ASSOCIATION OF BLINDNESS TO INTENSIFICATION OF GLYCEMIC CONTROL IN INSULIN-DEPENDENT DIABETES-MELLITUS

Intensive glycemic control (IGC) in previously hyperglycemic insulin-d ependent diabetes mellitus (IDDM) patients is associated with a decrea sed long-term risk of progression of diabetic retinopathy (DR); up to 12 months after institution of IGC, however, the risk of progression o f DR transiently increases. In an observational study, a cohort of 122 patients with IDDM was followed prospectively for changes in glycosyl ated hemoglobin (HbA1, normal <8%) and in DR 0-12 months after institu tion of IGC. In six of these patients (women, mean age 24 years, durat ion of diabetes 14.3 years, with incipent nephropathy and retinopathy) a total of seven eyes went blind after 6-12 months of IGC, despite la ser coagulation treatment. From the whole sample, a control groups of eight patients (six women) was set up, matched for age, duration of ID DM, degree of retinopathy, visual acuity, blood pressure, and microalb uminuria, with preserved vision after 12 months of IGC. In the case pa tients, the mean (95% confidence interval) initial HbA1 was 14.9% (13. 8%-16.1%), versus 13.4% (12.4%-14.4%) in the control patients (p < 0.0 5). The mean HbA1 decrements after 4 months of IGC, were 3.0% (1.9%-4. 1%) in the cases, and 2.1% (1.2%-3.0%) in the controls (NS); and after 12 months, the respective decrements were 4.9% (2.4%-7.4%) in the cas es versus 2.0% (0.5%-3.5%) in the controls (p = 0.04). In conclusion, IGC with a decrement of >2% per year is associated with a high risk of progression of antecedent diabetic retinopathy to blindness in IDDM p atients with an extremely high initial HbA1. Such patients should, the refore, be excluded from diabetes treatment programs aiming at immedia te IGC.