<b>Frequency of Hyperphosphatemia in Chronic Kidney Disease Patients Admitted to Ayub Teaching Hospital Abbottabad</b>

Background: Hyperphosphatemia is a major biochemical disturbance in chronic kidney disease (CKD) and contributes to accelerated vascular calcification, cardiovascular morbidity, and CKD–mineral and bone disorder. Despite its clinical importance, limited data exist from Pakistani tertiary-care settings describing the stage-wise burden of hyperphosphatemia among hospitalized CKD patients. Objective: To determine the frequency of hyperphosphatemia in CKD patients admitted to a tertiary hospital in Abbottabad and to assess its association with demographic, socioeconomic, and clinical variables across CKD stages. Methods: This descriptive cross-sectional study included 289 adults with CKD recruited consecutively from February to May 2025. Serum phosphate was measured using a standardized enzymatic assay, with hyperphosphatemia defined as >4.5 mg/dL. Data on demographics, BMI, comorbidities, socioeconomic status, and CKD stage were collected. Statistical analysis included chi-square tests, odds ratios with 95% confidence intervals, and effect-size estimation. Results: Hyperphosphatemia was observed in 53.96% of patients (95% CI: 48.0–59.8). Its prevalence increased sharply from Stage 1 (26.19%) to Stage 5 (80.00%), with patients in Stages 4–5 having nearly nine-fold higher odds of hyperphosphatemia compared with Stages 1–2. Significant associations were found with BMI and socioeconomic status, while age, sex, diabetes, and hypertension showed no significant effect. Conclusion: Hyperphosphatemia is highly prevalent and increases markedly with declining renal function, underscoring the need for early monitoring and stage-specific management strategies.