The Correlation Between Left Ventricular Hypertrophy And Visceral Adipose Tissue Distribution On The Patients Of Essential Hypertension

Objective: Hypertensive Left ventricular hypertrophy(LVH) refers to the increase of left ventricular mass(LVM)caused by hypertension, including myocardial cell hypertrophy and connective tissue proliferation and Cell volume increases with no increase on cell number. Domestic and international studies have found that LVH is one of the most prominent phenomenons for the target organ damage in hypertensive patients, and it is an independent risk factor influencing the prognosis of patients with hypertension. The increase of LVH in hypertensive patients indicates a significant increase in the risk of cardiovascular complications. At present, at home and abroad the diagnosis of LVH are almost achieved by echocardiography, and the main measurement method used is from the U.S. Association of Echocardiography (ASE) recommendation, then Left Ventricular Mass Index (LVMI) is obtained via calculating the human body surface area.In 2003 the European Society of Hypertension has specified the LVH criteria as this: Male LVMI≥125g/m2, Women LVMI≥110g/m2.However, the joint discovery of domestic and international study found that LVH is not only a consequence of increased blood pressure, obesity, especially intra-abdominal fat accumulation also plays an important role in hypertensive LVH development. Most of the obese people also have the Insulin Resistance (IR), sympathetic nerve excitability increase,and the increase on blood volume and blood output in the meantime. All these factors will lead to LVH. If hypertension coexists with obesity, then the LVH will be more prominent.Body mass index (BMI), Waist-to-hip-ration (WHR) and waist-to-height -ration (WHtR) are the common indexes for obesity assessment. However, in recently years many people with normal BMI also have developed the obesity complications. Therefore the focus on the obesity research has shifted from the simple factors like fat volume and the obesity degree to the body adipose tissue (AT) distribution, then it also calls out for a measurement technology that can not only efficiently assess the total fat degree, but also can also measure the area distribution of adipose tissue quantitatively. CT has provided a more direct measuring method, as it can accurately measure the body obesity, AT volume in the whole body, especially for the area AT, such as sub- cutaneous AT or abdominal fat.Obesity as a risk factor of hypertensive LVH has been widely accepted, and the measuring and assessing abdominal fat (including visceral adipose fat and subcutaneous fat) via CT also have recognized, however, there is little research on whether it is more superior to predict the hypertensive LVH via CT abdominal fat measuring than the simple obesity assessment indexes such as BMI, WHR, WHtR. The aim of our study was to analyze the correlation between ratio of visceral and subcutaneous adipose tissue (VAT/SAT, V/S), BMI, WHR, WHtR and the essential hypertension. And this study also discusses whether it is superior to predict the hypertensive LVH via V/S than the simple obesity assessment indexes such as BMI, WHR, WHtR, and then it will provide foundation to more accurately predict the risk level of hypertension and provide evidence for the early clinical interference to control the risk factors.Methods: 80 patients who were treated in the Cardiology Department of the Hebei Medical University Second Hospital from March 2009 to October 2009, and whose symptoms were in line with diagnostic criteria for hypertension specified in the 2005 "Guidelines for Prevention and Treatment of Hypertension in China" were chosen as the sample group. Their age, gender, blood pressure, heights, weight, waist circumference, hip circumference were all been recorded when they were checked into the hospital, together with the cardiac ultrasound examination and the abdominal CT check on an empty stomach. Then the V/S, BMI, WHR, WHtR were all calculated. The patients were grouped as LVH-group and Non-LVH group according to the criteria below: male LVMI≥125g/m2 and female LVMI≥110g/m2. Still further the relationship between LVMI and every parameter (age, blood pressure, V/S, BMI, WHR, WHtR) also calculated out.All statistical analyses were perfromed using the SPSS13.0 program package. Date were expressed as the mean value±standard deviation ( x±s). Date between two groups were compared by t test. Analysis of risk factors was performed by multivariate linear stepwise regression analysis. A P value of less than 0.05 was considered to be statistically significant.Results: There were no significant differences in age, systolic pressure, and diastolic pressure between essential hypertensive LVH group and the essential hypertensive Non-LVH group(P>0.05). The V/s, BMI, WHR and WHtR was significantly higher in LVH than in Non-LVH(P<0.05). There was also the implication that under the same criteria for age and blood pressure for the essential hypertensive patients, the LVMI for the obese people had increased. And the result via multivariate linear stepwise regression analysis indicates the conclusion that there was linear regression between V/S, WHtR, WHR, BMI and LVMI, and the respective standardized regression coefficients were 0.612(P=0.000), 0.269(P=0.001), 0.137(P=0.011), 0.102(P=0.042).The result indicates that above all factors had impact on LVMI, and V/S had played the most significant role.Conclusion: There was no statistical implication for the difference of systolic pressure, diastolic pressure, and age between the essential hypertensive LVH group and essential hypertensive Non-LVH group. However, there was significant difference on V/S, BMI, WHR, WHtR between the two groups, and the LVH group had much higher value for all the four parameters than the Non-LVH group.We can get the indication that under the same age and blood pressure for the hypertensive patients, the obese people tended to have high LVMI readings. If we used LVMI as the induced variable, meanwhile V/S, BMI, WHR, WHtR as the independent variable, and after applied the multiple linear regression, we should get the conclusion that all 4 factors have impact on LVMI, and V/S has played the most significant role.We should be able to recognize that there was connection between obesity and essential hypertensive LVH, especially the connection between the visceral fat accumulation and the hypertensive LVH was more apparent. Then we can get the implication that the V/S which reflects the distribution of visceral fat was one the risky factors in influencing the hypertensive LVH.