[Effects of calcitriol [1,25[OH]2D3 treatment on control of glucose intolerance in hemodialysis patients]

Impaired carbohydrate metabolism is a common finding in patients with chronic renal failure. Although intermittent hemodialysis results in a significant improvement of impaired glucose metabolism of uremia, complete normalization did not occur. Vitamin D[3] deficiency, it seems is linked with disturbance of glucose metabolism. A role of vit D in endocrine pancreatic function has been suggested. The aim of this study was to determine the effects of 1,25 [OH]2D3 treatment on glucose tolerance, insulin resistance and beta cell function in hemodialysis patients. Of sixty-five patients with uremia on hemodialysis, twenty -seven who had never been treated with vitamin D or related drugs and without history of diabetes were selected for this study. These patients were randomly divided to two groups, group I were treated with oral calcitriol [0.5 mcg/day] for 8 weeks and group it received placebo for the 8 weeks. In all cases, before and 8 weeks after treatment fasting glucose, insulin, total cholesterol, triglycerides, HDL, LDL, calcium, phosphorous, PTH, HbA1C and blood sugar after 75 gr load of glucose were measured. Insulin resistance [homostatic model assessment-insulin resistance = HOMA-IR] and beta cell function [homostatic model assessment- insulin secretion =HOMA-SECR] were calculated and results of these measurements, before and after 8 weeks, in both groups were compared. In group I, after calcitriol treatment, blood sugar after 75 gr load of glucose [p= 0.045], HOMA -IR [p= 0.035], HbA1C [p=0.00], total cholesterol [p=0.037], and triglycerides [p=0.036] decreased, whereas calcium levels increased, significantly [0.014]; changes in other parameters were not significant. In group II [without treatment] after 8 weeks of observation, fasting blood sugar [p=0.002], HbA1C [p=0.004], HOMA -IR [p=0.036] significantly increased and beta cell function decreased significantly [p= 0.032]; again alterations in other parameters were not significant. These results seem to confirm that the active form of vitamin D influences glucose and lipid metabolism, by the improvement of insulin resistance