Metabolic surgery for the treatment of type 2 diabetes in patients with BMI lower than 35 kg/m2 : Why caution is still needed

Predictors of T2DM Remission after Bariatric Surgery in Patients with a BMI < 35 kg/m2: a Meta-Analysis

PURPOSE

Although a few studies have reported the predictors of postoperative diabetes remission in patients with body mass index (BMI) < 35 kg/m2, the conclusions are still inconsistent. This meta-analysis aimed to evaluate the preoperative clinical factors of type 2 diabetes mellitus (T2DM) remission after bariatric surgery.

MATERIALS AND METHODS

The PubMed, Embase, and Cochrane Library databases were systematically searched until April 2022. The Newcastle-Ottawa Scale was used for quality assessment. Statistical heterogeneity was assessed with the I2 statistic, followed by subgroup and sensitivity analyses.

RESULTS

16 studies involving 932 patients were selected. T2DM remission was negatively correlated with age, duration, insulin use, fasting plasma glucose, fasting insulin, and glycosylated hemoglobin levels. While BMI, body weight, waist circumference, and C-peptide levels were positive predictors of T2DM remission in patients with a BMI < 35 kg/m2. However, there was no significant association between gender, oral hypoglycemic agent, homeostasis model assessment, high-density lipoprotein, low-density lipoprotein, total cholesterol, triglycerides, systolic blood pressure, diastolic blood pressure, and remission rate.

CONCLUSION

Patients with younger age, short diabetes duration, more obesity, better glucose control, and better β cell function were more likely to achieve T2DM remission in patients with a BMI < 35 kg/m2 after bariatric surgery.

Proposal of an obesity classification based on weight history: an official document by the Brazilian Society of Endocrinology and Metabolism (SBEM) and the Brazilian Society for the Study of Obesity and Metabolic Syndrome (ABESO)

Obesity is a chronic disease associated with impaired physical and mental health. A widespread view in the treatment of obesity is that the goal is to normalize the individual's body mass index (BMI). However, a modest weight loss (usually above 5%) is already associated with clinical improvement, while weight losses of 10%-15% bring even further benefits, independent from the final BMI. The percentage of weight reduction is accepted as a treatment goal since a greater decrease in weight is frequently difficult to achieve due to metabolic adaptation along with environmental and lifestyle factors. In this document, the Brazilian Society of Endocrinology and Metabolism (SBEM) and the Brazilian Society for the Study of Obesity and Metabolic Syndrome (ABESO) propose a new obesity classification based on the maximum weight attained in life (MWAL). In this classification, individuals losing a specific proportion of weight are classified as having "reduced" or "controlled" obesity. This simple classification - which is not intended to replace others but to serve as an adjuvant tool - could help disseminate the concept of clinical benefits derived from modest weight loss, allowing individuals with obesity and their health care professionals to focus on strategies for weight maintenance instead of further weight reduction. In future studies, this proposed classification can also be an important tool to evaluate possible differences in therapeutic outcomes between individuals with similar BMIs but different weight trajectories.

Preconception diabetes remission, a viable approach to reduce pregnancy risks in women with recent diagnosis of Type 2 diabetes: Case report and clinical discussion

The prevalence of women diagnosed with Type 2 diabetes (T2D) at fertile age has been increasing over the last few decades, and pregnancy with T2D is associated with increased maternal and foetal risks. In the last few years, studies have shown that focusing on aggressive weight loss in individuals recently diagnosed with T2D can lead to diabetes remission. Here, we present a case report of a woman who achieved diabetes remission after massive weight loss and had an uncomplicated pregnancy. Diabetes remission before pregnancy could be offered to motivated women with T2D as a safe way to reduce the risks of pregnancy. As a plausible hypothesis, dedicated studies are warranted to demonstrate if this approach can lead to reduced adverse maternal and foetal outcomes.

Are Chinese Patients with Type 2 Diabetes and a Body Mass Index of 27.5-32.5 kg/m2 Suitable for Metabolic Surgery? A One-Year Post-Surgery Study

INTRODUCTION

The aim of this study was to clarify the efficacy and safety of metabolic surgery in Chinese patients with type 2 diabetes mellitus (T2DM) and a body mass index (BMI) of 27.5-32.5 kg/m².

METHODS

A total of 99 patients with T2DM were enrolled in this retrospective cohort study. Of these patients, 53 had a BMI of 27.5-32.5 kg/m² and had undergone metabolic surgery (n = 21) or were on conventional antidiabetic therapy (n = 32)]; 46 had a BMI ≥ 32.5 kg/m² and all had undergone metabolic surgery. Primary endpoints included the triple endpoint [hemoglobin A1c < 6.5%, low-density lipoprotein cholesterol (LDL-C) < 2.6 mmol/L, and systolic blood pressure (SBP) < 130 mmHg] and successful weight loss 1 year later. Remission of diabetes, glucose and lipid metabolism, medication usage, and adverse events were evaluated.

RESULTS

Of patients with BMI 27.5-32.5 kg/m² undergoing metabolic surgery, 33.33% achieved the composite endpoints, and 100% achieved successful weight loss. This result was similar to that in patients with BMI ≥ 32.5 and better than those with BMI 27.5-32.5 kg/m² receiving conventional antidiabetic therapy. A significant and similar reduction in BMI, waist circumference, SBP, serum LDL-C, hemoglobin A1c, and uric acid, as well as similar frequency postoperative adverse events, were confirmed in both metabolic surgery groups. Patients with BMI 27.5-32.5 kg/m² who had undergonemetabolic surgery showed more metabolic improvement than those only receiving medications but they experienced more adverse events.

CONCLUSION

A BMI cutoff of 27.5 kg/m² for metabolic surgery may be suitable for Chinese patients with T2DM.

Controlled obesity status: a rarely used concept, but with particular importance in the COVID-19 pandemic and beyond

Obesity is a chronic disease that causes and aggravates several other diseases, and early reports suggest it is an important risk factor for COVID-19 severity. Although a deeper understanding of this relationship is vital, it is also important to inform the general public about the risks and, ideally, offer strategies to mitigate the risks. As "resolution" of obesity in the short-term is not feasible, it is indeed possible that smaller weight losses and increase in physical activity can actually reduce the risks. In this context, we propose that a term called "controlled obesity" be more often used and studied, in which those who have lost over 10% of their maximal weight and, ideally, are physically active are considered healthier. This context can have much broader usefulness, beyond the pandemics, as evidence points that weight loss over 10% can significant reduce overall health risks, irrespective of final BMI.

Type 2 diabetes and metabolic surgery guidelines and recommendations should urgently be unified

Metabolic surgery has been studied in the last decades as an effective and safe treatment for type 2 diabetes (T2D), and randomized controlled trials generally found surgery superior when compared with medical treatment. In 2016, the DSS-II Joint Statement recognized the importance of metabolic surgery in the treatment of T2D and urged clinicians to discuss, recommend, or at least consider this procedure for their patients. Diabetes societies also cogitate metabolic surgery as an option for T2D patients in their guidelines. However, there are some differences in recommendations that could lead a careful reader to some confusion. This was potentialized in a recent document published by the same DSS-II group concerning prioritization for surgery after the COVID-19 pandemic, in which the criteria suggested for an expedited recommendation that is not exactly evidence-based, and collided substantially with several clinical guidelines worldwide, especially with regard to secondary prevention of cardiovascular disease. A more harmonious discussion and unified guidelines between clinicians and surgeons are needed in order to provide the same message for those who read different articles.

Obesity, Hypertension, and Bariatric Surgery

PURPOSE OF REVIEW

Obesity increases the risk of hypertension. However, blood pressure decreases before any significant loss of body weight after bariatric surgery. We review the mechanisms of the temporal dissociation between blood pressure and body weight after bariatric surgery.

RECENT FINDINGS

Restrictive and bypass bariatric surgery lower blood pressure and plasma leptin levels within days of the procedure in both hypertensive and normotensive morbidly obese patients. Rapidly decreasing plasma leptin levels and minimal loss of body weight point to reduced sympathetic nervous system activity as the underlying mechanism of rapid blood pressure decline after bariatric surgery. After the early rapid decline, blood pressure does not decrease further in patients who, while still obese, experience a steady loss of body weight for the subsequent 12 months. The divergent effects of bariatric surgery on blood pressure and body weight query the role of excess body weight in the pathobiology of the obesity phenotype of hypertension. The decrease in blood pressure after bariatric surgery is moderate and independent of body weight. The lack of temporal relationship between blood pressure reduction and loss of body weight for 12 months after sleeve gastrectomy questions the nature of the mechanisms underlying obesity-associated hypertension.

Bariatric surgery, compared to medical treatment, reduces morbidity at all ages but does not reduce mortality in patients aged < 43 years, especially if diabetes mellitus is present: a post hoc analysis of two retrospective cohort studies

BACKGROUND AND AIMS

Bariatric surgery (BS) reduces long-term mortality in comparison with medical treatment of obesity. Some studies indicate that this effect is significant for patients above mean age in different cohorts, but not for younger patients. These findings raise the question whether morbid obese patients should undergo BS as soon as possible, or whether patients might undergo surgery later in their life.

METHODS

We performed a post hoc analysis of two studies; we evaluated surgery-related long-term mortality in: (1) the whole cohort [857 surgery patients (163 diabetes) vs. 2086 controls (512 diabetes)]; (2) patients above mean age [> 43 years, 427 surgery patients (133 diabetes) vs. 1054 controls (392 diabetes)]; (3) patients below mean age [≤ 43 years, 432 surgery patients (30 diabetes) vs. 1032 controls (120 diabetes]. Then, we analyzed age-related long-term mortality in the whole cohort, as well as in surgery patients and in controls. Finally, we analyzed incident diseases (diabetes, cardiovascular disease, and cancer) as a function of surgery versus no-surgery and of mean age.

RESULTS

Surgery patients, compared with controls receiving standard medical/dietary treatment, had reduced mortality in the whole cohort (HR = 0.45, 95% CI 0.33-0.62, p = 0.001) and in the study group aged > 43 years (HR = 0.39, 95% CI 0.28-0.56, p = 0.001), but not in the study group aged ≤ 43 years (HR = 0.87, 95% CI 0.42-1.80, p = 0.711). Reduced mortality was observed in non-diabetic and diabetic patients aged > 43 years (HR = 0.37, 95% CI 0.23-0.62, p = 0.001 and HR = 0.45, 95% CI 0.27-0.74, p = 0.002, respectively) who underwent bariatric surgery. In contrast, in patients aged ≤ 43 years, no significant protective effect of bariatric surgery appeared in non-diabetic patients (HR = 0.64, 95% CI 0.24-1.71, p = 0.371), and mortality increased, almost significantly, in diabetic patients aged < 43 years (HR = 2.87, 95% CI 0.96-8.56, p = 0.058), and even more in diabetic patients aged 33-43 years; HR = 4.99, 95% CI 1.18-21.09, p = 0.029). As expected, age-related mortality was increased in the whole cohort (HR = 7.23, 95% CI 5.14-10.17, p = 0.001), in non-diabetic and diabetic controls (HR = 8.55, 95% CI 5.77-12.68, p = 0.001, and HR = 3.76, 95% CI 1.97-7.18, p = 0.001, respectively). The effect of aging was slightly reduced in surgery patients (HR = 3.76, 95% CI 1.87-7.58, p = 0.001), while it was not significant in diabetic surgery patients (HR = 0.70, 95% CI 0.26-1.90, p = 0.88), further emphasizing that diabetes per se has a strong negative effect on survival, also with concomitant bariatric surgery. In a supplementary analysis, HRs did not change when surgery and control parents were matched for the presence of diabetes. Incident diseases (cardiovascular, diabetes, and cancer) were less frequent in surgery than in control patients, irrespective of age.

CONCLUSION

Bariatric surgery reduces long-term mortality in comparison with medical treatment when performed in patients aged > 43 years, but not in younger patients, where it is neutral or could even increase mortality; reduction in morbidity occurs at any age.