Low incidence of hyperparathyroidism in diabetic renal failure.

The first study compared two groups on dialysis: 25 patients with diabetes mellitus and 25 matched non-diabetic patients, in relation to the presence of signs of hyperparathyroidism, to assess the reported low incidence of hyperparathyroidism in these patients. The diabetic group showed significantly lower values of PTH, Alk phosphatase, percentage of patients requiring vitamin D treatment, and less evidence of hyperparathyroidism on X-ray and in bone histomorphometry. In the second study 16 patients with chronic renal failure due to diabetic nephropathy were compared to 27 patients with the same degree of renal failure of other origin, the diabetic nephropathy group showed no increase in PTH, with falling creatinine clearance. Despite this low PTH, the phosphaturia was higher in the diabetic nephropathy group (Tm PO4/C Cr: 1.94 +/- 0.43 vs 2.5 +/- 0.68). In conclusion, patients with diabetes mellitus are less prone to develop hyperparathyroidism in progressive renal failure. This could be due to a relative increase in phosphaturia during declining function.