GLP-1 response to sequential mixed meals: influence of insulin resistance. Clin Sci (Lond). 2017;131:2901-2910. [PMID: 29097626 DOI: 10.1042/cs20171409]

The Association of Cardiometabolic, Diet and Lifestyle Parameters With Plasma Glucagon-like Peptide-1: An IMI DIRECT Study

CONTEXT

The role of glucagon-like peptide-1 (GLP-1) in type 2 diabetes (T2D) and obesity is not fully understood.

OBJECTIVE

We investigate the association of cardiometabolic, diet, and lifestyle parameters on fasting and postprandial GLP-1 in people at risk of, or living with, T2D.

METHODS

We analyzed cross-sectional data from the two Innovative Medicines Initiative (IMI) Diabetes Research on Patient Stratification (DIRECT) cohorts, cohort 1 (n = 2127) individuals at risk of diabetes; cohort 2 (n = 789) individuals with new-onset T2D.

RESULTS

Our multiple regression analysis reveals that fasting total GLP-1 is associated with an insulin-resistant phenotype and observe a strong independent relationship with male sex, increased adiposity, and liver fat, particularly in the prediabetes population. In contrast, we showed that incremental GLP-1 decreases with worsening glycemia, higher adiposity, liver fat, male sex, and reduced insulin sensitivity in the prediabetes cohort. Higher fasting total GLP-1 was associated with a low intake of wholegrain, fruit, and vegetables in people with prediabetes, and with a high intake of red meat and alcohol in people with diabetes.

CONCLUSION

These studies provide novel insights into the association between fasting and incremental GLP-1, metabolic traits of diabetes and obesity, and dietary intake, and raise intriguing questions regarding the relevance of fasting GLP-1 in the pathophysiology T2D.

Factors contributing to weight loss success after bariatric procedures in patient over 65 years old: a multicenter retrospective cohort study

BACKGROUND

Although bariatric surgery in patients over 65 years of age gives comparable results to treatment in the younger population, there are still controversies regarding the indications for surgery, risk assessment, and choice between different types of surgery. The study aimed to identify the factors contributing to weight loss success after bariatric surgery in patients over 65 years of age.

MATERIAL AND METHODS

This is a retrospective, multicenter cohort study of patients with obesity aged over 65 years undergoing primary laparoscopic bariatric surgery in the years 2008-2022. Data came from 11 bariatric centers. Patients were divided into two groups: responders (R) who achieved more than 50% EWL and nonresponders (NR) who achieved less than 50% EWL. Both groups were compared. Uni- and multivariate logistic regression was used to identify predictors of weight loss success.

RESULTS

Out of 274 analyzed patients, the average BMI before surgery was 42.9 kg/m 2 . The most common obesity-related diseases were hypertension (85.1%) and type 2 diabetes (53.3%). Sleeve gastrectomy was the most frequently performed procedure (85.4%). Uni- and multivariate logistic regression analysis confirmed preoperative BMI (OR=0.9, 95% CI: 0.82-0.98, P =0.02), duration of diabetes >10 years (OR=0.3, 95% CI: 0.09-0.82, P =0.02), balloon placement (OR=10.6, 95% CI: 1.33-84.83, P =0.03), time since first visit (OR=0.9, 95% CI: 0.84-0.99, P =0.04), preoperative weight loss (OR=0.9, 95% CI: 0.86-0.98, P =0.01), and OAGB (OR=15.7, 95% CI: 1.71-143.99, P =0.02) to have a significant impact on weight loss success 1 year after bariatric surgery.

CONCLUSIONS

Patients with higher preoperative weight loss may have a poorer response to surgery. OAGB emerged as the most beneficial type of surgery in terms of weight loss. Intragastric balloon placement before surgery may be effective in patients above 65 years of age and may be considered as a two-stage approach.

Effect of d-β-Hydroxybutyrate-(R)-1,3 Butanediol on Appetite Regulation in People with Prediabetes

SCOPE

The main aim of the present study is to study the effect of acute ketosis on parameters of appetite regulation in prediabetes.

METHODS AND RESULTS

This is a randomized controlled trial registered under ClinicalTrials.gov identifier NCT03889210. After an overnight fast, 18 adults with prediabetes are assigned to consume a ketone monoester (d-β-hydroxybutyrate-(R)-1,3 butanediol) drink and a placebo drink in cross-over fashion. Blood samples are collected every 30 min, from baseline to 150 min. Paired t test is used to compare the total area under the curve (AUC) for the changes in parameters of appetite regulation (acylated ghrelin, peptide YY [PYY], and hunger) following both drinks. Significant elevation in blood β-hydroxybutyrate from 0.2 to 3.5 mmol L^-1 (p < 0.001) is achieved within 30 min. Acute ketosis does not result in statistically significant differences in the AUCs for ghrelin, PYY, and hunger.

CONCLUSION

Acute ketosis consistently does not affect both objective and subjective parameters of appetite regulation in prediabetes.

Brain-gut-liver interactions across the spectrum of insulin resistance in metabolic fatty liver disease

Metabolic associated fatty liver disease (MAFLD), formerly named "nonalcoholic fatty liver disease" occurs in about one-third of the general population of developed countries worldwide and behaves as a major morbidity and mortality risk factor for major causes of death, such as cardiovascular, digestive, metabolic, neoplastic and neuro-degenerative diseases. However, progression of MAFLD and its associated systemic complications occur almost invariably in patients who experience the additional burden of intrahepatic and/or systemic inflammation, which acts as disease accelerator. Our review is focused on the new knowledge about the brain-gut-liver axis in the context of metabolic dysregulations associated with fatty liver, where insulin resistance has been assumed to play an important role. Special emphasis has been given to digital imaging studies and in particular to positron emission tomography, as it represents a unique opportunity for the noninvasive in vivo study of tissue metabolism. An exhaustive revision of targeted animal models is also provided in order to clarify what the available preclinical evidence suggests for the causal interactions between fatty liver, dysregulated endogenous glucose production and insulin resistance.

The relation between postprandial glucagon-like peptide-1 release and insulin sensitivity before and after bariatric surgery in humans with class II/III obesity

BACKGROUND

Glucagon-like peptide-1 (GLP-1) receptor agonist treatment is beneficial for the human glucose metabolism, and GLP-1 secretion is greatly enhanced following Roux-en-Y gastric bypass (RYGB).

OBJECTIVES

To elucidate the relationship between GLP-1 concentrations and insulin sensitivity in subjects with class II/III obesity without diabetes and to assess the relation between GLP-1 and the improvements in glucose metabolism following RYGB.

SETTING

Clinical research facility in a university hospital.

METHODS

We recruited 35 patients scheduled for RYGB and assessed their plasma GLP-1, insulin, and glucose responses to a high-fat mixed meal. Basal and insulin-mediated glucose fluxes were determined during a 2-step hyperinsulinemic-euglycemic clamp with stable isotope-labeled tracers. Out of 35 subjects, 10 were studied both before surgery and at 1 year of follow-up.

RESULTS

Plasma GLP-1 increased following the high-fat mixed meal. Postprandial GLP-1 excursions correlated positively with hepatic and peripheral insulin sensitivity, but not with body mass index. At 1 year after RYGB, participants had lost 24% ± 6% of their body weight. Plasma GLP-1, insulin, and glucose levels peaked earlier and higher after the mixed meal. The positive association between the postprandial GLP-1 response and peripheral insulin sensitivity persisted.

CONCLUSIONS

Postprandial GLP-1 concentrations correlate with insulin sensitivity in subjects with class II/III obesity without diabetes before and 1 year after RYGB. Increased GLP-1 signaling in postbariatric patients may, directly or indirectly, contribute to the observed improvements in insulin sensitivity and metabolic health.

An Exploration of the Role of Sugar-Sweetened Beverage in Promoting Obesity and Health Disparities

PURPOSE OF REVIEW

The mechanistic role of sugar-sweetened beverage (SSB) in the etiology of obesity is undetermined. We address whether, compared to other foods, does consumption of SSB (1) automatically lead to failure to compensate for the energy it contains? (2) fail to elicit homeostatic hormone responses? (3) promote hedonic eating through activation of the brain's reward pathways? We followed the evidence to address: (4) Would restriction of targeted marketing of SSB and other unhealthy foods to vulnerable populations decrease their prevalence of obesity?

RECENT FINDINGS

The data are lacking to demonstrate that SSB consumption promotes body weight gain compared with isocaloric consumption of other beverages or foods and that this is linked to its failure to elicit adequate homeostatic hormone responses. However, more recent data have linked body weight gain to reward activation in the brain to palatable food cues and suggest that sweet tastes and SSB consumption heightens the reward response to food cues. Studies investigating the specificity of these responses have not been conducted. Nevertheless, the current data provide a biological basis to the body of evidence demonstrating that the targeted marketing (real life palatable food cues) of SSB and other unhealthy foods to vulnerable populations, including children and people of color and low socioeconomic status, is increasing their risk for obesity. While the mechanisms for the association between SSB consumption and body weight gain cannot be identified, current scientific evidence strongly suggests that proactive environmental measures to reduce exposure to palatable food cues in the form of targeting marketing will decrease the risk of obesity in vulnerable populations.

Comparing the Anti-diabetic Effect of Sleeve Gastrectomy with Transit Bipartition Against Sleeve Gastrectomy and Roux-en-Y Gastric Bypass Using a Diabetic Rodent Model

PURPOSE

Roux-en-Y gastric bypass (RYGB) has superior long-term diabetes remission outcomes to sleeve gastrectomy (SG). However, in regions with a high prevalence of gastric cancer, RYGB may not be the best option. This study aimed to investigate the anti-diabetic effect of SG with transit bipartition (SG-TB) compared with SG and RYGB.

MATERIALS AND METHODS

A total of 32 diabetic Sprague-Dawley rat models were assigned to one of four groups: SG (n = 8), RYGB (n = 8), SG-TB (n = 8), and SHAM (n = 8). Body weight, food intake, blood glucose, and hormonal changes (glucagon-like peptide-1 (GLP-1), insulin, and glucagon) were measured to investigate the effect of surgery in all groups. Oral glucose tolerance test and insulin tolerance test were performed before and 8 weeks after surgery.

RESULTS

There were no significant differences in the postoperative changes in body weight and food intake among the SG, RYGB, and SG-TB groups. Postoperatively, the RYGB and SG-TB groups had significantly higher GLP-1 levels and lower insulin levels than the SG group. Further, RYGB and SG-TB had significantly better glucose control improvements than SG. There were no significant differences in GLP-1, insulin, glucagon, and homeostasis model assessment of insulin resistance levels between RYGB and SG-TB. The preoperative and postoperative values of all variables in the SHAM group did not show significant differences.

CONCLUSION

In this study using a diabetes-induced rodent model, we found that the anti-diabetic effect of SG-TB is superior to that of SG and non-inferior to that of RYGB.

Brain substrate metabolism and ß-cell function in humans: A positron emission tomography study

AIMS

Recent clinical studies have shown enhanced brain glucose uptake during clamp and brain fatty acid uptake in insulin-resistant individuals. Preclinical studies suggest that the brain may be involved in the control of insulin secretion. The aim of this study was to investigate whether brain metabolism assessed as brain glucose and fatty acid uptake is associated with the parameters of β-cell function in humans.

MATERIALS AND METHODS

We analysed cross-sectional data of 120 subjects across a wide range of BMI and insulin sensitivity. Brain glucose uptake (BGU) was measured during euglycaemic-hyperinsulinaemic clamp (n = 67) and/or during fasting (n = 45) using [18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET). In another group of subjects (n = 34), brain fatty acid uptake was measured using [18F]-fluoro-6-thia-heptadecanoic acid (FTHA) PET during fasting. The parameters of β-cell function were derived from OGTT modelling. Statistical analysis was performed with whole-brain voxel-based statistical parametric mapping.

RESULTS

In non-diabetics, BGU during euglycaemic hyperinsulinaemic clamp correlated positively with basal insulin secretion rate (r = 0.51, P = .0008) and total insulin output (r = 0.51, P = .0008), whereas no correlation was found in type 2 diabetics. BGU during clamp correlated positively with potentiation in non-diabetics (r = 0.33, P = .02) and negatively in type 2 diabetics (r = -0.61, P = .02). The associations in non-diabetics were not explained with whole-body insulin sensitivity or BMI. No correlations were found between baseline (fasting) BGU and basal insulin secretion rate, whereas baseline brain fatty acid uptake correlated directly with basal insulin secretion rate (r = 0.39, P = .02) and inversely with potentiation (r = -0.36, P = .04).

CONCLUSIONS

Our study provides coherent, though correlative, evidence that, in humans, the brain may be involved in the control of insulin secretion independently of insulin sensitivity.

Sleeping oxygen saturation, rapid eye movement sleep, and the adaptation of postprandial metabolic function in insulin sensitive and resistant individuals without diabetes

AIMS

Sleeping oxygen saturation (SaO₂) and sleep stage duration have been linked with prediabetic alterations but the pathogenic pathways are not well understood. This study of insulin sensitive and resistant adults examined the effect on postprandial metabolic regulation of repeated mixed-meal challenges of different carbohydrate loading. The aim was to examine whether the relationship between lower sleeping oxygen saturation (SaO₂) and poorer fasting and postprandial metabolic function may be linked with reduced slow wave sleep (SWS) and rapid eye movement (REM) duration, independent of age, sex and total adiposity.

METHODS

The 24 men and women, aged 25-54 years, had no diabetes or other diagnosed conditions, were evaluated with polysomnography to derive indices of SaO₂ and sleep architecture. In addition, an OGTT and two 14-h serial mixed-meal tests were administered over 3 successive in-patient days. The carbohydrate content of the mixed-meals was manipulated to compare a standard-load day with a double-load day (300 vs. 600 kcal/meal). Quantitative modeling was applied to derive β-cell glucose sensitivity (β-GS), early insulin secretion rate sensitivity (ESRS), and total postprandial insulinemia (AUC_INS).

RESULTS

Analyses showed that, for the 14-h tests, the SaO₂ relationship with metabolic outcomes was associated significantly with percent time spent in REM but not SWS, independent of age, sex and total adiposity. Specifically, indirect pathways indicated that lower SaO₂ was related to shorter REM duration, and shorter REM was respectively associated with higher β-GS, ESRS, and AUC_INS for the 300- and 600-load days (300 kcal/meal: β = -8.68, p < .03, β = -8.54, p < .002, and β = -10.06, p < .008; 600 kcal/meal: β = -11.45, p < .003, β = -11.44, p < .001, and β = -11.00, p < .03).

CONCLUSION

Sleeping oxygen desaturation and diminished REM duration are associated with a metabolic pattern that reflects a compensatory adaptation of postprandial insulin metabolism accompanying preclinical diabetic risk.