| Many clinical studies show that cluster of risk factors such as type 2 diabetes mellitus, impaired glucose tolerance, hypertension, disorder of lipid and central obesity often assembled with the same patient. This was identified as metabolic syndrome (MS) by WHO in 1999. The prevalence of MS and its cardiovascular complication is incredibly increasing in the past decades. Epidemiological studies show that left ventricular hypertrophy (LVH) can cause coronary heart disease and chronic cardiac insufficiency. LVH is regarded as an independent risk factor of cardiovascular disease. Many risk factors can influence on cardiac mass. Hemodynamics such as high blood pressure was a major determines of LVH, however numerous studies show that LVH still occurred in some patients with diabetes or hypertension although they are normotensive or their high blood pressure were well controlled. In addition, other factors such as age, gender, obesity and inheritance also have effects on LVH. Recently, some metabolic factors were also found to influence LVH. Subjects with MS have multiply cardiovascular risk factors which can cause LVH, but the clinical characteristics of their LVH are rarely reported compared with patients with diabetes and hypertension. This study aims to investigate the characteristics of LVH in MS subjects and provide some valuable suggestion to clinical prevention of cardiac damage in MS. Subjects and Methods1. Subjects Three hundred and eleven patients aged 43-80 years old (male, 152 and female 159) were divided into four groups. 1) Diabetes mellitus (DM); 2) normotensive MS; 3) essential hypertension (EH); 4) hypertensive MS (HMS). The MS definition was suggested by a working group consulted by the WHO in 1999 (glucose intolerance or insulin resistance or diabetes together with 2 or more the following risk factors: BP≧140/90 mmHg; TG>1.7, and/or HDL-C < 0.9 mmol/L; central body obesity and/or BMI ≧25; microalbuminuria). 2. MethodsAll patients were observed by Color Doppler echocardiography. At left ventriculardiastole period end point, Left ventricle inner diameter (LV), left ventricular posterior wall thickness (LVPW) and interventricular septum thickness (IVS) were measured, then calculated left ventricular mass (LVM) according to Dereveux formula. At left ventricular systole period end point, left atrium inner diameter (LA) and aortic inner diameter (AO) were measured. All patients were required to measure E and A flow of mitral valve during left ventricular diastole period, then calculated the ratio of E/A. Urinary microalbuminuria (UMA) and serum lipid were detected. ResultsCharacteristic of left ventricular structure and function 1. LA, IVS, LVPW, LVM and LVMI in MS and HMS group increased significantly compared with DM and EH group respectively; IVS, LVPW, LVM and LVMI in HMS group significantly increased compared with MS group.2. E/A ratio of HMS group was the lowest and DM group was the highest among the four groups. The occurrence rate of diastolic dysfunction in EH and HMS groups significantly increased compared with DM group, but this no difference between HMS and MS groups. 3. Percentage of normal left ventricular structure in DM group was 66%, and this percentage was lower in both MS and EH, and only 18.9 % HMS had normal left ventricular structure. The percentage of LVH in DM and MS was 11% and 19% respectively; both of them presented more eccentric LVH. The percentage of LVH in EH and HMS was 23% and 39% respectively, both of them presented more concentric LVH.Characteristic of aortic root dilation and valve degenerationAortic root inner diameter and the percentage of aortic root dilation were higher in HMS than other three groups. The percentage of valve degeneration increased significantly in MS compared with DM or EH group, whereas there was no difference in the percentage of valve degeneration between HMS and MS group. The aortic valve and combined valve degeneration were more frequently in HMS group.Relationship between LVM and its related... |
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