Weight reduction regresses left ventricular mass regardless of blood pressure level in obese subjects

Effects of Different Kinds of Physical Activity on Vascular Function

Regular exercise is one of the main non-pharmacological measures suggested by several guidelines to prevent and treat the development of hypertension and cardiovascular disease through its impact on the vascular system. Routine aerobic training exerts its beneficial effects by means of several mechanisms: decreasing the heart rate and arterial pressure as well as reducing the activation of the sympathetic system and inflammation process without ignoring the important role that it plays in the metabolic profile. Through all these actions, physical training counteracts the arterial stiffening and aging that underlie the development of future cardiovascular events. While the role of aerobic training is undoubted, the effects of resistance training or combined-training exercise on arterial distensibility are still questioned. Moreover, whether different levels of physical activity have a different impact on normotensive and hypertensive subjects is still debated.

Exercise Effects on Left Ventricular Remodeling in Patients with Cardiometabolic Risk Factors

Left ventricular (LV) remodeling is a dynamic process, which is characterized by changes in ventricular size, shape, and wall thickness, thus altering myocardial geometry and function, and is considered as a negative prognostic factor in patients with heart failure (HF). Hypertension, type 2 diabetes (T2D), and obesity are strongly correlated with the development and the progression of LV remodeling, LV hypertrophy, and LV systolic and/or diastolic dysfunction. Indeed, the beneficial impact of exercise training on primary and secondary prevention of cardiovascular disease (CVD) has been well-established. Recent studies have highlighted that exercise training enhances functional capacity, muscle strength and endurance, cardiac function, and cardiac-related biomarkers among patients with established coronary artery disease (CAD) or HF, thus substantially improving their cardiovascular prognosis, survival rates, and need for rehospitalization. Therefore, in this review article, we discuss the evidence of LV remodeling in patients with cardiometabolic risk factors, such as hypertension, T2D, and obesity, and also highlight the current studies evaluating the effect of exercise training on LV remodeling in these patients.

Optimized electrocardiographic criteria for the detection of left ventricular hypertrophy in obesity patients

Background

Despite a generally high specificity, electrocardiographic (ECG) criteria for the detection of left ventricular hypertrophy (LVH) lack sensitivity, particularly in obesity patients.

Objectives

The aim of the study was to evaluate the accuracy of the most commonly used ECG criteria (Cornell voltage and Sokolow‐Lyon index), the recently introduced Peguero‐Lo Presti criteria and the correction of these criteria by body mass index (BMI) to detect LVH in obesity patients and to propose adjusted ECG criteria with optimal accuracy.

Methods

The accuracy of the ECG criteria for the detection of LVH was retrospectively tested in a cohort of obesity patients referred for a transthoracic echocardiogram based on clinical grounds (test cohort, n = 167). Adjusted ECG criteria with optimal sensitivity for the detection of LVH were developed. Subsequently, the value of these criteria was prospectively tested in an obese population without known cardiovascular disease (validation cohort, n = 100).

Results

Established ECG criteria had a poor sensitivity in obesity patients in both the test cohort and the validation cohort. The adjusted criteria showed improved sensitivity, with optimal values for males using the Cornell voltage corrected for BMI, (RaVL+SV3)*BMI ≥700 mm*kg/m²; sensitivity 47% test cohort, 40% validation cohort; for females, the Sokolow‐Lyon index corrected for BMI, (SV1 + RV5/RV6)*BMI ≥885 mm*kg/m²; sensitivity 26% test cohort, 23% validation cohort.

Conclusions

Established ECG criteria for the detection of LVH lack sufficient sensitivity in obesity patients. We propose new criteria for the detection of LVH in obesity patients with improved sensitivity, approaching known sensitivity of the most commonly used ECG criteria in lean subjects.

Weight loss facilitates reduction of left ventricular mass in obese hypertensive patients: The Campania Salute Network

BACKGROUND AND AIMS

Reduction of left ventricular mass index (LVMi) during antihypertensive treatment is less likely to occur in obese subjects. The aim of the study was to assess whether weight loss influences reduction of LVMi in treated, obese, hypertensive patients.

METHODS AND RESULTS

From the Campania Salute Network registry, we identified 1546 obese hypertensive patients (50 ± 9 years, 43% women) with more than 12 months follow-up. Echocardiographic reduction of LVMi was considered as achievement of normal values (<47 g/m^2.7 in women or <50 g/m^2.7 in men) or a reduction of ≥10% during follow-up. Weight loss was considered as ≥5% reduction in body weight, and occurred in 403 patients (26%) during a median follow-up of 50 months (IQrange:31-93). Median weight loss was 8.6% (IQrange:6.5-12). Patients with weight loss had higher baseline body mass index (p < 0.05), while there was no difference in age, sex, duration of hypertension, prevalence of diabetes, metabolic syndrome and average blood pressure during follow-up. During follow-up, 152 patients (9.8%) exhibited reduction of LVMi. Reduction of LVMi was more frequent (12.9% vs 9.1%, p < 0.030) in patients losing weight than in those who did not. In logistic regression analysis, weight loss was associated with reduction of left ventricular mass index (OR 1.51 [95%CI 1.02-2.23], p = 0.039), independent of significant associations with younger age, lower average systolic blood pressure during follow-up, longer follow-up time and higher LVMi at baseline.

CONCLUSION

In treated obese hypertensive patients, weight loss during follow-up promotes significant reduction of LVMi, independent of baseline characteristics and blood pressure control.

Long-Term Effects of an Intensive Lifestyle Intervention on Electrocardiographic Criteria for Left Ventricular Hypertrophy: The Look AHEAD Trial

BACKGROUND

Left ventricular hypertrophy assessed by electrocardiography (ECG-LVH) is a marker of subclinical cardiac damage and a strong predictor of cardiovascular disease (CVD) events. The prevalence of ECG-LVH is increased in obesity and type 2 diabetes; however, there are no data on the long-term effects of weight loss on ECG-LVH. The purpose of this study was to determine whether an intensive lifestyle intervention (ILI) reduces ECG-LVH in overweight and obese adults with type 2 diabetes.

METHODS

Data from 4,790 Look AHEAD participants (mean age: 58.8 ± 6.8 years, 63.2% White) who were randomized to a 10-year ILI (n = 2,406) or diabetes support and education (DSE, n = 2,384) were included. ECG-LVH defined by Cornell voltage criteria was assessed every 2 years. Longitudinal logistic regression analysis with generalized estimation equations and linear mixed models were used to compare the prevalence of ECG-LVH and changes in absolute Cornell voltage over time between intervention groups, with tests of interactions by sex, race/ethnicity, and baseline CVD status.

RESULTS

The prevalence of ECG-LVH at baseline was 5.2% in the DSE group and 5.0% in the ILI group (P = 0.74). Over a median 9.5 years of follow-up, prevalent ECG-LVH increased similarly in both groups (odds ratio: 1.02, 95% confidence interval: 0.83-1.25; group × time interaction, P = 0.49). Increases in Cornell voltage during follow-up were also similar between intervention groups (group × time interaction, P = 0.57). Intervention effects were generally similar between subgroups of interest.

CONCLUSIONS

The Look AHEAD long-term lifestyle intervention does not significantly lower ECG-LVH in overweight and obese adults with type 2 diabetes.

CLINICAL TRIALS REGISTRATION

Trial Number NCT00017953 (ClinicalTrials.gov).

Coronary flow reserve in patients with resistant hypertension

Resistant hypertension is associated with increased risk for cardiovascular events. Coronary flow reserve (CFR) is impaired in patients with hypertension and an independent predictor of cardiac mortality. However, there are no published data on CFR in the subset of treatment-resistant hypertension. The aim of this study was to assess CFR in patients with resistant hypertension. Twenty-five consecutive patients with primary resistant hypertension, scheduled for renal denervation, 25 matched patients with controlled hypertension, and 25 healthy controls underwent transthoracic colour Doppler echocardiography at rest and during adenosine infusion. Patients with hypertension were pair-matched with regard to age, sex, ischemic heart disease, diabetes mellitus, smoking status, and body-mass index. Healthy controls were selected according to age and sex. Mean flow velocity was measured in the left coronary anterior descending artery. Baseline mean flow velocities were similar in patients with controlled and resistant hypertension. CFR was significantly lower in patients with resistant hypertension as compared to individuals with non-resistant hypertension (2.7 ± 0.6 vs. 3.1 ± 0.8; p = 0.03). Systolic office blood pressure was significantly higher in patients with resistant hypertension (169 ± 20 vs. 144 ± 21 mm Hg; p < 0.01). Heart rate, ventricular mass, and ejection fraction were similar in the two groups. Healthy controls showed significantly lower baseline velocity, higher CFR, and lower blood pressure as compared to hypertensives. Resistant hypertension was associated with impaired CFR as compared to individuals with non-resistant hypertension indicating impaired cardiac microvascular function which may contribute to the increased risk of adverse outcome in patients with resistant hypertension.

Obesity and hypertensive heart disease: focus on body composition and sex differences

There is evidence that hypertension is frequently associated with overweight/obesity even in kids and adolescents. Either conditions influence development of left ventricular (LV) hypertrophy (LVH), through different biological and hemodynamic mechanisms: obesity is conventionally thought to elicit a coherent growth of LV chamber dimensions and myocardial wall thickness (eccentric LV geometry), whereas a more accentuated increase in wall-thickness (concentric LV geometry) is attributed to hypertension. While during youth these differences are visible, proportion of LV concentric geometry, the most harmful LV geometric pattern, sharply raises in obese individuals during middle age, and becomes the most frequent geometric patterns among obese-hypertensive individuals. Two conditions with elevated hemodynamic impact, severe obstructive sleep apnea and masked hypertension contribute to the development of such a geometric pattern, but non-hemodynamic factors, and specifically body composition, also influence prevalence of concentric LV geometry. Contrasting a general belief, it has been observed that adipose mass strongly influences LV mass, particularly in women, especially when fat-free mass is relatively deficient. Thus, though blood pressure control is mandatory for prevention and reduction of LVH in obese hypertensive patients, without reduction of visceral adiposity regression of LVH is difficult. Future researches should be addressed on (1) assessing whether LVH resulting from alteration of body composition carries the same prognosis as pressure overload LVH; (2) defining tissue characterization of the hypertrophic heart in obese-hypertensive patients; (3) evaluating whether assessment of hemodynamic loading conditions and biological markers can help defining management of the association of obesity with hypertension.

Management of obesity cardiomyopathy

Obesity causes a variety of hemodynamic alterations that may lead to changes in cardiac structure and function. Although such abnormalities may occur in patients with mild-to-moderate obesity, they are most pronounced in those with morbid obesity. When these alterations produce congestive heart failure, obesity cardiomyopathy is said to be present. In this review, the authors will first discuss the pathogenesis and clinical manifestations of obesity cardiomyopathy and then describe the management of this clinical syndrome with emphasis on the effects of weight reduction.

Left ventricular geometry in obesity: Is it what we expect?

Obesity is characterized by the disproportionate growth of the components of body size, including adipose tissue and lean body mass. Left ventricular (LV) hypertrophy often develops, due to the coexistence of hemodynamic (cardiac workload) and non-hemodynamic components (including body composition and activity of visceral fat). While the hypertrophy of cardiomyocytes is produced by the hemodynamic load, through sarcomeric replication, there is a parallel growth of non-muscular myocardial components, including interstitial fat infiltration and accumulation of triglycerides in the contractile elements, which are thought to influence LV geometric pattern. Thus, pure intervention on hemodynamic load is unlikely to result in effective reduction of LV hypertrophy in obese. We review pathophysiology and prevalence of LV hypertrophy in obesity, with specific attention to LV geometric abnormalities and relations with body size.

Rate of weight loss can be predicted by patient characteristics and intervention strategies

BACKGROUND

Although dietary weight-loss counseling usually employs a 500 to 1,000 kcal/day energy deficit to induce weight loss of 0.5 to 1 kg/week, this rate of weight loss is rarely achieved in research settings. Biological factors, such as changes in metabolic rate, are partly responsible, but would only account for a small deviation from expected weight loss. There must be other factors, behavioral or related to study design and implementation, that affect the rate of weight loss observed.

OBJECTIVE

To examine factors that influence the rate of weight loss obtained in clinical studies.

DESIGN

Thirty-five weight-loss studies published between 1995 and 2009 were identified that used dietary counseling to induce weight loss in healthy subjects. Studies were included if they had a duration of at least 6 weeks, used a strategy to counsel subjects to reduce free-living energy intakes, and reported weight-loss data based on a completers analysis. Variables that were associated with the rate of weight loss among age, sex (percent female subjects), initial body weight, frequency of dietary counseling, placebo use, exercise level, study length, and prescribed energy deficit were examined using linear regression analysis.

RESULTS

Study length was negatively related to the rate of weight loss (P<0.0001), whereas subject age (P<0.002), subject age squared (P=0.0073), initial body weight (P=0.0003), frequency of dietary counseling (P=0.0197), and prescribed energy deficit (P<0.0001) were positively related to the rate of weight loss observed in clinical studies.

CONCLUSIONS

These findings provide a tool for investigators and clinical dietitians to predict the rate of weight loss that can be expected within a population given the age, initial body weight, frequency of dietary counseling, and energy deficit prescription. These data from clinical studies suggest that the rate of weight loss is greater in older and heavier subjects and with higher contact frequency and caloric restriction.

Progressive regression of left ventricular hypertrophy two years after bariatric surgery

BACKGROUND

Obesity is a systemic disorder associated with an increase in left ventricular mass and premature death and disability from cardiovascular disease. Although bariatric surgery reverses many of the hormonal and hemodynamic derangements, the long-term collective effects on body composition and left ventricular mass have not been considered before. We hypothesized that the decrease in fat mass and lean mass after weight loss surgery is associated with a decrease in left ventricular mass.

METHODS

Fifteen severely obese women (mean body mass index [BMI]: 46.7+/-1.7 kg/m(2)) with medically controlled hypertension underwent bariatric surgery. Left ventricular mass and plasma markers of systemic metabolism, together with body mass index (BMI), waist and hip circumferences, body composition (fat mass and lean mass), and resting energy expenditure were measured at 0, 3, 9, 12, and 24 months.

RESULTS

Left ventricular mass continued to decrease linearly over the entire period of observation, while rates of weight loss, loss of lean mass, loss of fat mass, and resting energy expenditure all plateaued at 9 [corrected] months (P <.001 for all). Parameters of systemic metabolism normalized by 9 months, and showed no further change at 24 months after surgery.

CONCLUSIONS

Even though parameters of obesity, including BMI and body composition, plateau, the benefits of bariatric surgery on systemic metabolism and left ventricular mass are sustained. We propose that the progressive decrease of left ventricular mass after weight loss surgery is regulated by neurohumoral factors, and may contribute to improved long-term survival.

Effect of moderate diet-induced weight loss and weight regain on cardiovascular structure and function

OBJECTIVES

The objective of this prospective, single-site, 2-year dietary intervention study was to evaluate the effects of moderate weight reduction and subsequent partial weight regain on cardiovascular structure and function.

BACKGROUND

Obesity is associated with adverse cardiac and vascular structural and functional alterations.

METHODS

Sixty obese subjects (age 46 + or - 10 years, body mass index 37 + or - 3 kg/m(2)) were evaluated during their participation in a weight loss study. Cardiac and vascular ultrasound studies were performed at baseline and at 3, 6, 12, and 24 months after start of intervention.

RESULTS

Forty-seven subjects (78%) completed the entire 2-year follow-up. Average weight loss was 7.3 + or - 4.0%, 9.2 + or - 5.6%, 7.8 + or - 6.6%, and 3.8 + or - 7.9% at 3, 6, 12, and 24 months, respectively. Age- and sex-adjusted mixed linear models revealed that the follow-up time was significantly associated with decreases in weight (p < 0.0001), left ventricular (LV) mass (p = 0.001), and carotid intima-media thickness (p < 0.0001); there was also significant improvement in LV diastolic (p < or = 0.0001) and systolic (p = 0.001) function. Partial weight regain diminished the maximal observed beneficial effects of weight loss, however cardiovascular parameters measured at 2 years still showed a net benefit compared with baseline.

CONCLUSIONS

Diet-induced moderate weight loss in obese subjects is associated with beneficial changes in cardiovascular structure and function. Subsequent weight regain is associated with partial loss of these beneficial effects. (The Safety and Effectiveness of Low and High Carbohydrate Diets; NCT00079547).

Safety and efficacy of bariatric surgery in morbidly obese patients with severe systolic heart failure

BACKGROUND

Morbid obesity (MO) is a risk factor for congestive heart failure (CHF). The presence of MO impairs functional status and disqualifies patients for cardiac transplantation. Bariatric surgery (BAS) is a frontline, durable treatment for MO; however, the safety and efficacy of BAS in advanced CHF is unknown.

HYPOTHESIS

We hypothesized that by utilizing a coordinated approach between an experienced surgical team and heart failure specialists, BAS is safe in patients with advanced systolic CHF and results in favorable outcomes.

METHODS

We performed a retrospective chart review of 12 patients with MO (body mass index [BMI] 53 +/- 7 kg/m2) and systolic CHF (left ventricular ejection fraction [LVEF] 22 +/- 7%, New York Heart Association [NYHA] class 2.9 +/- 0.7) who underwent BAS, and then compared outcomes with 10 matched controls (BMI 47.2 +/- 3.6 kg/m2, LVEF 24 +/- 7%, and NYHA class 2.4 +/- 0.7) who were given diet and exercise counseling.

RESULTS

At 1 y, hospital readmission in BAS patients was significantly lower than controls (0.4 +/- 0.8 versus 2.5 +/- 2.6, p = 0.04); LVEF improved significantly in BAS patients (35 +/- 15%, p = 0.005), but not in controls (29 +/- 14%, p = not significant [NS]). The NYHA class improved in BAS patients (2.3 +/- 0.5, p = 0.02), but deteriorated in controls (3.3 +/- 0.9, p = 0.02). One BAS patient was successfully transplanted, and another listed for transplantation.

CONCLUSIONS

Bariatric surgery is safe and effective in patients with MO and severe systolic CHF, and should be considered in patients who have failed conventional therapy to improve clinical status.

Regular physical activity prevents development of left ventricular hypertrophy in hypertension

AIMS

The longitudinal relationship between aerobic exercise and left ventricular (LV) mass in hypertension is not well known. We did a prospective study to investigate the long-term effect of regular physical activity on development of LV hypertrophy (LVH) in a cohort of young subjects screened for Stage 1 hypertension.

METHODS AND RESULTS

We assessed 454 subjects whose physical activity status was consistent during the follow-up. Echocardiographic LV mass was measured at entry, every 5 years, and/or at the time of hypertension development before starting treatment. LVH was defined as an LV mass >/=50 g/m(2.7) in men and >/=47 g/m(2.7) in women. During a median follow-up of 8.3 years, 32 subjects developed LVH (sedentary, 10.3%; active, 1.7%, P = 0.000). In a logistic regression, physically active groups combined (n = 173) were less likely to develop LVH than sedentary group with a crude OR = 0.15 (CI, 0.05-0.52). After controlling for sex, age, family history for hypertension, hypertension duration, body mass, blood pressure, baseline LV mass, lifestyle factors, and follow-up length, the OR was 0.24 (CI, 0.07-0.85). Blood pressure declined over time in physically active subjects (-5.1 +/- 17.0/-0.5 +/- 10.2 mmHg) and slightly increased in their sedentary peers (0.0 +/- 15.3/0.9 +/- 9.7 mmHg, adjusted P vs. active = 0.04/0.06). Inclusion of changes in blood pressure over time into the logistic model slightly decreased the strength of the association between physical activity status and LVH development (OR = 0.25, CI, 0.07-0.87).

CONCLUSION

Regular physical activity prevents the development of LVH in young stage 1 hypertensive subjects. This effect is independent from the reduction in blood pressure caused by exercise.

Prolonged caloric restriction in obese patients with type 2 diabetes mellitus decreases myocardial triglyceride content and improves myocardial function

OBJECTIVES

This study sought to assess the effects of prolonged caloric restriction in obese patients with type 2 diabetes mellitus (T2DM) on myocardial triglyceride (TG) content and myocardial function.

BACKGROUND

Myocardial TG content is increased in patients with T2DM and may reflect altered myocardial function. It is unknown whether myocardial TG content is influenced during a therapeutic intervention.

METHODS

Myocardial TG content (magnetic resonance [MR] spectroscopy), myocardial function (MR imaging), plasma hemoglobin A1c, and body mass index (BMI) were measured in 12 obese, insulin-treated T2DM patients before and after a 16-week very-low-calorie diet (VLCD) (450 kcal/day) to achieve substantial weight loss. Insulin was stopped during the VLCD.

RESULTS

The BMI decreased from 35.6 +/- 1.2 kg/m(2) (baseline, mean +/- SEM) to 27.5 +/- 1.3 kg/m(2) (after the VLCD, p < 0.001) and was associated with an improvement in hemoglobin A1c from 7.9 +/- 0.4% (baseline) to 6.3 +/- 0.3% (after the VLCD, p = 0.006). Myocardial TG content decreased from 0.88 +/- 0.12% to 0.64 +/- 0.14%, respectively (p = 0.019), and was associated with improved diastolic function (reflected by the ratio between the early and atrial filling phase) from 1.02 +/- 0.08 to 1.18 +/- 0.06, respectively (p = 0.019).

CONCLUSIONS

Prolonged caloric restriction in obese T2DM patients decreases BMI and improves glucoregulation associated with decreased myocardial TG content and improved diastolic heart function. Therefore, myocardial TG stores in obese patients with T2DM are flexible and amendable to therapeutic intervention by caloric restriction.

O. Blood pressure and cardiorenal responses to antihypertensive therapy in obese women

OBJECTIVE: Blood pressure(BP) and target organ responses to antihypertensive drugs are not well established in hypertensive obese patients. This study is aimed at evaluating the effects of obesity and adiposity distribution patterns on these responses. METHODS: 49 hypertensive obese women were designated to different groups according to waist to hip ratio measurements - 37 with troncular and 12 with peripheral obesity. Patients were treated for 24-weeks on a stepwise regimen with cilazapril alone or a cilazapril/hydrochlorothiazide/amlodipine combination therapy to achieve a BP lower than 140/90mmHg. Ambulatory blood pressure monitoring (ABPM), echocardiography, and albuminuria were assessed before and after the intervention. RESULTS: After 24 weeks, weight loss was less than 2% in both groups. ABPM targets were achieved in 81.5% of patients upon a combination of 2(26.5%) or 3(55.1%) drugs. Similar reductions in daytime-SBP/DBP: -22.5/-14.1(troncular obesity) / -23.6/-14.9mmHg (peripheral obesity) were obtained. Decrease in nocturnal-SBP was greater in troncular obesity patients. Upon BP control, microalbuminuria was markedly decreased, while only slight decrease in left ventricular mass was observed for both groups. CONCLUSIONS: In the absence of weight loss, most patients required combined antihypertensive therapy to control their BP, regardless of their body fat distribution pattern. Optimal target BP and normal albuminuria were achieved in the group as a whole and in both obese patient groups, while benefits to cardiac structure were of a smaller magnitude.

Obesity cardiomyopathy: diagnosis and therapeutic implications

Obesity is associated with an increased risk of heart failure. Apparently healthy obese individuals can, however, exhibit subclinical left ventricular dysfunction. The use of myocardial imaging techniques to detect this subclinical change could have important management implications with respect to initiating prophylactic therapy. In this Review, we evaluate possible pharmacologic and nonpharmacologic strategies for treating obesity cardiomyopathy in the context of currently understood mechanisms, including myocardial remodeling and small vessel disease, and more speculative mechanisms such as insulin resistance, and activation of the renin-angiotensin-aldosterone and sympathetic nervous systems.

Noninvasive assessment of target organ injury in children with the metabolic syndrome

The prevalence of overweight has increased sharply since the 1980s, with morbid obesity rising at an even higher rate. Comorbidities related to adiposity now consume almost 10% of all US health care dollars. Unfortunately, overweight children already demonstrate elevations in cardiovascular risk factors. These children are extremely likely to remain obese in adulthood and are likely to progress to diabetes and heart and kidney diseases. It is not surprising, therefore, that the diagnosis of the metabolic syndrome is being made with increasing frequency in American adolescents. The authors show that noninvasive methods are now available to measure target organ damage related to obesity and the metabolic syndrome in children. They explore the data linking the cardiovascular risk factors that cluster as the metabolic syndrome to early subclinical atherosclerotic change such as left ventricular hypertrophy, carotid intima-media thickness, vascular function abnormalities, and microalbuminuria. Evidence for the benefits of treatment and guidelines for the assessment for target organ damage in children are provided.

Impact of obesity and bariatric surgery on cardiovascular disease

Morbid obesity is a growing public health concern with multiple associated cardiovascular comorbidities. Bariatric surgery has emerged as a safe and effective treatment for morbidly obese patients at risk for, or already suffering from, cardiovascular disease. Weight loss induced by the surgery has been shown to improve cardiovascular risk factors, cardiac structure and function, and the clinical course of established cardiovascular disease. The role of adipocyte-derived cytokines in mediating cardiovascular pathophysiology in obesity-and its modulation after weight loss-is under active investigation.

Reduced left ventricular mass after treatment of obese patients with sibutramine: An echocardiographic multicentre study

AIM

In obesity, left ventricular hypertrophy is frequently observed, especially in the presence of hypertension. Following body weight reduction, the left ventricular mass (LVM) is reduced. It is not known to which extent this occurs after treatment with sibutramine.

METHODS

In this multicentre trial, 195 male and female patients (18-65 years of age, body mass index 30-40 kg/m2) were treated for 12 weeks with either 15 mg/day sibutramine or placebo. They were advised to follow mildly hypocaloric reducing diets. Exclusion criteria were blood pressure values >180/110 mmHg and tachycardia (heart rate > or =100 beats/min). Echocardiography in M-mode was performed to determine LVM as well as systolic function.

RESULTS

Body weight was reduced by 6.9 +/- 0.3 kg under sibutramine and by 2.1 +/- 0.6 kg under placebo; body fat was reduced by 5.2 +/- 0.4 kg and 1.6 +/- 0.7 kg respectively. In the sibutramine group, LVM was reduced by 10.9 +/- 24.2 g; LVM indexed for body surface area was reduced by 2.3 +/- 11.8 g/m2 and LVM indexed for body height was reduced by 2.5 +/- 6.0 g/m(2.7). In the placebo group, LVM and LVM indices were not significantly changed. Changes in LVM correlated with reductions in body weight and initial LVM but not with changes in blood pressure or heart rate.

CONCLUSIONS

After 3 months of treatment with sibutramine, obese patients lost about three times as much of body weight and LVM than patients treated with placebo. Therefore, sibutramine may be recommended not only to reduce body weight but also to obtain a regression of the LVM in obese patients with and without hypertension.

Atrophy-related ubiquitin ligases atrogin-1 and MuRF-1 are associated with uterine smooth muscle involution in the postpartum period

The regulation of cell size depends on a delicate balance between protein synthesis and breakdown. Skeletal and cardiac muscle adapt to hormonal and neuronal stimuli and can rapidly hypertrophy and atrophy; however, the extent to which these processes occur in smooth muscle is less clear. Atrophy in striated muscle results from enhanced protein breakdown and is associated with a common transcriptional profile and activation of the ubiquitin-proteasome pathway, including induction of the muscle-specific ubiquitin protein ligases atrogin-1 and muscle ring-finger protein 1 (MuRF-1). Here we show that atrogin-1 is also expressed in smooth muscle, and that both atrogin-1 and MuRF-1 are upregulated in the uterus following delivery, as rapid involution occurs. While these two genes are similarly induced in all types of muscle during rapid loss of cell mass, other striated muscle atrophy-specific transcriptional changes are not observed during uterine involution, suggesting different underlying molecular mechanisms. These results raise the possibility that activation of atrogin-1 and MuRF-1 may be a common general adaptation in cells undergoing a rapid reduction in size.

Obesity and cardiovascular disease: pathophysiology, evaluation, and effect of weight loss: an update of the 1997 American Heart Association Scientific Statement on Obesity and Heart Disease from the Obesity Committee of the Council on Nutrition, Physical Activity, and Metabolism

Obesity is becoming a global epidemic in both children and adults. It is associated with numerous comorbidities such as cardiovascular diseases (CVD), type 2 diabetes, hypertension, certain cancers, and sleep apnea/sleep-disordered breathing. In fact, obesity is an independent risk factor for CVD, and CVD risks have also been documented in obese children. Obesity is associated with an increased risk of morbidity and mortality as well as reduced life expectancy. Health service use and medical costs associated with obesity and related diseases have risen dramatically and are expected to continue to rise. Besides an altered metabolic profile, a variety of adaptations/alterations in cardiac structure and function occur in the individual as adipose tissue accumulates in excess amounts, even in the absence of comorbidities. Hence, obesity may affect the heart through its influence on known risk factors such as dyslipidemia, hypertension, glucose intolerance, inflammatory markers, obstructive sleep apnea/hypoventilation, and the prothrombotic state, in addition to as-yet-unrecognized mechanisms. On the whole, overweight and obesity predispose to or are associated with numerous cardiac complications such as coronary heart disease, heart failure, and sudden death because of their impact on the cardiovascular system. The pathophysiology of these entities that are linked to obesity will be discussed. However, the cardiovascular clinical evaluation of obese patients may be limited because of the morphology of the individual. In this statement, we review the available evidence of the impact of obesity on CVD with emphasis on the evaluation of cardiac structure and function in obese patients and the effect of weight loss on the cardiovascular system.

Obesidade visceral, hipertensão arterial e risco cárdio-renal: uma revisão

A maior parte da adversidade atribuída à obesidade é dada pelo risco cardiovascular/coronariano imputado à mesma, particularmente presente nos obesos com distribuição visceral de gordura corporal. O acúmulo de gordura visceral está sabidamente associado à maior prevalência de desarranjos metabólicos, hormonais, inflamatórios e hemodinâmicos, que no conjunto implicarão em maior acometimento da microvasculatura e impacto negativo sobre os órgãos-alvo, particularmente sobre o eixo cárdio-renal. Neste sentido, além da associação clássica com a doença coronariana, têm-se verificado uma associação maior da obesidade visceral com a hipertrofia ventricular esquerda e microalbuminúria, ambos fatores de risco cardiovascular e nefrológico reconhecidos. Assim, a abordagem terapêutica dos pacientes obesos, particularmente dos hipertensos, deve levar em conta a estratificação de risco baseada na distribuição de gordura corporal, o que permitirá uma terapêutica mais adequada, visando-se não só o controle dos fatores de risco como a monitorização do acometimento de órgãos-alvo nestas populações.

The FOXO3a transcription factor regulates cardiac myocyte size downstream of AKT signaling

Although signaling mechanisms inducing cardiac hypertrophy have been extensively studied, little is known about the mechanisms that reverse cardiac hypertrophy. Here, we describe the existence of a similar Akt/forkhead signaling axis in cardiac myocytes in vitro and in vivo, which is regulated by insulin, insulin-like growth factor (IGF), stretch, pressure overload, and angiotensin II stimulation. FOXO3a gene transfer prevented both IGF and stretch-induced hypertrophy in rat neonatal cardiac myocyte cultures in vitro. Transduction with FOXO3a also caused a significant reduction in cardiomyocyte size in mouse hearts in vivo. Akt/FOXO signaling regulated the expression of multiple atrophy-related genes "atrogenes," including the ubiquitin ligase atrogin-1 (MAFbx). In cardiac myocyte cultures, transduction with constitutively active Akt or treatment with IGF suppressed atrogin-1 mRNA expression, whereas transduction with FOXO3a stimulated its expression. FOXO3a transduction activated the atrogin-1 promoter in both cultured myocytes and mouse heart. Thus, in cardiomyocytes, as in skeletal muscle, FOXO3a activates an atrogene transcriptional program, which retards or prevents hypertrophy and is down-regulated by multiple physiological and pathological stimuli of myocyte growth.

Effects of sibutramine-induced weight loss on cardiovascular system in obese subjects

BACKGROUND AND AIM

To assess efficacy of sibutramine in obese subjects, and influence on hemodynamics, valve function and left ventricular (LV) geometry and performance.

METHODS AND RESULTS

Three-month double-blind, parallel groups, randomized, placebo-controlled of 15 mg o.i.d. sibutramine administration combined with diet. Twenty-five to 65 year-old males or postmenopausal females, were enrolled if their BMI was between 30 and 40 kg/m(2), without evidence of concomitant diseases. Body weight, BMI, blood pressure (BP), echocardiographic LV mass, cardiac output, and diastolic function were measured. Body weight and BMI were better reduced with sibutramine (weight loss of 5% or more in 9 of 11 patients) than placebo group (weight loss of 5% or more in 5 of 9 patients; all p<0.05). Systolic and diastolic BP decreased similarly in both arms. No difference in mean heart rate was detected between treatments. The two groups had slightly different LV geometry at baseline. LV mass decreased with weight loss, more in the sibutramine group (p<0.05), due to reduction in LV chamber size. Stroke volume tended to be reduced in the sibutramine group, influencing diastolic pattern. E/A ratio tended to decrease in the sibutramine group without changes in isovolumic relaxation time and deceleration time of E velocity. No onset or increased severity of valve regurgitation was detected.

CONCLUSIONS

Combined to hypocaloric diet, sibutramine increases weight loss in obese individuals. Weight changes have positive effect on reduction of BP and contribute to reduce LV mass, the hallmark of markers of preclinical cardiovascular disease and most powerful predictor of adverse outcome.

Clinical Implications of Obesity With Specific Focus on Cardiovascular Disease

Obesity adversely affects cardiac function, increases the risk factors for coronary heart disease, and is an independent risk factor for cardiovascular disease. The risk of developing coronary heart disease is directly related to the concomitant burden of obesity-related risk factors. Modest weight loss can improve diastolic function and affect the entire cluster of coronary heart disease risk factors simultaneously. This statement from the American Heart Association Council on Nutrition, Physical Activity, and Metabolism reviews the relationship between obesity and the cardiovascular system, evaluates the effect of weight loss on coronary heart disease risk factors and coronary heart disease, and provides practical weight management treatment guidelines for cardiovascular healthcare professionals. The data demonstrate that weight loss and physical activity can prevent and treat obesity-related coronary heart disease risk factors and should be considered a primary therapy for obese patients with cardiovascular disease.

Healthy aging: health promotion and disease prevention

Successful aging includes the ability to perform functional tasks. This ability to perform functional tasks, or functional ability, is influenced by musculoskeletal and cardiovascular functioning and the presence and severity of symptoms of chronic disease. Empirical evidence indicates that musculoskleletal and cardiovascular functioning and symptoms of chronic disease in later life are strongly related to lifestyle choices involving physical activity and nutritional intake. Previous researchers have demonstrated that increases in physical activity and appropriate changes in nutritional intake can be effective interventions to prevent and treat symptoms of chronic disease and improve musculoskeletal and cardiovascular functioning. As a result of this evidence, several organizations have developed physical activity and nutritional intake recommendations aimed at maintaining or increasing the functional ability of older adults. These physical activity recommendations include engaging in cardiorespiratory, flexibility, strength, and balance training 3 to 5 days per week. Broad nutritional recommendations for older adults include a low-fat, plant-based diet including fruits, vegetables, whole grains, 8 glasses of water per day, and a vitamin and mineral supplement.

Left ventricular hypertrophy and QT interval in obesity and in hypertension: effects of weight loss and of normalisation of blood pressure

BACKGROUND

Left ventricular hypertrophy (LVH) and prolonged QT interval at ECG (QTc) are common in both obesity and arterial hypertension (AH), and are risk factors for cardiovascular disease and sudden death.

METHODS

We compared the frequencies of LVH (ECG criteria) and QTc in obese-AH (n=41), in normotensive obese (n=75), in lean-AH (n=30), and in lean controls (n=68) comparable for age and sex; in obese patients, LVH and QTc were evaluated under basal conditions and 1 y later, that is, after a significant weight loss induced by bariatric surgery.

RESULTS

LVH was more frequent, and QTc was longer, in obese-AH, in normotensive obese, and in lean-AH than in lean controls; after weight loss, frequency of LVH decreased in obese subjects becoming normotensive (n=87), not in obese subjects remaining hypertensive (n=29), while QTc decreased in all obese subjects.

CONCLUSION

Weight loss can effectively reduce QTc; when concomitant AH disappears, weight loss can also reduce the prevalence of LVH. In obese patients remaining hypertensive, aggressive pharmacological treatment is therefore indicated to correct LVH.

Metabolic and cardiovascular improvements after biliopancreatic diversion in a severely obese patient

BACKGROUND

Severe obesity is associated with important morbidity and increased mortality. The successes of lifestyle modifications and drug therapy have been partial and mostly unsustained in reducing obesity and its comorbidities. Bariatric surgery, particularly biliopancreatic diversion with duodenal switch reduces efficiently excess body weight and improves metabolic and cardiovascular functions.

CASE PRESENTATION

A 56-year-old man with severe clinical obesity underwent a biliopancreatic diversion with a duodenal switch after unsuccessful treatment with weight loss pharmacotherapy. He had diabetes, hypertension and sleep apnea syndrome and was on three medications for hypertension and two hypoglycemic agents in addition to > 200 insulin units daily. Eleven months after the surgery, he had lost 40% of his body weight. The lipid profile showed great improvement and the hypertension and diabetes were more easily controlled with no more insulin needed. The pseudonormalized pattern of left ventricular diastolic function improved and ventricular walls showed decreased thickness.

CONCLUSION

Biliopancreatic diversion may bring metabolic and cardiovascular benefits in severely obese patients from a cardiovascular perspective.

Effects of dietary modification to reduce vascular risks and treatment of obesity

This article has considered a vast literature attesting to the efficacy of dietary intervention on risk factors for CHD and on vascular outcomes. Rather than relying solely on pharmacotherapy to improve risk factors and vascular outcomes, physicians, nurses, dietitians, pharmacists, and medical providers should emphasize the benefits of a well-balanced, nutritionally sound dietary program. The diet should be low in saturated fatty acids, controlled in calories to avoid (or reduce) obesity, and rich in fruits, vegetables, whole grain products, and good sources of protein. Emphasis on foods rich in n-3 fatty acids shows promise for reducing cardiovascular outcomes, particularly sudden death.

Akt signaling mediates postnatal heart growth in response to insulin and nutritional status

Akt is a serine-threonine kinase that mediates a variety of cellular responses to external stimuli. During postnatal development, Akt signaling in the heart was up-regulated when the heart was rapidly growing and was down-regulated by caloric restriction, suggesting a role of Akt in nutrient-dependent regulation of cardiac growth. Consistent with this notion, reductions in Akt, 70-kDa S6 kinase 1, and eukaryotic initiation factor 4E-binding protein 1 phosphorylation were observed in mice with cardiac-specific deletion of insulin receptor gene, which exhibit a small heart phenotype. In contrast to wild type animals, caloric restriction in these mice had little effect on Akt phosphorylation in the heart. Furthermore, forced expression of Akt1 in these hearts restored 70-kDa S6 kinase 1 and eukaryotic initiation factor 4E-binding protein 1 phosphorylation to normal levels and rescued the small heart phenotype. Collectively, these results indicate that Akt signaling mediates insulin-dependent physiological heart growth during postnatal development and suggest a mechanism by which heart size is coordinated with overall body size as the nutritional status of the organism is varied.

Effects of sibutramine on ventricular dimensions and heart valves in obese patients during weight reduction

BACKGROUND

Obesity enhances hemodynamic alterations that predispose to a subsequent increase in left ventricular (LV) wall stress leading to LV hypertrophy. In obese subjects, weight reduction regresses LV mass (LVM), regardless of blood pressure. Sibutramine can increase blood pressure and heart rate, which may attenuate the reductions in LVM associated with weight loss.

METHODS

Outpatients (n = 184, age 18-65 y, body mass index > or =30 to <40 kg/m2) were randomly assigned to 6 months of once daily double-blind treatment with sibutramine 10 mg or 20 mg, or placebo. LV dimensions, status and function of the valves, weight loss, blood pressure, heart rate, and electrocardiogram were assessed.

RESULTS

For end point data sets, the mean +/- SD LVM index (LVM/height) changes were -3.0 +/- 11.9 g/m for placebo (n = 56), -4.4 +/- 10.7 g/m for sibutramine 10 mg (n = 61), and -4.3 +/- 10.9 g/m for sibutramine 20 mg (n = 56). The reductions observed in the sibutramine groups were statistically significant compared with baseline (P <.01), but pairwise comparison results with placebo were not statistically significant. There was no difference in overall status of the cardiac valves. A statistically significant greater weight loss was found in patients on both doses of sibutramine compared with placebo (P <.001). No statistically significant differences between the groups were observed in respect to blood pressure and electrocardiographic intervals, but a statistically significant increase in pulse rate (7 beats/min) was noted for patients with sibutramine treatment.

CONCLUSION

A 6-month treatment with sibutramine does not affect ventricular dimensions, heart valves, and electrocardiogram variables.

Obstáculos diagnósticos e desafios terapêuticos no paciente obeso

Obesidade é uma doença complexa, de mútiplas etiologias e suficientemente comum para constituir um problema de saúde pública, assim como um dilema clínico importante. Especialistas da área clínica e cirúrgica são freqüentemente desafiados pelas alterações fisiopatológicas associadas com a obesidade. Essas alterações comprometem virtualmente todos os sistemas do organismo, podendo apresentar-se como barreiras no diagnóstico e na terapêutica. Há evidências marcantes de que obesidade acarreta risco excessivo para a saúde; de fato, a mortalidade aumenta de forma aguda quando o índice de massa corporal ultrapassa 30 kg/m2, principalmente quando há distribuição central de tecido adiposo concomitante. O autor discute os efeitos da obesidade nos sistemas respitatório, cardiovascular, digestório e geniturinário. Os obstáculos enfrentados em procedimentos diagnósticos ordinários, prescrição de medicamentos, traumas, assim como descrições patológicas raras de lipomas, são apresentados.

Exercise in weight management of obesity

Obesity is a chronic metabolic disorder associated with CVD and increased morbidity and mortality. When the BMI is > or = 30 kg/m2, mortality rates from all causes, and especially CVD, are increased by 50% to 100%. There is strong evidence that weight loss in overweight and obese individuals improves risk factors for diabetes and CVD. Additional evidence indicates that weight loss and the associated diuresis reduce blood pressure in both overweight hypertensive and nonhypertensive individuals, reduce serum TG levels, increase high-density lipoprotein cholesterol levels, and may produce some reduction in low-density lipoprotein cholesterol concentrations. Of interest, even if weight loss is minimal, obese individuals showing a good level of cardiorespiratory fitness are at reduced risk for cardiovascular mortality than lean but poorly fit subjects. Insulin and catecholamines have pronounced metabolic effects on human adipose tissue metabolism. Insulin stimulates LPL and inhibits HSL; the opposite is true for catecholamines. There is regional variation in adipocyte TG turnover favoring lipid mobilization in the visceral fat depots and lipid storage in the peripheral subcutaneous sites. The hormonal regulation of adipocyte TG turnover is altered in obesity and is most marked in central obesity. There is resistance to insulin stimulation of LPL; however, LPL activity in fasted obese subjects is increased and remains so following weight reduction. Catecholamine-induced lipolysis is enhanced in visceral fat but decreased in subcutaneous fat. Numerous adaptive responses take place with physical training. These adaptations result in a more efficient system for oxygen transfer to muscle, which is now able to better utilize the unlimited lipid stores instead of the limited carbohydrate reserves available. In addition, the reduced adipose tissue mass represents an important mechanical advantage, allowing better long-term work. Gender differences have been reported in the adaptation of adipose tissue metabolism to aerobic exercise training. Physical training helps counteract the permissive and affluent environment that predisposes reduced-obese subjects to regain weight. An exercise program using weight resistance modalities may also be included safely, and it improved program retention in a multidisciplinary weight management program that was designed for obese children. Thirty to 45 minutes of physical activity of moderate intensity, performed 3 to 5 days a week, should be encouraged. All adults should set a long-term goal to accumulate at least 30 minutes or more of moderate-intensity physical activity on most, and preferably all days. Public health interventions promoting walking are likely to be the most successful. Indeed, walking is unique because of its safety, accessibility, and popularity. It is noteworthy that there is a clear dissociation between the adaptation of cardiorespiratory fitness and the improvements in the metabolic risk profile that can be induced by endurance training programs. It appears that as long as the increase in energy expenditure is sufficient, low-intensity endurance exercise is likely to generate beneficial metabolic effects that would be essentially similar to those produced by high-intensity exercise. The clinician should therefore focus on the improvement of the metabolic profile rather than on weight loss alone. Realistic goals should be set between the clinician and the patient, with a weight loss of approximately of 0.5 to 1 pound per week. It should be kept in mind that since it generally takes years to become overweight or obese, a weight loss pattern of 0.5 or 1 pound per week will require time and perseverance to reach the proposed target. However, the use of physical activity as a method to lose weight seems inversely related to patients' age and BMI and directly related to the level of education. Thus, public health interventions helping these groups to become physically active remain a challenge and further emphasize the importance of the one-on-one interaction between the clinician/health care professional with the obese individual "at risk" of CVD. This notion is critical, as it has been shown that less than half of obese adults have reported being advised to lose weight under the guidance of health care professionals.

Management of obesity cardiomyopathy

Therapy of acute exacerbations of congestive heart failure associated with obesity cardiomyopathy consists of dietary salt restriction, inspired oxygen, diuretics, and angiotensin-converting enzyme inhibitors or, if left ventricular systolic dysfunction is present, hydralazine/isosorbide dinitrate. Digitalis may be indicated in selected cases. These measures may also be useful chronically in association with weight loss. Substantial weight loss is capable of reversing all of the hemodynamic abnormalities associated with obesity except elevation of left ventricular filling pressure. Substantial weight loss may also reduce left ventricular mass and improve left ventricular diastolic filling in those with left ventricular hypertrophy before weight loss. Left ventricular systolic function also improves after weight loss in those with impaired pre-weight-loss systolic function. These beneficial effects of weight loss occur partly because of favorable alterations in left ventricular loading conditions. Substantial weight loss in patients with congestive heart failure associated with obesity cardiomyopathy produces a reversal of many of the clinical manifestations of cardiac decompensation and improves New York Heart Association functional class in most patients.

Left ventricular mass and systolic function in human immunodeficiency virus-infected patients after weight loss

Transthoracic echocardiography was performed on 27 patients with human immunodificiency virus after weight loss and in 20 lean controls. Left ventricular mass index was significantly higher and left ventricular fractional shortening was significantly lower in patients with human immunodificiency virus after weight loss than in lean, normal controls.

Obesity, body fat distribution, and coronary artery disease

Obesity is an independent risk factor for the development of coronary artery disease (CAD). Obesity also increases risk for CAD indirectly through its association with insulin resistance, hyperlipidemia, and hypertension. An increased accumulation of fat in the intraabdominal cavity, termed visceral adiposity, is highly correlated with an adverse coronary risk profile. In patients at risk for coronary artery disease, the treatment of obesity results in an improved coronary risk profile. The prevalence of obesity is extremely high in coronary populations, yet the effect of weight loss on cardiovascular outcomes in CAD patients has received relatively little attention. Observational studies in the cardiac rehabilitation setting showed that patients who lose weight and exercise show an improvement in coronary risk profile. Further research is needed to better define the clinical effectiveness of weight loss programs and their benefits in coronary patients.

Effects of dietary modification and treatment of obesity. Emphasis on improving vascular outcomes

This article has considered a vast literature attesting to the efficacy of dietary intervention on risk factors and on vascular outcomes. Rather than rely solely on pharmacotherapy to improve risk factors and vascular outcomes, physicians, nurses, dietitians, pharmacists, and medical providers should emphasize the benefits of a well-balanced, nutritionally sound dietary program. It should be low in SFA; controlled in calories to avoid (or reduce) obesity; and rich in fruits, vegetables, whole-grain products, and good sources of protein. Emphasis on foods rich in n-3 fatty acids shows promise for reducing cardiovascular outcomes. Further studies using these and antioxidants are eagerly awaited.