Continuous subcutaneous insulin infusion in children

100 Years of Insulin: Lifesaver, immune target, and potential remedy for prevention

In this review, we bring our personal experiences to showcase insulin from its breakthrough discovery as a life-saving drug 100 years ago to its uncovering as the autoantigen and potential cause of type 1 diabetes and eventually as an opportunity to prevent autoimmune diabetes. The work covers the birth of insulin to treat patients, which is now 100 years ago, the development of human insulin, insulin analogues, devices, and the way into automated insulin delivery, the realization that insulin is the primary autoimmune target of type 1 diabetes in children, novel approaches of immunotherapy using insulin for immune tolerance induction, the possible limitations of insulin immunotherapy, and an outlook how modern vaccines could remove the need for another 100 years of insulin therapy.

Modern insulin therapy in children and adolescents

Clear evidence exists that near-normal blood glucose control will prevent serious late diabetic complications. This review summarizes the targets for blood glucose control and discusses why insulin replacement therapy is so complicated in children and adolescents. It is important that diabetes treatment teams have excellent knowledge of insulin preparations, insulin pharmacokinetics and action profiles and the limitations and pitfalls of therapy. This is necessary to be able to optimize and individualize treatment. A detailed summary of different insulin regimens is given and discussed to help treatment teams choose a suitable regimen for the individual patient. The use of home blood glucose measurement is necessary to reach the targets of treatment. If economic resources are limited, alternative strategies are suggested. In wealthy countries the lifestyle of adolescents demands great flexibility and a suggestion for systematic training to increase flexibility in daily life is presented.

Practical aspects of managing preschool children with type 1 diabetes

Day-to-day variations in diet and physical exercise, large variations in the glucose response to small changes in insulin doses, and high insulin sensitivity are characteristic of preschool children with diabetes. Hence, difficulties in achieving adequate metabolic control and stable glycaemia in preschool children are common. In addition, hypoglycaemic episodes tend to be frequent and severe in this age group. Problems identifying and treating hypoglycaemia present an additional challenge for the diabetes team and for the family caring for the young child with diabetes. Specific glucose targets are provided for this age group: premeal levels of 6-12 mmoll(-1)(110-220 mg dl(-1)) with bedtime levels above 8 mmoll(-1)(140 mg dl(-1)). It is important to note that children who suffer severe hypoglycaemic events at a young age show evidence of subtle cognitive deficits when tested during adolescence. The question of whether or not the years before pubertal onset contribute less towards the development of diabetes-related microvascular complications than do the years starting with the onset of puberty remains controversial. Twice-daily or multiple insulin injections, dietary adjustments and considerations, home blood-glucose monitoring, family education, support groups and 24-h hotline information facilities can help to achieve good metabolic control without severe hypoglycaemia in the preschool child. In general, good metabolic control without severe hypoglycaemia can be achieved using frequent counselling and a caring team approach.

[Remission of severe hypoglycemic incidents in young diabetic children treated with subcutaneous infusion]

BACKGROUND

Conventional insulin therapy for diabetes mellitus can be inadequate for controlling glycemia in young patients in whom the risk of hypoglycemia is particularly high.

PATIENTS

A retrospective study comparing all the children under 6 years of age treated in our department by continuous subcutaneous insulin infusion (group P, n = 10, mean age: 3.7 years) to 17 children with conventional insulin therapy (group C, mean age: 5.1 years) was conducted during a mean period of 2 years.

RESULTS

Mean insulin doses, HbAlc, pre-prandial and daily glycemic levels, measured at 0, 3, 6, 12, 18 and 24 months, did not differ significantly between both groups. Mean HbAlc levels remained < or = 8% in the two groups. There was no episode of severe hypoglycemia in group P vs ten episodes in group C (P < 0.05); this benefit was confirmed in those six children belonging to group P who had previously followed a conventional therapy: 11 episodes during the conventional period vs 0 episode during the pump period (P < 0.05). Nine out of ten families were very satisfied with the treatment by pump mainly because of a more comfortable life style and a reduction of parents' anxiety due to disappearance of severe hypoglycemias. The insulin pump therapy had some limits: cutaneous complications and technical ones were responsible for two keto-acidosis episodes (0.1 episode per year-patient) and a higher frequency of hospitalizations. In group C, hospitalizations were caused by severe hypoglycemias and unbalanced glycemic control.

CONCLUSIONS

Insulin pump therapy could be indicated in young diabetic children at high risk of severe hypoglycemia under conditions of a specialized medical and educational supervision and knowledge of the limits of such a treatment.

Side effects and indwelling times of subcutaneous catheters for insulin injections: a new device for injecting insulin with a minimum of pain in the treatment of insulin-dependent diabetes mellitus

For 2 months we observed side-effects and indwelling times when using a subcutaneous catheter (Insuflon, Viggo AB, Sweden) for insulin injections. This method is used by approximately 600 children and adolescents with IDDM in Sweden today. 22 children and adolescents aged 4-19 years with a diabetes duration of 4.0 +/- 3.0 (mean +/- SD) years participated. Their HbA1c was 5.8 +/- 1.0%. All used 4-6 dosages of insulin per day. The catheter was placed subcutaneously in the abdominal wall, and replaced by parents when home tests showed increased blood or urine glucose, when the child experienced pain or when skin changes were observed. The 22 patients used 239 catheters with a mean time between changing catheters of 4.8 +/- 2.2 (range 0.5-17) days (= 1147 catheter days). Noted side effects were (% of catheter days): fixation problems, 5.6%; minor infection/irritation (= redness greater than 1 mm), 5.6%; pain, 2.8%; sore skin from plastic wings, 2.4%; itching/dry skin, 2.0%; eczema from band-aid, 1.7%; blocked catheter/injection needle, 1.6%; leakage of insulin, 1.3%, transient lipohypertrophies, 1.1%; hematoma/blood in catheter, 0.8%, and moist skin, 0.3%. No major infections requiring surgical or antibiotic treatment occurred. In conclusion, the use of indwelling insulin catheters seems to be a safe method to lessen the pain of insulin injections with a low frequency of side effects. The long-term metabolic control was not altered in this group of well-controlled children. We therefore find that we can recommend the use of indwelling catheters to children and adolescents who have difficulties with injections because of needle phobia or pain, particularly when using MIT.

Continuous subcutaneous insulin infusion (CSII) versus conventional injection therapy in newly diagnosed diabetic children: two-year follow-up of a randomized, prospective trial

The effect of continuous subcutaneous insulin infusion (CSII), begun at diagnosis, on blood glucose control and endogenous insulin production was studied in a group of consecutively referred newly diagnosed diabetic children. In a random order, 15 children started CSII (age 9.5 +/- 4.2 (+/- SD) years) and 15 conventional injection therapy (age 7.0 +/- 3.6 years). For 2 years HbA1 and urinary C-peptide were measured monthly, C-peptide responses to glucagon 6-monthly, and insulin antibodies every 3 months. None of the patients requested change of therapy during the study period, but at 28 months 1 adolescent girl changed to injection therapy from CSII. Severe hypoglycaemia was observed once in each group, but ketoacidosis only once, in the injection therapy group. From 2 months after diagnosis onwards the CSII group had significantly lower HbA1 levels. Urinary and plasma C-peptide levels did not differ between the two groups and similar insulin doses were used throughout the study. At the end of the 2 years of therapy, the CSII group had significantly lower insulin antibody levels. The observations suggest that CSII is well accepted in newly diagnosed children and improves metabolic control, but does not prolong endogenous insulin production.