Lower Vitamin D Levels, but Not VDR Polymorphisms, Influence Type 2 Diabetes Mellitus in Brazilian Population Independently of Obesity

• Main Authors: Kathryna Fontana Rodrigues, Nathalia Teixeira Pietrani, Adriana Aparecida Bosco, Maira Cândida Rodrigues de Sousa, Ieda de Fátima Oliveira Silva, Josianne Nicácio Silveira, Karina Braga Gomes
• Format: Article
• Language: English
• Published: MDPI AG 2019-05-01
• Series: Medicina
• Subjects: vitamin D; obesity; type 2 diabetes mellitus; vitamin D receptor; polymorphisms
• Online Access: https://www.mdpi.com/1010-660X/55/5/188

<i>Background and Objectives</i>: Vitamin D levels have been associated with a diversity of diseases, including obesity. Vitamin D presents a pleiotropic action, and can regulate insulin secretion and inflammatory responses. Vitamin D receptor (<i>VDR</i>) gene polymorphisms are involved in the gene expression regulation and have been associated with type 2 diabetes mellitus (T2DM). This study aimed to evaluate the association between the polymorphisms ApaI (rs7975232), BsmI (rs1544410), FokI (rs10735810), and TaqI (rs731236) in the <i>VDR</i> gene in people diagnosed with T2DM, and plasma 25-hydroxivitamin D levels [25(OH)D]. <i>Materials and Methods</i>: A total of 101 T2DM patients and 62 gender, age, and body mass index (BMI) matched non-diabetic controls were included in this study. Molecular analyzes were performed by polymerase chain reaction&#8722;restriction fragment length polymorphism (PCR-RFLP). The plasma 25(OH)D levels were measured by high performance liquid chromatography. <i>Results</i>: The plasma 25(OH)D levels were lower in T2DM patients (17.2 (16.6) ng/mL) when compared with the control subjects (30.8 (16.2) ng/mL, <i>p</i> &lt; 0.0001), independently of obesity status. We found no difference between genotypic and allelic frequencies of the <i>VDR</i> polymorphisms when comparing the T2DM group and control group (<i>p</i> &gt; 0.05 for all), and did not show any association with plasma 25(OH)D levels. <i>Conclusions</i>: These results suggest that T2DM is associated with lower plasma 25(OH)D levels, which are not related to BMI and <i>VDR</i> gene polymorphisms.