As pediatric diabetes specialists, we tend to practice in the “preventive mode.” As such, we tend to discuss diabetes related complications in terms of events that may never happen if we can establish excellent diabetes control. If I truly did not believe this statement, it would be extremely difficult for me to see patients on a daily basis and profess optimism. The lauded Diabetes Control and Complications trial published in the New England Journal of Medicine in 1993 was the first of many studies to demonstrate that tight glycemic control in patients with type 1 diabetes will decrease microvascular (kidney, eye and nerve) damage. The NIDDK study published years later proved the same for those with type 2 diabetes. Further studies have demonstrated reduced macrovascular complications (cardiac) with tight blood sugar control as well.
In the past I wrote about research demonstrating marked improvement of survival rates of people with diabetes as we have improved our treatment and developed new insulins and technology.
Today I would like to discuss a paper written by LeCaire, Palta, Klein, Klein, and Cruickshanks, “Assessing Progress in Retinopathy Outcomes in Type 1 Diabetes, “ in Diabetes Care, DOI: 10.2337/dc12-0863, published online November 27, 2012. According to the authors, in years past, some evidence of Diabetic Retinopathy was present in most individuals by 15-20 years of diabetes duration. However, as I have mentioned in previous recent blogs, there have been studies demonstrating a decline in diabetic retinopathy in the current era of improved diabetes care both in those people who developed diabetes early in life as well as those who have long-standing diabetes. Another past blog discussed glycemic memory in which patients that have had long standing excellent glycemic control following initial diagnosis developed lower rates of future retinopathy.
The objective of the study was to compare cohorts of the Wisconsin Diabetes Registry Study with those of the Wisconsin Epidemiologic Study of Diabetic Retinopathy. “The Wisconsin Diabetes Registry study (WDRS) cohort consisted of patients diagnosed with T1DM in the same geographic region as, but 8-34 years later than the Wisconsin Epidemiologic Study of DR (WESDR) cohort.” This comparison provided an excellent chance to denote complication rate. The authors thus estimated the current prevalence and severity of diabetes retinopathy at 20 years post development of type 1 diabetes and compared these between eras and evaluated the influence of diabetes management.
What did they find?
Not surprisingly, average hb A1c levels were lower in the WDRS than in the WESDR cohorts, respectively (8.0 vs. 9.3 percent). These results are statistically significant (p<0.001). Ninety-three vs. 21 percent (P<0.001) used multiple daily injections (greater than 3) or an insulin pump, respectively. In the later cohort (WDRS), 18 percent had retinopathy that threatened vision versus 43 percent in the earlier cohort (WESDR).