Renal function at the time of nephrology referral but not dialysis initiation as a risk for death in patients with diabetes mellitus

Background: Renal patients with diabetes mellitus are at very high risk of death before and after chronic dialysis initiation. Risk factors for death in this population are not clearly identified.

Methods: We performed a retrospective survival analysis in 861 patients with diabetes mellitus consecutively followed up in the 2000-13 period in a nephrology setting.

Results: The mean age was 70 ± 10 years [men 65.2%; diabetes duration 13.7 ± 10.3 years; mean estimated glomerular filtration rate (eGFR) 42.4 ± 21.0 mL/min/1.73 m²). During follow-up (median 60 months; up 15 years), 263 patients died (184 before and 79 after dialysis initiation) and 183 started chronic dialysis. In multivariate analyses, age, elevated systolic and low diastolic arterial pressures, peripheral artery disease, cancer, loop diuretic use and atrial fibrillation at baseline and acute kidney injury (AKI), heart failure (HF) and amputation during follow-up were identified as risk factors for death. After adjustments on these parameters, eGFRs at the time of the first outpatient visit-eGFR <45 mL/min/1.73 m² {hazard ratio [HR] 1.58 [95% confidence interval (CI) 1.15-2.17]}, P = 0.005 and eGFR <30 [HR 1.53 (1.05-2.05)], P = 0.004, but not eGFR <60-were powerful risk factors for death. When initiation of dialysis was entered into the multivariate models, it was not associated with a risk of premature death [HR 1.19 (95% CI 0.91-1.55), P = 0.2069], even in patients >80 years of age [HR 1.08 (95% CI 0.64-1.81), P = 0.7793].

Conclusions: In patients with diabetes mellitus, high systolic and low diastolic arterial pressure, peripheral artery disease and development of AKI and HF are significant risk factors for death. In addition to these parameters, eGFR <45 mL/min/1.73 m² at the time of referral is also a powerful risk factor for death.