High intact fibroblast growth factor 23 levels associated with low hemoglobin levels in patients on chronic hemodialysis

Yu-Wei Fang; Jing-Tong Wang; Tzu Yun Lin; Chung-Jen Lee; Tsrang-Neng Jang; Ming-Hsien Tsai; Hung-Hsiang Liou

doi:10.3389/fmed.2023.1098871

High intact fibroblast growth factor 23 levels associated with low hemoglobin levels in patients on chronic hemodialysis

Front Med (Lausanne). 2023 Apr 4:10:1098871. doi: 10.3389/fmed.2023.1098871. eCollection 2023.

Authors

Yu-Wei Fang^{1

2}, Jing-Tong Wang¹, Tzu Yun Lin³, Chung-Jen Lee⁴, Tsrang-Neng Jang^{2

5}, Ming-Hsien Tsai^{1

2}, Hung-Hsiang Liou³

Affiliations

¹ Division of Nephrology, Department of Internal Medicine, Shin-Kong Wu Ho-Su Memorial Hospital, New Taipei City, Taiwan.
² Department of Medicine, School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.
³ Division of Nephrology, Department of Internal Medicine, Hsin-Jen Hospital, New Taipei City, Taiwan.
⁴ Department of Nursing, Tzu Chi University of Science and Technology, Hualien, Taiwan.
⁵ Department of Internal Medicine, Shin-Kong Wu Ho-Su Memorial Hospital, New Taipei City, Taiwan.

Abstract

Introduction: A negative association between C-terminal fibroblast growth factor 23 (cFGF23) and hemoglobin (Hb) levels has been reported in patients with predialysis chronic kidney disease. In dialysis patients, the dominant form of serum FGF23 is intact FGF23 (iFGF23); however, its association with the Hb level remains unclear. Therefore, simultaneously monitoring iFGF23 and cFGF23 levels is crucial. In this study, we investigated the associations between both forms of FGF23 (iFGF23 and cFGF23) and renal anemia in chronic hemodialysis (CHD) patients.

Methods: We included 166 CHD patients from two hospitals in this cross-sectional, observational study. The primary predictors were serum iFGF23, cFGF23, and iFGF23/cFGF23 levels. The main outcome was the Hb level.

Results: Among the CHD patients included, 60.8% were men with a mean age of 59.4 ± 12.7 years. In the crude analysis, iFGF23 and iFGF23/cFGF23 levels showed a significant negative association (-0.27, p = 0.004 and -0.22, p = 0.034, respectively) with the Hb level. Even after adjusting for multiple variables (a parsimonious model), every increment of natural log transformation by 1 for (ln)iFGF23 and ln(iFGF23/cFGF23) levels showed a negative correlation with the Hb level (estimate: -0.27 [95%CI: -0.44, -0.10, p = 0.001]; -0.19 [95%CI: -0.37, -0.01, p = 0.042], respectively), whereas both were positively associated with erythropoietin-stimulating agent (ESA) hyporesponsiveness (odds ratio [OR]: [95%CI: 2.30, 1.26-4.17], p = 0.006; 1.95 [95%CI: 1.08-3.50], p = 0.025). Moreover, these abovementioned associations were more dominant in patients with diabetes who used angiotensin receptor blockers.

Discussion: In conclusion, a negative association between serum iFGF23 or iFGF23/cFGF23 level and the Hb level was observed in our CHD patients. Meanwhile, a higher iFGF23 or iFGF23/cFGF23 level may predispose patients to ESA hyporesponsiveness.

Keywords: C-terminal fibroblast growth factor 23; anemia; erythropoiesis; hemodialysis; intact fibroblast growth factor 23.

Grants and funding

This study was sponsored by the Shin-Kong Wu Ho-Su Memorial Hospital (2019SKHADR006) and the National Science and Technology Council (105-2628-B-341-001-MY3).