Relationship Between Plasma N-terminal Pro-B-type Natriuretic Peptide Levels And Metabolic Syndrome

The metabolic syndrome (MetS) is a worldwide problem, which refers to a constellation of coronary heart diseases risk factors including obesity and abdominal fat distribution, disorders of glucose and lipid metabolism, and hypertension. The studies have shown that MetS is an important risk factor of heart failure recently. Meanwhile, heart failure has a close relationship with NT-proBNP. But uncertain data exist on the relation of NT-proBNP to MetS. Thus, we sought to observe the differences of NT-proBNP between MetS patients and non-MetS controls and elucidate the relations between plasma NT-proBNP levels, heart failure and the metabolic syndrome. This study was divided into two parts:Part One Plasma Levels of NT-proBNP in Patients with Metabolic SyndromeObjective: To observe the differences of NT-proBNP levels between metabolic syndrome (MetS) patients and non-MetS controls and investigate the possible reason for the decreased NT-proBNP levels of MetS patients.Methods:A retrospective analysis was made on clinical data of 230 cases of MetS and 239 cases of non-MetS admitted to department of cardiology and endocrinology of Huashan Hospital from July 2005 to August 2009. Correlation analysis and multiple linear regression analysis was performed to assess the association between levels of NT-proBNP and potential influencing factors. Covariance analysis was used for group comparisons. Then the subjects with MetS were divided into subgroups according to the definition of MetS. Covariance analysis was used for comparisons between MetS subgroup and non-MetS group respectively.Results:(1)Simple correlation analysis showed Log(NT-proBNP) was positively correlated with Age, Cr, UA, AOD, LAD, LVIDd, LVPWd, LVM and LVMI, but was negatively correlated with total cholesterol, triglycerides, low density lipoprotein, left ventricular ejection fraction and hemoglobin(Hb).(2)Log NT-proBNP levels was independently related with age, gender, body mass index, systolic blood pressure, diastolic blood pressure, fasting blood glucose, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol, left ventricular mass index and left ventricular ejection fraction in multiple linear regression analysis. (3)Plasma levels of log NT-proBNP are significantly lower in all participants with MetS than those in non-MetS group (P=0.001). Further analysis found that the decrease of NT-proBNP levels in patients with MetS remained significant for men and for women after the same adjustment. (4)Individuals with hyperlipidemia, elevated body mass index, diastolic blood pressure, fasting plasma glucose and normal systolic blood pressure had lower levels of log NT-proBNP than those without MetS (P<0.05).Conclusions:Plasma levels of NT-proBNP in MetS patients were lower, which was probably related to its pathoglycemia, hyperlipoidemia and dysarteriotony. Key words: Metabolic syndrome; N-Terminal Pro-B-Type Natriuretic PeptidePart Two The role of NT-proBNP in the evaluation of heart failure in MetS patientsObjective:To observe the differences of NT-proBNP levels in MetS patients with and without heart failure (HF) and investigate the role of NT-proBNP in the evaluation of heart failure in MetS patients.Methods: A retrospective analysis was made on clinical data of 281 cases of MetS admitted to department of cardiology of Huashan Hospital from July 2005 to August 2009. Participants were divided into 2 groups according to diagnostic criteria of heart failure:MetS with HF and MetS without HF. Multivariate logistic regression analysis was performed to assess the association between levels of NT-proBNP and potential factors. The receiver operating characteristic (ROC) curve was used to evaluate diagnostic value of NT-proBNP for identification of those patients with MetS to detect HF.Results:(1)Plasma levels of NT-proBNP were significantly higher in MetS patients with HF than those without HF group(P<0.001). The MetS with HF group was further divided into 2 subgroups:MetS with systolic HF (SHF) and MetS with diastolic HF (DHF). The results showed that both of plasma NT-proBNP levels in SHF and DHF group were significantly higher than MetS without HF group(P<0.001); In addition to that, the plasma levels of NT-proBNP for SHF patients were higher than that for DHF patients(P<0.001). (2)The modified multivariate logistic regression analysis found that elder MetS patients, FPG, HDL, Cr, NT-proBNP, LAD and IVSd were correlated with increased risk of DHF in the final model. Smoking patients, FPG, LP(α), NT-proBNP, LAD and LVIDd were correlated with increased risk of SHF in the final model, while IVSd was shown to be reversely correlated with the risk of SHF.(3) The optimal plasma NT-proBNP cut-point for diagnosing DHF was 208.1 pg/ml, with a sensitivity of 62.7%,a specificity of 93.3%, a positive predictive value of 92.9% and a negative predictive value of 64.1%. The optimal plasma NT-proBNP cut-point for diagnosing SHF was 480.6 pg/ml, with a sensitivity of 63.1%, a specificity of 81.5%, a positive predictive value of 50.6% and a negative predictive value of 88.0%.Conclusions:Plasma levels of NT-proBNP in MetS patients with HF were higher than those without HF. The assessment of the blood concentration of NT-proBNP is of potential value for identification of those patients with MetS to detect HF.