Albuminuric and non-albuminuric reduced eGFR phenotypes in youth with type 1 diabetes: factors associated with cardiometabolic risk

Background and aim: Albuminuria and reduced eGFR are hallmarks of Diabetic Kidney Disease in adults. Our aim was to analyze factors associated with albuminuric and nonalbuminuric mildly reduced eGFR phenotypes in youths with type 1 diabetes. Methods and Results: This multicenter cross-sectional study included 1549 youths (age 5-17 years) with type 1 diabetes enrolled at 14 Italian Pediatric Diabetes Centers. Albuminuria, creatinine, glycosylated hemoglobin (HbA1c), lipids, blood pressure (BP), neutrophils (N) and lymphocytes (L) count were analyzed. Uric acid (UA) was available in 848 individuals. Estimated GFR (eGFR) was calculated using bedside Schwartz’s equation. The sample was divided in three phenotypes: 1) normoalbuminuria and eGFR ≥90 mL/min/1.73m2 (reference category, n =1204), 2) albuminuric and normal GFR phenotype (n =106), 3) non-albuminuric mildly reduced GFR (MRGFR) phenotype (eGFR 60-89 mL/min/1.73m2, n =239). Albuminuric and non-albuminuric reduced eGFR phenotypes were significantly associated with autoimmune thyroiditis (P=0.028 and P=0.044, respectively). Albuminuric phenotype showed high risk of high HbA1c (P=0.029), high BP (P <0.001), and low HDL-C (P =0.045) vs reference category. Nonalbuminuric MRGFR phenotype showed high risk of high BP (P <0.0001), low HDL-C (P=0.042), high Triglycerides/HDL-C ratio (P =0.019), and high UA (P <0.0001) vs reference category. Conclusion: Non albuminuric MRGFR phenotype is more prevalent than albuminuria phenotype and shows a worst cardiometabolic risk (CMR) profile). Both phenotypes are associated with autoimmune thyroiditis. Our data suggest to evaluate both albuminuria and eGFR earlier in type 1 diabetes to timely identify young people with altered CMR profile.