Anemia is less likely to develop in patients with chronic kidney disease (CKD) who live at higher altitudes, according to a report in the American Journal of Kidney Diseases.
Yue-Harn Ng, MD, of the University of New Mexico in Albuquerque, and collaborators analyzed data from the initial screening visits of 120,429 participants in the Kidney Early Evaluation Program (KEEP). Although participants lived in places as high as 2809 meters, 95% lived at elevations of 1360 meters or less, according to the investigators. After adjusting for sex, age, race, ethnicity, and other potential confounders, each 1-km increment in elevation was associated with significant 33% decreased odds of anemia, Dr Ng’s team reported. Anemia risk was higher in patients with lower estimated glomerular filtration rates (eGFRs), especially rates below 30 mL/min/1.73 m2, but the investigators observed no interaction between eGFR and elevation with anemia.
The investigators defined anemia as a hemoglobin level below 10 g/dL because it is the cutoff for initiation of erythropoiesis stimulating agents recommended by KDIGO (Kidney Disease: Improving Global Outcomes) guidelines and by the FDA package inserts for epoetin alfa and darbepoetin.
Ng YH, Meyers O, Shore X, et al. The association of altitude and the prevalence of anemia among people with CKD. Am J Kidney Dis. 2019; published online ahead of print.