Irreversible progression of severe retinopathy in young type I insulin-dependent diabetes mellitus patients after improved metabolic control.

The impact of metabolic control on the development of rapidly progressive severe retinopathy was studied in 14 young type I insulin-dependent diabetes mellitus (IDDM) patients. Glycosylated hemoglobin (HbAlc) levels 45 months prior to and 12 months after the diagnosis of retinopathy were compared with HbAlc levels in 17 type I IDDM patients with no or minimal background retinopathy, matched for age and duration of diabetes. HbAlc levels were generally higher in patients with severe retinopathy (p less than 0.05) from 39 months until 6 months before the diagnosis of retinopathy. Thereafter, there was a gradual decrease in HbAlc levels reaching the same level as in control patients 6 months after diagnosis of retinopathy. Patients with severe retinopathy required higher doses of insulin prior to the diagnosis of retinopathy (p less than 0.05), but the insulin requirement decreased, and 12 months afterward, the insulin dosage was similar to patients with background retinopathy. Systolic blood pressure levels were slightly increased and higher in patients with severe retinopathy compared with control patients from 18 months before to diagnosis of retinopathy (p less than 0.05). Diastolic blood pressure levels likewise differed at 18 and 12 months before and at the time of diagnosis of retinopathy as well as 12 months afterward (p less than 0.05); however, no differences were seen in urinary albumin or serum creatinine levels between the groups. Thus, years of poor metabolic control, drastically improved, preceded the development of irreversible severe retinopathy in these young type I IDDM patients.