β-2 microglobulin level is negatively associated with global left ventricular longitudinal peak systolic strain and left atrial volume index in patients with chronic kidney disease not on dialysis

OBJECTIVE: There are many factors related to high left atrial volume index (LAVI) and global left ventricular longitudinal peak systolic strain (GLS-%) decline in chronic kidney disease. The purpose of our study is to investigate the relation between the β-2 microglobulin (β-2µ) and GLS-% and LAVI in patients with chronic kidney disease not yet on dialysis. METHODS: Our study was a non-randomized, controlled, prospective study. We included 87 consecutive patients with eGFR levels below 60 ml/min/m(2) not on dialysis and 82 normal healthy individuals with complaints of atypical chest pain and negative stress tests as control group in our study. Patients with hospitalization related to dialysis or heart failure attacks within 3 months, active malignancy, malnutrition, pregnancy, and uncontrolled hypertension were excluded. Brachial pulse wave velocity (PWV), augmentation index, augmentation pressure and central hemodynamics, and PWV analysis were performed in order to assess the arterial stiffness and blood pressure. According to the distribution of data, Spearman and Pearson correlations and multiple linear regression were used to determine significant and independent factor associated with high LAVI and low GLS-%. RESULTS: There were significant correlations between β-2µ with LAVI (r=0.313, p=0.004) and with GLS-% (r=–0.222, p=0.04). In multiple linear regression, the relationship between β-2µ with GLS-% [β=–0.037, 95% CI (–0.062, –0.013), p=0.004] and LAVI [β=4.522, 95% CI (2.806, 6.238), p<0.001] was independent of age, PWV, central and peripheral blood pressures, parathormone, CalciumXPhospor, Hgb levels, and eGFR. CONCLUSION: Increasing β-2µ levels were found to be associated with increased LAVI and decreased GLS-%. Additional experimental studies are needed to clarify these relationships.