Sickle Cell Trait, Hemoglobin Levels and Anemia among Black Patients with Predialysis Chronic Kidney Disease: A Post Hoc Analysis

Objective: To assess the relationship between SCT, hemoglobin levels and anemia in CKD black patients. Method: A post-hoc analysis of data from 188 patients, enrolled in a cross-sectional study of sickle cell trait (SCT) and chronic kidney disease (CKD), was performed to assess the relationship between SCT, hemoglobin (Hb) levels and anemia defined as Hb < 12 g/dl in men and <11 g/dl in women. Student t test, Mann Whitney and Chi square test were used as appropriate for different comparisons. P < 0.05 defined the level of statistical significance. Results: SCT (HbAS) and normal hemoglobin (HbAA) were present in 39 (21%) and 149 (79%) CKD patients, respectively. Despite similar estimated GFR (eGFR) and age, HbAS patients had significantly lower Hb levels (8.8 ± 1.8 vs 10 ± 2.2 g/dl; p = 0.001) and a higher proportion of anemia (95% vs 72%, p = 0.001). In multiple linear regression analysis, eGFR, BMI, SBP and SCT emerged as independent determinants of Hb levels. The presence of SCT was associated with 1.185 g/dl decrease in Hb levels. Conclusion: In the present case series, SCT was associated with lower Hb levels suggesting its potential contribution to the pathogenesis of CKD-associated anemia.