Are left ventricular mass, geometry and function related to vascular changes and/or insulin resistance in long-standing hypertension? ICARUS: a LIFE substudy

Clinical Update: Cardiovascular Disease in Diabetes Mellitus: Atherosclerotic Cardiovascular Disease and Heart Failure in Type 2 Diabetes Mellitus - Mechanisms, Management, and Clinical Considerations

Cardiovascular disease remains the principal cause of death and disability among patients with diabetes mellitus. Diabetes mellitus exacerbates mechanisms underlying atherosclerosis and heart failure. Unfortunately, these mechanisms are not adequately modulated by therapeutic strategies focusing solely on optimal glycemic control with currently available drugs or approaches. In the setting of multifactorial risk reduction with statins and other lipid-lowering agents, antihypertensive therapies, and antihyperglycemic treatment strategies, cardiovascular complication rates are falling, yet remain higher for patients with diabetes mellitus than for those without. This review considers the mechanisms, history, controversies, new pharmacological agents, and recent evidence for current guidelines for cardiovascular management in the patient with diabetes mellitus to support evidence-based care in the patient with diabetes mellitus and heart disease outside of the acute care setting.

In-treatment stroke volume predicts cardiovascular risk in hypertension

OBJECTIVE

To evaluate whether lower stroke volume during antihypertensive treatment is a predictor of cardiovascular events independent of left ventricular geometric pattern.

METHODS

The association between left ventricular stroke volume and combined cardiovascular death, stroke and myocardial infarction, the prespecified primary study endpoint, was assessed in Cox regression analysis using data from baseline and annual follow-up visits in 855 patients during 4.8 years of randomized losartan-based or atenolol-based treatment in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) echocardiography substudy.

RESULTS

During follow-up, a total of 91 primary endpoints occurred. At baseline, lower left ventricular stroke volume was associated with smaller body size, female sex, lower left ventricular mass and stress-corrected midwall shortening, higher relative wall thickness and total peripheral resistance, more concentric left ventricular geometry and impaired diastolic relaxation (all P < 0.01). Baseline stroke volume did not predict outcome. However, in time-varying multivariable Cox regression analysis, lower in-treatment left ventricular stroke volume indexed for height was associated with higher risk of cardiovascular events {hazard ratio 1.69 per 1 SD (6 ml/m) lower stroke volume [95% confidence interval (CI) 1.35-2.11], P < 0.001} independent of in-treatment left ventricular mass and concentric geometry and in a secondary model also independent of stress-corrected midwall shortening, impaired diastolic relaxation, heart rate, new-onset atrial fibrillation and study treatment [hazard ratio 1.46 per 1 SD (6 ml/m) lower stroke volume (95% CI 1.13-1.88)].

CONCLUSION

Assessment of in-treatment left ventricular stroke volume may reflect cardiac and vascular remodeling and impairment and, hence, adds information on cardiovascular risk in treated hypertensive patients beyond assessment of left ventricular structure alone.

CLINICAL TRIAL REGISTRATION INFORMATION

NCT 00338260.

Relations of insulin resistance and glycemic abnormalities to cardiovascular magnetic resonance measures of cardiac structure and function: the Framingham Heart Study

BACKGROUND

Data regarding the relationships of diabetes, insulin resistance, and subclinical hyperinsulinemia/hyperglycemia with cardiac structure and function are conflicting. We sought to apply volumetric cardiovascular magnetic resonance (CMR) in a free-living cohort to potentially clarify these associations.

METHODS AND RESULTS

A total of 1603 Framingham Heart Study Offspring participants (age, 64+/-9 years; 55% women) underwent CMR to determine left ventricular mass (LVM), LVM to end-diastolic volume ratio (LVM/LVEDV), relative wall thickness (RWT), ejection fraction, cardiac output, and left atrial size. Data regarding insulin resistance (homeostasis model, HOMA-IR) and glycemia categories (normal, impaired insulinemia or glycemia, prediabetes, and diabetes) were determined. In a subgroup (253 men, 290 women) that underwent oral glucose tolerance testing, we related 2-hour insulin and glucose with CMR measures. In both men and women, all age-adjusted CMR measures increased across HOMA-IR quartiles, but multivariable-adjusted trends were significant only for LVM/ht(2.7) and LVM/LVEDV. LVM/LVEDV and RWT were higher in participants with prediabetes and diabetes (in both sexes) in age-adjusted models, but these associations remained significant after multivariable adjustment only in men. LVM/LVEDV was significantly associated with 2-hour insulin in men only, and RWT was significantly associated with 2-hour glucose in women only. In multivariable stepwise selection analyses, the inclusion of body mass index led to a loss in statistical significance.

CONCLUSIONS

Although insulin and glucose indices are associated with abnormalities in cardiac structure, insulin resistance and worsening glycemia are consistently and independently associated with LVM/LVEDV. These data implicate hyperglycemia and insulin resistance in concentric LV remodeling.

Non-alcoholic fatty liver disease is associated with left ventricular diastolic dysfunction in essential hypertension

BACKGROUND AND AIM

Insulin resistance is recognized as the pathophysiological hallmark of non-alcoholic fatty liver disease (NAFLD). A relation between insulin sensitivity and left ventricular morphology and function has been reported in essential hypertension, where a high prevalence of NAFLD has been recently found. We investigated the inter-relationship between left ventricular morphology/function, metabolic parameters and NAFLD in 86 never-treated essential hypertensive patients subdivided in two subgroups according to the presence (n = 48) or absence (n = 38) of NAFLD at ultrasonography.

METHODS AND RESULTS

The two groups were similar as to sex, age and blood pressure levels. No patient had diabetes mellitus, obesity, hyperlipidemia, or other risk factors for liver disease. Body mass index, waist circumference, triglycerides, glucose, insulin, homeostasis model of assessment index for insulin resistance (HOMA-IR), aspartate aminotransferase and alanine aminotransferase were higher and adiponectin levels were lower in patients with NAFLD than in patients without NAFLD, and were associated with NAFLD at univariate analysis. Patients with NAFLD had similar prevalence of left ventricular hypertrophy compared to patients without NAFLD, but a higher prevalence of diastolic dysfunction (62.5 vs 21.1%, P < 0.001), as defined by E/A ratio <1 and E-wave deceleration time >220 ms. Diastolic dysfunction (P = 0.040) and HOMA-IR (P = 0.012) remained independently associated with NAFLD at backward multivariate analysis.

CONCLUSIONS

Non-alcoholic fatty liver disease was associated with insulin resistance and abnormalities of left ventricular diastolic function in a cohort of patients with essential hypertension, suggesting a concomitant increase of metabolic and cardiac risk in this condition.

Subclinical impairment of left ventricular function in young obese women: contributions of polycystic ovary disease and insulin resistance

CONTEXT

Obesity and insulin resistance (IR) may produce disturbances of left ventricular (LV) function. Obese women with polycystic ovary syndrome (PCO), characterized by hormonal and metabolic abnormalities, are thought to be at particularly increased cardiovascular risk.

OBJECTIVES

We sought to determine the influence of IR on LV function in obese young women with and without PCO and without other comorbidities.

DESIGN

This was a cross-sectional study.

SETTING

The study was performed at a university hospital.

PATIENTS

A total of 150 women aged younger than 40 yr with a body mass index (BMI) of 30 kg/m(2) or more was classified into three groups: with both PCO and IR, without PCO and with IR, and without either PCO or IR.

MAIN OUTCOME MEASURES

Tissue Doppler-derived myocardial velocities, strain-rate and strain, and metabolic and hormonal measurements were calculated.

RESULTS

Subclinical impairment of LV systolic and diastolic function as indicated by lower peak strain (P < 0.001), peak systolic strain rate (P < 0.001), peak early diastolic strain rate (P < 0.001), and peak early diastolic velocity (P < 0.01) was demonstrated in both groups with IR. IR subjects with and without PCO did not differ in any LV function indices. Strain was independently associated with fasting insulin (beta = -0.39; P < 0.001), urinary albumin excretion (UAE) (beta = -0.36; P < 0.001), and BMI (beta = -0.22; P < 0.03), and peak early diastolic strain rate was associated with UAE (beta = -0.35; P < 0.001), fasting insulin (beta = -0.24; P < 0.02), BMI (beta = -0.23; P < 0.02), and SHBG (beta = 0.20; P < 0.04).

CONCLUSIONS

In obese young women, fasting insulin, BMI, SHBG, and UAE are independent correlates of impaired LV performance. The contribution of PCO to LV function abnormalities is linked to IR, but not to other hormonal aberrations associated with this condition.

Cardiac disease in children with mild-to-moderate chronic kidney disease

PURPOSE OF REVIEW

Studies in pediatric populations may provide sensitive insights into the prevalence, evolution and underlying mechanisms of cardiovascular complications of chronic kidney disease, without confounding factors such as aging and diabetes. This review reflects on recent echocardiographic studies assessing left-ventricular mass, geometry and function in children with mild-to-moderate chronic kidney disease.

RECENT FINDINGS

A cross-sectional assessment of a large pediatric cohort established a 33% prevalence of left-ventricular hypertrophy in children with chronic kidney disease stages 2-4. Concentric and eccentric geometry are found equally frequently, suggesting variable contributions of enhanced left-ventricular preload and afterload and/or nonhemodynamic mechanisms. Concentric left-ventricular hypertrophy is frequently associated with systolic dysfunction as evidenced by impaired circumferential shortening at the myocardial midwall level. Left-ventricular mass and dysfunction tend to be inversely correlated with glomerular filtration rate. Furthermore, male sex, obesity, anemia and inflammation appear to be associated with left-ventricular hypertrophy, whereas blood pressure shows surprisingly little association with left-ventricular mass, geometry or function.

SUMMARY

Significant abnormalities of cardiac morphology and function are observed in children with early chronic kidney disease, demonstrating a marked intrinsic impact on the cardiovascular system. Regular echocardiographic screening appears indicated in the pediatric population with chronic kidney disease.

Insulin resistance and plasma triglyceride level are differently related to cardiac hypertrophy and arterial stiffening in hypertensive subjects

OBJECTIVE

The frequent association between the type 2 diabetes mellitus and cardio-vascular diseases suggests that metabolic factors may contribute to cardio-vascular remodeling. The aim of our study was to examine the relationships between left ventricular posterior wall thickness (LVPWT), pulse wave velocity (PWV), and the metabolic abnormalities of insulin resistance syndrome, in hypertensive patients.

METHODS

In 227 consecutive hypertensives, we examined the relationships between LVPWT, PWV, and metabolic factors: plasma glucose, insulin, total cholesterol, high density lipoprotein (HDL)-cholesterol, triglycerides levels as well as the homeostasis model assessment of insulin resistance (HOMA). The Pearson correlation coefficient and multiple regression analysis (including age, gender, body mass index, and 24-hour systolic blood pressure) were used as statistical tests.

RESULTS

In univariate analysis, glucose, HDL-cholesterol, and triglycerides levels were related to LVPWT (r = 0.19, p < 0.05; r = -0.26, p < 0.001; r = 0.31, p < 0.001, respectively); all metabolic variables, except HDL-cholesterol, correlated to PWV (plasma glucose r = 0.25, p < 0.001; total cholesterol r = 0.22, p < 0.01; triglycerides r = 0.20, p < 0.01; insulin r = 0.19, p < 0.01; HOMA r = 0.27; p < 0.001). In the multivariate model, plasma triglycerides remained correlated with LVPWT (beta = 0.19, p < 0.02) independently of systolic blood pressure, plasma aldosterone, and normetanephrine. Only HOMA and insulin level remained associated with PWV (beta = 0.14; beta = 0.13 respectively, p < 0.05).

CONCLUSIONS

These data suggest that among typical metabolic abnormalities of insulin resistance syndrome, plasma triglycerides, and insulin as well as degree of insulin resistance may contribute to cardiac hypertrophy and arterial stiffening independently of hemodynamic and hormonal factors.

Left ventricular geometry in children with mild to moderate chronic renal insufficiency

Left ventricular hypertrophy (LVH) is the most important independent marker of cardiovascular risk in adults with chronic kidney disease. Cardiovascular morbidity seems increased even in children with chronic renal insufficiency (CRI), but the age and stage of CRI when cardiac alterations become manifest are unknown. For assessing the prevalence and factors associated with abnormal LV geometry in children with CRI, echocardiograms, ambulatory BP monitoring, and biochemical profiles were obtained in 156 children aged 3 to 18 yr with stages 2 through 4 chronic kidney disease (GFR 49 +/- 19 ml/min per 1.73 m2) and compared with echocardiograms obtained in 133 healthy children of comparable age and gender. LV mass was indexed to height2.7. Concentric LV remodeling was observed in 10.2%, concentric LVH in 12.1%, and eccentric LVH in 21% of patients. LVH was more common in boys (43.3 versus 19.4%; P < 0.005). Probability of LVH independently increased with male gender (odds ratio [OR] 2.62; P < 0.05) and standardized body mass index (OR 1.56; P = 0.01). Low hemoglobin, low GFR, young age, and high body mass index were independent correlates of LV mass index (0.005 < P < 0.05). LV concentricity (relative wall thickness) was positively associated with serum albumin (P < 0.05). Probability of abnormal LV geometry increased with C-reactive protein >10 mg/dl (OR 26; P < 0.001). In conclusion, substantial cardiac remodeling of both concentric and eccentric type is present at young age and early stages of CRI in children. Prevalence of LVH is related to male gender, anemia, and ponderosity but not to BP. Additional effects of volume status and inflammation on cardiac geometry are also evident.