SAN DIEGO—Hematocrit decreases as estimated glomerular filtration rate (eGFR) declines in hypertensive chronic kidney disease (CKD) patients, according to findings from a longitudinal study presented at Kidney Week 2012.
Teresa K. Chen, MD, MHS, of Johns Hopkins University in Baltimore, and colleagues analyzed 12 years of follow-up data from the African-American Study of Kidney Disease and Hypertension (AASK). They identified 1,094 African-American patients with hypertensive CKD. Covariates included gender, age at randomization, baseline and longitudinal eGFR, baseline proteinuria, and randomized drug group.
At baseline, the mean hematocrit was 39% and 441 subjects (40%) had anemia. In longitudinal analyses, the hematocrit decline for each eGFR decline of 10 mL/min/1.73 m2 was steeper for individuals with baseline eGFR values less than 40 ml/min/1.73 m2 compared with values of 40 ml/min/1.73 m2 or more.
For baseline eGFR values less than 40 mL/min/1.73 m2, researchers also found a greater decrease in hematocrit per unit decrease in longitudinal eGFR among males, whereas for baseline eGFR values greater than 40, patients with baseline proteinuria had steeper longitudinal eGFR-hematocrit associations. Those randomized to ramipril were not more likely to have lower hematocrits.
The researchers concluded by recommending that anemia screening be more individualized, with more intensive testing on the different CKD patient subgroups.