Improvement in metabolic control in diabetic adolescents by the use of increased insulin dose

Continuous subcutaneous insulin injection for self-care of young patients with insulin-dependent diabetes mellitus

Continuous subcutaneous insulin injection was used for the self-care of five patients aged 10-18 years with insulin-dependent diabetes mellitus. After an introduction to the concept and procedures for continuous subcutaneous injection, the patients soon became familiar with self-care using an insulin pump at home and at school. Three months later, the control of blood glucose improved with smaller doses of insulin in four cases and milder hypoglycemia was observed compared to when using multiple injections. Significantly decreased variations and lowered means of early morning blood glucose values were observed and seemed to explain the reason for better glycemic control. Buffered regular insulin continuously injected by pumps brought a more stable nocturnal blood glucose level compared to isophane insulin injected at bedtime, the absorption of which seemed to vary considerably. On the contrary, unbuffered regular insulin injected by pumps brought frequent nocturnal hypoglycemia, sudden worsening of glycemic control and skin infections and thus, was deemed inadequate for continuous subcutaneous injection.

Urinary excretion and clearance of insulin in diabetic and normal children and adolescents

Seventy-two diabetic (38 males) and 86 normal (41 males) children provided timed overnight urine collections. Fourteen of the diabetic and 33 of the normal children had concurrent overnight plasma insulin profiles. Urinary insulin clearance in the diabetic subjects was compared with excretion of albumin, growth hormone, retinol-binding protein, and N-acetyl-beta-D-glucosaminidase. In the normal subjects, urinary insulin excretion correlated with mean overnight plasma levels in the boys (r = 0.82, p < 0.001) but not in the girls (r = 0.32), and varied with puberty stage in the boys. Insulin clearance was greater in boys than girls during puberty, and fell in both sexes with advancing puberty. Insulin excretion was greater in diabetic than normal children in both sexes at all puberty stages. Insulin clearance was also greater in diabetic than normal subjects (1.05 +/- 0.1 ml min-1 1.73 m-2 vs 0.48 +/- 0.05 ml min-1 1.73 m-2, p < 0.001). Insulin excretion as a percentage of the filtered load was also greater in diabetic than normal subjects (1.9 +/- 0.27% vs 0.85 +/- 0.09%, p < 0.01). In the diabetic children, there was a correlation between urinary insulin and growth hormone excretion (r = 0.52, p < 0.02), and retinol-binding protein in those (n = 10) with higher retinol binding protein excretion (r = 0.76, p = 0.01). The value of urinary insulin excretion as a measure of free plasma insulin levels in normal and diabetic children may be limited by sex differences in renal insulin clearance, and by proximal renal tubular dysfunction in children with diabetes.

Glucose tolerance and insulin release in adolescent female

The increase in insulin requirement at the onset of adolescence is compensated by an increase of insulin secretion. This metabolic pattern persists during adolescence but is no longer present in adults. It is supposed to depend on a decrease of insulin sensitivity of uncertain origin. We compared the metabolic pattern of late adolescent girls (13-16 year old) with young women (21-30 year old) with similar body mass indexes, testing subjects with iv glucose tolerance test (IVGTT) (glucose 0.33 g/kg) and arginine test (ATT) (arginine 30 g in 30 min). In late adolescent vs adult women we observed: i) IVTT: similar k of glucose tolerance and higher insulin and C-peptide responses; ii) ATT: unmodified plasma glucose, insulin and glucagon values, higher GH plasma levels; iii) in adolescent girls GH and CPR incremental areas significantly correlated (r = 0.755, p less than 0.05). These data show that: i) the adolescent pattern of glucose metabolism persists after completion of sexual development and, ii) there is a positive correlation between GH response to arginine and beta-cell response to glucose. So GH should play a role in the impairment of glucose metabolism during adolescence.

Improved diabetic control in a district general hospital clinic

A clinic for diabetic children was established in 1983 in a district general hospital to coordinate the changeover to a standard 100 unit insulin regimen. The children's progress was monitored for the next three years. Glycated haemoglobin A1 (HbA1c), measured at the same time each year, fell from a mean (SD) of 15.8 (4.7)% to 9.9 (2.6)% over the three years. A similar degree of improvement was seen when newly diagnosed patients were excluded from the analysis. This improvement was associated with a rise in mean (SD) insulin dosage from 0.89 (0.29) U/kg/day to 1.17 (0.35) U/kg/day. Good control was achieved more easily in children who had been diabetic for less than two years and in those who were prepubertal (particularly boys). A combination of isophane and soluble insulin appeared to be more effective than zinc and soluble insulin in maintaining good control. Ten complications of diabetes were noted in eight patients from 5.2 to 12.4 years after diagnosis. These results show that setting up a diabetic clinic for children in a district general hospital had a beneficial effect on the quality of diabetic control and such improvement may help to reduce the incidence of diabetic complications.

The metabolic and hormonal effects of continuous subcutaneous insulin infusion therapy in diabetic children

To find out whether the concurrent metabolic and hormonal abnormalities are corrected when normoglycaemia is achieved, two groups of diabetic children (newly-diagnosed and chronically-treated) were treated with insulin pumps. Fasting levels of metabolites, lipids and hormones were measured before and after 8 to 10 days of pump treatment and the immediate postprandial hormonal and metabolic changes after a test-meal were also measured. Restoration of normoglycaemia was accompanied by correction of multiple metabolic abnormalities including the normalisation of fasting plasma free insulin, growth hormone, free fatty acid, triglyceride and total cholesterol levels. Plasma glucagon, however, decreased below normal, and significant hypoketonaemia developed in newly-diagnosed diabetic children. The fall in (VLDL + LDL)-cholesterol levels was accompanied by a substantial increase in HDL2-cholesterol concentration in newly-diagnosed diabetic children, whereas pump-treatment resulted in a decrease of the HDL3-cholesterol subfraction in chronically-treated diabetic children. The postprandial blood glucose and free insulin profiles were similar to that of control subjects, but there was an "abnormal" postmeal fall in plasma glucagon and free fatty acid levels. These changes together with the fasting hypoglucagonaemia and hypoketonaemia indirectly suggest that optimal glycaemic control is only achievable at the expense of "increased insulin action" despite the failure to detect peripheral hyperinsulinaemia. Furthermore, the restoration of normoglycaemia and the simultaneous normalisation of the metabolic and endocrine milieu is not entirely possible with this mode of therapy.

Outpatient management of diabetes mellitus

Outpatient encounters form the mainstay of managing type I diabetes mellitus in children and adolescents. Management philosophy rests on the premise that normal physical and emotional growth is attainable and long-term complications minimized by maintenance of metabolic (glycemic) control. Management principles involve a coordinated team approach of physician, nurse-educator, and dietitian interacting with the family unit to educate them in the appropriate use and adjustment of insulin regimens, to recognize and treat the Somogyi and dawn phenomena, adjustment of nutritional needs, short- and long-term monitoring via home blood glucose and glycosylated hemoglobin measurements, and clues from the history and physical examination that permit anticipatory or reactive steps to achieve the treatment goals.

Puberty decreases insulin sensitivity

Puberty is commonly associated with an increase in insulin requirement in patients with insulin-dependent diabetes. To investigate whether this pubertal increase in insulin requirement is confined to diabetic subjects, we examined insulin responses during oral glucose tolerance testing with glucose loads per unit weight (1.75 g/kg) or unit surface area (55 g/m2), and insulin sensitivity via euglycemic-hyperinsulinemic clamp in prepubertal and pubertal children without diabetes. Irrespective of glucose dose, glucose tolerance testing elicited a threefold greater insulin response, but equivalent euglycemia, in pubertal versus prepubertal children (P less than 0.05). As assessed by the clamp procedure, prepubertal children were approximately 30% more sensitive than their pubertal counterparts (P less than 0.01). Insulin sensitivity correlated inversely with body mass index (r = -0.49, P less than 0.02), serum dehydroepiandrosterone sulphate concentration (r = -0.57, P less than 0.01), and log somatomedin C/insulinlike growth factor I (r = -0.45, P less than 0.05). We conclude that puberty is associated with decreased sensitivity to insulin that normally is compensated for by increased insulin secretion. Thus, in patients with insulin-dependent diabetes, an approximately 30% increase in insulin dosage should be anticipated with the onset of puberty.

Metabolic rhythms in adolescents with diabetes during treatment with porcine or human insulin

Metabolic rhythms were studied over 24 hours in eight adolescent diabetic patients during treatment with porcine insulin and after transfer to human insulin. Despite an increase in dose with human insulin no significant changes were found in fasting blood glucose, 24h mean blood glucose, or glycosylated haemoglobin concentrations. Significantly higher 24h mean blood lactate concentrations and lower total ketone bodies and glycerol concentrations were observed during treatment with human insulin. These findings are consistent with the increase in insulin dose and do not necessarily imply different metabolic responses to species differences in insulin.