Is Strict Glycemic Control of Diabetes Necessary and Feasible in Most Children and Adolescents?

Is strict control of diabetes necessary in children and adolescents? This part of the “Therapeutic Controversy” is easy to answer in the affirmative. The results of the Diabetes Control and Complications Trial (DCCT) demonstrated that intensive therapy of type 1 diabetes was able to delay the onset and slow the progression of early diabetic complications to an extent that even the most optimistic proponent of strict diabetes control did not anticipate. Not only did intensive therapy delay the onset and progression of retinopathy, the primary end point of the DCCT, it also markedly lowered the risk of developing microalbuminuria, clinical proteinuria, and clinical neuropathy (1). It is noteworthy that the benefits of intensive vs. conventional treatment have persisted even 4 yr after completion of the study (2). Because only approximately 14% of subjects were between 13 and 17 yr of age on entry into the DCCT, the most obvious question is whether intensive therapy was as beneficial in the adolescent subset of patients in the DCCT as it was in adults. This is a valid question because biologic factors, such as elevated concentrations of GH and insulin-like growth factor-I that are observed during puberty, might independently influence the response to the two treatments, especially with respect to retinopathy (3). To address this issue, separate subset analyses were carried out in the 195 patients who were between 13 and 17 yr of age on entry into the DCCT (125 primary prevention and 70 secondary intervention patients), and their results were compared with those in adults who were entered into the trial. In both age groups, intensive therapy lowered the risk of developing retinopathy by ∼30%, of retinopathy progression by ∼60%, and of developing microalbuminuria by 35–45% (4). Although the incidence of neuropathy and macrovascular complications was minimal or nonexistent in adolescent subjects in the DCCT, intensive treatment also improved nerve conduction velocities and caused a modest lowering of fasting low-density lipoprotein concentrations in this age group.