To evaluate the prevalence of different CKD phenotypes, Dr. Eleonora Russo from the University of Pisa, Italy, and colleagues looked at two cohorts of Italian patients with type 1 diabetes (T1DM). The first cohort (C1) involved 777 patients recruited from 2001 to 2009 at an outpatient clinic, and the second cohort (C2) involved 936 patients from the EURODIAB IDDM Complications Study who attended 9 diabetic centers in 1989-1991.

Results of the study indicated that albuminuria was more frequent in the C2 group compared to the C1 group. The albuminuric (Alb+) and non-albuminuric (Alb-) phenotypes were present in 41.4% and 58.6% of stages ≥3 in C1 compared to 72.2% and 27.8% in C2 (p<0.039).

In both groups, normoalbuminuria was further divided into normal albuminuria (ACR <10mg/g) and low-microalbuminuria (ACR =10-29mg/g), and stage 1-2 CKD was stratified into 2a (eGFR =75-89) and 2b (eGFR=60-74ml/min/1.73m2). In stage 2b, the prevalence of normoalbuminuria was higher in C1 than C2 (88.7% vs 67.5%, p=0.006). Similarly, when considering stage 2b and stage ≥3 together, normoalbuminuria was present in 80% of C1 compared to 55% of C2 (p=0.001).

According to the researchers, there are several factors that may contribute to the different rate of non-albuminuric CKD phenotypes. ”It is conceivable that more effective treatments might have contributed to the different distribution of CKD phenotypes, but is also possible that these differences reflect changes in the impact of the pathogenetic mechanisms affecting the onset and the progression of the disease process.”

Practice Pearls:

• Data from this study suggested that the prevalence of non-albuminuric CKD is increasing over time.
• Future studies should be conducted to explain the difference in distribution of CKD phenotypes.

Russo E, Penno G, Garofolo M, et al. Prevalence of nonalbuminuric chronic kidney disease is increasing in patients with type 1 diabetes mellitus. EASD Virtual Meeting. 17 Sep 2014. Web. 25 Sep 2014.