Anti-renin-angiotensin-system drugs and development of anemia in chronic kidney disease.

Background: A variable inhibition of erythropoiesis has been reported in uremic patients with renal anemia receiving anti-renin-angiotensin-system (RAS) drugs (angiotensin-converting-enzyme inhibitors, and angiotensin-receptor-antagonists). The time to development of renal anemia before dialysis is still unknown.
Methods: A retrospective cohort study (1 to 15 years) on records of 327 out-patients (217 males, 110 females) without anemia and with chronic renal insufficiency (creatinine clearance 16 to 75 mL/min) was conducted to estimate the time to development of renal anemia (Hb < 11.5 g/dL in females and Hb < 12.5 g/dL in men), and the time to decrease of Hb by 1 and 2 g/dL or more, irrespective of anemia development. Two treatment groups were analyzed: 142 patients with, and 185 without anti-RAS drugs.
Results: Median survival time to development of anemia was 81 months, 59 months to the loss of Hb > 1 g/dL, and 94 months for the loss of Hb > 2 g/dL. Anemia developed significantly earlier in patients with initial Ccr < 40 mL/min and in those with initial Hb < 14 g/dL. In the multivariate analysis (Cox model), male gender, Ccr < 40 mL/min, and Hb < 14 g/dL, in increasing order of relative risk, significantly contributed to prediction of anemia development without any influence of the treatment with anti-RAS drugs. The same results were obtained considering survival to the loss of either Hb > 1 g/dL or Hb > 2 g/dL.
Conclusions: Development of renal anemia in mild to severe chronic kidney disease is not influenced by treatment with anti-RAS drugs.