Correlation between hypervolemia, left ventricular hypertrophy and fibroblast growth factor 23 in hemodialysis patients.

Introduction: Left ventricular hypertrophy (LVH) is a significant risk factor for cardiovascular complications in hemodialysis (HD) patients. Hypervolemia has been accepted as an independent risk factor for progressive LVH in HD patients. Additionally, high FGF23 levels have been a significant predictor of cardiovascular mortality and morbidity in chronic kidney disease and HD patients. The aim of our study is to investigate the correlation among LVH, interdialytic volume increase and FGF-23 in the patients on a chronic hemodialysis program.

Design And Methods: A total of 97 chronic hemodialysis patients (64.43 ± 11.28 years old, M/F:47/50) were included in the study. Human FGF-23 ELISA kit was used for FGF-23 analysis of predialysis blood samples. Echocardiographic evaluation was performed in all of the patients after dialysis. Left Ventricular Mass Index (LVMI) was calculated by using the Devereux Formula. We collected the following data: LVMI, FGF-23 levels, interdialytic fluid gain, blood pressure changes, and the other biochemical and clinical parameters.

Results: Mean LVMI of the patients was 184.41 ± 48.62 g/m(2). LVMI of the patients with daily urine output > 250 mL was found significantly lower. Statistically significant positive correlation was found between predialysis systolic blood pressure, predialysis diastolic blood pressure, predialysis mean arterial blood pressure and LVMI measurements (p < 0.01). Mean interdialytic volume excess was correlated with LVMI measurements of the patients (r = 0.459; p < 0.01). Increased FGF-23 levels (159.79 ± 134.99 ng/L) predicted increased LVMI measurements of the patients (r = 0.322; p < 0.01). In addition, FGF-23 levels were also increased as the interdialytic fluid volume increased (r = 0.326; p < 0.05). A positive correlation was also found between FGF-23 levels and interventricular septum thickness (r = 0.238; p < 0.05). Predialysis mean arterial blood pressure, predialysis volume overload and presence of diabetes were determined to be independent risk factors on LVMI on multivariate regression analysis.

Conclusion: Our study showed that interdialytic volume overload increased both LVMI and FGF-23 values. We can consider that interdialytic volume control exerts positive effects on increased FGF-23 levels which predict the negative cardiovascular outcomes.