HYPERCALCIURIA AND GROWTH FAILURE IN CHILDREN WITH DIABETES

Abstract

Growth failure and hypercalciuria have been noted independently in children with insulin-dependent diabetes mellitus (IDDM). We evaluated growth and calcium metabolism in 175 IDDM children and 38 non-diabetic (ND) sibs of similar ages. Height was determined by 2 of the authors using a Stadiometer. Blood and urine were collected in the AM before food and insulin had been taken. Results: (mean ± SEM) urine calcium/creatinine (Ca/Cr) (ND=0.13±.01, IDDM=0.21±.01 p<.001), serum Ca (ND=9.7±.07 mg/dl, IDDM=9.6±.02 mg/dl p=NS), alkaline phosphatase (ND=105.8±7.0 IU, IDDM 284.9±7.5 IU p<.001) Vitamin D3 ND=20.0±1.8 ng/ml, IDDM=23.0±2.0 ng/ml p=NS), PTH (ND=140.3±7.9 pg/ml, IDDM=158.4±5.2 p=NS), Ht (ND=54±3.8 percentile, IDDM=43.7±2.3 percentile p<.05). Ca/Cr correlated with coincident serum glucose r=.28 p<.0002, HbA1c r=.24 p<.0004, but not with serum Ca, alkaline phosphatase, vitamin D or PTH. Ca/Cr correlated inversely with Ht percentile r=.20 p<.01. IDDM with Ca/Cr>ND range were shorter 37±3.2 percentile than ND 54±3.8 percentile p<.01. Hypercalciuria was associated with both poor glycemic control and growth failure in IDDM children. When coincident serum glucose, HbA1c and duration of IDDM are factored out of the analysis of variance the Ca/Cr continues to have a negative correlation to height percentile. Hypercalciuria appears to be an important factor in the growth failure associated with IDDM.