Effect of type 2 diabetes mellitus on left ventricular geometry and systolic function in hypertensive subjects: Hypertension Genetic Epidemiology Network (HyperGEN) study

Hemodynamic and echocardiographic profiles in African American compared with White offspring of hypertensive parents: the HyperGEN study

BACKGROUND

Alterations in cardiovascular structure and function have been shown to precede the finding of elevated blood pressure.

METHODS

This study is part of the Hypertension Genetic Epidemiologic Network (HyperGEN) in which genetic and environmental determinants of hypertension were investigated in 5 geographical field centers. All nonhypertensive offspring (n = 1,035) were included from the entire HyperGEN study population that consists of 2,225 hypertensive patients and 1,380 nonhypertensive patients who had adequate echocardiographic left ventricular (LV) mass measurements. Participants were compared by self-declared race (African American and white).

RESULTS

Nonhypertensive African American offspring were younger (aged 31 years vs. 38 years), more likely to be female, and had a higher body mass index (BMI) and higher systolic blood pressure (SBP) than their white counterparts. After adjusting for age, sex, SBP, pulse pressure (PP), BMI, diabetes status, and family effects, we observed statistically significant and potentially pathophysiological differences (all with P ≤ 0.001) with greater LV mass/height, relative wall thickness, and posterior wall thickness and with lesser midwall shortening, PP/stroke volume, and (PP/stroke volume)/fat-free body mass.

CONCLUSION

This study shows that ethnic differences in hemodynamic and echocardiographic profiles exist in a large, population-based cohort of nonhypertensive offspring of hypertensive parents.

Does accessory pathway significantly alter left ventricular twist/torsion? A study in Wolff-Parkinson-White syndrome by velocity vector imaging

BACKGROUND

The aim of this study was to determine the impact of manifest accessory pathway on left ventricle (LV) twist physiology in Wolff-Parkinson-White (WPW) patients. Although this issue was addressed in 1 study based on speckle tracking method, there was no comparative study with a different technique. We planned to use velocity vector imaging (VVI) to find out how much an accessory pathway can affect LV twist mechanics.

METHODS

Thirty patients were enrolled regarding inclusion and exclusion criteria. Two serial comprehensive transthoracic echocardiography evaluations were performed before and after radiofrequency catheter ablation (RFCA) within 24 hours. Stored cine loops were analyzed using VVI technique and LV twist and related parameters were extracted.

RESULTS

Comparing pre- and post-RFCA data, no significant changes were observed in LV systolic and diastolic dimensions, LV ejection fraction (LVEF), and Doppler and tissue Doppler-related parameters. VVI study revealed remarkable rise in peak LV apical rotation (10.3º ± 3.0º to 13.8º ± 3.6º, P < 0.001) and basal rotation (-6.0 ± 1.8º to -7.7 ± 1.8º, P < 0.001) after RFCA. Subsequently LV twist showed a surge from 14.7º ± 3.9º to 20.2º ± 4.4º (P < 0.001). LV untwisting rate changed significantly from -96 ± 67 to -149.0 ± 47.5°/sec (P < 0.001) and apical-basal rotation delay showed a remarkable decline after RFCA (106 ± 81 vs. 42.8 ± 26.0 msec, P < 0.001).

CONCLUSION

Accessory pathways have a major impact on LV twist mechanics.

Plasma glucose levels and left ventricular diastolic function in nondiabetic hypertensive patients

BACKGROUND

Changes in left ventricular (LV) diastolic filling anticipate diastolic heart failure and are frequently detected in patients with hypertension or diabetes. We tested the hypothesis that increased fasting and postload glucose levels are associated with diastolic dysfunction as assessed by tissue Doppler imaging (TDI) in hypertensive patients.

METHODS

In 104 untreated, nondiabetic, hypertensive patients free of cardiovascular complications, we measured glucose and insulin at fast and after an oral glucose load, calculated the Homeostatic Model Assessment (HOMA) index, and performed electrocardiogram (ECG), conventional echocardiography, and TDI.

RESULTS

Thirty-one patients who had impaired fasting glucose/impaired glucose tolerance had more frequent LV strain at ECG and worse TDI markers of diastolic function than patients with normal plasma glucose but no differences in variables LV mass, LV geometry, systolic function, and early-/late-wave transmitral diastolic velocity. TDI detected diastolic dysfunction in 46 patients who were older and had greater body mass index, blood pressure, fasting and postload glucose, insulin, HOMA index, LV mass, and left atrial diameter than patients with preserved diastolic function. Variables of diastolic function measured at TDI were significantly related with age, body mass index, LV mass, and fasting and postload plasma glucose. Stepwise regression analysis showed that the relationship of markers of diastolic dysfunction with both fasting and postload glucose levels was independent of possible confounders.

CONCLUSIONS

Initially abnormal fasting and postload glucose levels are associated with more prominent diastolic impairment in uncomplicated hypertensive patients, suggesting that hyperglycemia might increase the risk of diastolic heart failure even in the absence of diabetes.

The increasing detection of asymptomatic left ventricular dysfunction in patients with type 2 diabetes mellitus without overt cardiac disease: data from the SHORTWAVE study

AIMS

Type 2 diabetes mellitus (DM) is associated with higher risk of heart failure. Over the last three decades several studies demonstrated the presence of asymptomatic systolic and/or diastolic left ventricular (LV) dysfunction (asymLVD) in patients with normal LV ejection fraction (LVEF). Purpose of our study was to assess the prevalence and factors associated with asymLVD in DM patients by echocardiographic indexes more sensitive than LVEF and transmitral flow detected by pulsed Doppler.

METHODS

386 DM patients without overt cardiac disease were enrolled from January to October 2011. Stress-corrected midwall shortening (sc-MS) and mitral annular peak systolic velocity (S') were considered as indexes of systolic function of circumferential and longitudinal myocardial fibers, respectively. Early diastolic velocity of transmitral flow was divided by early diastolic Tissue Doppler velocity of mitral annulus for identifying diastolic LVD.

RESULTS

asymLVD was detected in 262 patients (68%). 106 (27%) had isolated systolic asymLVD, 61 (16%) isolated diastolic asymLVD; in 95 (25%) systolic and diastolic asymLVD coexisted. Patients with asymLVD were older, had lower glomerular filtration rate, higher levels of glycated hemoglobin, C reactive protein, LV mass, relative wall thickness and prevalence of valve calcifications. Older age (HR 1.1 [1.02-1.18], p=0.01), aortic valve calcifications (HR 6.3 [1.31-30.31], p=0.02), LV concentric geometry defined as relative wall thickness ≥0.43 (HR 15.44 [2.96-80.44], p=0.001) were independent predictors of asymLVD at multivariate analysis.

CONCLUSIONS

Using suitable echocardiographic indexes, asymLVD is detectable in two/third of DM patients without overt cardiac disease and is predicted by older age, cardiac valve calcifications and LV concentric remodeling.

Genetic variants predicting left ventricular hypertrophy in a diabetic population: a Go-DARTS study including meta-analysis

Background

Left ventricular hypertrophy has multiple aetiologies including diabetes and genetic factors. We aimed to identify genetic variants predicting left ventricular hypertrophy in diabetic individuals.

Methods

Demographic, echocardiographic, prescribing, morbidity, mortality and genotyping databases connected with the Genetics of Diabetes Audit and Research in Tayside, Scotland project were accurately linked using a patient-specific identifier. Left ventricular hypertrophy cases were identified using echocardiographic data.

Genotyping data from 973 cases and 1443 non-left ventricular hypertrophy controls were analysed, investigating whether single nucleotide polymorphisms associated with left ventricular hypertrophy in previous Genome Wide Association Studies predicted left ventricular hypertrophy in our population of individuals with type 2 diabetes. Meta-analysis assessed overall significance of these single nucleotide polymorphisms, which were also used to create gene scores. Logistic regression assessed whether these scores predicted left ventricular hypertrophy.

Results

Two single nucleotide polymorphisms previously associated with left ventricular hypertrophy were significant: rs17132261: OR 2.03, 95% CI 1.10-3.73, p-value 0.02 and rs2292462: OR 0.82, 95% CI 0.73-0.93 and p-value 2.26x10^-3. Meta-analysis confirmed rs17132261 and rs2292462 were associated with left ventricular hypertrophy (p=1.03x10^-8 and p=5.86x10^-10 respectively) and one single nucleotide polymorphisms in IGF1R (rs4966014) became genome wide significant upon meta-analysis although was not significant in our study. Gene scoring based on published single nucleotide polymorphisms also predicted left ventricular hypertrophy in our study.

Rs17132261, within SLC25A46, encodes a mitochondrial phosphate transporter, implying abnormal myocardial energetics contribute to left ventricular hypertrophy development. Rs2292462 lies within the obesity-implicated neuromedin B gene. Rs4966014 lies within the IGF1R1 gene. IGF1 signalling is an established factor in cardiac hypertrophy.

Conclusions

We created a resource to study genetics of left ventricular hypertrophy in diabetes and validated our left ventricular hypertrophy phenotype in replicating single nucleotide polymorphisms identified by previous genome wide association studies investigating left ventricular hypertrophy.

The limited clinical value of a specific diabetic cardiomyopathy

AIMS

Diabetic patients show a higher likelihood of developing heart failure (HF), independently of the atherosclerotic process, than their nondiabetic counterparts. This suggests the presence of an intrinsic vulnerability of the heart in patients with diabetes mellitus.

DATA SYNTHESIS

A cardiomyopathy specific to the diabetic patient was first hypothesized by Rubler and co-workers, in 1972 and recognized as a nosologic entity by the World Health Organization (WHO) in 1995. All patients falling under Rubler's definition had ascertained diabetic glomerusclerosis, but were unaffected by major coronary artery disease (CAD). Notably, the mean plasma glucose in those patients was 417 ± 209 mg/dl. Since then, several studies conducted in both animals and in humans have focused on pathogenetic mechanisms, clinical manifestations, diagnostic as well as therapeutic approaches utilized for the treatment of diabetic cardiomyopathy (DCM). Despite the large body of literature available, the clinical entity and significance of this diabetic complication continue to be elusive.

CONCLUSIONS

In the present report, recent pathophysiological findings and diagnostic strategies to treat DCM are reviewed. Particular attention is dedicated to the clinical manifestation of DCM, that is to heart failure (HF), and to the implications of co-morbidities and metabolic control on its evolution.

A genetic variant of the atrial natriuretic peptide gene is associated with left ventricular hypertrophy in a non-diabetic population--the Malmö preventive project study

Background

Epidemiological studies have shown considerable heritability of blood pressure, thus suggesting a role for genetic factors. Previous studies have shown an association of a single nucleotide polymorphism rs5068 in the NPPA locus gene with higher levels of circulating atrial natriuretic peptide as well as with lower intra individual blood pressure, but up to date, no association between rs5068 and cardiac organ damage, i.e. left ventricular hypertrophy, has been accounted for in humans. We sought to explore if rs5068 is associated with left ventricular hypertrophy as measured by echocardiographic examination in a non-diabetic population.

Methods

968 non-diabetic individuals from the Malmö Preventive Project (mean age 67 years; 31% women) were genotyped and examined with echocardiography. Logistic regression was used to adjust for covariates.

Results

The minor allele of rs5068 was associated with decreased prevalence of left ventricular hypertrophy (p = 0.021) after adjustment for sex and age. In the multivariate logistic analysis including; age, sex, systolic blood pressure, antihypertensive and/or cardioprotective treatment, body mass index and fasting plasma glucose, the association of rs5068 with left ventricular hypertrophy was, as expected, attenuated (p = 0.061).

Conclusion

In a non-diabetic population, the minor allele of rs5068 was associated with lower left ventricular mass. These findings suggest that rs5068, or genetic variants in linkage disequilibrium, might affect susceptibility to left ventricular hypertrophy and support the possible protective role of natriuretic peptides.

Diabetic cardiomyopathy: understanding the molecular and cellular basis to progress in diagnosis and treatment

Diabetes mellitus is an important and prevalent risk factor for congestive heart failure. Diabetic cardiomyopathy has been defined as ventricular dysfunction that occurs in diabetic patients independent of a recognized cause such as coronary artery disease or hypertension. The disease course consists of a hidden subclinical period, during which cellular structural insults and abnormalities lead initially to diastolic dysfunction, later to systolic dysfunction, and eventually to heart failure. Left ventricular hypertrophy, metabolic abnormalities, extracellular matrix changes, small vessel disease, cardiac autonomic neuropathy, insulin resistance, oxidative stress, and apoptosis are the most important contributors to diabetic cardiomyopathy onset and progression. Hyperglycemia is a major etiological factor in the development of diabetic cardiomyopathy. It increases the levels of free fatty acids and growth factors and causes abnormalities in substrate supply and utilization, calcium homeostasis, and lipid metabolism. Furthermore, it promotes excessive production and release of reactive oxygen species, which induces oxidative stress leading to abnormal gene expression, faulty signal transduction, and cardiomyocytes apoptosis. Stimulation of connective tissue growth factor, fibrosis, and the formation of advanced glycation end-products increase the stiffness of the diabetic hearts. Despite all the current information on diabetic cardiomyopathy, translational research is still scarce due to limited human myocardial tissue and most of our knowledge is extrapolated from animals. This paper aims to elucidate some of the molecular and cellular pathophysiologic mechanisms, structural changes, and therapeutic strategies that may help struggle against diabetic cardiomyopathy.

Influencing factors on cardiac structure and function beyond glycemic control in patients with type 2 diabetes mellitus

BACKGROUND

We hypothesized that clinical factors other than glycemic control may influence abnormal cardiac function in patients with type 2 diabetes mellitus (T2DM). We aimed to investigate the independent factors for abnormal cardiac function among clinical factors in T2DM.

METHODS

We studied 148 asymptomatic patients with T2DM without overt heart disease. Echocardiographic findings were compared between diabetic patients and 68 age-matched healthy subjects. Early (E) and late (A) diastolic mitral flow velocity and early diastolic mitral annular velocity (e') were measured for assessing left ventricular (LV) diastolic function. We evaluated insulin resistance, non-esterified fatty acid, high-sensitive CRP, estimated glomerular filtration rate, waist/hip ratio, abdominal visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and other clinical characteristics in addition to glycemic control. VAT and SAT were quantified by computed tomography.

RESULTS

In T2DM, E/A and e' were significantly lower, and E/e', left atrial volume and LV mass were significantly greater than in control subjects. In multivariate liner regression analysis, VAT was an independent determinant of left atrial volume (β =0.203, p=0.011), E/A (β =-0.208, p=0.002), e' (β =-0.354, p<0.001) and E/e' (β=0.220, p=0.003). Age was also an independent determinant, whereas fasting plasma glucose and hemoglobin A1c levels were not. In addition to systolic blood pressure, waist-hip ratio (β=0.173, p=0.024) and VAT/SAT ratio (β=0.162, p=0.049) were independent determinants of LV mass.

CONCLUSION

Excessive visceral fat accompanied by adipocyte dysfunction may play a greater role than glycemic control in the development of diastolic dysfunction and LV hypertrophy in T2DM.

[Echocardiography in diabetic cardiomyopathy]

The term diabetic cardiomyopathy was initially introduced in the 1980s when evidence was found that diabetes leads to a distinct cardiomyopathy, independent of coronary artery disease or hypertension. The detection of diabetic cardiomyopathy using echocardiography is challenging because no pathognomonic signs exist; however, it is the merit especially of the newer echocardiographic techniques, such as deformation imaging, that it is now possible to describe the morphology and function of diabetic hearts. Unfortunately, no long-term echocardiography studies are available describing disease progression in detail. Therefore, staging and differential diagnosis of diabetic cardiomyopathy remains challenging. This review tries to fill this gap by presenting a possible echocardiographic staging algorithm. Early stages of diabetic cardiomyopathy are marked by a deterioration of longitudinal systolic function and a compensative elevated radial function. Diastolic dysfunction is another early sign. When the disease progresses the functional deterioration is accompanied by morphological changes, such as left ventricular concentric hypertrophy and fibrosis. End stage disease is characterized by reduced ejection fraction and ventricular dilatation. Very late stage can mimic dilative cardiomyopathy.

Impact of obstructive sleep apnea on the global myocardial performance beyond obesity

We aimed to assess the impact of obstructive sleep apnea (OSA) on the left ventricular (LV) function independent of obesity using the myocardial performance index (Tei index) and the global longitudinal LV strain (GLS) and its reversibility after surgery. Twenty-five newly diagnosed OSA patients, normal weight (n = 15) and obese (body mass index [BMI] ≥ 25; n = 20) controls without OSA were enrolled and underwent transthoracic echocardiographic evaluation. The OSA and obese groups had a significantly comparable increased BMI and LV chamber dimension, prolonged isovolumic relaxation time, reduced early mitral filling velocity, and increased late mitral filling velocity and Tei index as compared to the normal weight group. However, GLS was significantly reduced only in the OSA group (-16.5 ± 1.9%) as compared to the normal weight group (-20.6 ± 2.0%, P < 0.001) and obese group (-19.1 ± 2.5%, P < 0.001). As a treatment, 13 of 25 patients underwent surgical modification, and the follow-up echocardiogram revealed significantly improved Tei index and GLS as compared to baseline (0.37 ± 0.06 and -18.9 ± 3.3% vs. 0.42 ± 0.04 and -16.3 ± 2.4%, P = 0.006 and 0.031, respectively), which was comparable to the obese controls. A reduction in the apnea-hypopnea index had a significant effect on the improvement in the GLS (r = 0.73, P < 0.001). LV systolic and diastolic function significantly deteriorated in the patients with OSA beyond obesity, and an improvement in the LV function was observed within 6 months after the surgical modification. GLS is considered to be one of the parameters that can be used in the early detection of LV systolic dysfunction in patients with OSA and a normal ejection fraction.

Echocardiographic abnormalities in the assessment of cardiac organ damage in never-treated hypertensive patients

Hypertension-related cardiac organ damage, other than left ventricular (LV) hypertrophy (LVH), has been described: in particular, concentric remodeling, LV diastolic dysfunction (DD), and left atrial (LA) enlargement are significantly associated with cardiovascular morbility and mortality in different populations. This study evaluated the prevalence of these latter morphofunctional abnormalities, in never-treated essential hypertensive patients and the role of such a serial assessment of hypertensive cardiac damage in improving cardiovascular risk stratification in these patients. A total of 100 never-treated essential hypertensive subjects underwent a complete clinical and echocardiographic evaluation. Left ventricular morphology, systolic and diastolic function, and LA dimension (linear and volume) were evaluated by echocardiography. Left ventricular hypertrophy was present in 14% of the patients, whereas concentric remodeling was present in 25% of the subjects. Among patients free from LV morphology abnormalities, the most frequent abnormality was LA enlargement (global prevalence 57%); the percentage of patients with at least one parameter consistent with DD was 22% in the entire population, but DD was present as the only cardiac abnormality in 1% of our patient. Left atrial volume indexed for body surface area was the most sensitive parameter in identifying hypertension-related cardiac modification. The global prevalence of cardiac alteration reached 73% in never-treated hypertensive patients. Left ventricular remodeling and LA enlargement evaluation may grant a better assessment of cardiac organ damage and cardiovascular risk stratification of hypertensive patients without evidence of LVH after routine examination.

Effects of valsartan or ramipril addition to amlodipine/hydrochlorothiazide combination on left ventricular mass in diabetic hypertensive patients with left ventricular hypertrophy

OBJECTIVE

The objective of this study was to compare valsartan or ramipril addition to amlodipine + hydrochlorothiazide (HCTZ) on blood pressure (BP) and left ventricular hypertrophy (LVH) in hypertensive diabetic patients with LVH.

RESEARCH DESIGN AND METHODS

293 patients were treated with amlodipine 10 mg + HCTZ 12.5 combination and then randomized to receive valsartan 160 mg or ramipril 5 mg, in addition to the previous therapy, for 1 year.

MAIN OUTCOME MEASURES

Clinic BP was measured every month; echocardiographic assessments were performed at the end of the placebo period, both before the randomization and after 1-year of triple combination therapy.

RESULTS

Both triple regimens similarly reduced SBP/DBP values (-13.5/10.9 mm Hg in the valsartan group and -13.4/10.4 mm Hg in the ramipril group). Triple combination including valsartan better reduced LVMI (-20.1%, p < 0.001), interventricular septal thickness (IVST) (-20.3%, p < 0.001) and left ventricular posterior wall thickness (PWT) (-16.3%, p < 0.001), compared with triple combination including ramipril (-14%, p < 0.01; -16.2%, p < 0.001 and -9%, p < 0.01, respectively); the difference between treatments being statistically significant (p < 0.05). Triple combination with valsartan gave a greater increase of E/A ratio (p < 0.05 between groups).

CONCLUSIONS

Valsartan addition to dual therapy with amlodipine + HCTZ was more effective than ramipril addition in reducing LVH.

Diabetic cardiomyopathy: myth or reality?

Diabetes mellitus has reached an epidemic level worldwide. Cardiovascular diseases are the primary cause of death in diabetic patients, not only because of coronary artery disease and associated hypertension but also because of a direct adverse effect of diabetes on the heart, independent of other potential aetiological factors. However, the existence of this 'diabetic cardiomyopathy' remains controversial. We aimed to review current evidence for the existence of diabetic cardiomyopathy, focusing particularly on the clinical setting.

Losartan and amlodipine on myocardial structure and function: a prospective, randomized, clinical trial

AIMS

To compare the effects of losartan and amlodipine on myocardial structure and function in hypertensive patients with Type 2 diabetes and left ventricular hypertrophy.

METHODS

After a 4-week placebo period, patients were randomized to losartan 50 mg (n = 90) or amlodipine 5 mg (n = 91) for 12 months, with a doubling of the dose in patients who did not respond after 4 weeks. Blood pressure was measured in the clinic every month, while conventional echocardiography and acoustic densitometry (integrated backscatter analysis) were performed at the end of the placebo period and after 12 months of treatment.

RESULTS

Both drugs reduced systolic/diastolic blood pressure to a comparable extent. Losartan significantly reduced left ventricular mass index (-19%, P < 0.001), interventricular septal thickness (-16.6%, P < 0.01) and left ventricular posterior wall thickness in diastole (-13.7%, P < 0.01). Amlodipine also decreased such measurements (-10%, P < 0.01 for left ventricular mass index, -9.3%, P < 0.05 for interventricular septal thickness in diastole and -10.1%, P < 0.05 for posterior wall thickness in diastole), but to a lesser extent than losartan. Both drugs significantly increased the ratio of peak filling velocity at early diastole to that at atrial contraction (E/A ratio) and decreased isovolumetric relaxation time: +13.7% and -8.5% with losartan,(both P < 0.01), and +7.9% and -4.9%, with amlopidine (both P < 0.05). Losartan, but not amlodipine, significantly reduced the relative integrated backscatter compared to baseline of the intraventricular septum (-10%, P < 0.01), and of the left ventricular posterior wall (-12%, P < 0.01), while increasing the cyclic variation of integrated backscatter of both the intraventricular septum (+35%, P < 0.001) and the left ventricular posterior wall (+32%, P < 0.001).

CONCLUSIONS

Losartan provided a greater attenuation of left ventricular hypertrophy than amlodipine, seemingly as a result of a greater reduction of myocardial fibrosis.

The Effect of Metabolic Syndrome on Myocardial Contractile Reserve during Exercise in Non-Diabetic Hypertensive Subjects

Background

Metabolic syndrome (MS) is associated with increased left ventricular (LV) mass and diastolic dysfunction. This study uses relatively load-independent Doppler tissue echocardiography to examine whether MS is associated with decreased longitudinal contractile reserve during dynamic exercise.

Methods

A total of 112 patients with relatively well-controlled, treated hypertension who complained of exertional dyspnea were enrolled (average age: 56.7 ± 10.5 years). Fifty-six were non-diabetic patients with MS (Group 1), and 56 were age-sex matched hypertensive patients without MS (Group 2). Exercise stress echo was performed using a symptom-limited, multistage, supine bicycle exercise test. Multiple Doppler parameters were obtained at baseline, at each stage of exercise, and during recovery.

Results

There was no significant difference between the two groups in terms of age, gender, and hemodynamic variables. E/E', an index of LV filling pressure, was significantly higher in the MS group at rest and during exercise. The longitudinal contractile reserve, the change in S' (longitudinal tissue velocity) from baseline to peak exercise, was significantly lower in the MS group (2.00 ± 1.65 vs. 2.90 ± 1.66, p = 0.015). Multiple regression analysis showed independent association of MS with longitudinal contractile reserve when controlled for confounding factors, such as LV mass index, gender, blood pressure, and age (β = -0.235, p = 0.035).

Conclusion

Longitudinal contractile reserve was reduced in MS patients compared to others, although both groups demonstrated similar longitudinal contractile function at rest. We present the first demonstration that metabolic syndrome is independently associated with LV systolic dysfunction during exercise in hypertensive patients.

Early alterations in left ventricular diastolic function in normotensive diabetic patients

In diabetes mellitus, structural and functional alterations of the heart can be already present at the time of first diagnosis. However, how early these alterations may occur has never been fully clarified. The present study aimed at investigating cardiac functional abnormalities in uncomplicated hypertensive or normotensive patients with a recent diagnosis of diabetes mellitus. We studied 40 diabetics (24 normotensives and 16 hypertensives) by means of routine echocardiography plus pulse tissue Doppler analysis. Data were compared with those obtained in healthy age- and sex-matched controls. Left ventricular remodelling was more evident in hypertensive diabetics than in normotensive diabetics vs controls. Diastolic function was altered in diabetic patients only when detected by pulse tissue Doppler analysis and not by conventional transmitral Doppler evaluation. Normotensive patients with type 2 diabetes with little or no evidence at standard echocardiography of alterations in cardiac structure and function, already displayed an alteration in diastolic function when the evaluation was based on the tissue Doppler approach. Patients with type 2 diabetes combined to hypertension showed more evident functional cardiac alterations at echocardiography. These findings support the conclusion that cardiac abnormalities are very early phenomena in type 2 diabetes.

Diabetes and the risk of heart failure

Prevalence of diabetes and heart failure are increasing exponentially worldwide. Diabetes is well-known to increase the risk of heart failure independent of other traditional risk factors and ischemia. Current evidence indicates the presence of several biochemical and molecular changes associated with diabetes that lead to diastolic dysfunction or American Heart Association stage B heart failure. Some, if not all, changes may also predate the development of frank diabetes. In this review, the authors present some of the epidemiologic evidence and a brief description of major mechanistic pathways that favor the development of heart failure in prediabetic and diabetic states.

Effects of perindopril-indapamide on left ventricular diastolic function and mass in patients with type 2 diabetes: the ADVANCE Echocardiography Substudy

BACKGROUND

The Action in Diabetes and Vascular Disease (ADVANCE) Study demonstrated that a fixed combination of perindopril and indapamide reduced the risk of major vascular events and mortality in patients with type 2 diabetes. This Echocardiographic Substudy was designed to determine the effects of this treatment on left ventricular diastolic function and left ventricular mass.

METHODS

Five hundred and fifty-five patients entering ADVANCE underwent quantitative echocardiography prior to randomization and after 6 months and 4 years of treatment with perindopril-indapamide or placebo. Main end points were left ventricular diastolic function (ratio of mitral E velocity/early medial mitral annular tissue Doppler velocity, E/Em, and left atrial volume index) and left ventricular mass index.

RESULTS

Overall, blood pressure was reduced in the perindopril-indapamide group compared with placebo. E/Em and left atrial volume index both increased over the 4 years. There was no effect of perindopril-indapamide on E/Em, although there was a small attenuation of the increase in left atrial volume index with active treatment. Left ventricular mass index was reduced by 2.7 g/m with active treatment (95% confidence interval -5.0 to -0.1, P = 0.04).

CONCLUSION

Compared with placebo, the perindopril-indapamide combination reduced blood pressure and left ventricular mass in patients with diabetes, but did not improve left ventricular diastolic function. Left ventricular diastolic function worsened in both groups over 4 years, despite blood pressure reduction and reduction in left ventricular mass. Improving left ventricular diastolic function remains a challenge in patients with diabetes.

Cardiac structure and function, remodeling, and clinical outcomes among patients with diabetes after myocardial infarction complicated by left ventricular systolic dysfunction, heart failure, or both

AIMS

The mechanisms responsible for the increased risk of heart failure (HF) post-myocardial infarction (MI) may differ between patients with versus without diabetes. We hypothesized that after high-risk MI, patients with diabetes would demonstrate patterns of remodeling that are suggestive of reduced ventricular compliance and that are associated with an increased risk of death or HF.

METHODS AND RESULTS

We performed quantitative echocardiographic analysis in 153 patients with diabetes and 451 patients without diabetes enrolled in the VALIANT Echo study. Diabetes was associated with a higher risk of death or HF in age-adjusted models (hazard ratio 1.44, 95% CI 1.04-2.00, P = .028). Diabetic patients were similar to nondiabetic patients with respect to left ventricular (LV) volume and ejection fraction but had higher LV mass index (104.1 ± 27.5 vs 97.1 ± 28.6 g/m(2), P = .009), relative wall thickness (0.41 ± 0.08 vs 0.38 ± 0.07, P < .0001), and left atrial volume index (LAVi) (26.2 ± 8.1 vs 24.0 ± 8.2 mL/m(2), P = .008)-all parameters that were significantly related to the risk of death or HF hospitalization. Changes in LV volume and ejection fraction from baseline to 20 months were not different, although diabetic patients demonstrated greater increase in LAVi (4.4 ± 7.7 vs 2.2 ± 6.7 mL/m(2), P = .01).

CONCLUSIONS

After high-risk MI, diabetic patients were at higher risk of death or HF and demonstrated greater baseline LV mass index, relative wall thickness, and LAVi as well as greater left atrial enlargement at 20-month follow-up. These findings suggest greater baseline concentric remodeling and long-term elevation in LV diastolic pressure post-MI among diabetic patients, which may partially mediate this risk.

Left ventricular systolic and diastolic function, remodelling, and clinical outcomes among patients with diabetes following myocardial infarction and the influence of direct renin inhibition with aliskiren

AIMS

We assessed the relationship between diabetes and cardiac structure and function following myocardial infarction (MI) and whether diabetes influences the effect of direct renin inhibition on change in left ventricular (LV) size.

METHODS AND RESULTS

The ASPIRE trial enrolled 820 patients 2-8 weeks after MI with ejection fraction ≤ 45% and randomized them to the direct renin inhibitor aliskiren (n= 423) or placebo (n = 397) added to standard medical therapy. Echocardiography was performed at baseline and after 36 weeks in 672 patients with evaluable paired studies. Compared with non-diabetic patients, diabetic patients (n = 214) were at higher risk for a composite of cardiovascular (CV) death, heart failure hospitalization, recurrent MI, stroke, or aborted sudden death (14 vs. 7%; adjusted hazard ratio 1.63, 95% confidence interval 1.01-2.64, P= 0.045), despite similar left ventricular ejection fraction (37.9 ± 5.3 vs. 37.6 ± 5.2%, P= 0.48) and end-systolic volume (ESV) (84 ± 25 vs. 82 ± 28 mL, P= 0.46). Diabetic patients demonstrated greater concentric remodelling (relative wall thickness 0.38 ± 0.07 vs. 0.36 ± 0.07, P= 0.0002) and evidence of higher LV filling pressure (E/E' 11.1 ± 5.3 vs. 9.1 ± 4.3, P= 0.0011). At 36 weeks, diabetic patients experienced similar per cent reduction in ESV overall (-4.9 ± 17.9 vs. -5.5 ± 16.9, P= 0.67) but tended to experience greater reduction in ESV than non-diabetic patients when treated with aliskiren (interaction P = 0.08).

CONCLUSIONS

Compared with non-diabetic patients, diabetic patients are at increased risk of CV events post-MI despite no greater LV enlargement or reduction in systolic function. Diabetic patients demonstrate greater concentric remodelling and evidence of higher LV filling pressure, suggesting diastolic dysfunction as a potential mechanism for the higher risk observed among these patients.

Comparison of left ventricular mass in normotensive type 2 diabetes mellitus patients with that in the nondiabetic population

Cardiovascular disease is increased in individuals with type 1 or type 2 diabetes mellitus (DM). Left ventricular hypertrophy (LVH), which is an ominous prognostic sign and an independent risk factor for cardiac events, is often present in type 2 DM patients. The aim of our cross-sectional study was to evaluate the prevalence of LVH, and risk factors for its development, in normotensive type 2 diabetic patients without antihypertensive medication. The objectives of the study were to find out the prevalence of high left ventricular mass (LVM) in normotensive type 2 diabetic patients and compare it with nondiabetics and to uncover the risk factors for the development of high LVM in normotensive type 2 diabetic patients. A total of 130 age- and sex-matched subjects were selected (65 cases, diabetic normotensive, and 65 controls, nondiabetic normotensive) and baseline data were collected. LVM and left ventricular mass index (LVMI) were calculated using echocardigraphic parameters and body surface area. LVMI was significantly higher in patients with type 2 DM compared with age-, sex-matched healthy population (104.9 ± 21 vs. 78.5 ± 22.7 g/m², respectively; P < 0.05). BMI, HbA1c, and duration of diabetes were significantly associated with LVH whereas sexes, age, PPBS, were not.

The effects of obesity and type 2 diabetes mellitus on cardiac structure and function in adolescents and young adults

AIMS/HYPOTHESIS

We sought to evaluate the effects of obesity and obesity-related type 2 diabetes mellitus on cardiac geometry (remodelling) and systolic and diastolic function in adolescents and young adults.

METHODS

Cardiac structure and function were compared by echocardiography in participants who were lean, obese or obese with type 2 diabetes (obese diabetic), in a cross sectional study. Group differences were assessed using ANOVA. Independent determinants of cardiac outcome measures were evaluated with general linear models.

RESULTS

Adolescents with obesity and obesity-related type 2 diabetes were found to have abnormal cardiac geometry compared with lean controls (16% and 20% vs <1%, p < 0.05). These two groups also had increased systolic function. Diastolic function decreased from the lean to obese to obese diabetic groups with the lowest diastolic function observed in the obese diabetic group (p < 0.05). Regression analysis showed that group, BMI z score (BMIz), group × BMIz interaction and systolic BP z score (BPz) were significant determinants of cardiac structure, while group, BMIz, systolic BPz, age and fasting glucose were significant determinants of the diastolic function (all p < 0.05).

CONCLUSIONS/INTERPRETATION

Adolescents with obesity and obesity-related type 2 diabetes demonstrate changes in cardiac geometry consistent with cardiac remodelling. These two groups also demonstrate decreased diastolic function compared with lean controls, with the greatest decrease observed in those with type 2 diabetes. Adults with diastolic dysfunction are known to be at increased risk of progressing to heart failure. Therefore, our findings suggest that adolescents with obesity-related type 2 diabetes may be at increased risk of progressing to early heart failure compared with their obese and lean counterparts.

The inter-relationship of diabetes and left ventricular systolic function on outcome after high-risk myocardial infarction

AIMS

Diabetes is a potent risk factor for death and heart failure (HF) hospitalization following myocardial infarction (MI). Whether diabetes modifies the relationship between left ventricular ejection fraction (LVEF) and outcomes in the post-MI population is unknown.

METHODS AND RESULTS

The Valsartan in Acute Myocardial Infarction trial (VALIANT) enrolled 14 703 patients with acute MI complicated by HF, systolic dysfunction, or both. We compared the risk of death, HF hospitalization, and/or recurrent MI among patients with and without diabetes using Cox proportional hazards models. To assess the relationship between diabetes, LVEF and outcomes, we assessed the relative influence of baseline LVEF on outcomes in diabetic and non-diabetic patients. Totally, 11 325 subjects (3095 diabetics) with site-reported LVEF and known diabetes status were included. At any given LVEF, diabetes was associated with a higher risk of all-cause mortality [adjusted hazard ratio (HR) 1.37, 95% CI 1.25-1.51], death or HF hospitalization (adjusted HR 1.42, 95% CI 1.31-1.51), and death or recurrent MI (adjusted HR 1.36, 95% CI 1.24-1.48). Diabetes modified the relationship between LVEF and death or HF hospitalization (P for interaction = 0.0109), such that the association between diabetes and increased risk was greater in magnitude at higher LVEF. No interaction was noted between diabetes and LVEF on risk of all-cause mortality or death or recurrent MI.

CONCLUSION

Diabetes is associated with a higher risk of death or HF hospitalization across the spectrum of LVEF in high-risk post-MI patients. The magnitude of reduction in risk of death or HF hospitalization associated with increasing LVEF is significantly attenuated among patients with diabetes when compared to patients without diabetes.

The impact of hypertension and diabetes on outcome in patients undergoing percutaneous coronary intervention

OBJECTIVE

Information relating the outcome of percutaneous coronary intervention to diabetes mellitus or hypertension is limited. The study objective was to describe the outcome in patients undergoing percutaneous coronary intervention in relation to diabetes and hypertension.

METHODS

Data were extracted from 5 national registers: the Swedish Coronary Angiography and Angioplasty Register (all percutaneous coronary interventions), the Prescribed Drug Registry (all prescribed pharmaceuticals purchased in Swedish pharmacies), the Swedish Hospital Discharge Register (data on myocardial infarction, revascularization, stroke, and congestive heart failure from in-hospital and specialist health care), and the National Population Register and Cause of Death Register (data on death). We included all "first percutaneous coronary interventions" between January 1, 2006, and December 31, 2008 (n=44,268; followed an average of 1.9 [± 0.9] years).

RESULTS

Mortality was 6.4% and highest in patients with diabetes plus hypertension. Hypertension per se did not increase mortality or the risk for repeat intervention, but carried a 10% increased risk for subsequent myocardial infarction, increasing to a 4-fold increase when combined with diabetes. Stroke occurred in 2%; the importance of hypertension was evident in nondiabetic patients, but even stronger in diabetic patients. Congestive heart failure caused hospital admission in 8%, with a negative influence from hypertension with and without diabetes.

CONCLUSION

After percutaneous coronary intervention and with modern pharmacotherapy, diabetes had a negative effect on the outcome, especially when combined with hypertension. Hypertension per se was not associated with increased mortality but with an increased risk for myocardial infarction, stroke, and congestive heart failure, probably related to widespread coronary artery disease. Improved diabetes care might improve the prognosis.

Implications of prevalent and incident diabetes mellitus on left ventricular geometry and function in the ageing heart: the MONICA/KORA Augsburg cohort study

BACKGROUND AND AIM

It is unclear to what extent diabetes modulates the ageing-related adaptations of cardiac geometry and function.

METHODS AND RESULTS

We examined 1005 adults, aged 25-74 years, from a population-based survey at baseline in 1994/5 and at follow-up in 2004/5. We compared persistently non-diabetic individuals (ND; no diabetes at baseline and at follow-up, n=833) with incident (ID; non-diabetic at baseline and diabetic at follow-up, n=36) and with prevalent diabetics (PD; diabetes at baseline and follow-up examination, n=21). Left ventricular (LV) geometry and function were evaluated by echocardiography. Statistical analyses were performed with multivariate linear regression models. Over ten years the PD group displayed a significantly stronger relative increase of LV mass (+9.34% vs. +23.7%) that was mediated by a more pronounced increase of LV end-diastolic diameter (+0% vs. +6.95%) compared to the ND group. In parallel, LA diameter increased (+4.50% vs. +12.7%), whereas ejection fraction decreased (+3.02% vs. -4.92%) more significantly in the PD group. Moreover, at the follow-up examination the PD and ID groups showed a significantly worse diastolic function, indicated by a higher E/EM ratio compared with the ND group (11.6 and 11.8 vs. 9.79, respectively).

CONCLUSIONS

Long-standing diabetes was associated with an acceleration of age-related changes of left ventricular geometry accumulating in an eccentric remodelling of the left ventricle. Likewise, echocardiographic measures of systolic and diastolic ventricular function deteriorated more rapidly in individuals with diabetes.

Global left ventricular performance in non-diabetic non-hypertensive metabolic syndrome adults

AIM

To evaluate the left ventricular structure and function in isolated metabolic syndrome.

METHODS

One hundred and fifty six consecutive adults with metabolic syndrome were enrolled in the study. Fifty nine had isolated metabolic syndrome (group A) and 97 had metabolic syndrome with hypertension and/or diabetes (group B). There was a control group of 34 healthy adults. In addition to classic echocardiographic assessment of myocardial structural and functional changes, the Tei index was used to evaluate global left ventricular performance.

RESULTS

There were no statistically significant differences between group A and controls in all parameters of left ventricular structural, systolic, and diastolic function except global myocardial performance (Tei index). On the other hand, significant differences were observed between group B and the control group in most of the parameters of left ventricular structural and global performance.

CONCLUSION

The early identification of isolated metabolic syndrome in non-diabetic, non-hypertensive adults may be an indication that aggressive preventive measures should not be postponed until overt obesity, hypertension or diabetes mellitus has developed.

The adverse impact of diabetes mellitus on left ventricular remodeling and function in patients with severe aortic stenosis

BACKGROUND

The diabetic heart exhibits increased left ventricular (LV) mass and reduced ventricular function. However, this relationship has not been studied in patients with aortic stenosis (AS), a disease process that causes LV hypertrophy and dysfunction through a distinct mechanism of pressure overload. The aim of this study was to determine how diabetes mellitus (DM) affects LV remodeling and function in patients with severe AS.

METHODS AND RESULTS

Echocardiography was performed on 114 patients with severe AS (mean aortic valve area [AVA], 0.6 cm(2)) and included measures of LV remodeling and function. Multivariable linear regression models investigated the independent effect of DM on these aspects of LV structure and function. Compared to patients without diabetes (n=60), those with diabetes (n=54) had increased LV mass and LV end-systolic and end-diastolic dimensions, and decreased LV ejection fraction (EF) and longitudinal systolic strain (all P<0.01). In multivariable analyses adjusting for age, sex, systolic blood pressure, AVA, body surface area, and coronary disease, DM was an independent predictor of increased LV mass (β=26 g, P=0.01), LV end-systolic dimension (β=0.5 cm, P=0.008), and LV end-diastolic dimension (β=0.3 cm, P=0.025). After also adjusting for LV mass, DM was associated with reduced longitudinal systolic strain (β=1.9%, P=0.023) and a trend toward reduced EF (β=-5%, P=0.09). Among patients with diabetes, insulin use (as a marker of disease severity) was associated with larger LV end-systolic dimension and worse LV function. LV mass was a strong predictor of reduced EF and systolic strain (both P<0.001).

CONCLUSIONS

DM has an additive adverse effect on hypertrophic remodeling (increased LV mass and larger cavity dimensions) and is associated with reduced systolic function in patients with AS beyond known factors of pressure overload.

Role of oxidative stress and indoxyl sulfate in progression of cardiovascular disease in chronic kidney disease

Several abnormalities of the cardiovascular system are observed in most cases of chronic kidney disease (CKD). Mechanisms underlying these abnormalities are complicated, and several factors contribute to their pathogenesis. Of these factors, oxidative stress and uremic toxins are considered to play key roles in the progression of cardiovascular disease (CVD) in CKD. Oxidative stress increases significantly in CKD and accelerates proteinuria and renal dysfunction. In addition, oxidative stress has been reported to induce cardiac hypertrophy and fibrosis. Indoxyl sulfate, a uremic toxin, has recently been suggested to play a crucial role in the development of CVD. Recent in vitro data suggest that indoxyl sulfate increases oxidative stress. Some reports have shown that AST-120, which is an oral charcoal adsorbent, can reduce oxidative stress by lowering serum indoxyl sulfate levels. Recently, we have also demonstrated that indoxyl sulfate is associated with the production of oxidative stress, and that increased oxidative stress is significantly correlated with cardiac hypertrophy and fibrosis. Furthermore, results of our basic and clinical studies suggested that AST-120 can prevent progression of cardiac hypertrophy by reducing oxidative stress in CKD. Thus, one of the main targets of the management of CKD and CVD is the control of oxidative stress and uremic toxins, such as indoxyl sulfate.

Systemic hemodynamics in young adults with the metabolic syndrome: the Cardiovascular Risk in Young Finns Study

OBJECTIVE

We conducted the present study to examine associations of three different metabolic syndrome (MetS) definitions and their components to arterial stiffness, systemic vascular resistance, and left ventricular function at population level. In addition, the objective of the study was to examine associations of spontaneous recovery from MetS over 6 years' follow-up to systemic hemodynamics.

METHODS

The study population consisted of 1,741 Finnish young adults (aged 30-45 years) who had complete MetS risk factor and hemodynamic data available at 2007. Associations of spontaneous recovery from MetS to systemic hemodynamics was studied on a subpopulation of 1,391 subjects who had also complete MetS risk factor data available at 2001. Hemodynamic measurements were performed using a whole-body impedance cardiography device.

RESULTS

MetS and increasing number of MetS components were associated with lower stroke index (P < 0.001) and higher systemic vascular resistance index (P < 0.005) and arterial pulse wave velocity (P < 0.005). In MetS persistent group, stroke index was lower (P = 0.024), and pulse wave velocity was higher (P = 0.003) compared to MetS recovery group.

CONCLUSION

All current MetS definitions identify young adults with altered systemic hemodynamics, and recovery from MetS is associated with a favorable hemodynamic profile.

Diabetic cardiomyopathy: from the pathophysiology of the cardiac myocytes to current diagnosis and management strategies

Diabetic cardiomyopathy (DCM), although a distinct clinical entity, is also a part of the diabetic atherosclerosis process. It may be independent of the coexistence of ischemic heart disease, hypertension, or other macrovascular complications. Its pathological substrate is characterized by the presence of myocardial damage, reactive hypertrophy, and intermediary fibrosis, structural and functional changes of the small coronary vessels, disturbance of the management of the metabolic cardiovascular load, and cardiac autonomic neuropathy. These alterations make the diabetic heart susceptible to ischemia and less able to recover from an ischemic attack. Arterial hypertension frequently coexists with and exacerbates cardiac functioning, leading to the premature appearance of heart failure. Classical and newer echocardiographic methods are available for early diagnosis. Currently, there is no specific treatment for DCM; targeting its pathophysiological substrate by effective risk management protects the myocardium from further damage and has a recognized primary role in its prevention. Its pathophysiological substrate is also the objective for the new therapies and alternative remedies.

Correlates of echocardiographic indices of cardiac remodeling over the adult life course: longitudinal observations from the Framingham Heart Study

BACKGROUND

The heart progressively remodels over the life course, yet longitudinal data characterizing such remodeling in the community are limited.

METHODS AND RESULTS

Using multilevel modeling, we analyzed up to 4 serial echocardiographic observations obtained over a 16-year period in 4062 Framingham Heart Study participants (mean age 45 years, 54% women; 11 485 person-observations). We related left ventricular (LV) wall thickness, LV systolic and diastolic dimensions, and fractional shortening to age, sex, body mass index, blood pressure (including antihypertensive medication use), smoking, and diabetes mellitus (separate analyses for each echocardiographic measure). With advancing age, LV dimensions decreased, whereas fractional shortening and LV wall thickness increased concomitantly. Male sex, body mass index, and blood pressure indices/hypertension treatment were significantly related to both greater LV dimensions and LV wall thickness. The effect of age on cardiac remodeling was influenced by key covariates (P<0.05 for all interactions): Women and individuals with diabetes mellitus experienced greater age-associated increases in LV wall thickness; presence of diabetes or a higher blood pressure was associated with a lesser decrease in LV diastolic dimensions with increasing age; and antihypertensive medication use was a marker of an attenuated increase in fractional shortening with aging.

CONCLUSIONS

Cardiac remodeling over the adult life course is characterized by a distinct pattern of increasing LV wall thickness, decreasing LV dimensions, and increasing fractional shortening with advancing age. Overall, female sex, greater blood pressure load, and presence of diabetes mellitus serve to attenuate this remodeling pattern. These observations suggest a mechanism for the preponderance of women with hypertension and individuals with diabetes among patients with diastolic heart failure.

Effect of diabetes and hypertension on left ventricular diastolic function in a high-risk population without evidence of heart disease

AIMS

To assess the independent and combined effects of diabetes and hypertension on left ventricular (LV) diastolic function in a community-based cohort at high cardiovascular risk.

METHODS AND RESULTS

Two-dimensional echocardiography was performed in 708 subjects from the Cardiac Abnormalities and Brain Lesions (CABL) study. Peak diastolic early (E) and late (A) transmitral flow, and tissue Doppler-derived early mitral annulus velocity (E') were recorded, and E/A and E/E' ratios were calculated. The population was divided into four groups: those without hypertension or diabetes (HT-/DM-), those with only hypertension (HT), only diabetes (DM), and with hypertension plus diabetes (HT + DM). In multivariate analysis, hypertension and diabetes were independent predictors of worse diastolic function. The coexistence of hypertension and diabetes was associated with greater impairment of diastolic function (higher E/E' ratio than HT-/DM-, HT, or DM, all P < 0.05), independent of covariates. The negative, synergistic effect of hypertension and diabetes on LV diastolic function was present both in lean participants and in overweight/obese ones. An E/E' ratio >15, suggestive of increased LV filling pressure, was found in 2.2% of HT-/DM-, 8.9% of HT, 5.9% of DM, and 14.7% of HT + DM (P < 0.01).

CONCLUSION

Hypertension and diabetes are independently associated with impaired LV diastolic function, independent of the effect of overweight/obesity and other covariates. Their coexistence results in a negative synergistic effect on LV diastolic mechanics and is associated with higher LV filling pressures than either condition alone.

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.

The development of heart failure in patients with diabetes mellitus and pre-clinical diastolic dysfunction a population-based study

OBJECTIVES

The purpose of this study was to evaluate the outcomes of pre-clinical diastolic dysfunction in diabetic patients.

BACKGROUND

Studies have reported a high prevalence of pre-clinical diastolic dysfunction among patients with diabetes mellitus.

METHODS

We identified all diabetic patients with a tissue Doppler imaging assessment of diastolic function in Olmsted County, Minnesota, from 2001 to 2007. Diastolic dysfunction was defined as a passive transmitral left ventricular (LV) inflow velocity to tissue Doppler imaging velocity of the medial mitral annulus during passive filling (E/e') ratio >15. The main outcome was the development of heart failure (HF). Secondary outcomes were the development of atrial fibrillation and death.

RESULTS

Overall, 1,760 diabetic patients with a tissue Doppler echocardiographic assessment of diastolic function were identified; 411 (23%) patients had diastolic dysfunction. Using multivariable Cox's proportional hazard modeling, we determined that for every 1-U increase in the passive transmitral LV inflow velocity to tissue Doppler imaging velocity of the medial mitral annulus during passive filling (E/e') ratio, the hazard ratio (HR) of HF increased by 3% (HR: 1.03; 95% confidence interval [CI]: 1.01 to 1.06; p = 0.006) and that diastolic dysfunction was associated with the subsequent development of HF after adjustment for age, sex, body mass index, hypertension, coronary disease, and echocardiographic parameters (HR: 1.61; 95% CI: 1.17 to 2.20; p = 0.003). The cumulative probability of the development of HF at 5 years for diabetic patients with diastolic dysfunction was 36.9% compared with 16.8% for patients without diastolic dysfunction (p < 0.001). Furthermore, diabetic patients with diastolic dysfunction had a significantly higher mortality rate compared with those without diastolic dysfunction.

CONCLUSIONS

We demonstrated that an increase in the passive transmitral LV inflow velocity to tissue Doppler imaging velocity of the medial mitral annulus during passive filling (E/e') ratio in diabetic patients is associated with the subsequent development of HF and increased mortality independent of hypertension, coronary disease, or other echocardiographic parameters.

Association of leukocyte telomere length with echocardiographic left ventricular mass: the Framingham heart study

BACKGROUND

Leukocyte telomere length (LTL) decreases over the adult life course owing to the cumulative burden of oxidative stress, inflammation, and exposure to vascular risk factors. Left ventricular (LV) mass is a biomarker of long-standing exposure to cardiovascular disease risk factors. We hypothesized that LTL is related inversely to LV mass.

METHODS AND RESULTS

We related LTL (measured by Southern blot analysis) to echocardiographic LV mass and its components (LV diastolic dimension and LV wall thickness) in 850 Framingham Heart Study participants (mean age 58 years, 58% women) using multivariable linear regression with adjustment for age, sex, height, weight, systolic blood pressure, hypertension treatment, and smoking. Overall, multivariable-adjusted LTL was positively related to LV mass (beta-coefficient per SD increase 0.072; P=0.001), LV wall thickness (beta=0.053; P=0.01), and LV diastolic dimension (beta=0.035; P=0.09). We observed effect modification by hypertension status (P for interaction=0.02 for LV mass); LTL was more strongly associated with LV mass and LV wall thickness in individuals with hypertension (beta-coefficient per SD increment of 0.10 and 0.08, respectively; P<0.01 for both). Participants with hypertension who were in the top quartile of LV mass had LTL that was 250 base pairs longer than those in the lowest quartile (P for trend across quartiles=0.009).

CONCLUSIONS

In contrast to our expectation, in the present community-based sample, LTL was positively associated with LV mass and wall thickness, especially so in participants with hypertension. These data are consistent with the hypothesis that longer LTL may be a marker of propensity to LV hypertrophy.

Antihypertensive medications: benefits of blood pressure lowering and hazards of metabolic effects

Blood pressure reduction is associated with significant reduction in adverse cardiovascular outcomes. Certain blood pressure-lowering drugs have adverse effects on glucose homeostasis, and have been associated with the development of both prediabetes and diabetes during use. There is controversy over the significance of diabetes that develops during treatment with antihypertensives and whether the benefits of blood pressure reduction offset the hazards of dysglycemia that can lead to diabetes. Many treatment guidelines have recently undergone revisions to include consideration for the metabolic effects of antihypertensive drugs, particularly in high-risk populations. This review summarizes the data related to the benefits of blood pressure reduction as well as the adverse metabolic effects and new-onset diabetes associated with some medications.

Electrocardiographic left ventricular hypertrophy regression induced by an angiotensin receptor blocker-based regimen in hypertensive patients with diabetes: data from the SARA study

INTRODUCTION

This study examined the influence of diabetes on left ventricular hypertrophy (LVH) detected by different electrocardiographic (ECG) criteria and its changes induced by a 12-month candesartan-based regimen.

METHODS

The patients were treated for a 12-month period with a candesartan-based regimen (8/16 mg + hydrochlorothiazide12.5 mg + additional drugs to target blood pressure < 140/90 mmHg [< 130/80 in diabetics]). Cornell voltage index (CorV), Cornell product (CorP), Sokolow-Lyon voltage index (SokV), and Sokolow-Lyon product (SokP) were calculated. In total 276 patients were included, 51 with diabetes.

RESULTS

At study end, blood pressure was reduced 19.0+/-9.2/7.3+/-3.4 mmHg in diabetic patients and 18.8+/-9.1/8.0+/-3.2 mmHg in non-diabetic subjects (both p<0.01 vs. baseline; p=0.85 between groups).At baseline, 37.5% of diabetic and 26.4% of non-diabetic patients fulfilled criteria of ECG-LVH by CorP (p=0.02), 25.7% and 23.2%, respectively, by SokP (p=0.18), 11.8% and 13.7% by CorV (p=0.16), and 14.3% and 11.6% by SokV (p=0.10).At study end, the prevalence of ECG-LVH was reduced to 25.1% (relative risk reduction [RRR] 33.3%, p=0.001) and 18.2% (RRR 29.2%, p=0.001) by CorP and SokP, in diabetic patients, respectively. In non-diabetic patients, only the CorP criterion showed a significant decrease (RRR 18.9%, p=0.01). No significant changes were observed by other criteria.The RRR of ECG-LVH with treatment was significantly higher in diabetics according to CorP and SokP criteria.

CONCLUSIONS

The prevalence of ECG-LVH detected by CorP was higher in diabetics. Diabetics achieved higher reductions in ECG-LVH prevalence than non-diabetics with a candesartan-based regimen.

Is the nocturnal fall in blood pressure reduced in essential hypertensive patients with metabolic syndrome?

OBJECTIVE

The aim of this study was to examine whether an impaired reduction in nocturnal blood pressure (BP), defined on the basis of two periods of ambulatory BP monitoring (ABPM), is present in hypertensive patients with metabolic syndrome, as defined by the NCEP criteria.

METHODS

460 grade 1 and 2 untreated essential hypertensives (mean age 45.9 +/- 11.9 years) referred for the first time to our outpatient hospital clinic underwent the following procedures: 1) medical history and physical examination; 2) repeated clinic BP measurements; 3) routine examinations; 4) ABPM over two 24-hour periods within 4 weeks. Metabolic syndrome was defined as at least three of the following alterations: increased waist circumference, increased triglycerides, decreased HDL-cholesterol, increased BP, or high fasting glucose. Nocturnal dipping was defined as a night-time reduction in average SBP and DBP >10% compared to average daytime values.

RESULTS

The 135 patients with metabolic syndrome (group I) were similar for age, gender and known duration of hypertension to the 325 patients without it (group II). There were no significant differences between the two groups in average 48-hour, daytime, night-time SBP/DBP values and the percentage nocturnal SBP and DBP decrease (-17.7 / -15.7 vs. -18.4 / -16.2, p = ns). A reproducible nocturnal dipping (decrease in BP >10% from mean daytime in both ABPM periods) and non-dipping profile (decrease in BP < or =10% in both ABPM periods) was found in 74 (54.8%) and 29 (21.4%) in group I and in 169 (52.1%) and 73 (22.4%) in group II, respectively (p = ns); 32 patients (23.7%) in group I and 83 patients (25.5%) in group II had a variable dipping profile (p = ns).

CONCLUSIONS

This study shows that no significant difference exists in nocturnal BP patterns, assessed by two ABPMs, in untreated essential hypertensive patients with metabolic syndrome compared to those without it.