Hematological and biochemical alterations across stages of chronic kidney disease: a cross-sectional study in a tertiary hospital

Background: Chronic kidney disease (CKD) is a systemic condition associated with predictable hematological complications (particularly anemia) and biochemical derangements involving acid–base balance, electrolytes, mineral metabolism, and lipid handling. However, local stage-stratified laboratory profiling across advanced CKD and dialysis populations is often inconsistent, limiting practical risk stratification in routine care (KDIGO CKD Work Group, 2024; Webster et al., 2017). Methods: We conducted a hospital-based cross-sectional study using routinely collected clinical data from adults with confirmed CKD. CKD stage was defined by estimated glomerular filtration rate (eGFR) calculated using the CKD-EPI 2021 creatinine equation and categorized according to KDIGO staging principles (Inker et al., 2021; KDIGO CKD Work Group, 2024). Hematological indices (complete blood count and available iron indices) and biochemical markers (electrolytes, bicarbonate/total CO₂, albumin, lipid profile, and CKD-mineral and bone disorder markers where available) were compared across stages and by dialysis status. Multivariable linear and logistic regression models were used to identify independent correlates of key abnormalities. Results: The analytic cohort comprised 487 patients distributed across CKD categories G3 (33.9%), G4 (29.2%), G5 non-dialysis (15.0%), and G5 on maintenance dialysis (22.0%). Anemia prevalence increased stepwise using KDIGO sex-specific thresholds, with mean hemoglobin decreasing across stages. Bicarbonate declined markedly with progression, and metabolic acidosis (bicarbonate