Association between baseline intact parathyroid hormone levels, COVID-19 severity, and long-term outcomes in patients undergoing hemodialysis: A multicenter retrospective study

Abstract

The COVID-19 pandemic poses unique challenges for vulnerable populations, including patients undergoing maintenance hemodialysis (HD). This study explores the relationship between baseline intact parathyroid hormone (iPTH) levels and COVID-19 severity, post-acute hospitalization, and mortality rates in HD patients. Methods. A multicenter retrospective cohort study was conducted across multiple centers, encompassing 142 patients undergoing HD treatment in three regions of Ukraine. The study spanned from March 2020 to May 2022. Baseline iPTH levels, demographic characteristics, and relevant clinical indicators were systematically recorded. Key endpoints included the severity of COVID-19, post-acute hospitalization, and mortality rates. Results. Of the initially eligible 165 patients, 23 were excluded, resulting in a final cohort of 142 patients. During the acute phase of COVID-19, distinct patterns emerged in terms of hospitalization rates, oxygen support requirements, and mortality. Lower iPTH levels were significantly associated with severe COVID-19-associated pneumonia (p < 0.0001). A 20-month follow-up revealed a significant association between serum iPTH concentration <174 pg/mL and increased rates of post-acute COVID-19 hospitalization [HR 6.3 (95% CI 2.9; 13.7)] and all-cause mortality [HR 34.3 (95% CI 6.9; 74.5)]. Conclusion. This multicenter retrospective study suggests potential links between baseline iPTH levels and COVID-19 outcomes in patients undergoing HD. Serum iPTH concentration ≤174 pg/mL was significantly associated with increased post-acute hospitalization and mortality rate in our patient cohort. The findings emphasize the need for further research to elucidate underlying mechanisms and establish the prognostic value of iPTH in this specific patient population.