Evolving kidney disease phenotypes in type 2 diabetes: declining albuminuria and increasing isolated low eGFR

Background: This study investigated the prevalence and clinical correlates of renal phenotypes in two cohorts of type 2 diabetes (T2D) patients, assessed temporal trends, and evaluated associations with treatment regimens. These figures were compared to those previously recorded in a similar, real world cohort 15 years earlier in Italy. Methods: Clinical data from 378 914 T2D patients attending the AMD network in 2023 in Italy were retrieved and compared to a similar cohort of prevalent patients in 2009. Renal phenotypes were classified as isolated albuminuria, isolated reduced eGFR (<60 ml/min/1.73 m²), or both. Multivariate logistic regression identified factors associated with these phenotypes. Results: In the 2023 study cohort, 51.3% of patients showed preserved renal function, 17.9% had isolated low eGFR, 17.4% had isolated albuminuria, and 13.3% exhibited both conditions. Female gender was independently associated with isolated low eGFR (OR = 1.28), whereas male gender was linked to albuminuria. Age was significantly related to both renal abnormalities, while longer diabetes duration increased the likelihood of low eGFR. Conclusions: Compared with the 2009 cohort, the prevalence of CKD in T2D remains stable in 2023, with albuminuric phenotypes decreasing and isolated low eGFR phenotypes increasing. These trends may reflect the aging population and evolving treatment practices, including a growing use of nephroprotective agents such as RAS inhibitors, SGLT2 inhibitors, and GLP-1 receptor agonists as well as better control of blood pressure. Longitudinal ad hoc studies are needed to address changing clinical scenarios.