Relationship between left ventricular mass and serum cholesterol level in the untreated hypertensive

Combined superposition effect of hypertension and dyslipidemia on left ventricular hypertrophy

BACKGROUND

Hypertension and dyslipidemia are considered reversible risk factors for cardiovascular disease. The purpose of this study was to explore the impact of traditional and nontraditional blood lipid profiles on the risk of left ventricular hypertrophy (LVH) and to explore the superposition effect of dyslipidemia combined with hypertension.

METHODS

Data on 9134 participants (53.5 ± 10.3 years old) from the Northeast China Rural Cardiovascular Health Study (NCRCHS) were statistically analyzed. The blood lipid profile was measured by total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total glyceride (TG), and calculated nontraditional blood lipid indices including non-HDL-C, atherosclerosis index (AI), TC/HDL-C, and residual cholesterol (RC).

RESULTS

After the adjustment of age and gender, the odds ratios (ORs) of LVH in patients with hypertension, high LDL-C, high non-HDL-C, high AI, and high TC/HDL-C were 3.97 (3.31-4.76), 1.27 (1.02-1.59), 1.21 (1.04-1.39), 1.33 (1.15-1.53), and 1.42 (1.22-1.65), respectively. After full adjustment of potential confounding factors, high AI and TC/HDL-C were associated with LVH rather than traditional blood lipid indices. The combination of hypertension and nontraditional dyslipidemia (defined by high AI and TC/HDL-C) was associated with the highest risk of LVH, especially in participants under 45 years of age. The risk was more significant in men, 5.09-fold and 6.24-fold, respectively, compared with 3.66-fold and 4.01-fold in women.

CONCLUSIONS

People with dyslipidemia defined by nontraditional blood lipid indices (high AI and high TC/HDL-C) and hypertension were more likely to develop LVH.

The impact of nontraditional lipid profiles on left ventricular geometric abnormalities in general Chinese population

BACKGROUND

Despite current interest in the unfavorable impact of nontraditional lipid profiles on cardiovascular disease, information regarding its relations to abnormal left ventricular (LV) geometry has not been systemically elucidated. This study sought to understand predictive implication of nontraditional lipid profiles in specific LV geometric patterns in the general population of rural China.

METHODS

Analyses were based upon a cross-sectional study of 10,756 participants (mean age 53.8 years; 54.0% females) who underwent assessment of biochemical, anthropometric, and blood pressure variables in rural areas of China. Participants were classified into four groups of LV morphologic pattern according to left ventricular mass index (LVMI) and relative wall thickness with quantitative echocardiographic data.

RESULTS

By multivariable-adjusted linear regression models, nontraditional lipid profiles were positive determinants of concentricity index and LV wall thickness (all P < 0.05), with modest effects on LVMI. Non-high-density lipoprotein cholesterol (non-HDL-C) emerged as an independent correlate of concentric LV hypertrophy (LVH) (adjusted odds ratio [OR]: 1.174 per 1 SD increment in non-HDL-C, 95% confidence interval [CI]: 1.075-1.281), followed by low-density lipoprotein cholesterol (LDL-C)/HDL-C ratio (1.158 [1.059-1.266]), total cholesterol (TC)/HDL-C ratio (1.150 [1.050-1.260]), and triglyceride (TG)/HDL-C ratio (1.134 [1.030-1.249]). The ORs for concentric LVH by tertiles further provided insight into that excess risk was associated with the highest tertile of nontraditional lipid profiles. The areas under the ROC curves to predict concentric LVH were statistically identical among nontraditional lipid parameters.

CONCLUSION

Nontraditional lipid profiles, easily measured in the everyday routine examination, were responsible for increased risk of concentric LVH, potentially providing enhanced clinical utility at no additional cost, which emphasized the beneficial effect of these markers to supplement and improve CVD risk stratification.

Inverse association of total testosterone with central haemodynamics and left ventricular mass in hypertensive men

BACKGROUND

There is evidence for inverse association between endogenous testosterone and blood pressure. Furthermore, low plasma testosterone is associated with increased risk of major cardiovascular events in middle-aged hypertensive men. Central (aortic) blood pressures determine left ventricular hypertrophy and predict cardiovascular mortality. The aim of the present study was to assess the relationship of total testosterone (TT) with central haemodynamics and left ventricular mass in hypertensive men.

METHODS

We investigated 134 non-diabetic, middle-aged, hypertensive men and 60 age-matched normotensive males. All participants were subject to measurement of aortic systolic (aoSBP) and pulse pressure (aoPP) by pulse wave analysis using the SphygmoCor device. Wave reflections were assessed by the measurement of heart rate corrected augmentation index (AIx75). Echocardiography was performed in all individuals and left ventricular mass (LVM) was calculated using the Devereux's formula. Plasma TT was measured by enzyme immunoassay.

RESULTS

In hypertensive men, univariate analysis showed an inverse, significant correlation between TT and aoSBP (r = -20, p = 0.02), aoPP (r = -0.21, p = 0.01), AIx75 (r = -0.22, p = 0.01) and LVM (r = -0.19, p = 0.008). Multivariate regression analysis demonstrated an independent inverse association of TT with aoPP (b = -0.21, p = 0.02), AIx75 (b = -0.19, p = 0.03) and LVM (b = -0.28, p = 0.005) after adjustment for age, BMI, smoking, total cholesterol, triglycerides, fasting glucose, mean arterial pressure, antihypertensive treatment and statin use. Independent associations were retained even after inclusion of normotensive subjects in the analysis.

CONCLUSIONS

In hypertensive men, TT is independently and inversely associated with central pulse pressure, wave reflections and left ventricular mass. Considering the adverse prognostic role of central blood pressures and LV hypertrophy on cardiovascular outcomes in hypertensive patients, the present findings might explain part of the increased cardiovascular risk associated with low testosterone. Whether measurement of central haemodynamics may improve risk stratification in hypertensive men with low testosterone warrants further investigation.

Cross-sectional relations of lipid concentrations to left ventricular structural attributes

Although previous investigations reported on the associations of lipid concentrations with left ventricular remodeling in specific subpopulations, few data exist on these associations in a community-based sample of subjects without cardiovascular disease. In this study, 3,554 Framingham Heart Study participants (mean age 47 years, 53% women) without preexisting clinical cardiovascular disease were examined, and no meaningful associations of high-density lipoprotein cholesterol or non-high-density lipoprotein cholesterol with echocardiographic indexes of left ventricular structure were observed. In conclusion, these data do not support an independent association between lipid concentrations and left ventricular structure.

Relations of lipid concentrations to heart failure incidence: the Framingham Heart Study

BACKGROUND

The relations of lipid concentrations to heart failure (HF) risk have not been elucidated comprehensively.

METHODS AND RESULTS

In 6860 Framingham Heart Study participants (mean age, 44 years; 54% women) free of baseline coronary heart disease, we related high-density lipoprotein cholesterol (HDL-C) and non-HDL-C to HF incidence during long-term follow-up, adjusting for clinical covariates and myocardial infarction at baseline and updating these at follow-up examinations. We evaluated dyslipidemia-specific population burden of HF by calculating population attributable risks. During follow-up (mean of 26 years), 680 participants (49% women) developed HF. Unadjusted HF incidence in the low (<160 mg/dL) versus high (> or =190 mg/dL) non-HDL-C groups was 7.9% and 13.8%, respectively, whereas incidence in the high (> or =55 [men], > or =65 [women] mg/dL) versus low (<40 [men], <50 [women] mg/dL) HDL-C groups was 6.1% and 12.8%, respectively. In multivariable models, baseline non-HDL-C and HDL-C, modeled as continuous measures, carried HF hazards (confidence intervals) of 1.19 (1.11 to 1.27) and 0.82 (0.75 to 0.90), respectively, per SD increment. In models updating lipid concentrations every 8 years, the corresponding hazards (confidence intervals) were 1.23 (1.16 to 1.31) and 0.77 (0.70 to 0.85). Participants with high baseline non-HDL-C and those with low HDL-C experienced a 29% and 40% higher HF risk, respectively, compared with those in the desirable categories; the population attributable risks for high non-HDL-C and low HDL-C were 7.5% and 15%, respectively. Hazards associated with non-HDL-C and HDL-C remained statistically significant after additional adjustment for interim myocardial infarction.

CONCLUSIONS

Dyslipidemia carries HF risk independent of its association with myocardial infarction, suggesting that lipid modification may be a means for reducing HF risk.

Differential effects of lipids on the risk of heart failure and coronary heart disease: the Physicians' Health Study

BACKGROUND

It is understood that coronary heart disease (CHD) is one cause of heart failure, and many risk factors are common to both entities. Hypercholesterolemia, however, being a well-recognized risk factor for CHD, has an unclear association with incident heart failure.

METHODS

We evaluated the relations of total and high-density lipoprotein (HDL) cholesterol to incident heart failure and CHD in 10,813 US male physicians (mean age, 68 years). Total and HDL cholesterol were analyzed both as continuous and as categorical (in quartiles) variables.

RESULTS

There were 222 incident heart failure cases on follow-up (mean, 6 years). In Cox models, after adjusting for traditional coronary risk factors, 1-SD increase in total cholesterol (36.7 mg/dL) and HDL cholesterol (15.3 mg/dL) was not related to incident heart failure with a hazard ratio and 95% CI of 0.91 (0.79-1.05) for total cholesterol and 0.95 (0.82-1.11) for HDL cholesterol. In categorical models, heart failure risk in second, third, and fourth quartiles of total and HDL cholesterol was statistically not different from those in the lowest quartile; hazard ratios with 95% CI were 0.72 (0.49-1.05), 0.76 (0.52-1.11), 0.73 (0.50-1.09) for total cholesterol, and 0.78 (0.53-1.15), 0.66 (0.43-1.00), and 1.03 (0.69-1.54), for HDL cholesterol. Further adjustment for CHD on follow-up or exclusion of individuals with CHD at baseline did not alter the results. In contrast, high total cholesterol and low HDL cholesterol increased the risk of incident CHD (P < .001).

CONCLUSION

In healthy males, total and HDL cholesterol levels were not related to incident heart failure.

Prevention of heart failure: a scientific statement from the American Heart Association Councils on Epidemiology and Prevention, Clinical Cardiology, Cardiovascular Nursing, and High Blood Pressure Research; Quality of Care and Outcomes Research Interdisciplinary Working Group; and Functional Genomics and Translational Biology Interdisciplinary Working Group

The increase in heart failure (HF) rates throughout the developed and developing regions of the world poses enormous challenges for caregivers, researchers, and policymakers. Therefore, prevention of this global scourge deserves high priority. Identifying and preventing the well-recognized illnesses that lead to HF, including hypertension and coronary heart disease, should be paramount among the approaches to prevent HF. Aggressive implementation of evidence-based management of risk factors for coronary heart disease should be at the core of HF prevention strategies. Questions currently in need of attention include how to identify and treat patients with asymptomatic left ventricular systolic dysfunction (Stage B HF) and how to prevent its development. The relationship of chronic kidney disease to HF and control of chronic kidney disease in prevention of HF need further investigation. Currently, we have limited understanding of the pathophysiological basis of HF in patients with preserved left ventricular systolic function and management techniques to prevent it. New developments in the field of biomarker identification have opened possibilities for the early detection of individuals at risk for developing HF (Stage A HF). Patient groups meriting special interest include the elderly, women, and ethnic/racial minorities. Future research ought to focus on obtaining a much better knowledge of genetics and HF, especially both genetic risk factors for development of HF and genetic markers as tools to guide prevention. Lastly, a national awareness campaign should be created and implemented to increase public awareness of HF and the importance of its prevention. Heightened public awareness will provide a platform for advocacy to create national research programs and healthcare policies dedicated to the prevention of HF.

Echocardiography-based left ventricular mass estimation. How should we define hypertrophy?

Left ventricular hypertrophy is an important risk factor in cardiovascular disease and echocardiography has been widely used for diagnosis. Although an adequate methodologic standardization exists currently, differences in measurement and interpreting data is present in most of the older clinical studies. Variability in border limits criteria, left ventricular mass formulas, body size indexing and other adjustments affects the comparability among these studies and may influence both the clinical and epidemiologic use of echocardiography in the investigation of the left ventricular structure. We are going to review the most common measures that have been employed in left ventricular hypertrophy evaluation in the light of some recent population based echocardiographic studies, intending to show that echocardiography will remain a relatively inexpensive and accurate tool diagnostic tool.

Risk factors for heart failure

Despite remarkable therapeutic advances in the management of patients with heart failure (HF), the mortality due to this syndrome remains high. Identifying free-living individuals who are at high risk for developing HF may allow implementing strategies that can prevent HF. Prospective epidemiologic studies have identified several risk factors and risk markers for HF. This article reviews current knowledge regarding conventional and newer risk markers for HF, outlines possible underlying mechanisms for the increased HF risk, and provides a framework for clinical multivariate risk prediction using HF risk factors.

Left Ventricular Concentric Geometry During Treatment Adversely Affects Cardiovascular Prognosis in Hypertensive Patients

Left ventricular (LV) mass and geometry predict risk for cardiovascular events in hypertension. Regression of LV hypertrophy (LVH) may imply an important prognostic significance. The relation between changes in LV geometry during antihypertensive treatment and subsequent prognosis has not yet been determined. A total of 436 prospectively identified uncomplicated hypertensive subjects with a baseline and follow-up echocardiogram (last examination 72+/-38 months apart) were followed for an additional 42+/-16 months. Their family doctor gave antihypertensive treatment. After the last follow-up echocardiogram, a first cardiovascular event occurred in 71 patients. Persistence of LVH from baseline to follow-up was confirmed as an independent predictor of cardiovascular events. Cardiovascular morbidity and mortality were significantly greater in patients with concentric (relative wall thickness > or =0.44) than in those with eccentric geometry (relative wall thickness <0.44) in patients presenting with LVH (P=0.002) and in those without LVH (P=0.002) at the follow-up echocardiogram. The incidence of cardiovascular events progressively increased from the first to the third tertile of LV mass index at follow-up (partition values 91 and 117 g/m2), but for a similar value of LV mass index it was significantly greater in those with concentric geometry (OR: 4.07; 95% CI: 1.49 to 11.14; P=0.004 in the second tertile; OR: 3.45; 95% CI: 1.62 to 7.32; P=0.001 in the third tertile; P<0.0001 in concentric versus eccentric geometry). Persistence or development of concentric geometry during follow-up may have additional prognostic significance in hypertensive patients with and without LVH.

Reversal of left ventricular hypertrophy: what have recent trials taught us?

Regression of left ventricular hypertrophy (LVH) is an important intermediate target for antihypertensive therapy. Thus, several trials and meta-analyses have attempted to compare the effects of different antihypertensive agents on LVH, but flawed study designs and methodologic problems have limited the utility of these studies. PRESERVE (Prospective Randomized Enalapril Study Evaluating Regression of Ventricular Enlargement), LIVE (LVH: Indapamide Sustained Release Versus Enalapril) and LIFE (Losartan Intervention For Endpoint reduction in hypertension) represent a new generation of large well designed trials with the power to compare different antihypertensive drugs. These studies have shown that treatment regimens based on enalapril and a nifedipine gastrointestinal therapeutic system are of similar efficacy (PRESERVE), that indapamide sustained release (SR) is superior to enalapril (LIVE), and that a regimen based on losartan is superior to a regimen based on atenolol (LIFE) in reversing hypertensive LVH. LIVE incorporated on-treatment echocardiographic quality control, with centralized readers blinded for both treatment and sequence of recording. The findings of these rigorous studies, to some extent in disagreement with results of previous meta-analyses, support the notion that antihypertensive drugs need to be judged on their individual effects on important intermediate endpoints such as LVH in well designed and adequately sized studies. However, extrapolation of the results of these studies in terms of class effects could be misleading and should be made with caution.

Spontaneous baroreflex sensitivity: toward an ideal index of cardiovascular risk in hypertension?

OBJECTIVE

Estimating the risk entailed by classical risk factors like blood pressure (BP) or serum cholesterol may be difficult because of their variability and the often unknown duration of exposure. Having variables integrating the impact of those classical risk factors on the cardiovascular system would probably aid the prediction of cardiovascular events. The present study aimed at determining whether cardiac baroreflex sensitivity (BRS), correlates with several risk factors and thus is a good candidate for being such an integrative variable. As a comparison, left ventricular mass (LVM), pulse wave velocity (PWV), and creatinine were also tested for association with risk factors.

DESIGN

A total of 302 subjects referred for hypertension, were considered. They had a 24-h BP recording and a determination of BRS by two different methods (sequence and alpha coefficient), in two different positions (lying and standing). They were also tested for the presence of left ventricular hypertrophy (LVH) (by echocardiography and electrocardiogram) and had a PWV measurement. Biological testing included serum lipids, blood glucose, creatinine, proteinuria and urinary excretion of microalbumin.

RESULTS

There was a strong correlation between the two methods of BRS measurement in each position (P < 0.001). BRS determined by the sequence method in the lying position was correlated significantly and independently with age, 24-h systolic BP, heart rate, and serum cholesterol with P values < 0.001, < 0.001, < 0.01, and < 0.05, respectively. In an univariate analysis, BRS was also correlated with echocardiographic LVM index (r = -0.21, P < 0.05) and PWV (r = -0.27, P < 0.001), which possibly reflects its dependence on both vascular and cardiac damages.

CONCLUSION

The present study supports the hypothesis that BRS could encompass the impact over time of several risk factors on the cardiovascular system. Thus, it may constitute a valuable parameter in assessing more precisely the risk of cardiovascular events.

High-density lipoprotein cholesterol and left ventricular hypertrophy in essential hypertension

OBJECTIVE

The proportion of left ventricular (LV) mass variability explained by blood pressure in essential hypertension is small, and several non-haemodynamic determinants of LV mass have been identified or hypothesized. This study examines the possible relation between blood lipids and LV mass in hypertension.

DESIGN

Never-treated non-diabetic hypertensive patients.

SETTING

Hospital hypertension outpatient clinics in Umbria, Italy.

PATIENTS

We investigated the association between high-density lipoprotein (HDL)-cholesterol and echocardiographic LV mass in 1306 never-treated subjects with essential hypertension. Subjects with previous cardiovascular events, diabetes and current or previous antihypertensive or lipid-lowering therapy were excluded.

RESULTS

HDL-cholesterol showed an inverse association with LV mass (r = -0.30, P < 0.001). No association was found between LV mass and total or low-density lipoprotein cholesterol. With multiple linear regression analysis we tested the independent contribution of several potential determinants of LV mass in women and in men. Average 24 h blood pressure (both pulse and mean), body mass index, height, stroke volume, age (all P < 0.01) and low HDL-cholesterol (P < 0.0001 in women, P < 0.001 in men) were associated with a greater LV mass in both sexes. Triglycerides showed a weak univariate association with LV mass in women (r = 0.11, P < 0.02), which did not hold in a multivariate analysis.

CONCLUSIONS

Low HDL-cholesterol is an independent predictor of LV mass in untreated hypertensive subjects. Common hormonal and metabolic mechanisms, including insulin resistance, could explain this association, which may contribute to the adverse prognostic significance of low HDL-cholesterol levels.

Left ventricular mass is not related to insulin sensitivity in never-treated primary hypertension

OBJECTIVE

Insulin has been suggested to promote myocardial cell growth and the development of left ventricular (LV) hypertrophy. This study examines the possible relationship between LV mass and insulin sensitivity.

DESIGN

Previously untreated non-diabetic hypertensive patients.

PATIENTS

Fifty-one patients with mean age 51 +/- 8 years, body mass index (BMI) 25.9 +/- 3.2 kg/m2 and blood pressure 158/102 mmHg were included. LV mass was determined by echocardiography. Glucose metabolism was assessed by an euglycemic insulin clamp (40 mU/m2 body surface area/min).

RESULTS

Insulin sensitivity index (MI) and insulin clearance were inversely related to LV mass (r = -0.37, P < 0.01 and -0.33, P < 0.05, respectively) and LV mass indexed to height (r = -0.33, P < 0.05 and -0.29, P < 0.05, respectively). C-peptide and fasting insulin were related to LV mass (r = 0.33, P < 0.05 and r = 0.36, P < 0.01, respectively) and LV mass indexed to height (r = 0.30, P < 0.05 and r = 0.34, P < 0.05, respectively). In contrast, when LV mass was indexed by body surface area there was no longer a relation to MI, insulin clearance, C-peptide or fasting insulin. When adjusting for BMI in a multiple regression analysis, MI and LV mass no longer showed a relation. Indeed, MI, insulin clearance, C-peptide and insulin were all strongly related to weight and BMI.

CONCLUSION

Insulin sensitivity is related to body size in untreated hypertension. However, insulin sensitivity is not related to LV mass, if adjusting for body size. This does not support a direct growth-promoting effect of insulin on the myocardium. Insulin does not appear to be strongly involved in development of hypertensive LV hypertrophy.