Age-related markers and predictors of diabetic kidney disease progression in type 2 diabetes patients: a retrospective cohort study

Background: Diabetic kidney disease (DKD) is characterized by reduced estimated glomerular filtration rate (eGFR) and albuminuria, which play a pivotal role in both diagnosing and determining the disease's progression. This study aimed to assess the trajectory of these markers concerning age in individuals with DKD and identify predictive factors for the decline in eGFR decline, variation in albuminuria, mortality, and progression to renal replacement therapy (RRT). Design: This retrospective cohort encompassed patients with type 2 diabetes (T2D), divided into two age categories: <75 and >75 years old. Methods: Over a 3-year span, the study evaluated eGFR (CKD-EPI) and 24-h albuminuria. Univariate and multivariate analyses were employed to pinpoint factors associated with deteriorating renal function and mortality. Significance was set at p < 0.05, and Kaplan-Meier survival curves were constructed to illustrate renal and overall survival. Results: The analysis comprised 304 patients. Comparable eGFR declines were evident in both age groups during the transition from the first to the second year and from the second to the third year. Nonetheless, a more pronounced rise in albuminuria was evident in the >75 years group during the first to the second year. Multivariate analysis unveiled that systolic blood pressure (SBP) measurements in the first year positively forecasted eGFR decline. Age was associated with heightened albuminuria and mortality, while hospitalizations linked to cardiovascular causes robustly predicted mortality. Hospitalizations due to sepsis and cardiovascular reasons, coupled with first-year SBP measurements, served as predictive indicators for progression to RRT. Conclusion: Both age groups experienced similar declines in eGFR, though the >75 years group displayed a more significant increase in albuminuria during the first to the second year. Age, hospitalizations, and higher blood pressure levels were correlated with exacerbated renal function deterioration and/or elevated mortality in DKD. Timely intervention and tailored management strategies stand as critical components for enhancing outcomes among DKD patients.