Hyperphosphatemia and anemia are associated with various complications in chronic kidney disease (CKD) patients. This study aimed to identify the risk factors for hyperphosphatemia and its relationship with anemia in hemodialysis (HD) patients, as well as to determine the prevalence of both conditions.

A prospective cross-sectional study was conducted with 146 HD patients from a single center in Iran between 2024 and 2025. All participants were aged 18 and older and on maintenance HD. Phosphorus levels were categorized based on the upper normal limit for HD patients (5.5 mg/dL). We employed parametric and nonparametric statistics, including Pearson and Spearman correlations, and both simple and multiple linear regressions.

Among the patients, 36.9% had phosphorus levels ≤ 5.5 mg/dL (normophosphatemic group), while 63.1% had levels >5.5 mg/dL (hyperphosphatemic group). Additionally, 60.9% had hemoglobin (Hb) < 10 g/dL. Significant factors affecting phosphorus levels included age, type of HD access, phosphate binders, parathyroid hormone (PTH), and calcium. Most patients (89.7%) used arteriovenous fistulas for HD access, and the duration on HD was longer in the normophosphatemic group. Logistic regression analysis showed that hyperphosphatemia increased with rising urea and creatinine levels, while the odds decreased with longer HD duration. No significant correlation between phosphorus and Hb levels was found.

This study revealed a high prevalence of hyperphosphatemia and anemia among HD patients in Iran, with no correlation between phosphorus and hemoglobin levels, contrasting with previous studies. Further research is needed to explore this relationship and establish optimal phosphorus levels concerning anemia and other comorbidities.