Study On The Influencing Factors Of BNP And Its Relationship With Cardiac Function In Non-dialysis Patients With Chronic Kidney Disease

Research purposeTo analyze the influencing factors of plasma B-type natriuretic peptide?BNP?level and its relationship with cardiac structure and function in non-dialysis patients with chronic kidney disease?CKD?,and to early explore its application value of evaluating and predicting cardiovascular disease?CVD?in these patients.Research methodsWe enrolled a total of 315 in-hospital patients with chronic kidney disease from the Second Affiliated Hospital of Guangzhou Medical University from 2017 to 2019,and detailed clinical data were collected.Those who were under the age of 18,or had cardiovascular events?angina pectoris,myocardial infarction,heart failure,arrhythmia?or infection events in three months from baseline,or suffered from an acute renal failure,or received dialysis treatment,or received renal replacement therapy were excluded.The method of cross-sectional study was adopted.Grouping the patients based on the quartiles of BNP,the differences between groups were compared by rank-sum test,one-way ANOVA or chi-square test according to variables'characteristics.Univariate and multivariate regression analysis were used to explore the influencing factors of BNP.Its relationship with left ventricular hypertrophy?LVH?,left ventricular diastolic function and left ventricular systolic function was analyzed with binary Logistic regression and linear regression analysis.The receiver operating characteristic?ROC?curve was utilized to further explore the marker'value of predicting CVD.Research results1.315 patients were recruited,male 45.1%,with an age of 66.1±15.3 years.The primary cause for renal disease were attributed to 109 cases?34.6%?of diabetic nephropathy,108cases?34.3%?of hypertensive nephrosclerosis,77 cases?24.4%?of chronic glomerulonephritis and 21 cases?6.7%?of other causes,including obstructive nephropathy,gouty nephropathy,lupus nephritis,ANCA-associated nephritis and so on.27.3%of patients have a history of smoking.The proportion of CKD1?5?1?2?3a?3b?4?5?stages were 16.5%?30.8%?9.2%?10.8%?15.2%and 17.5%respectively.2.Median level of BNP was 76.65?31.75?162.90?ng/L,with 8.9%undetectable.37.8%greater than 99th percentile of the general population.There was no significant difference in plasma BNP level between the groups in CKD1?2 stages?p>0.05?while it went up from CKD 3 to CKD 5 stage,with significant difference between groups?p<0.05?.3.Left ventricular mass index?LVMI?was 95.27±31.81 g/m²,with the proportion of left ventricular hypertrophy?LVH?19.7%,concentric remodeling 43.2%,eccentric hypertrophy10.2%.concentric hypertrophy 9.5%.Left ventricular ejection fraction?LVEF?was?63.28±6.04?%,with the porportion of LVEF greater than 50%96.5%,between 40 and50%2.5%.1ess than 40%1.0%.5.7%patients had left ventricular diastolic dysfunction.4.Multivariate linear regression analysis showed that higher BNP was significantly associated with older age,higher plasma parathyroid hormone,uric acid,LVMI,the incidence of left ventricular diastolic insufficiency and lower hemoglobin,plasma albumin,eGFR_MDRD,LVEF and plasma high density lipoprotein cholesterol?p<0.05?.5.BNP had negative association with eGFR_MDRD?regression coefficient:-0.005;95%CI:-0.009?-0.001,p<0.05?,with statistical significance in early CKD(eGFR_MDRD?60mL/min/1.73m²)stages and mid-late CKD(eGFR_MDRD<60mL/min/1.73m²)stages,with regression coefficients of-0.006?95%CI:-0.012?-0.001,P<0.05?and-0.031?95%CI:-0.043?-0.019,P<0.05?,it was suggested that BNP level is closely related to renal function.6.Compared with the lowest quartile of BNP,the highest quartile was approximatelyfive times as likely to have LVH?OR,5.409;95%CI:2.876?10.175,P<0.05?in univariate analysis and it was approximately three times as likely?OR,2.761;95%CI:1.171?6.505,P<0.05?in the fully adjusted model.BNP level had a more modest association with LVEF in univariate?OR,-0.858;95%CI:-1.422?-0.294,P<0.05?and multivariate regression analysis?OR,-0.955;95%CI:-1.547?-0.036,P<0.05?.The highest quartile was approximately two times as likely to have left ventricular diastolic dysfunction?OR,1.689;95%CI:1.261?4.128,P<0.05?compared with the lowest one in univariate analysis,which lost statistical significance in the fully adjusted model.From the perspective of varied CKD stages,BNP had statistically significant association with LVH in CKD 3a/4/5 stages,with LVEF in CKD 2/3a/5 stages,with left ventricular diastolic dysfunction in CKD 4/5 stage?P<0.05?.7.When evaluated as a screening test,the aera under the curve?AUC?of ROC curves for BNP evaluating LVH,LVEF<40%,40%?LVEF<50%and left ventricular diastolic dysfunction were 0.713,0.900,0.764,0.737 respectively?P<0.05?.8.With a specificity of 90%as the diagnostic criterion,from CKD1 stage to CKD 5 stage,the diagnostic values of BNP to evaluate LVH,LVEF<40%,40%?LVEF<50%and left ventricular diastolic dysfunction ascended.Research conclusion1.Among CKD non-dialysis patients,inflencing factors of serum BNP were age,hyperuricemia,hypoalbuminemia,plasma low HDL cholesterol level,anemia,hyperparathyroidemia,degree of renal injury,and cardiovascular disease.2.BNP were valuable for evaluating LVH,left ventricular systolic insufficiency,median systolic function and left ventricular diastolic dysfunction in non-dialysis patients with CKD.It will be of great importance to monitor the marker regularly as to screen patients with high cardiovascular events risk in clinical practice and provide early preventive intervention.