Bone mineral density and serum calcium hotheostasis in Egyptian children and adolescents with insulin-dependent diabetes mellitus

ABSTRACT

Although osteopenia is often reported as a complication of insulin-dependent-diabetes mellitus [IDDM], studies of bone mineral density [BMD] and serum calcium homeostasis in IDDM have yielded conflicting results. To determine BMD and serum calcium homeostasis in children and adolescents with IDDM and evaluate its relationship to metabolic control and disease duration. BMD was measured by dual-energy X-ray absorptiometry [DXA] in the lumbar spine [L2-L4] in 38 patients with IDDM [14 males, 24 females; aged 4-15 years; duration of diabetes 1.5-10 years] and their values were compared to those of 352 healthy Egyptian children and adolescents-[195 boys and 157 girls, aged 1-15 years]. In addition, glycosylated hemoglobin [HbA1c], serum calcium, phosphorus, 25 [OH] D3, and intact parathyroid hormone [iPTH] were measured in the diabetic patients and in 12 healthy controls of matched age and sex. As compared to normal BMD of Egyptian children and adolescents, nine patients [23.7%] had severe osteopenia [Z-score-2 SD or more negative] and 5 patients [13.1%] had mild osteopenia [Z-score-1 to<-2 SD]; 24 [63.2%] patients had normal BMD. A negative correlation was found between BMD Z-score and disease duration [r-0.44, p=0,01], No relationship was found between BMD Z-score and metabolic control [HbA1c] or calcium homeostatic parameters. Diabetic patients had significantly lower iPTH compared to controls. On the other hand, serum calcium, phosphorus, and 25 [OH] D3 were not significantly different in IDDM patients compared to controls. IDDM in Egyptian children and adolescents was associated with osteopenia, which is significantly related to disease duration but not the degree of metabolic control. Calcium homeostasis was within normal in IDDM. iPTH was significantly lower in diabetic patients compared to controls. Periodic assessment of BMD in diabetic children and adolescents is mandatory