Aims: The concentration of fibroblast growth factor 23 (FGF-23) is elevated in patients on dialysis. FGF receptors have been implicated in the pathogenesis of left ventricular (LV) hypertrophy. The objective of this study was to examine the associations between high plasma FGF-23 concentration and LV systolic dysfunction.
Methods: We tested the hypothesis that high plasma FGF-23 concentration is associated with LV dysfunction in 110 chronic dialysis patients from the Homocysteine study who had paired echocardiograms performed for clinical indications. C-terminal FGF-23 concentrations were measured in stored plasma samples. Multivariate regression analyses were performed to evaluate the association of FGF-23 concentration with LV dysfunction.
Results: Participants had a mean age of 60 ± 11 years. Median FGF-23 level and mean ejection fraction (EF) at baseline were 4,632 (1,384 - 14,997) RU/ml and 50 ± 13%, respectively. Median follow-up time was 1.9 years. Higher FGF-23 concentration was directly associated with decreases in EF during follow-up. After adjustment for demographics, baseline EF, hypertension, diabetes, cardiovascular disease, body mass index, systolic blood pressure, hemoglobin and markers of mineral metabolism, participants with FGF-23 in the highest tertile had an 8% decrease in EF compared to participants in the lowest tertile (β -8.0, 95% CI -15.5 to -0.53; p = 0.04). When FGF-23 was evaluated as a continuous variable, for every log10 increase in FGF-23, EF decreased during follow-up by 6.5% (β -6.5, 95% CI -11.3 to -1.73; p = 0.01).
Conclusion: In conclusion, higher FGF-23 concentration is independently associated with LV systolic dysfunction in chronic dialysis patients.