Weight Loss After Bariatric Surgery Significantly Improves Carotid and Cardiac Function in Apparently Healthy People with Morbid Obesity

Impact of bariatric surgery on carotid intima-media thickness and arterial stiffness in metabolically healthy obesity: a prospective study

PURPOSE

Cardiovascular disease is one of the leading causes of mortality in patients with obesity. Metabolically healthy obesity (MHO), in which people do not have metabolic disorders, is a transient state of obesity. However, over the long term, a proportion of individuals with MHO develop metabolic syndrome (MetS). We aimed to investigate the effect of substantial weight loss following bariatric surgery in MHO on carotid intima-media thickness (CIMT) and pulse-wave velocity (PWV), which are independent predictors of subclinical atherosclerosis.

METHODS

This prospective study included 38 patients (34 women, four men) undergoing bariatric surgery who had severe obesity but without comorbidities (hypertension, diabetes, and hyperlipidemia), and 28 control individuals who were matched for age and sex. CIMT and PWV of the left common carotid artery were measured. At 12-month follow-up after bariatric surgery, measurements were repeated in the 38 patients with obesity.

RESULTS

Mean baseline body mass index (BMI) in the MHO group was 40.55 ± 3.59 kg/m2, which decreased by 33.1% after bariatric surgery. Compared with controls, CIMT and PWV were increased in MHO (543.53 ± 55.29 vs. 407.82 ± 53.09 μm, 6.70 ± 1.22 vs. 5.45 ± 0.74 m/s, respectively; all P < 0.001). At 12 months post-bariatric surgery, CIMT in MHO was lower than baseline (466.79 ± 53.74 vs. 543.53 ± 55.29 μm, P = 0.009), but PWV was not significantly different from baseline (6.27 ± 0.86 vs. 6.70 ± 1.22 m/s, P = 0.132). Multivariate regression showed that BMI was an independent predictor of CIMT (β = 0.531, P < 0.001).

CONCLUSION

Carotid artery structure and function were impaired in MHO, and improved carotid artery structure was associated with weight loss in MHO after bariatric surgery.

The effect of significant weight loss after bariatric surgery on echocardiographic indices: an observational study focusing on left ventricular deformation by 2D speckle echocardiography and right ventricular size

BACKGROUND

Obesity is a known risk factor for atherosclerosis and cardiac disease.

HYPOTHESIS

This study evaluated the effect of significant weight loss following bariatric surgery on myocardial deformation indices and right ventricular size (RV). This was a prospective cohort study. Morbid obese patients scheduled for bariatric surgery from July 2017 to February 2018 at Firoozgar Hospital were included in our study and referred for transthoracic echocardiography at Rajaie Cardiovascular Medical and Research Center.

RESULTS

Thirty-four patients entered the study. The absolute value of global longitudinal strain (GLS) at baseline, 3, and 6 months after surgery was 17.42 ± 2.94%, 18.24 ± 3.09%, and 19.52 ± 2.78%, respectively, with a statistically significant difference from baseline to after six months (P value < 0.001). The absolute value of global circumferential strain (GCS) at baseline, 3, and 6 months after surgery was 20.14 ± 4.22%, 23.32 ± 4.66%, and 24.53 ± 4.52%, respectively, with statistically significant changes (P value < 0.001) from baseline to three months and from baseline to six months and no significant difference from three months to six months. A significant decrease was reported in mechanical dispersion of circumferential strain (38.05 ± 23.81-23.37 ± 20.86 ms, P value = 0.006) 6 months after surgery. Right ventricular size three- and six-month post-surgery showed a significant decrease relative to baseline echocardiography.

CONCLUSIONS

Bariatric surgery could enhance cardiac function, as proven by 2D speckle echocardiography. Changes in RV size may be related to weight loss and should be considered when assessing patients who have undergone bariatric surgery.

Adiposity influences on myocardial deformation: a cardiovascular magnetic resonance feature tracking study in people with overweight to obesity without established cardiovascular disease

The objective of this study was to assess whether dietary-induced weight loss improves myocardial deformation in people with overweight to obesity without established cardiovascular disease applying cardiovascular magnetic resonance (CMR) with feature tracking (FT) based strain analysis. Ninety people with overweight to obesity without established cardiovascular disease (age 44.6 ± 9.3 years, body mass index (BMI) 32.6 ± 4 kg/m2) underwent CMR. We retrospectively quantified FT based strain and LA size and function at baseline and after a 6-month hypocaloric diet, with either low-carbohydrate or low-fat intake. The study cohort was compared to thirty-four healthy normal-weight controls (age 40.8 ± 16.0 years, BMI 22.5 ± 1.4 kg/m2). At baseline, the study cohort with overweight to obesity without established cardiovascular disease displayed significantly increased global circumferential strain (GCS), global radial strain (GRS) and LA size (all p < 0.0001 versus controls) but normal global longitudinal strain (GLS) and normal LA ejection fraction (all p > 0.05 versus controls). Dietary-induced weight loss led to a significant reduction in GCS, GRS and LA size irrespective of macronutrient composition (all p < 0.01). In a population with overweight to obesity without established cardiovascular disease subclinical myocardial changes can be detected applying CMR. After dietary-induced weight loss improvement of myocardial deformation could be shown. A potential clinical impact needs further studies.

Impact of Bariatric Surgery on Cardiac Function and Structure in Chinese Patients with Obesity

Introduction: Obesity contributes to cardiac dysfunction and has an impact on atherosclerotic cardiovascular disease. Bariatric surgery (BS) is being considered a therapeutic option for patients with obesity and also can improve cardiac function. Very few studies considered the Chinese population. This study aimed to examine the effect of BS on cardiac function and structure in Chinese subjects with obesity. Methods: A single-center retrospective analysis of 143 patients with obesity was included. To observe and analyze the short-term, midterm, and long-term effects of BS on cardiovascular function and structure, the study population was divided into three groups according to the time of review. Fifty-two patients in group T1 (re-examination within 12 months); 53 patients in group T2 (re-examination within 12 to 24 months); and 38 patients in group T3 (re-examination over 24 months). The effects of BS on the cardiac function and structure were evaluated by analyzing the echocardiographic parameters. Results: After BS, body mass index (BMI) decreased from 39.7 ± 8.0 to 28.4 ± 6.4 kg/m2 (P < 0.001). Blood pressure decreased significantly. Left ventricular mass index (LVMI) decreased (43.7 ± 16.4 to 37.8 ± 13.4 g/m2.7, P < 0.001). The change in LVMI was correlated with the change in BMI (R2 = 0.14, P < 0.001). In subgroup analyses at different follow-ups, echocardiographic parameters showed varying degrees of change compared with the baseline. Conclusions: Significant weight loss by BS was associated with improved left ventricular structure and function in Chinese patients with obesity, suggesting potential favorable effects of BS on the cardiac function and structure.

Comparison of Hemodynamic and Cerebral Oxygenation Responses during Exercise between Normal-Weight and Overweight Men

Obesity has negative impacts on cardiovascular function and may increase cerebrovascular complications during exercise. We compared hemodynamic and cerebral oxygen changes during high-intensity exercise between overweight (OW) and normal-weight (NW) individuals. Eighteen NW and fourteen OW male individuals performed high-intensity (70% of peak oxygen uptake, VO₂peak) cycling exercises for 30 min. Hemodynamics were measured using a bioelectrical impedance device, and cerebral oxygenation status was measured using a near-infrared spectrophotometer during and after exercise. The VO₂peak of NW individuals was significantly higher than that of OW individuals (41.3 ± 5.7 vs. 30.0 ± 5.0 mL/min/kg, respectively; p < 0.05). During the 30 min exercise, both groups exhibited an increase in oxygenated hemoglobin (O₂Hb) (p < 0.001), deoxygenated hemoglobin (p < 0.001), and cardiac output with increasing time. Post-exercise, cardiac output and systemic vascular resistance were significantly higher in the OW group than in the NW group (p < 0.05). The O₂Hb in the NW group was significantly higher at post-exercise times of 20 min (13.9 ± 7.0 μmol/L) and 30 min (12.3 ± 8.7 μmol/L) than that in the OW group (1.0 ± 13.1 μmol/L and 0.6 ± 10.0 μmol/L, respectively; p = 0.024 vs. 0.023, respectively). OW participants demonstrated lower cerebral oxygenation and higher vascular resistance in the post-exercise phase than non-OW subjects. These physiological responses should be considered while engaging OW and obese individuals in vigorous exercise.

The Impact of Bariatric Surgery on Cardiac Structure, and Systolic and Diastolic Function in Patients with Obesity: A Systematic Review and Meta-analysis

The purpose of this study was to provide pooled data from all studies on the impact of bariatric surgery on cardiac structure, and systolic and diastolic function evaluated by either echocardiography or cardiac magnetic resonance. PubMed, Web of Science, Embase, and Scopus databases were searched. Almost all of cardiac left-side structural indices improved significantly after bariatric surgery. However, right-side structural indices did not change significantly. Left ventricular ejection fraction and most of the diastolic function indices improved significantly after the bariatric surgery. The subgroup analysis showed that the left ventricular mass index decreased more in long-term follow-up (≥ 12 months). In addition, subgroup analysis of studies based on surgery type did not reveal any difference in outcomes between gastric bypass and sleeve gastrectomy groups.

Longitudinal Effect of Bariatric Surgery on Retinal Microcirculation and Target Organ Damage: the BASTOD Study

PURPOSE

Obesity is associated with increased cardiovascular risk. Bariatric surgery (BS) improves the clinical and metabolic profile. Retinal caliber changes could precede cardiovascular events. Different studies have shown an improvement in retinal caliber after BS. The aim of this study was to examine retinal caliber and other cardiovascular target organ damage before and after BS.

MATERIALS AND METHODS

Monocentric, prospective cohort study at the Montpellier University Hospital. Biologic features, vessel stiffness, echocardiograph variables, and retinal caliber at baseline and 6 and 12 months were assessed in consecutive patients with class 2 or 3 obesity undergoing BS. A mixed linear model adjusted for age and sex was used.

RESULTS

We included 88 patients (75 women). The mean (SD) age was 43 years (11) and mean (SD) baseline weight 117 (21) Kg. Mean changes in the first year after BS were - 5.1 µm in central retinal vein equivalent (CRVE) (p < 0.0001), + 0.02 in arteriole-to-venule ratio (AVR) (p < 0.0001), - 1.4 mmol/L in glycemia (p < 0.0001), - 1.0 mg/L in natural logarithm of C-reactive protein (p < 0.0001), and - 54.0 g in left ventricular mass (p = 0.0005). We observed no significant improvement in arterial stiffness markers. Predictors of improvement in CRVE were high baseline weight (p = 0.030), male sex (p = 0.025), and no diabetes history (p Dynamic links between variations = 0.047).

CONCLUSION

The retinal microvascular phenotype improved during the first year after bariatric surgery, with decreased CRVE and increased AVR. Factors associated with retinal microvascular plasticity were male sex, high baseline weight, and absence of diabetes. Longitudinal assessment of retinal vascular calibers may offer new insights into the pathophysiology of subclinical vascular processes.

Effects of weight loss after bariatric surgery on atrial electromechanical delay in obese subjects

Background: The authors investigated the relationship between weight loss after sleeve gastrectomy and change in atrial electromechanical delay values. Methods: A total of 41 patients were included. The primary end point was any effect of total weight loss on atrial electromechanical delay parameters. Results: The mean loss of body weight was 25.50 ± 11.07 kg. There was a significant correlation between mean body weight change and change in interatrial and left intra-atrial electromechanical delays (Pearson's correlation coefficient: 0.575 and 0.871, respectively; p < 0.001). Only change in body weight was significantly related to change in interatrial electromechanical delay (regression coefficient: 0.707; p < 0.01). Conclusion: In this study, a significant relationship was found between amount of body weight loss and decrease in atrial electromechanical values.

Transfer-function-free technique for the noninvasive determination of the human arterial pressure waveform

The estimation of central aortic blood pressure is a cardinal measurement, carrying effective physiological, and prognostic data beyond routine peripheral blood pressure. Transfer function-based devices effectively estimate aortic systolic and diastolic blood pressure from peripheral pressure waveforms, but the reconstructed pressure waveform seems to preserve features of the peripheral waveform. We sought to develop a new method for converting the local diameter distension waveform into a pressure waveform, through an exponential function whose parameters depend on the local wave speed. The proposed method was then tested at the common carotid artery. Diameter and blood velocity waveforms were acquired via ultrasound at the right common carotid artery while simultaneously recording pressure at the left common carotid artery via tonometer in 203 people (122 men, 50 ± 18 years). The wave speed was noninvasively estimated via the lnDU-loop method and then used to define the exponential function to convert the diameter into pressure. Noninvasive systolic and mean pressures estimated by the new technique were 3.8 ± 21.8 (p = 0.015) and 2.3 ± 9.6 mmHg (p = 0.011) higher than those obtained using tonometery. However, differences were much reduced and not significant in people >35 years (0.6 ± 18.7 and 0.8 ± 8.3 mmHg, respectively). This proof of concept study demonstrated that local wave speed, estimated from noninvasive local measurement of diameter and flow velocity, can be used to determine an exponential function that describes the relationship between local pressure and diameter. This pressure-diameter function can then be used for the noninvasive estimation of local arterial pressure.

Impact of Bariatric Surgery on Pulse Wave Velocity as a Measure of Arterial Stiffness: a Systematic Review and Meta-analysis

PURPOSE

Weight loss during post-bariatric surgery period has been linked to both reduced ASCVD mortality and overall mortality. Atherosclerosis causes arteries to lose their elasticity and become more stiff resulting in increased pulse wave velocity (PWV). It has been revealed that PWV favorably predicts subsequent ASCVDs. The goal of this systematic review and meta-analysis was to see how bariatric surgery affected PWV, an index of arterial stiffness.

MATERIALS AND METHODS

A systematic literature search in four databases was performed. Also, Cochrane guidelines were reviewed to determine bias possibility in the related studies. Comprehensive Meta-Analysis (CMA) V2 software is used to conduct the meta-analysis. Studies were evaluated regarding heterogeneity in design, populations under investigation, and treatment duration using random-effects model and the generic inverse variance weighting approach. A random-effect meta-regression approach was used to investigate the association with the estimated effect size. Evaluation of funnel plot, Egger's weighted regression, and Begg's rank correlation tests were utilized to estimate the presence of publication bias in the meta-analysis.

RESULTS

The results of meta-analysis on 13 trials including 1426 individuals demonstrated a remarkable decline of PWV after bariatric surgery (WMD: -0.652, 95% CI: -1.004, -0.301, p<0.001). The random-effects meta-regression revealed no evidence of significant correlation between the changes in PWV and initial BMI, BMI changes, or duration of follow-up.

CONCLUSION

The decrease of PWV might be utilized as an independent surrogate marker of improvement of ASCVD risk after bariatric surgery.

Obesity cardiomyopathy: evidence, mechanisms, and therapeutic implications

The prevalence of heart failure is on the rise and imposes a major health threat, in part, due to the rapidly increased prevalence of overweight and obesity. To this point, epidemiological, clinical, and experimental evidence supports the existence of a unique disease entity termed “obesity cardiomyopathy,” which develops independent of hypertension, coronary heart disease, and other heart diseases. Our contemporary review evaluates the evidence for this pathological condition, examines putative responsible mechanisms, and discusses therapeutic options for this disorder. Clinical findings have consolidated the presence of left ventricular dysfunction in obesity. Experimental investigations have uncovered pathophysiological changes in myocardial structure and function in genetically predisposed and diet-induced obesity. Indeed, contemporary evidence consolidates a wide array of cellular and molecular mechanisms underlying the etiology of obesity cardiomyopathy including adipose tissue dysfunction, systemic inflammation, metabolic disturbances (insulin resistance, abnormal glucose transport, spillover of free fatty acids, lipotoxicity, and amino acid derangement), altered intracellular especially mitochondrial Ca²⁺ homeostasis, oxidative stress, autophagy/mitophagy defect, myocardial fibrosis, dampened coronary flow reserve, coronary microvascular disease (microangiopathy), and endothelial impairment. Given the important role of obesity in the increased risk of heart failure, especially that with preserved systolic function and the recent rises in COVID-19-associated cardiovascular mortality, this review should provide compelling evidence for the presence of obesity cardiomyopathy, independent of various comorbid conditions, underlying mechanisms, and offer new insights into potential therapeutic approaches (pharmacological and lifestyle modification) for the clinical management of obesity cardiomyopathy.

Improvement of Arterial Stiffness One Month after Bariatric Surgery and Potential Mechanisms

Arterial stiffness (AS) is an independent predictor of cardiovascular risk. We aimed to analyze changes (Δ) in AS 1-month post-bariatric surgery (BS) and search for possible pathophysiological mechanisms. Patients with severe obesity (43% hypertensives) were prospectively evaluated before and 1-month post-BS, with AS assessed by pulse-wave velocity (PWV), augmentation index (AIx@75) and pulse pressure (PP). Ambulatory 24 h blood pressure (BP), anthropometric data, renin-angiotensin-aldosterone system (RAAS) components and several adipokines and inflammatory markers were also analyzed. Overall reduction in body weight was mean (interquartile range (IQR)) = 11.0% (9.6–13.1). A decrease in PWV, AIx@75 and PP was observed 1-month post-BS (all, p < 0.01). There were also significant Δ in BP, RAAS components, adipokines and inflammatory biomarkers. Multiple linear regression adjusted models showed that Δaldosterone was an independent variable (B coeff.95%CI) for final PWV (B = −0.003, −0.005 to 0.000; p = 0.022). Angiotensin-converting enzyme (ACE)/ACE2 and ACE were independent variables for final AIx@75 (B = 0.036, 0.005 to 0.066; p = 0.024) and PP (B = 0.010, 0.003 to 0.017; p = 0.01), respectively. There was no correlation between ΔAS and anthropometric changes nor with Δ of adipokines or inflammatory markers except high-sensitivity C-reactive protein (hs-CRP). Patients with PWV below median decreased PWV (mean, 95%CI = −0.18, −0.25 to −0.10; p < 0.001) and both AIx@75 and PP at 1-month, but not those with PWV above median. In conclusion, there is an improvement in AS 1-month post-BS that correlates with ΔBP and Δrenin-angiotensin-aldosterone components. The benefit is reduced in those with higher PWV.

Dapagliflozin decreases ambulatory central blood pressure and pulse wave velocity in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled clinical trial

OBJECTIVES

Sodium-glucose co-transporter 2 (SGLT-2) inhibitors reduce the incidence of heart failure and death in patients with type-2 diabetes mellitus. Arterial stiffness is a prominent risk factor for heart failure and overall mortality. The aim of this study was to evaluate the effects of dapagliflozin on ambulatory brachial and central blood pressure (BP) levels and arterial stiffness parameters in patients with type-2 diabetes mellitus.

METHODS

This is a double-blind, randomized, placebo-controlled clinical trial including 85 adult patients with type-2 diabetes mellitus on monotherapy or combination therapy with two of: metformin, sulphonylurea, DPP-4 inhibitor, or insulin. Patients were randomized in a 1 : 1 ratio to oral dapagliflozin 10 mg per day or placebo for 12 weeks. Study participants underwent 24-h ambulatory BP monitoring with the Mobil-O-Graph NG monitor at baseline and study-end.

RESULTS

Baseline demographic, clinical and laboratory parameters were similar in the two groups. During follow-up, 24-h brachial SBP/DBP (129.0 ± 12.6/77.3 ± 7.3 vs. 123.2 ± 12.4/75.1 ± 6.4 mmHg; P < 0.001/P = 0.008) and central SBP/DBP (117.4 ± 10.5/78.9 ± 7.3 vs. 113.3 ± 8.8/77.3 ± 6.5 mmHg; P = 0.002/P = 0.047) significantly decreased in dapagliflozin but not in the placebo group. Corresponding reductions of 24-h brachial SBP (-5.8 ± 9.5 vs. -0.1 ± 8.7, P = 0.005) and central SBP (-4.1 ± 8.0 vs. -0.7 ± 7.8; P = 0.046) were greater with dapagliflozin than placebo. Twenty-four-hour heart-rate adjusted augmentation index significantly decreased with dapagliflozin and insignificantly with placebo. Importantly, there was a significant difference in change of estimated 24-h PWV (-0.16 ± 0.32 vs. 0.02 ± 0.27; P = 0.007) favoring dapagliflozin. In generalized linear mixed models including 24-h brachial SBP as a random covariate, the adjusted marginal means of delta 24-h central SBP and delta 24-h PWV were not significantly different between-groups.

CONCLUSION

Treatment with dapagliflozin significantly reduces ambulatory brachial and central BP levels and PWV in patients with type-2 diabetes mellitus. Improvement in these parameters may substantially contribute to the cardiovascular benefits of SGLT-2 inhibitors.