Decreasing Incidence of Severe Diabetic Microangiopathy in Type 1 Diabetes

Abstract

OBJECTIVE -Conflicting evidence of a decline in incidence of microvascular complications in type 1 diabetes during the last decades has been reported. To assess recent trends in the cumulative incidence of diabetic microangiopathy in type 1 diabetes, we analyzed data from long-term prospective observational studies lasting Ն20 years. RESULTS -In patients followed for Ն20 years, the cumulative incidence (95% CI) of diabetic nephropathy after 20 years of diabetes (urinary albumin excretion Ͼ300 mg/24 h) was reduced in patients with more recent diabetes onset (groups A-D): 31.1% (22.5-39.7) vs. 28.4% (19.8 -37.0) vs. 18.9% (10.9 -26.9) vs. 13.7% (6.2-21.2) (P ϭ 0.015). Similarly, the cumulative incidence of proliferative retinopathy was as follows: 31.2% (22.2-39.8) vs. 30.3% (22.2-38.4) vs. 19.3% (11.2-27.4) vs. 12.5% (5.2-19.8) (P Ͻ 0.01). In the latter groups, antihypertensive treatment was started earlier, blood pressure and HbA 1c were lower, and fewer patients smoked. RESEARCH DESIGN AND METHODSCONCLUSIONS -Our study demonstrates a decrease in the cumulative incidence of diabetic microangiopathy in type 1 diabetes over the past 35 years. Improved glycemic control, lower blood pressure (in part due to early aggressive antihypertensive treatment), and reduced prevalence of smoking rates were associated with the improved prognosis.

Declining incidence of severe retinopathy and persisting decrease of nephropathy in an unselected population of Type 1 diabetes—the Linköping Diabetes Complications Study

“…In the EuroDiab Study in 1990, the prevalence was at the same level, 18% after 20 to 24 years disease duration [20]. A new follow-up from the Copenhagen area in 2000 showed a marked decrease of the cumulative incidence of nephropathy to 13.7% after 20 years of diabetes duration [14]. The decrease was observed in the cohort with onset of diabetes between 1979 and 1984, that is, 10 to 15 years later than in our study.…”

“…To our knowledge, this has not been previously reported for an unselected population with diabetes beginning in childhood. In a study from Denmark with follow-up until the year 2000, they also found a declining trend with increasing calendar year of diagnosis [14]. The patients were older at diagnosis and the study was clinic-based.…”

School performance in children with type 1 diabetes—a population-based register study

“…Over the past few years, the efforts to improve metabolic control in childhood diabetes have probably contributed to the decreasing prevalence of diabetic complications [1][2][3]. Particularly since the strong proof provided by the Diabetes Control and Complications Trial (DCCT) [4], attempts to keep HbA 1c below the proposed threshold value have been adopted by most clinicians, including those in paediatric clinics, especially as it has been shown that, as early as in the first years of type 1 diabetes, metabolic control has an impact on markers of late complications [5,6].…”

Low cumulative incidence of proliferative retinopathy in childhood-onset type 1 diabetes: a 24-year follow-up study

“…In type 1 diabetes, previous studies have demonstrated a cumulative incidence of PDR of 20 to 40% after 20 to 25 years of disease duration [8][9][10][11][12][13]. PDR was reported to develop in as many as 70% of youth-onset patients after 30 years of diabetes diagnosed in the years 1950 to 1960 [11].…”