Hypercalciuria in children with diabetes mellitus

Seventeen of 75 diabetic children without nephropathy had urinary calcium excretion of more than 4 mg/kg/day. Neither diurnal variation in calciuria, nor correlations between calcium excretion and glucose excretion as well as HbA1 levels were observed. The findings suggest that about one quarter of diabetic children is at risk for hypercalciuria and may be for renal damage due to hyperexcretion of calcium.     

Fibronectin in children with diabetes mellitus.

Fibronectin plasma concentrations were determined in 28 children with type I diabetes mellitus and 22 healthy children. No statistically significant difference was observed between the fibronectin concentrations in diabetic and non-diabetic children. Even in children with poor glycaemic control the fibronectin concentrations (glycosylated haemoglobin greater than 10%) were not significantly higher.     

Blood pressure in children with diabetes mellitus

Blood pressure measurements were evaluated in 151 children aged 2-19 years old with insulin-dependent diabetes mellitus (DM) of a duration of few months to 15 1/2 years. Compared with a reference group, the diabetic children had lower diastolic blood pressure (DBP) shortly after start of DM. There was no difference for the systolic blood pressure (SBP). After duration of diabetes of 5 years there were no significant differences in SBP and only significantly lower DBP in girls (median difference 5 mmHg, p less than 0.01), while the difference in boys is insignificant (median difference 2 mmHg, p = 0.32). In a model describing the intraindividual variation in blood pressure and its dependence on age, weight and height it was found that age was insignificant when weight and height were included. For DBP height was also insignificant when weight was included. For the 9 children with retinal microaneurysms the average SBP was significantly higher than expected for diabetic children of that weight and height.     

Humoral factors in children with diabetes mellitus

Clinical and laboratory studies into the physiochemical properties of circulating immune complexes, serum IgA, IgM, IgG and antibodies against insulin contained by blood serum and circulating immune complexes were conducted in 102 children aged 7-14 years. Of these, 60 children were affected with insulin-dependent diabetes mellitus (IDDM) and 42 were normal. The data obtained point to the activity of autoimmune processes in IDDM patients in the first years of the disease, which manifested itself by the high content of circulating immune complexes and antibodies against insulin. The content of circulating immune complexes may serve an additional immunological indicator of compensation and prognosis of the disease.     

Insulin antibodies in 104 children with diabetes mellitus

Binding capacity for porcine, bovine, and human insulin was estimated in 104 diabetic children using homologous systems of iodinated and noniodinated insulin. All patient sera bound porcine and bovine insulin whilst 11.5% did not bind human insulin. There was no clear correlation between duration of insulin treatment and binding capacity. However, some patients with only short duration of treatment had high binding capacity for porcine insulin. The binding capacity for human insulin was low in most patients. High insulin requirement was on average combined with high binding for bovine insulin. Cases of diabetes, which are difficult to control, treated with individual mixtures of porcine and bovine insulin, often showed high binding for porcine and also for human insulin. The value of estimations of insulin-binding capacity in diabetic children is debatable. However, the high incidence of antibodies seems to justify the use of low immunogenic (monocomponent) insulin preparations.     

Hyperlipidemia in children with type 2 diabetes mellitus

Atherosclerosis is the leading cause of morbidity and mortality in patients with type 2 diabetes mellitus (DM). The increased risk of coronary artery disease in patients with type 2 DM is partly due to the lipoprotein abnormalities associated with DM. Dyslipidemia outweighs all other risk factors for cardiovascular disease in adults with type 2 DM. Hypertriglyceridemia and low levels of high-density lipoprotein (HDL)-cholesterol are the most common abnormalities in adults with type 2 DM. These abnormalities may improve, but commonly persist, after optimal glycemic control has been achieved. Children with type 2 DM also have hypertriglyceridemia, low levels of HDL-, as well as elevated levels of total and low-density lipoprotein (LDL)-cholesterol levels. Screening for dyslipidemia is recommended in children with type 2 DM. Several adult clinical trials that included patients with DM have demonstrated the efficacy of lowering LDL-cholesterol in preventing death from coronary artery disease. Weight loss, changing dietary habits, increasing physical activity, and improving glycemic control are initial approaches to the treatment of hyperlipidemia in children with type 2 DM. When goals are not met, drug therapy should be considered.     

Hematuria and hypercalciuria in children with diabetes mellitus

Hematuria of unknown origin occurs in 30% of patients with diabetic nephropathy. In nondiabetic persons, hematuria may be caused by hypercalciuria with or without nephrolithiasis. Eight children with type I diabetes mellitus, hematuria, and hypercalciuria were observed in our clinic during a 1-year period. Two of these also had evidence of renal papillary necrosis. To assess the importance of hypercalciuria in the pathogenesis of hematuria in children with diabetes mellitus, we measured urinary calcium excretion in a large population of such patients. The calcium to creatinine ratio in the urine of diabetic children (0.21 +/- 0.01) was greater than that of nondiabetic children (0.12 +/- 0.01). A calcium to creatinine ratio of 0.28 was established as the upper limit of normal in our nondiabetic population, and 27% of the diabetic children were hypercalciuric on this basis. The diabetic children with hypercalciuria also had hyperphosphaturia and a urinary CaHPO4 X 2H2O molar ion product three times that found in the nondiabetic control population. These data suggest that many children with diabetes are at risk for renal damage due to hypercalciuria. Because hypercalciuria is more common in diabetic than nondiabetic children, it may play a previously unrecognized role in the renal disease associated with diabetes mellitus.     

Calcitonin secretion in children with insulin-dependent diabetes mellitus

To test the hypothesis that calcitonin (CT) deficiency may contribute to bone mineral loss in insulin-dependent diabetes mellitus (IDDM), we studied basal and calcium stimulated (2 mg/kg body wt. in 5 min) CT levels in 15 children with IDDM and osteopenia. Ten age-sex matched healthy children were studied as controls. Since extractable CT (exCT) allows more sensitive and specific measurement of CT monomer, we measured both total serum CT (tCT) and exCT. Diabetic children had slightly but significantly (P<0.05) higher basal levels of both tCT (24.5±7.1 ng/l) and exCT (5.6±1.6 ng/l) than controls (tCT: 18.7±5.4 ng/l; exCT: 4.3±1.2 ng/l). Calcium stimulation test pointed out significant increase (P<0.001) of tCT and exCT in both groups with peak values not significantly different in IDDM in respect to controls. However, diabetic children showed a reduced CT reserve evidenced by a lower peak/basal ratio (diabetics: tCT 1.68, exCT 1.84; controls: tCT 2.49, exCT 2.88) and by a more rapid decrease in CT levels. We conclude that CT deficiency is not a causative factor of diabetic osteopenia. The slightly higher basal CT values suggest that an increased bone reabsorption may be operative in IDDM and it stimulates CT secretion. This chronic C cell stimulation may induce the reduction in CT reserve observed employing the calcium infusion test.