Relationships of serum 25-hydroxyvitamin D concentrations, diabetes, genetic susceptibility and new-onset chronic kidney disease

Objective: The prospective relation of vitamin D status with risk of chronic kidney diseases (CKD) remains uncertain. We aimed to examine the association of serum 25-hydroxyvitamin D (25OHD) with new-onset CKD in participants with and without diabetes at baseline, and examine the potential modifications by genetic susceptibility on the association.

Research Design and Methods: A total of 348,243 adults from UK Biobank without prior CKD at baseline were included. Serum 25OHD concentrations were measured by chemiluminescent immunoassay method. Genetic risk score of CKD was calculated by 263 single nucleotide polymorphisms, which showed significant associations with estimated glomerular filtration rate. The primary outcome was new-onset CKD.

Results: During a median follow-up duration of 12.1 years, 9,344 new-onset CKD were documented. Overall, there was a significant inverse association between baseline serum 25OHD and new-onset CKD in participants with diabetes (Per SD increment, adjusted HR, 0.91; 95%CI: 0.86-0.96), but not in those without diabetes (Per SD increment, adjusted HR, 0.98; 95%CI: 0.96-1.01; P-interaction between serum 25OHD and diabetes =0.004). Accordingly, among participants with diabetes, compared with those baseline serum 25OHD <25 nmol/L, a significantly lower risk of new-onset CKD was found in those with 25OHD ≥50 nmol/L (adjusted HR, 0.77; 95%CI: 0.67-0.89). Moreover, the genetic risk of CKD did not significantly modify the association between baseline serum 25OHD and new-onset CKD among participants with diabetes (P-interaction=0.127).

Conclusions: There was an inverse association between baseline serum 25OHD and new-onset CKD in participants with diabetes. The inverse association was not found in participants without diabetes.