Revised: October 14, 2013
Accepted: November 1, 2013
Published online: February 6, 2014
AIM: To examine the risk of renal events in patients with biopsy-proven diabetic nephropathy (DN) and its possible associated factors.
METHODS: Clinical and histological data of 60 patients diagnosed with diabetic nephropathy were retrospectively collected. Patients with evidence or suspicion of other nephropathies were excluded from the study. The final event was defined as renal replacement therapy (RRT) initiation or progression of chronic kidney disease (CKD), according to the KDIGO 2012 definition of a decrease in CKD category and a decrease in GFR of 25% or more.
RESULTS: A total of 45 patients with a follow-up of at least 3 mo were included. Most of the patients presented type 2 DM, with a mean age of 58.3 years old. The time of evolution of DM was 9.6 ± 7.8 years, although in 13 patients, it was less than 5 years. A total of 62% of patients reached the final event in a median period of 3.4 years (95%CI: 2.1-4.7), with 21 of them requiring dialysis. The factors that were independently associated with renal survival were estimated glomerular filtration rate (eGFR) at the time of biopsy, cardiovascular disease (CVD) history and HbA1c less than 7%. Therefore, for each 10 mL/min per 1.73 m2 reduction in eGFR, we obtained a DN progression risk of HR = 2 (1.3-3.0) (P = 0.001); patients with CVD were at greater risk for DN progression (HR = 2.8, 1.1-7.1, P = 0.032), and CKD patients with HbA1c < 7% demonstrated greater renal risk than patients with HbA1c ≥ 7%, with an HR of 2.9 (1.0-8.4) (P = 0.054).
CONCLUSION: A past history of CVD is a risk factor for DN progression. Levels of HbA1c less than 7% could favor an eGFR decrease in these patients.
Core tip: There are other forms of presentation of diabetic nephropathy (DN), in addition to progressive proteinuria, that can result in renal insufficiency. In some cases, DN is diagnosed in advanced stages, without previous suspicion of this diagnosis. The clinical course can be atypical, and the time of evolution of diabetes mellitus can be short. Not all the factors that play a role in the evolution of DN have been elucidated. Our findings suggest that in patients with chronic kidney disease secondary to DN, a previous history of cardiovascular disease and HbA1c less than 7%, are negative prognostic factors for renal function.