Study on the association between vitamin D receptor gene fokI (T/C) polymorphisms and the susceptibility to type 2 diabetic kidney disease of Han nationality in south of China.

Aims: To investigate the distribution of vitamin D receptor fokI gene polymorphism in Yunnan Han population, and to explore the relationship between SNP of fokI and type 2 diabetic kidney disease.

Methods: We included 276 individuals of Han population of Yunnan in this study: 91 type 2 diabetes patients without kidney disease (DM group), their duration of diabetes is more than 10 years, 89 type 2 diabetes patients with diabetic kidney disease (DKD group), their duration of diabetes is less than 10 years and 96 healthy controls (NC group). We compared the concentration of 25 hydroxy vitamin D in different groups and used taqman probe to detect the genotype and allele of fokI, then analysed the relationship between the polymorphisms of fokI and the susceptibility of diabetic kidney disease.

Results: (1) NC group had a significantly higher plasma concentrations of 25 (OH) D than DKD group and DM group (P < 0.01); (2) 25 (OH) D and age, BMI, HbA1c, TG showed a weak negative correlation (P < 0.01); (3) Genotype of fokI showed no differences in DM group and DKD group, same as in DM group and NC group; FF genotype in DKD group is relatively lower than NC group (P < 0.05), and there is no difference in Ff and ff genotype (P > 0.05); In DKD group, f allele was 53.4%, higher than DM group (RR = 1.46, P < 0.05); (4) Logistic regression analysis showed that ff genotype may be a susceptible factor for DKD (P = 0.04, OR = 2.37).

Conclusion: FokI Ff genotype accounted for a larger proportion of the Han population in Yunnan, and ff genotype may be a susceptible factor for DKD in Yunnan Han population.