Malnutrition as a risk factor for cardiac valve calcification in patients under maintenance dialysis: a cross-sectional study

Abstract

Purpose: Cardiac valve calcification (CVC) is a significant risk factor for cardiovascular morbidity and mortality in patients with chronic kidney disease on maintenance hemodialysis. The aim of this study was to investigate the association of several risk factors and particularly of malnutrition on CVC.

Methods: In this cross-sectional cohort study, we included stable adult patients on maintenance hemodialysis. Calcification of cardiac valves was evaluated using two-dimensional echocardiography. Nutritional assessment and body composition measurements were performed using the MQSGA clinical tool and bioelectrical impedance analysis, respectively. Biochemical parameters such as serum calcium, phosphorus, iPTH, 1.25 hydroxy-vitamin-D, triglycerides, total cholesterol, HDL-C, LDL-C, total proteins, albumin, creatinine and CRP were assessed as potentially risk factors. The receiver operating characteristic (ROC) curve analysis was used to evaluate the prognostic ability of the aforementioned variables on severe degree CVC. Binary logistic regression analysis was also performed to identify independent variables of severe CVC.

Results: Overall, 42 patients were included in the study with half of them exhibiting mitral calcification, 38% aortic valve calcification, and 16.7% calcification in both valves. ROC analysis indicated that aging (p = 0.011), increased CRP (p = 0.038) and decreased value of serum albumin to total proteins ratio (p = 0.012) were positive prognostic factors for moderate to severe degree cardiac valve calcification. Low phase angle was also associated with CVC, although with moderate specificity.

Conclusion: Aging, inflammation, low serum albumin to total proteins ratio and low phase angle values as indicators of malnutrition are predictors of severe CVC in end-stage renal disease patients on hemodialysis.

Keywords: Cardiac valve calcification; End-stage kidney disease; Malnutrition; Serum albumin to total protein ratio.