Albuminuria in Type 2 Diabetes and Risk of Cardiorenal Outcomes

Background: Albuminuria is strongly associated with cardiorenal morbidity and mortality. However, real-world prevalence and the associated risks remain unclear. Objectives: This study aims to investigate the prevalence of patients with type 2 diabetes (T2D) with and without albuminuria and the subsequent risk of cardiorenal outcomes, and the eligibility for treatment with cardiovascular and renoprotective drugs. Methods: Using the Danish nationwide registers, we identified patients ≥18 years with T2D at index January 1, 2015, with a urinary albumin-to-creatinine ratio (UACR) and a creatinine level measured within 365 days prior. Patients were grouped by albuminuria (UACR ≥30 mg/g) and normoalbuminuria (UACR <30 mg/g). The primary endpoint was a composite of heart failure, myocardial infarction, stroke, or all-cause death, and the secondary endpoint was a composite of end-stage renal disease or a sustained decrease in the estimated glomerular filtration rate ≥50%. Absolute 4-year risks were calculated using the Kaplan-Meier and Aalen-Johansen estimators. Results: We included 74,014 patients, of whom 29,581 (40%) had albuminuria. Patients with albuminuria had a longer duration of diabetes (8.2 vs 6.9 years), lower estimated glomerular filtration rate (76 vs 83) and males were over-represented (62.6% vs 50.5%). The absolute 4-year risk of the primary outcome was 28.6% (95% CI: 28.1%-29.1%) vs 18.7% (95% CI: 18.4%-19.1%) for albuminuria vs normoalbuminuria, and for the secondary outcome, it was 8.7% (95% CI: 8.4%-9.0%) vs 2.9% (95% CI: 2.8%-3.1%), respectively. Conclusions: The prevalence of patients with T2D and albuminuria was 40% and may benefit from cardiovascular and renoprotective drugs, whereas 60% with normoalbuminuria still have a high residual risk of cardiovascular disease, warranting increased focus.