Calcium metabolism in adolescents and young adults with type 1 diabetes mellitus without and with persistent microalbuminuria.

Alterations in calcium metabolism can be demonstrated in the course of insulin-dependent diabetes mellitus. In order to clarify if the presence of persistent microalbuminuria (MA) can affect the main parameters of calcium metabolism, we studied 22 diabetic adolescents and young adults with persistent MA and compared them with 24 patients without MA and 24 healthy controls. Mean values of serum calcium, phosphorus and magnesium were similar in diabetic children and young adults without persistent MA and in controls. In addition, the mean values of PTH and 25-OHD, 1,25 (OH)2D3 and OC did not differ between these diabetics and controls. Diabetics with persistent MA showed no significant difference from the values of either controls or the group of diabetics without persistent MA for the mean values of serum calcium, phosphorus and magnesium and PTH. In contrast, diabetics with persistent MA had significantly (p<0.01) lower 25-OHD (26.5+/-5.2 ng/ml) and 1,25 (OH)2D3 (24.7+/-5.6 pg/ml) as well as OC levels (9.8+/-2.5 ng/ml; p<0.001) than controls (38.1+/-4.9 ng/ml, 40.7+/-6.4 pg/ml and 16.5+/-5.8 ng/ml, respectively) and subjects with normoalbuminuria (36.0+/-4.5 ng/ml, 38.8+/-8.9 pg/ml and 14.5+/-3.2 ng/ml). In conclusion, our study suggests that abnormalities in 25-OHD, 1,25(OH)2D3 and OC can be present in diabetic adolescents and young adults with incipient nephropathy.