Association of BsmI Polymorphisms in Vitamin D Receptor Gene With Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a common cause of end stage renal disease (ESRD). Data from Indonesian Renal Registry (2011) revealed that 25% etiology of patients who underwent hemodialysis is DKD. Risk factors that are associated with DKD include blood glucose control, hypertension, dyslipidemia, duration of diabetes mellitus, high body mass index (BMI), age, sex, ethnicity, vitamin D deficiency, high sodium diet, high protein diet, and smoking.

The roles of vitamin D that are related to kidney are inhibition of renin transcription process, angiotensin II, renal inflammation process, and albumin excretion, prevention of podocytes damage, glomerulosclerosis process, and transformation from kidney epithelial cell into mesenchymal cell. Current studies on association between vitamin D deficiency and DKD had shown conflicting results. It may be related to genetic factor which is vitamin D receptor polymorphisms. The vitamin D receptor polymorphism is affected by Cdx2, ApaI, BsmI, FokI, and TaqI gene, where Asian population is mostly affected by ApaI, FokI, and Cdx2.

Several studies had reported the association between BsmI polymorphisms in vitamin D receptor gene and DKD in various population. Zhang, et al (2012) study revealed the association between BsmI polymorphisms in vitamin D receptor gene and DKD in Han Chinese population, while study from Vedralova, et al (2012) in Caucasian race showed opposite result. However, the association between BsmI polymorphism in vitamin D receptor gene and DKD has not been investigated in Indonesian-Malay race.

This is a cross-sectional study that investigate the association between BsmI polymorphisms in vitamin D receptor gene and DKD in Indonesian-Malay race. The investigators collected data about study participants' characteristics, conducted physical examination and laboratory examination, which include BsmI polymorphisms in vitamin D receptor gene.