Renal Complications and Duration of Diabetes: An International Comparison in Persons with Type 1 Diabetes

INTRODUCTION: Renal complications are both a marker of previous suboptimal glycaemic control and a major risk factor for cardiovascular disease in persons with type 1 diabetes (T1D). The aim of the study was to evaluate the prevalence of renal complications in persons with T1D in four geographical regions. METHODS: Nationwide registry data from Austria/Germany, Sweden and the US were used to estimate the prevalence of renal complications from January 2016 until September 2018. Chronic kidney disease (CKD) and albuminuria in the study population and each registry were analysed by diabetes duration. Risk factors for renal complications were described by registry. RESULTS: In the total cohort of 78.926 adults with T1D, mean age was 44.4 ± 18.43 years and mean diabetes duration was 21.6 ± 22 years. Mean estimated glomerular filtration rate (eGFR) was 94.0 ± 31.45 ml/min, 13.0% had microalbuminuria and 3.9% had macroalbuminuria. Mean age, diabetes duration, use of insulin pumps and continuous glucose monitoring, as well as presence of albuminuria, varied between registries. Albuminuria was present in approximately 10% of persons with diabetes duration < 20 years and impaired renal function (eGFR < 60 ml/min) was present in 17%. In persons with diabetes duration > 40 years, approximately one-third had albuminuria and 25% had impaired renal function. CONCLUSIONS: This analysis used three nationwide registries of persons with T1D. Despite recent use of more effective diabetes therapies, a substantial proportion of persons with T1D have renal complications at < 20 years after diagnosis. Efficient glucose-lowering and renal-protective strategies are needed in persons with T1D.