Cardiac remodeling in obesity and after bariatric and metabolic surgery; is there a role for gastro-intestinal hormones?

Global collaborative research in metabolic and bariatric surgery (GCRMBS): current status and directions for the future

Obesity has been recognized as a chronic disorder by the World Health Organisation (WHO) and was first reported in the Paleolithic age. In the recent years there has not been an international collaborative that facilitates professional cooperation on a worldwide level to increase the output of high-level evidence in the fields of obesity treatment and metabolic and bariatric surgery (MBS). In other surgical and medical fields, international collaborative research networks have shown to increase the quality and amount of treatment-changing evidence. In general, Global Collaborative Research in MBS (GCRMBS) should have the following goals: (1) clinical specialty-based research in obesity and MBS, (2) designing research protocols and studies to generate long-term data in obesity and MBS, (3) understanding the uncommon/rare complications and events associated with obesity and MBS, (4) increasing the number of participants in research and (5) investigating ethical and racial disparities in bariatric research. This review gives an overview of the current status and the future of international collaborative research in MBS.

Diabetes and obesity: A debate on bariatric interventions and its implications

In this editorial, we comment on an article by Tang et al published in the World Journal of Diabetes. Obesity and diabetes are two pathological situations that are intrinsically related. Neither lifestyle changes nor pharmacological treatments have achieved diabetes remission. From this perspective, bariatric surgery has been widely used as an approach for weight loss in obese patients and as a strategy to promote metabolic modulation. The main effects of bariatric surgery involve direct action in improving cardiovascular function and endothelial function and reducing insulin resistance, leading to diabetes remission in the short term following surgery. In this context, it has been observed that hormones from the gastrointestinal tract and endothelium play a prominent role in this process. By reversing endothelial dysfunction, it is possible to balance pro-inflammatory cytokine production, improving the availability of nitric oxide and inhibiting vascular oxidative stress. Furthermore, it can be considered an efficient anti-inflammatory strategy, alleviating interferon-gamma-mediated adipose tissue inflammation. The current challenge must be to unravel the pathophysiological mechanisms and potential targets for treating metabolic diseases.

Association between the triglyceride-glucose index and subclinical left ventricular systolic dysfunction in obese patients

BACKGROUND

The association between the triglyceride-glucose (TyG) index and subclinical left ventricular (LV) systolic dysfunction in obese patients remains unclear. This study aimed to investigate the relationship between the TyG index and LV global longitudinal strain (GLS) in obese patients.

METHODS

A total of 1028 obese patients from January 2019 to January 2024 were included in the present study. Clinical parameters and biochemical and echocardiographic data were obtained from the participants. LV GLS was obtained from the GE EchoPAC workstation for evaluating subclinical LV function. The TyG index was calculated as Ln (fasting TG [mg/dL] × fasting glucose [mg/dL]/2). LV GLS was compared between obese patients with a high TyG index and those with a low TyG index.

RESULTS

Obese patients with a high TyG index had greater incidences of hypertension, diabetes mellitus and hyperlipidaemia. The LV GLS was significantly lower in the high TyG index group than in the low TyG index group (P = 0.01). After adjusting for sex, age, body mass index, heart rate, hypertension, diabetes mellitus, dyslipidaemia, blood urea nitrogen, serum creatinine, LV mass and LV hypertrophy, the TyG index remained an independent risk indicator related to an LV GLS < 20% (OR: 1.520, 95% CI: 1.040 to 2.221; P = 0.031).

CONCLUSIONS

We concluded that an increase in the TyG index is independently associated with subclinical LV systolic dysfunction in obese patients.

Evaluation of subclinical left ventricular systolic dysfunction in obese patients by global myocardial work

OBJECTIVE

To evaluate subclinical LV systolic dysfunction in obese patients by global myocardial work (MW).

METHODS

A total of 589 obese patients and 100 normal controls were enrolled in the study. The global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE) were generated by a noninvasive pressure-strain loop (PSL) in apical 3-, 4- and 2-chamber views acquired by two-dimensional echocardiography. All obese patients were divided into three groups: class I obesity (mild) 30-35 kg/m2, class II obesity (moderate) 35-40 kg/m2 and class III obesity (severe) > 40 kg/m2. These values were compared among the three groups. The independent influencing factors of subclinical LV systolic dysfunction in obese patients were explored by constructing a multiple regression model. ROC analysis was performed to determine the performance of MW to detect subclinical LV systolic dysfunction in obese patients.

RESULTS

The absolute value of GLS in obese patients was significantly lower than that in normal controls (P < 0.001). The values of GWI, GCW, GWE and GCW/GWW in obese patients were significantly lower than those in normal controls (P < 0.05), while GWW was significantly larger than that in normal controls (P < 0.001). Subgroup analysis and trend analysis showed that the values of GWI, GCW, GWE and GCW/GWW in severe obese patients were lower than those in moderate obese patients and lower than those in mild obese patients (P < 0.01), while GWW in severe obese patients was larger than that in moderate obese patients and larger than that in mild obese patients (P < 0.05). Female sex, BMI and SBP were independent influencing factors of impaired GWI (β = 0.15, P < 0.001) (β=-0.18, P < 0.001) (β = 0.50, P < 0.001) and GCW (β = 0.17, P < 0.001) (β=-0.19, P < 0.001) (β = 0.57, P < 0.001). ROC analysis showed that the AUC of the combined global MW was significantly higher than the AUCs of the individual indices (P < 0.05).

CONCLUSION

In this study, we conclude that subclinical LV systolic dysfunction was detected by the novel global MW technique in obese patients. Elevated BMI in obese patients results in an increased risk of subclinical LV systolic dysfunction, although the LVEF is normal. Controlling BMI in obese patients may reduce the impairment to the LV myocardial systolic function. Global MW is a novel and reproducible technique that can be well applied in the clinical evaluation of subclinical LV systolic dysfunction.

CHANGE OF GHRELIN CONCENTRATION IN TYPE 2 DIABETES MELLITUS ASSOCIATED WITH OBESITY IN THE EARLY AND DELAYED PERIOD AFTER LAPAROSCOPIC SLEEVE GASTRECTOMY

Laparoscopic sleeve gastrectomy (LSG) is an effective method of treating obesity complicated by type 2 diabetes mellitus (T2DM). The performance of this metabolic surgical intervention involves removal fundus of the stomach, which in turn leads to an effect on the eating behavior of patients in the form of a decrease in appetite and loss of excess body weight with a parallel effect on the compensation of T2DM in the postoperative period, regardless of the loss of body weight. At present, mechanisms of T2DM compensation after LSG have not yet been clearly defined. The aim of our study was to study the effect of LSG on the dynamics of changes in the blood plasma ghrelin levels in patients with T2DM associated with obesity. The plasma ghrelin levels were assessed in the fasted state, 15, 30, 60, and 90 min after a standard breakfast carbohydrate preload, which included 125 ml of Nutricia Nutridrink, a balanced high-energy protein. The examination was carried out before the operation, on the 4th postoperative day and 3 months after the operation. 7 patients were diagnosed with T2DM for the first time, 3 had a history of diabetes for 2 years, one patient had a history of 3.5 years, and another had a history of 10 years. The average content of glycated hemoglobin before the operation was 7.7%, 3 months after LSG - 5.9%. The fasting ghrelin concentration before LSG performing was 6.8 ng/ml, on the 4th postoperative day – 4.6 ng/ml, and 3 months after the operation – 4.4 ng/ml (P = 0.001) in comparison with preoperative indicators). The peak insulin concentration was noted 30 min after the carbohydrate preload 3 months after the operation and was 175.1 μU/ml, and its fasting levels in the postoperative period reached a statistically significant difference compared to the preoperative values (30 μU/ml before surgery and 25.3 μU/ml 3 months after LSG). Thus, LSG leads to an early and significant suppression of fasting ghrelin secretion in patients with obesity-associated T2DM and likely to restore insulin secretion and/or reduce insulin resistance. Rapid postoperative improvement of carbohydrate metabolism components indicates the importance of the early reduction of ghrelin secretion in combination with the incretin effect of LSG in the implementation of the mechanisms of early compensation of T2DM and explains the metabolic activity of this operation and the significant role of the stomach in the regulation of glucose metabolism.

The many faces of diabetes. Is there a need for re-classification? A narrative review

The alarming rise in the worldwide prevalence of obesity and associated type 2 diabetes mellitus (T2DM) have reached epidemic portions. Diabetes in its many forms and T2DM have different physiological backgrounds and are difficult to classify. Bariatric surgery (BS) is considered the most effective treatment for obesity in terms of weight loss and comorbidity resolution, improves diabetes, and has been proven superior to medical management for the treatment of diabetes. The term metabolic surgery (MS) describes bariatric surgical procedures used primarily to treat T2DM and related metabolic conditions. MS is the most effective means of obtaining substantial and durable weight loss in individuals with obesity. Originally, BS was used as an alternative weight-loss therapy for patients with severe obesity, but clinical data revealed its metabolic benefits in patients with T2DM. MS is more effective than lifestyle or medical management in achieving glycaemic control, sustained weight loss, and reducing diabetes comorbidities. New guidelines for T2DM expand the use of MS to patients with a lower body mass index.Evidence has shown that endocrine changes resulting from BS translate into metabolic benefits that improve the comorbid conditions associated with obesity, such as hypertension, dyslipidemia, and T2DM. Other changes include bacterial flora rearrangement, bile acids secretion, and adipose tissue effect.This review aims to examine the physiological mechanisms in diabetes, risks for complications, the effects of bariatric and metabolic surgery and will shed light on whether diabetes should be reclassified.

Obesity May Not Be Associated with 28-Day Mortality, Duration of Invasive Mechanical Ventilation and Length of Intensive Care Unit and Hospital Stay in Critically Ill Patients with Severe Acute Respiratory Syndrome Coronavirus-2: A Retrospective Cohort Study

Background and Objectives: The aim of this study was to investigate the association between obesity and 28-day mortality, duration of invasive mechanical ventilation and length of stay at the Intensive Care Unit (ICU) and hospital in patients admitted to the ICU for SARS-CoV-2 pneumonia. Materials and Methods: This was a retrospective observational cohort study in patients admitted to the ICU for SARS-CoV-2 pneumonia, in a single Dutch center. The association between obesity (body mass index > 30 kg/m2) and 28-day mortality, duration of invasive mechanical ventilation and length of ICU and hospital stay was investigated. Results: In 121 critically ill patients, pneumonia due to SARS-CoV-2 was confirmed by RT-PCR. Forty-eight patients had obesity (33.5%). The 28-day all-cause mortality was 28.1%. Patients with obesity had no significant difference in 28-day survival in Kaplan-Meier curves (log rank p 0.545) compared with patients without obesity. Obesity made no significant contribution in a multivariate Cox regression model for prediction of 28-day mortality (p = 0.124), but age and the Sequential Organ Failure Assessment (SOFA) score were significant independent factors (p < 0.001 and 0.002, respectively). No statistically significant correlation was observed between obesity and duration of invasive mechanical ventilation and length of ICU and hospital stay. Conclusion: One-third of the patients admitted to the ICU for SARS-CoV-2 pneumonia had obesity. The present study showed no relationship between obesity and 28-day mortality, duration of invasive mechanical ventilation, ICU and hospital length of stay. Further studies are needed to substantiate these findings.

Weight Loss as the First-Line Therapy in Patients with Severe Obesity and Obstructive Sleep Apnea Syndrome: the Role of Laparoscopic Sleeve Gastrectomy

PURPOSE

The objective of this study is to investigate the effects of laparoscopic sleeve gastrectomy (LSG) on the polysomnographic parameters related to OSAS.

MATERIALS AND METHODS

We conducted this 3-year prospective cohort study in a tertiary care center between December 2016 and December 2019. In total, we enrolled 31 patients with severe obesity who underwent full-night polysomnography (PSG) before LSG. Later, the patients were re-evaluated by full-night PSG 12 months after the surgery.

RESULTS

The mean age of the patients was 44.1 ± 9.6 years. The mean body mass index (BMI) decreased significantly from a mean value of 49.8 ± 8.5 kg/m² at baseline to 33.2 ± 8.2 kg/m² and a percent BMI (%BMI) reduction of 33.8 ± 10.4% and a percent total weight loss (%TWL) of 35.4 ± 10.8% was achieved on the same day of the postsurgical PSG (p < 0.001). There was a remarkable improvement in the AHI (baseline: 36.1 ± 27.1, 12 months after the surgery: 10.3 ± 11.8; difference: 25.8 ± 22.8 events per hour) (p < 0.001). Importantly, there was a decrease in the percentage of non-rapid eye movement (NREM) 2 (p < 0.001), whereas NREM 3 and REM stages witnessed a significant increase (p = 0.001 and p < 0.001, respectively) after the surgery.

CONCLUSION

The results of this study showed that weight loss after LSG yields improvement not only in AHI but also in many polysomnographic parameters such as sleep quality and desaturation indices.

Caloric restriction in heart failure: A systematic review

BACKGROUND AND AIMS

Nutrition exerts a determinant role in maintaining cardiac function, regulating insulin and mitochondrial efficiency, that are essential to support energy production for contractility. In patients with heart failure (HF), myocardial tissue efficiency is reduced because of decreased mitochondrial oxidative capacity. In HF conditions, cardiomyocytes shift toward glucose and a reduction in fatty acid utilization. Calorie restriction induces weight loss in obese patients and can be beneficial in some HF patients, although this has generated some controversy. This study aims to evaluate the impact of the CR diet on myocardial efficiency in HF patients.

METHODS

On Pubmed and Embase, articles related to the keywords: "chronic heart failure" with "diet," "nutrition," "insulin resistance," and "caloric restriction" have been searched, Studies, including exercise or food supplementation, were excluded.

RESULTS

The retrieved articles showed that weight loss, through the activation of insulin and various kinase pathways, regulates the efficiency of myocardial tissue. In contrast, insulin resistance represents a strong cardiovascular risk factor that reduces myocardial function.

CONCLUSION

CR diet represents the first therapy in overweight HF patients, both with preserved ejection fraction (HFpEF) and with reduced ejection fraction (HFrHF) because reducing body fat, the myocardial function increased. Insulin activity is the critical hormone that regulates mitochondrial function and cardiac efficiency. However, a severely restricted diet may represent a severe risk factor correlated with all-cause mortality, particularly in underweight HF patients. Long-term studies conducted on large populations are necessary to evaluate the effects of CR on myocardial function in HF patients.