15.3% vs 23.4 ng/dL, P <0.05). At the time of presentation 8 of 124 patients (6.4%) were receiving Vit D supplementation (2 with normal Vit D levels, 4 with moderate Vit D deficiency, 2 with severe Vit D deficiency). The results showed a high prevalence (91.1%) of Vit D deficiency in T2DM. Only 6.4% of patients were taking Vit D supplements when first seen at the endocrine clinic, despite regular primary care visits. The inverse relationship between Vit D level and glycemic control in this sample supports an active role of Vit D in the pathogenesis of T2DM. The finding of lower Vit D and higher HbA1c levels in Black patients underscores the importance of aggressive screening and supplementation in the population. Since a majority of T2DM patients are diagnosed and treated by primary care providers, screening and Vit D supplementation as part of routine primary care may improve health outcomes in this highly prevalent condition. Kant R, Chandra R, Arzumanyan H, Krug E. Sinai Hospital of Balitmore, Baltimore, Maryland, USA Editor's CommentT2DM is associated with obesity that is often the result of increased energy intake, but not necessarily with an appropriate Vit D intake for the calories consumed. These studies were done in Maryland where sunlight exposure may also be lacking, particularly during the winter months. Vit D is known to regulate the expression of over 200 different genes - including the ones related to apoptosis and immune modulation. There has been an important shift in the views about the actions of Vit D during the past decade. In addition to its well-established role in the regulation of calcium metabolism, Vit D deficiency has been associated with the risk of several extraskeletal diseases. It has been suggested that changes in Vit D intake and sun exposure during the past few decades have contributed to the recent increased prevalence of diabetes, including T1DM, as well as other chronic conditions.1 Is the higher prevalence of T1DM and T2DM and of Vit D deficiency casually related? Well-designed, randomized, controlled trials are needed to determine whether the observed associations are indeed causal. Fima Lifshitz, MD Reference - (linked to
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Volume 26 Number 1
September 2010
www.GGHjournal.com
ISSN 1932-9032
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