Determinants of hyperphosphatemia and its relation with hemoglobin levels among hemodialysis patients in two hospitals from Syria: a prospective cross-sectional study

Abstract

Introduction: Hyperphosphatemia and anemia were both associated with several complications in chronic kidney disease (CKD) patients. This study aimed to determine the risk factors of hyperphosphatemia and its relation with anemia among hemodialysis (HD) patients. Secondly, it aimed to determine the prevalence of hyperphosphatemia and anemia. Material and methods: A prospective cross-sectional study was conducted among 146 HD patients from two HD centers in Syria, between June 2021 and March 2022. All patients at least 18 years old on maintenance HD were enrolled. The threshold of phosphorus (phos) level was divided by the upper normal range among HD patients (5.5 mg/dl). We used parametric and nonparametric statistics, the Pearson and Spearman correlations with simple and multiple linear regressions between study variables. Results: 36.9% of patients had a serum phos level of 5.5 or less (norm phos group), and 63.1% of patients had a serum phos level higher than 5.5 (high phos group). Also, 60.9% of patients had hemoglobin (Hb) less than 10 g/dl, and 40.4% of patients had Hb at least 10 g/dl. Age, type of HD access, phos binders (P-binders), parathyroid hormone (PTH), and calcium (Ca) showed significant effects on phos levels. Most patients were using arteriovenous fistula (AVF) (89.7%) as a HD access, and the meantime on HD was higher in the norm phos group compared to the high phos group. In a multivariate and univariate logistic regression analysis, hyperphosphatemia increased with increasing urea (Ur) and creatinine (Cr) levels, while the odds declined with increasing time on HD. Hb did not show a significant relation with phos by using several statistical methods. Discussion/Conclusion: A high prevalence of hyperphosphatemia and anemia was encountered among this sample of HD patients from Syria. There was no correlation between phos and Hb levels in contrast to previous conflicting studies, which mandates future studies to evaluate this correlation and further efforts to determine the range of phos that could have a benefit on anemia with respect to other comorbidities.