Serum alkaline phosphatase and infection-related mortality in hemodialysis patients: ten-year outcomes of the Q-cohort study

• Published in: Clinical and experimental nephrology Vol. 26; no. 11; pp. 1119 - 1129
• Main Authors: Kitamura, Hiromasa, Yotsueda, Ryusuke, Hiyamuta, Hiroto, Taniguchi, Masatomo, Tanaka, Shigeru, Yamada, Shunsuke, Tsuruya, Kazuhiko, Nakano, Toshiaki, Kitazono, Takanari
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.11.2022; Springer Nature B.V
• Subjects: Alkaline phosphatase; Cardiovascular diseases; Cohort analysis; Hemodialysis; Infections; Medicine; Medicine & Public Health; Mortality; Nephrology; Original Article; Phosphatase; Urology; Alkaline phosphatase; Infection-related mortality; All-cause mortality; Hemodialysis; Cohort study
• ISSN: 1342-1751; 1437-7799
• DOI: 10.1007/s10157-022-02255-4

Background High serum alkaline phosphatase (ALP) levels are associated with excess all-cause and cardiovascular mortality in patients undergoing hemodialysis (HD). However, the long-term relationship between serum ALP levels and infection-related mortality remains unclear. Methods A total of 3502 maintenance HD patients were registered in the Q-Cohort Study, an observational cohort study in Japan. The primary outcome was infection-related mortality during a 10-year follow-up period. The covariate of interest was serum ALP levels at baseline. The association between serum ALP levels and infection-related mortality was calculated using a Cox proportional hazards model and a Fine–Gray subdistribution hazards model with non-infection-related death as a competing risk. Results During the follow-up period, 446 patients died of infection. According to their baseline serum ALP levels, the patients were categorized into sex-specific quartiles (Q1–Q4). Compared with patients in the lowest serum ALP quartile (Q1), those in the highest quartile (Q4) had a significantly higher multivariable-adjusted hazard ratio (HR) of 1.70 [95% confidence interval (CI) 1.24–2.32] for infection-related mortality. Furthermore, the HR for every 50 U/L increase in serum ALP levels was 1.24 (95% CI 1.12–1.36) for infection-related mortality. These associations remained consistent in the competing risk model: subdistribution HR, 1.47; 95% CI 1.07–2.03 for Q4 compared with Q1. Conclusion Higher serum ALP levels were significantly associated with a higher risk of infection-related mortality in patients undergoing HD.