The Role of Sleeve Gastrectomy in Reducing Cardiovascular Risk

New insights on the association of weight loss with the reduction in carotid intima-media thickness among patients with obesity: an updated systematic review and meta-analysis

OBJECTIVES

Carotid intima-media thickness (CIMT) is a noninvasive marker of atherosclerosis, a typical pathologic process underlying cardiovascular diseases (CVDs). It is essential to explore the relationships between weight loss and the reduction of CIMT.

STUDY DESIGN

This was an updated systematic review and meta-analysis.

METHODS

A systematic literature search was conducted to collect relevant clinical trials. The pooled results of meta-analyses were assessed by weighted mean difference (WMD) and the corresponding 95 % confidence interval (95% CI).

RESULTS

Thirty-three articles involving 2273 participants were collected in this meta-analysis. Among all participants with obesity, the pooled mean of weight loss was -23.26 kg (95% CI: -27.71 to -18.81), and the pooled mean change of CIMT was -0.06 mm (95% CI: -0.08 to -0.04). Compared with Non-surgical interventions, Surgical ones could lead to much higher weight loss (Pbetween groups < 0.001). A more significant CIMT reduction was identified among Surgical intervention patients than among Non-surgical intervention participants (Pbetween groups < 0.001).

CONCLUSIONS

Effective interventions, especially Surgical interventions, could reduce the weight of patients with obesity, followed by the decline of CIMT, which might further disturb atherosclerosis progression and lower CVD risk.

Impact of bariatric surgery on carotid intima-media thickness, flow-mediated dilation, and nitrite-mediated dilation: a systematic review and meta-analysis

Obesity is considered one of the independent risk factors for atherosclerosis and is strongly correlated with cardiovascular morbidity and mortality. Previous studies showed carotid intima-media thickness (CIMT), flow-mediated dilation (FMD), and nitrite-mediated dilatation (NMD) are reliable non-invasive markers of arterial damage and dysfunction. The aim of this study was to evaluate the effect of bariatric surgery on CIMT, FMD, and NMD markers in patients with obesity. A systematic search was performed in the PubMed, Embase, Scopus, and Web of Science databases until May 2022. All the English-published studies on the effect of bariatric surgery on CIMT, FMD, and NMD were included. A quantitative meta-analysis was performed, as well as subgroup analyses for the type of procedure and duration of follow-up. Meta-analysis of 41 studies with 1639 patients showed CIMT was significantly reduced by .11 mm after bariatric surgery (95% CI, -.14 to -.08; P < .001; mean follow-up = 10.8 mo). The pooled analysis of 23 studies with 1106 patients showed an increase of FMD by 4.57% after bariatric surgery (95% CI, 2.69-6.44; P < .001; mean follow-up = 11.5 mo). The results of a pooled analysis of 12 studies with 346 patients showed a significant increase of NMD by 2.46% after bariatric surgery (95% CI, .99-3.94; P < .001; mean follow-up = 11.4 mo). The random effect meta-regression demonstrated that baseline CIMT and FMD significantly affect the changes in CIMT and FMD. This meta-analysis showed bariatric surgery can improve CIMT, FMD, and NMD markers in patients with obesity. These improvements show the known effect of metabolic surgery in decreasing cardiovascular risk.

Effect of Bariatric Surgery on Flow-Mediated Vasodilation as a Measure of Endothelial Function: A Systematic Review and Meta-Analysis

Objectives. Flow mediated vasodilation (FMD) is a marker of endothelial function and its decline is related to increased cardiovascular risk. This systematic review and meta-analysis evaluated the impact of bariatric surgery on FMD. Materials and methods. A systematic literature search in PubMed, Scopus, Embase, and Web of Science was performed to 1 May 2021. Meta-analysis was performed using Comprehensive Meta-Analysis (CMA) V2 software. All types of bariatric surgery were considered, with the inclusion that FMD had to have been tested before and after the surgical procedure. Meta-analysis was carried out using a random-effects model and the generic inverse variance approach. The leave-one-out approach was used for sensitivity analysis. To assess metabolic parameter confounders, a weighted random-effects meta-regression was used. Results. A meta-analysis and a systematic review of 23 studies (n = 891 individuals) demonstrated improvement in FMD following bariatric surgery (weighted mean difference (WMD): 5.867, 95% CI: 4.481, 7.252, p < 0.001; I2: 96.70). Iteratively removing each item in the meta-analysis did not result in a significant alteration in the pooled estimate of effect size. There was an improvement in FMD for up to 6 months following bariatric surgery in a meta-analysis from 7 trials that included 356 subjects (WMD: 5.248, 95% CI: 2.361, 8.135, p < 0.001; I2: 98.18). The meta-analysis from 9 trials (n = 414 subjects) showed an improvement in FMD 6 to 12 months after bariatric surgery (WMD: 5.451, 95% CI: 3.316, 7.587, p < 0.001; I2: 94.18). The meta-analysis from 10 trials (n = 414 subjects) demonstrated an improvement in FMD 12 months after bariatric surgery (WMD: 2.401, 95% CI: 0.944, 3.859, p = 0.001; I2: 88.35). Random-effects meta-regression did not show any association between the alteration in FMD and percent body mass index (BMI) change (slope: 0.0258; 95% CI: −0.323, 0.375; p = 0.884), or changes in blood pressure; however, there was an association between the changes in FMD and the duration of follow-up (slope: −0.106; 95% CI: −0.205, −0.008; p = 0.033) with greater changes in FMD after 12 months. Conclusions. Bariatric surgery significantly improved FMD that increased with time, and the resultant improvement in endothelial function was independent of weight loss or a reduction in blood pressure.

Effect of bariatric surgery on flow-mediated dilation and carotid intima-media thickness in patients with morbid obesity: 1-year follow-up study

Objective:

Obesity is associated with increased cardiovascular (CV) mortality and morbidity. Bariatric surgery (BS) is currently an established therapeutic approach for severely obese patients. Carotid intima-media thickness (CIMT) and brachial artery flow-mediated dilation (FMD) provide important prognostic information beyond traditional CV risk factors. This study aimed to examine the effect of bariatric surgery-induced weight loss on CIMT and brachial artery FMD in morbidly obese patients.

Methods:

A total of 23 morbidly obese patients (40.4±5.6 years, 13 females) were examined before and after BS for 1 year with 3-month periods. CIMT, FMD, body composition, and metabolic parameters were determined.

Results:

All the patients exhibited significant weight loss following BS (p<0.001). Carotid intima-media thickness reduction was not significant from baseline to 6 months (p=0.069), but at 9 months (p=0.004), it became significant. Similarly, the difference between the preoperative and 6-month FMD assessments was not significant (p=0.057), but at 9 months (p<0.001), it became significant.

Conclusion:

Our study reveals that weight loss following BS causes improvements in CV risk factors, which is evident after 9 months of surgery.

Joint influences of obesity, diabetes, and hypertension on indices of ventricular remodeling: Findings from the community-based Framingham Heart Study

Introduction

Obesity, hypertension, and diabetes are independently associated with cardiac remodeling and frequently co-cluster. The conjoint and separate influences of these conditions on cardiac remodeling have not been investigated.

Materials and methods

We evaluated 5,741 Framingham Study participants (mean age 50 years, 55% women) who underwent echocardiographic measurements of left ventricular (LV) mass (LVM), LV ejection fraction (LVEF), global longitudinal strain (GLS), mitral E/e’, left atrial end-systolic (peak) dimension (LASD) and emptying fraction (LAEF). We used multivariable generalized linear models to estimate the adjusted-least square means of these measures according to cross-classified categories of body mass index (BMI; normal, overweight and obese), hypertension (yes/no), and diabetes (yes/no).

Results

We observed statistically significant interactions of BMI category, hypertension, and diabetes with LVM, LVEF, GLS, and LAEF (p for all 3-way interactions <0.01). Overweight and obesity (compared to normal BMI), hypertension, and diabetes status were individually and conjointly associated with higher LVM and worse GLS (p<0.01 for all). We observed an increase of 34% for LVM and of 9% for GLS between individuals with a normal BMI and without hypertension or diabetes compared to obese individuals with hypertension and diabetes. Presence of hypertension was associated with higher LVEF, whereas people with diabetes had lower LVEF.

Conclusions

Obesity, hypertension, and diabetes interact synergistically to influence cardiac remodeling. These findings may explain the markedly heightened risk of heart failure and cardiovascular disease when these factors co-cluster.

The Effect of Laparoscopic Sleeve Gastrectomy on Subclinical Atherosclerosis in Patients with Severe Obesity

PURPOSE

Cardiovascular diseases (CVD) are one of the leading causes of mortality in obese patients. In this study, we investigated the effects of laparoscopic sleeve gastrectomy (LSG) operation on carotid intima-media thickness (CIMT), epicardial fat thickness (EFT), and serum endocan levels, which are independent predictors of subclinical atherosclerosis.

MATERIALS AND METHODS

A total of 47 patients (35 females and 12 males) with a mean age of 38 ± 10.48 with standard indications for LSG were prospectively included in the study. Mean CIMT values with B-mode duplex ultrasound, EFT measurements with standard transthoracic 2D echocardiography, and serum endocan levels were measured before the operation and 6 months after the operation. Delta (Δ) values were obtained by subtracting sixth month values from baseline values.

RESULTS

Body mass index (BMI) decreased significantly from an average of 47.31 ± 6.10 to 37.25 ± 5.61 kg/m² in the sixth month after LSG (p < 0.001). EFT, CIMT, and serum endocan values decreased significantly in the sixth month after surgery (0.67 ± 0.15 vs. 0.60 ± 0.14 mm, p < 0.001; 1.07 ± 0.05 vs. 1.00 ± 0.14 mm, p < 0.001; and 89.18 ± 66.22 vs. 37.74 ± 15.37, p < 0.001, respectively). There were mild-moderate positive relationships between Δ-BMI and the values of EFT and CIMT (r = 0.386, p = 0.007 and r = 0.314, p = 0.024, respectively). We also found weak linear relationships between Δ-BMI and Δ-endocan (r = 0.267, p = 0.036), and between Δ-EFT and Δ-CIMT (r: 0.221; p: 0.046).

CONCLUSION

LSG can lead to reduction in the risk of cardiovascular disease by providing improvements in CIMT, EFT, and serum endocan values, which reflect early structural atherosclerotic changes in patients with severe obesity.

Skin Autofluorescence and Carotid Intima-Media Thickness Evaluation Following Bariatric Surgery in Patients with Severe Obesity

PURPOSE

Advanced glycation end product (AGE) is a marker of metabolic memory. Accumulated AGEs in skin collagen measured with skin autofluorescence (SAF) was found to be associated with subclinical atherosclerosis. We aimed to evaluate SAF and carotid intima-media thickness (CIMT) and its association with clinical and biochemical parameters in severely obese patients before and after bariatric surgery.

MATERIALS AND METHODS

In this observational study, 432 morbid obese patients evaluated before and after 6 and 12 months of bariatric surgery for metabolic and anthropometric parameters, CIMT and SAF. SAF was assessed in the forearm with an AGE Reader.

RESULTS

SAF measurements were higher in diabetic (2.04 ± 0.52 AU) obese patients compared to non-diabetic (1.78 ± 0.40 AU) obese patients (p < 0.0001). Although bariatric surgery-induced weight loss resulted in a decrease in CIMT in the 6th and 12th months compared to baseline, weight loss and metabolic improvements were not associated with a parallel decrease in SAF measurements. SAF measurements were positively correlated with body mass index (r 0.527, p < 0.0001), HbA1c (r 0.362, p < 0.0001), and CIMT (r 0.319, p < 0.0001). Multivariate analysis showed the presence of diabetes (but not BMI, age, and sex) was independently associated with SAF (R² = 7.62%), and the presence of diabetes, low-density cholesterol, and systolic blood pressure were independently associated with CIMT measurements (R² = 21.7%).

CONCLUSION

Bariatric surgery-induced weight loss and metabolic improvement were found to be associated with improvement in CIMT, while skin AGE accumulation was not regressed in the first year of surgery.

Incidence of Diabetes Mellitus, Cardiovascular Diseases, and Cancer in Patients Undergoing Malabsorptive Surgery (Biliopancreatic Diversion and Biliointestinal Bypass) vs Medical Treatment

BACKGROUND AND AIMS

Bariatric surgeries such as gastric banding (LAGB), gastric bypass (RYGB), vertical banded gastroplasty (VBG), and sleeve gastrectomy (LSG) decrease body weight in morbid obesity, leading to the resolution of coexisting diabetes mellitus and arterial hypertension in the majority of cases as well as improvements of renal function and liver steatosis. BS (LAGB, RYGB, VBG, and LSG) also reduce incident cases of diabetes, of cardiovascular diseases, and of cancer; these therapeutic and preventive effects on comorbidities of obesity have not been analyzed for malabsorptive surgeries such as biliopancreatic diversion (BPD) or biliointestinal bypass (BIBP). The aim of this study was to analyze the incidence of comorbidities, i.e., diabetes, cardiovascular diseases, and cancer, in obese subjects undergoing BPD and BIBP, in comparison with standard medical treatment of obesity.

PATIENTS AND METHODS

Medical records of 1983 obese patients (body mass index (BMI) > 35 kg/m², aged 18-65 years, undergoing surgery (n = 472, of which 111 with diabetes) or medical treatment (n = 1511, of which 422 with diabetes), during the period 1999-2008 (visit 1)) were collected; incident cases of comorbidities were ascertained through December 31, 2016.

RESULTS

Observation period was 12.0 ± 3.48 years (mean ± SD). Compared to non-surgical patients matched for age, body mass index, and blood pressure, malabsorptive surgeries were associated with reduced new incident cases of diabetes (p = 0.001), cardiovascular diseases (p = 0.001), hyperlipidemia (p = 0.001), oculopathy (p = 0.021), and cancer (p = 0.001). The preventive effect of BS was similar in both nondiabetic and diabetic patients for cardiovascular diseases and hyperlipidemia (both p = 0.001). The preventive effect was significant in nondiabetic subjects for coronary heart disease and for cancer, not significant in diabetic subjects.

CONCLUSION

Patients undergoing malabsorptive bariatric surgery show less incident cases of diabetes, cardiovascular diseases, hyperlipidemia, oculopathy, and cancer than controls receiving medical treatment.

Endothelial Function in Obese Patients Treated with Bariatric Surgery

PURPOSE

Bariatric surgery (BS) is becoming an increasingly frequent treatment option especially in people with morbid obesity, demonstrating that it is able to reduce total mortality and cardiovascular (CV) risk. Despite endothelial dysfunction is an essential requisite contributing to atherosclerosis and predicting CV events, only some studies have investigated the effects of BS on endothelial function with controversial results. In this study, the effects of weight loss on endothelial function were investigated in obese patients after BS and compared with patients after medical nutrition treatment (MNT).

PATIENTS AND METHODS

Seventeen obese patients who underwent BS procedures (9 adjustable gastric bands, 3 gastric by-passes and 5 biliopancreatic diversions) were included in the study and compared with 18 obese individuals who underwent MNT. Endothelial function was investigated by flow-mediated dilation (FMD) of the brachial artery. Also, carotid intima-media thickness (c-IMT) was measured as a marker of subclinical atherosclerosis.

RESULTS

At the end of follow-up, the mean weight loss was 18.8% in the BS group and 7.0% in the MNT group. After treatment, FMD significantly decreased in the BS group (mean ± SD before: 9.0 ± 4.7; after: 6.1 ± 2.9%; P= 0.04); however, no significant change was observed in the MNT group (before: 9.4 ± 5.8; after: 8.3 ± 5.3; P= 0.41). The modification of endothelial function was negatively correlated with c-IMT change in the BS group (r= -0.63; P <0.007).

CONCLUSION

A significant endothelial dysfunction occurred following BS but not after MNT. Furthermore, the decline of endothelial function observed in the BS group might have contributed to atherosclerosis.

Microcirculatory Improvement Induced by Laparoscopic Sleeve Gastrectomy Is Related to Insulin Sensitivity Retrieval

AIMS

Microvascular dysfunction is a potential factor explaining the association of obesity, insulin resistance, and vascular damage in morbidly obese subjects. The purpose of the study was to evaluate possible determinants of microcirculatory improvement 1 year after laparoscopic sleeve gastrectomy (LSG) intervention.

METHODS

Thirty-seven morbidly obese subjects eligible for bariatric surgery were included in the study. Post-occlusive reactive hyperemia (PORH) of the forearm skin was measured as area of hyperemia (AH) by laser-Doppler flowmetry before LSG and after a 1-year follow-up.

RESULTS

After intervention, we observed a significant reduction in BMI, HOMA index, HbA1c, and a significant increase of AH in all patients after surgery; this variation was significant only in those patients having insulin resistance or prediabetes/diabetes. Although significant correlation between the increase of AH and the reduction of both BMI, HOMA index, and HbA1c was observed, BMI was the only independent predictor of AH variation after LSG at the linear regression analysis.

CONCLUSIONS

Our study shows that LSG intervention is correlated with a significant improvement in the microvascular function of morbidly obese subjects; this improvement seems to be related to the baseline degree of insulin-resistance and to the retrieval of insulin-sensitivity post-intervention.

Effects of Sleeve Gastrectomy on Blood Pressure and the Renal Renin-Angiotensin System in Rats with Diet-Induced Obesity

OBJECTIVE

Sleeve gastrectomy (SG) has been reported to decrease blood pressure (BP), although the reason has not been revealed. The present study aimed to establish the reason why SG decreases BP.

METHODS

Male Sprague-Dawley rats were subjected to surgical (sham operation or SG) and dietary interventions (fed a normal diet or high-fat diet ad libitum or fed by pair-feeding [PF]). Systolic BP (SBP), urinary sodium excretion, and endocrine parameters were examined 4 weeks after surgery.

RESULTS

Both SG and PF rats had reduced body weight compared with SO rats fed normal diet or high-fat diet ad libitum. SG rats exhibited a reduction in SBP compared with PF, which was associated with a reduction in renal renin, angiotensin II, and catechol-O-methyltransferase levels (P < 0.01 for each). SG increased plasma cholecystokinin (CCK) levels compared with PF (P < 0.0001 for each), whereas glucagon-like peptide 1 and peptide YY were not changed in fasting. Exogenous administration of CCK reduced renal catechol-O-methyltransferase (P = 0.0233), renin (P < 0.0001), and angiotensin II (P < 0.0001) levels and SBP (P = 0.0053).

CONCLUSIONS

SG reduced SBP, at least in part, through suppression of sympathetic nerve action by elevation of CCK, which was followed by suppression of the intrarenal renin-angiotensin system.

Visceral Adipose Tissue Accumulation and Residual Cardiovascular Risk

PURPOSE OF THE REVIEW

Low-grade systemic inflammation increases residual cardiovascular risk. The pathogenesis of low-grade systemic inflammation is not well understood.

RECENT FINDINGS

Visceral adipose tissue accumulates when the subcutaneous adipose tissue can no longer store excess nutrients. Visceral adipose tissue inflammation initially facilitates storage of nutrients but with time become maladaptive and responsible for low-grade systemic inflammation. Control of low-grade systemic inflammation requires reversal of visceral adipose tissue accumulation with intense and sustained aerobic exercise or bariatric surgery. Alternatively, pharmacologic inhibition of the inflammatory signaling pathway may be considered. Reversal visceral adipose tissue accumulation lowers residual cardiovascular risk.

Impact of weight loss on epicardial fat and carotid intima media thickness after laparoscopic sleeve gastrectomy: A prospective study

BACKGROUND AND AIMS

Cardiovascular disease (CVD) is one of the leading causes of mortality in obese patients. We aimed to investigate the influence of significant weight loss following laparoscopic sleeve gastrectomy (LSG) on carotid intima media thickness (CIMT) and epicardial fat thickness (EFT) which are the independent predictors of subclinical atherosclerosis.

METHODS AND RESULTS

Patients were recruited for standard indications. A total of 105 patients (79 women and 26 men) with the mean age of 43.61 ± 12.42 were prospectively enrolled. On B-mode duplex ultrasound; the mean CIMT at the far wall of both left and right common carotid arteries were measured. EFT was measured on the free wall of the right ventricle at end-diastole from the parasternal long-axis view by standard transthorasic 2D echocardiography. Delta (Δ) values were obtained by subtracting sixth month values from the baseline values. Body mass index (BMI) was significantly reduced from 46.95 ± 7.54 to 33.54 ± 6.41 kg/m2 (p < 0.001) in sixth months after LSG. Both EFT and CIMT were significantly decreased after surgery (8.68 ± 1.95 mm vs. 7.41 ± 1.87 mm; p < 0.001 and 0.74 ± 0.13 mm vs. 0.67 ± 0.11 mm; p < 0.001 respectively). A significant correlation between ΔEFT and ΔBMI (r = 0.431, p < 0.001) was shown. ΔCIMT is significantly correlated with ΔEFT, ΔBMI and Δ systolic blood pressure (r = 0.310, r = 0.285 and r = 0.231 respectively, p < 0.05 for all). In multivariate stepwise linear regression analysis; among variables only ΔBMI was the independent predictor of ΔEFT (β = 153, p = 0.001).

CONCLUSION

Early atherosclerotic structural changes may be reversed or improved by sustained weight loss after LSG in asymptomatic obese patients.