| ObjectiveAccumulating evidences indicate that abnormal renal function and abnormal cardiac structure are both regarded as independent risk factors for heart failure, arrythmia, and sudden cardiac death (SCD).Abnormal cardiac structure principally indicates left ventricle (LV) or left atrium (LA) enlargement and assessment of abnormal renal function is usually based on serum levels of blood urea nitrogen (BUN), creatinine (Cre),β2-microglobulin (β2-MG) and/or cystatin C.Recently, Cystatin C has been proposed as a more sensitive marker of renal dysfunction and β2-MG has been studied as markers of tubular dysfunction when assessing mild to moderate renal impairment, and high serum levels of them can detect the compensatory stage of renal insufficiency although blood urea nitrogen and creatinine are normal. These qualities make Cystatin C and β2-MG measurement attractive for the detection of subtle changes in renal function. Furthermore, Cystatin C has been shown to be a risk factor for heart failure and cardiovascular disease mortality.Renal insufficiency is usually associated with hypertension and hypervolemia, leading to elevated left ventricle filling pressures, which leads to left atrium enlarge ment. LA enlargement is supposed to one of the earliest manifestations of left ventricle diastolic dysfunction. Left ventricular filling abnormalities are common in asymptomatic patients. Their presence contributes to poor tolerance of rapid changes in fluid status, blood pressures, and pulse changes. Therefore, LA size is a surrogate marker of left ventricle diastolic dysfunction, atrial fibrillation, heart failure, or even SCD.Data previously has showed that higher levels of cystatin C are associated with increased LV mass and a concentric LV hypertrophy phenotype. However, little is known the relationship between circulating levels of cystatin C and J32-MG and left atrium size. Hence, we aimed to explore the possible relationships between circulating levels of cystatin C and β2-MG and impaired cardiac struction (LA enlargement) in a series of patients with coronary artery disease and controls after angiography, which is almost like another link between kidney and heart.MethodsThree hundred patients felt chest tightness or chest pain were recruited into the study and underwent coronary angiography. According to the results, two hundred and two consecutive patients were diagnosed with coronary artery disease (CAD) and ninty eight patients without CAD (non-CAD). All the laboratory measurements included liver, kidney function(urea nitrogen, creatinine, β2-MG and cystatin C), fasting glucose and lipids analysis, ect. Echocardiology was used to evaluate the cardiac structure and function. All data was analyzed with SPSS16.0statistical software. Data are presented as mean±SD for continuous variables or proportions. After testing for normal distribution of variables, student’s2-tail t-test and one-way analysis of variance (anova) followed by the post hoc least significant difference test were used where appropriate. Relation among variables was performed using Pearson correlation test or Spearman rank order correlation test, as appropriate. Multivariate logistic regression analysis was used to evaluate the contribution of independent factors. Statistical analyses were performed using SPSS16.0(SPSS, Chicago, IL, USA) software. A two-tailed P value <0.05was considered statistically significant.ResultsSignificant differences of β2-MG and cystatin C exist between the two groups. LA diameters were significantly positively related to circulating levels of β2-MG in CAD group (r=0.450, P<0.001) and non-CAD group (r=0.360, P<0.001), and the similar relationships between LA diameters and circulating levels of Cystatin C in CAD group (r=0.302, P<0.001) and non-CAD group (r=0.243, P=0.016). After multivariate logistic regression analysis, the data showed that the independent cardiovascular risk factors of LA enlargement for the patients with CAD were age, BMI, systolic blood pressure, LV mass, LVEDD, E/A, Em/Am, and circulating levels of β2-MG (OR=1.630,95%CI:1.115-2.384, P=0.012), Cystatin C (OR=4.504,95%CI:1.478-13.726, P=0.008).ConclusionsA significant linear correlation existed between circulating levels of β2-MG or cystatin C and LA diameters; Higher circulating levels of β2-MG or cystatin C are independent cardiovascular risk factors of LA enlargement in patients with CAD;... |
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