Early intensive treatment improves outcomes in patients with glomerular hyperfiltration and type 2 diabetes

Approximately 24-40% of patients with type 2 diabetes mellitus (T2DM) develop kidney damage. Our objective was to evaluate the long-term evolution of renal function using isotopic determination of GFR and urinary albumin excretion (UAE) in patients with T2DM undergoing intensive treatment for renal and cardiovascular risk factors.

This was a single-center, prospective study of 201 patients with T2DM and UAE who initiated intensive treatment. They were followed for 17.2±6.5 years. Patients were divided into three groups, according to renal function: 167(85.6%) had stable renal function, 16(8.2%) had creatinine levels that doubled and 12(6.2%) began renal replacement therapy (RRT). We performed periodic isotopic determinations of GFR using (125)I-iothalamate.

There were significant differences between the three groups with respect to age, duration of T2DM at baseline, years of follow-up in the study and systolic blood pressure, serum creatinine, isotopic GFR, and UAE at baseline. Renal function evolution slopes were -1.55mL/min/1.73m(2)/year in patients with stable creatinine, -2.49mL/min/1.73m(2)/year in those with doubled creatinine, and -8.16mL/min/1.73m(2)/year in those requiring RRT. We also found that differences in renal events were determined by delayed initiation of intensive treatment.

Patients with glomerular hyperfiltration who were undergoing treatment with renin angiotensin aldosterone system blockers exhibited a better evolution in renal function, possibly because these patients initiated intensive treatment earlier. Although diabetic nephropathy is associated with classic risk factors, early initiation of intensive treatment should be a priority in order to prevent worsening renal function.