Continuous Subcutaneous Insulin Infusion—A Better Way to Manage Type 1 Diabetes in Adolescents

Abstract & Commentary

Synopsis: Continuous subcutaneous insulin infusion (CSII) is an effective way to control diabetes mellitus in adolescents with type 1 diabetes. When compared to multiple daily insulin injection (MDI), children treated with CSII for 12 months had lower levels of HbA1c, a lower risk of hypoglycemia, and enhanced coping skills.

Source: Boland EA, et al. Continuous subcutaneous insulin infusion. A new way to lower risk of severe hypoglycemia, improve metabolic control, and enhance coping in adolescents with type 1 diabetes. Diabetes Care 1999;22:1779-1784.

A group of 75 children, 12-20 years of age, with insulin-dependent diabetes mellitus type 1, were given the option of CSII vs. MDI treatment. Fifty children chose MDI, 24 chose CSII. Routine visits with advance practice nurse practitioners were conducted every 4-6 weeks and these included diabetes education. Patients were taught carbohydrate counting by a registered dietician and were instructed how to vary their insulin doses based upon food intake and planned exercise. Psychosocial evaluations were performed using Diabetes Quality of Life Youth questionnaires, which assess life satisfaction, disease impact, and disease-related worries. Data concerning episodes of hypoglycemia and ketoacidosis were also collected at each visit.

In both groups, mean HbA1c levels decreased significantly during the first six months of treatment. Between six and 12 months, HbA1c levels increased in the MDI but not in the CSII group and were statistically lower in the CSII group (7.5 ± 0.9 vs 8.1 ± 1.0; P = 0.02).

Rates of hypoglycemia requiring assistance or resulting in coma were reduced by nearly 50% in the CSII group compared to the MDI group. There were no differences between the groups of episodes of diabetic ketoacidosis. Both groups had comparable improvement in psychosocial assessments of quality of life, depression, and self-efficacy. However, the adolescents using CSII found coping with diabetes to be less difficult than those using MDI.

Comment by Myron Genel, MD, FAAP

The past few decades have seen a dramatic shift in the philosophy of management of type 1 or insulin-dependent diabetes in children and adolescents. Improved technology, in particular the development of blood glucose monitoring techniques as well as new preparations of insulin, accounts for this in part. More important, however, is recognition among pediatricians that there is a direct correlation between diabetes control and prevention of the long-term catastrophic complications of diabetes. Most of these complications (kidney, retina, etc.) usually occur outside the pediatric age group when the patient’s care has been assumed by adult practitioners and specialists. Near-normalization of blood glucose profiles that could be achieved when "insulin pump therapy" or, more accurately, continuous subcutaneous insulin infusion (CSII ) was introduced 20 years ago—as well as by multiple daily injections. The initial devices for CSII were cumbersome and cosmetically unattractive. This has changed significantly in the past few years with miniaturization—not to mention the publicity that came with the selection of the 1998 Miss America, Nicole Johnson, who manages her diabetes with a small pump.

A risk of intensive insulin therapy with either the pump or multiple injections is hypoglycemia. Adolescents are particularly susceptible, in part because the relative insulin resistance of puberty necessitates the use of higher doses and the pharmacodynamics of regular insulin are such that post-prandial hypoglycemia may result. Blunting of the normal compensatory catecholamine response to hypoglycemia further increases this risk.

In more than one year of observation, Boland and associates at Yale were able to achieve better control, as reflected in lower hemoglobin A1c levels in adolescents using the pump compared to patients on multiple daily injections, while at the same time observing an almost 50% reduction in severe hypoglycemic episodes. Nevertheless, the number of hypoglycemia episodes continues to be a problem. Hopefully, substitution of newer and more rapidly acting insulins such as Lispro will enable more effective control while also reducing the risk of hypoglycemia.

As noted in an editorial by Wolfsdorf,1 the type of education, self-management, training, professional support, and monitoring described in the Boland study requires supervision by expert multidisciplinary teams in regional centers of excellence.

Reference

1. Wolfsdorf JI. Improving diabetes control. Diabetes Care 1999;22:1767-1768.

Diabetes in adolescent patients:

a. is associated with a high rate of clinical retinal and renal vasculitis.

b. may be difficult to control because of a relative insulin resistance.

c. is better controlled by multiple daily insulin injections than CSII.

d. hypoglycemia can be prevented by CSII.