Mechanisms of sustained long-term weight loss after RYGB: α-MSH is a key factor

A high Diabetes Risk Reduction Score (DRRS) is associated with a better cardio-metabolic profile among obese individuals

BACKGROUND

Dietary indices and scores are valuable predictive markers against chronic diseases. Several previous studies have revealed the beneficial effects of diabetes risk reduction score (DRRS) against diabetes and cancer incidence. However, its association with metabolic abnormalities among obese individuals have not been revealed before. In the current study, we aimed to investigate the association between DRRS and metabolic risk factors among obese individuals.

METHODS

In the current cross-sectional study, 342 obese individuals [Body mass index (BMI) ≥ 30 kg/m²] aged 20-50 years were included. Dietary intake was assessed by a validated semi-quantitative food frequency questionnaire (FFQ) of 168 food items and DRRS was calculated. Metabolic syndrome (MetS) was defined based on the guidelines of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III). Enzymatic methods were used to assess serum lipids, glucose, and insulin concentrations. Blood pressure was measured by a sphygmomanometer and body composition with bioelectrical impedance analysis (BIA).

RESULTS

Those with a higher adherence to DRRS had a significantly higher intake of energy, fiber, and lower protein compared with those in the lower quartiles. Moreover, lower intakes of trans fats, meat, sugar sweetened beverages (SSB), and glycemic index (GI) with higher intakes of fruits, cereal fiber, polyunsaturated fatty acids/ saturated fatty acids (PUFA/ SFA) ratio, coffee, and nuts were observed in the highest versus lowest DRRS categories. Lower systolic blood pressure, diastolic blood pressure, triglyceride and, higher high-density lipoprotein values were observed in higher DRRS categories. Logistic regression analysis showed that hypertension was significantly associated with adherence to DRRS among obese individuals, the odds ratio (OR) was 0.686 (95% confidence interval [CI], 0.26-0.84) after adjustment for potential confounders. But the risk of other components of MetS was not significantly associated with higher quartiles of adherence to DRRS. Also, a non-significantly lower prevalence of MetS was observed in the higher quartile of DRRS.

CONCLUSIONS

According to the results of the current study, higher DRRS was associated with lower blood pressure, modified serum lipids, and lower Mets prevalence. Further studies in different populations are warranted for better generalization of the obtained findings.

Low-frequency Coding Variants Associated With Body Mass Index Affect the Success of Bariatric Surgery

CONTEXT

A recent study identified 14 low-frequency coding variants associated with body mass index (BMI) in 718 734 individuals predominantly of European ancestry.

OBJECTIVE

We investigated the association of 2 genetic scores (GS) with i) the risk of severe/morbid obesity, ii) BMI variation before weight-loss intervention, iii) BMI change in response to an 18-month lifestyle/behavioral intervention program, and iv) BMI change up to 24 months after bariatric surgery.

METHODS

The 14 low-frequency coding variants were genotyped or sequenced in 342 French adults with severe/morbid obesity and 574 French adult controls from the general population. We built risk and protective GS based on 6 BMI-increasing and 5 BMI-decreasing low-frequency coding variants that were polymorphic in our study.

RESULTS

While the risk GS was not associated with severe/morbid obesity status, BMI-decreasing low-frequency coding variants were significantly less frequent in patients with severe/morbid obesity than in French adults from the general population. Neither the risk nor the protective GS was associated with BMI before intervention in patients with severe/morbid obesity, nor did they affect BMI change in response to a lifestyle/behavioral modification program. The protective GS was associated with a greater BMI decrease following bariatric surgery. The risk and protective GS were associated with a higher and lower risk of BMI regain after bariatric surgery.

CONCLUSION

Our data indicate that in populations of European descent, low-frequency coding variants associated with BMI in the general population also affect the outcomes of bariatric surgery in patients with severe/morbid obesity.

Updates on Monogenic Obesity in a Multifactorial Disease

Obesity is a worldwide epidemic with rates nearly doubling over the last 30 years. Despite increasing prevalence, the multifactorial pathogenesis of obesity continues to be widely misunderstood. Investigating genetic drivers in the development of obesity is an important area of focus, as genetics move to the forefront of medicine and personalized treatment evolves. Thus, this narrative review focused on four genes which have genome-wide association study-documented links to obesity and obesity syndromes. We explored their involvement in the predisposition, progression, and prognosis of obesity. Leptin, leptin receptor, pro-opiomelanocortin, and melanocortin 4 receptor are our four genes of interest, and herein we elaborated on the current literature, pathogenesis, and available treatments for patients with these specific genetic mutations.

Impact of dietary patterns according to NOVA food groups: 2 y after Roux-en-Y gastric bypass surgery

INTRODUCTION

Appropriate eating habits are crucial for sustained weight loss after bariatric surgery. A qualitative analysis of food consumption in the late postoperative period of bariatric surgery is thus advisable, even more so considering the increasing consumption of obesity-impacting ultra-processed foods.

OBJECTIVE

This study aimed to analyze the contribution of unprocessed, processed, and ultra-processed foods 2 y after Roux-en-Y gastric bypass (RYGB).

METHODS

This was a prospective study performed with 32 patients undergoing RYGB. Anthropometric and food intake data were analyzed. A food intake evaluation was conducted with a focus on quantitative and qualitative analyses. The latter was performed by categorizing food according to the NOVA classification.

RESULTS

There was a reduction in body mass, representing an excess weight loss of 83.80 ± 24.50% at 24 months postoperatively; and a reduction in calorie intake, macronutrients, fiber, and sodium after surgery. Regarding the qualitative analysis, 6 months after RYGB the calorie intake from processed and ultra-processed food decreased from 1398.47 ± 623.82 kcal to 471.80 ± 48.94 kcal (P < 0.05). However, between 6 and 24 months postoperatively there was an increase in 60.04% of the calorie consumption of these type of food (P < 0.01). The most important finding was that the consumption of processed and ultra-processed food exceeded 50% of the total calorie intake of the diet in all periods analyzed.

CONCLUSIONS

RYGB promotes quick results in weight loss and a reduction of food intake, but the quality of food may affect long-term prognosis and deserves attention in the population studied. These results highlight the importance of dietary counseling aimed at guiding better food choices, in the interest of promoting sustained weight loss after bariatric surgery.

Roux-en-Y gastric bypass in rat reduces mu-opioid receptor levels in brain regions associated with stress and energy regulation

Roux-en-Y gastric bypass surgery (RYGB) is the most common and effective weight loss procedure for severe obesity. However, a significant increase in addictive behaviors and new-onset substance use disorder (SUD) are sometimes observed post-surgery. The endogenous opioid system is known to play a major role in motivated behavior and reward, as well as the abuse of substances, including alcohol, tobacco, opioids and highly palatable foods. Here, we examined the effects of RYGB on mu-opioid receptor levels in the brain. Male Sprague-Dawley rats were assigned to one of four groups: standard diet with sham surgery (control), ad libitum high-energy high-fat (HF) diet with sham surgery, calorie restricted HF diet with sham surgery (Sham-FR), or HF diet with RYGB surgery. Control and HF groups were fed their respective diets for 8 weeks, with surgery performed on the eighth week. After 9 weeks on their respective diets post-surgery, animals were sacrificed for mu-opioid receptor autoradiography using the [³H] [D-Ala2,N-Me-Phe4-Gly5-ol]- enkephalin (DAMGO) ligand. Rats with RYGB showed reduced DAMGO binding in the central amygdala compared to sham-operated HF diet controls, and in the hypothalamus compared to high-fat fed Sham-FR. Diet alone did not change [³H] DAMGO binding in any region. These findings show that RYGB surgery, independent of diet or caloric restriction, decreases mu opioid signaling in specific regions important for stress and energy regulation. Thus, RYGB surgery may lead to greater stress sensitivity via downregulated mu opioid signaling in the central amygdala, which may contribute to the observed increased risk in some subjects for addictive behavior.