Lumbar spine bone mineral density in diabetic children with recent onset

To detect early abnormalities in bone mineralization, the lumbar spine bone mineral density (BMD) of diabetic children with a diabetes onset of less t han 5 years and treated with a similar insulin treatment scheme was measure d at the level of the lumbar spine by dual-energy X-ray absorptiometry (DEX A), a most sensitive technique for detecting osteopenia in children. Fiftee n male and 8 female children and adolescents (mean age +/- SD: 12.5 +/- 3.7 years), 1-5 years after the clinical onset of their diabetes, were studied . Measurements of the lumbar spine (L-1-L-4) BMD, expressed in gHA/cm(2) an d as a z-score for age, were performed with a commercial DEXA apparatus (Ho logic QDR 1000 W, Hologic Inc., Waltham, USA). Calcium-phosphorus metabolis m was studied by measuring the circulating levels of calcium, phosphorus, a lkaline phosphatase, osteocalcin, 25-OH-vitamin D and parathyroid hormone a nd the urinary excretion of calcium and phosphorus. The mean BMD of the stu died group was 0.75 (0.16) gHA/cm(2) giving a mean z-score of -0.31 +/- 0.9 5. Only 1 of the patients had a BMD lower than -2 SD. No sex difference in BMD z-score existed. BMD SD was positively correlated with height SD (R = 0 .56, p < 0.005), but not with the age of the patients, the duration of the disease, the degree of metabolic control or the studied parameters of the c alcium-phosphorus metabolism. In conclusion, diabetic children have a norma l lumbar spine BMD during the first years of the disease, when a good metab olic control and no abnormalities in the calcium-phosphorus metabolism are present. As in normal children, areal BMD by DEXA is highly dependent on th e body height, necessitating corrections if abnormalities in skeletal growt h or pubertal development exist.