Effects of Glucagon-Like Peptide-1 Receptor Agonists on Body Weight: A Meta-Analysis

Glucagon-Like Peptide-1 receptor agonists (GLP-1RAs), approved as glucose-lowering drugs for the treatment of type 2 diabetes, have also been shown to reduce body weight. An extensive Medline, Cochrane database, and Embase search for “exenatide,” “liraglutide,” “albiglutide,” “semaglutide,” and “lixisenatide” was performed, collecting all randomized clinical trials on humans up to December 15, 2011, with a duration of at least 24 weeks, comparing GLP-1 receptor agonists with either placebo or active drugs. Twenty two (7,859 patients) and 7 (2,416 patients) trials with available results on body weight at 6 and 12 months, respectively, were included. When compared with placebo, GLP-1RAs determine a reduction of BMI at 6 months of −1.0 [−1.3; −0.6] kg/m2. Considering the average BMI at baseline (32.4 kg/m2) these data means a weight reduction of about 3% at 6 months. This result could seem modest from a clinical standpoint; however, it could be affected by many factors contributing to an underestimation of the effect of GLP-1RA on body weight, such as non adequate doses, inclusion criteria, efficacy of GLP-1RA on reducing glycosuria, and association to non-pharmacological interventions not specifically aimed to weight reduction

Effect of Metformin on Glucagon-Like Peptide 1 (GLP-1) and Leptin Levels in Obese Nondiabetic Subjects

OBJECTIVE—To evaluate the effects of metformin on glucagon-like peptide 1 (GLP-1) and leptin levels. RESEARCH DESIGN AND METHODS—A total of 10 obese nondiabetic male patients were studied before and after a 14-day treatment with 2,550 mg/day metformin and were compared with 10 untreated obese control subjects. On days 0 and 15, leptin and GLP-1(7–36)amide/(7–37) levels were assessed before and after an oral glucose load during a euglycemic hyperinsulinemic clamp to avoid the interference of variations of insulinemia and glycemia on GLP-1 and leptin secretion. The effects of metformin on GLP-1(7–36)amide degradation in human plasma and in a buffer solution containing dipeptidyl peptidase IV (DPP-IV) were also studied. RESULTS—Leptin levels were not affected by the oral glucose load, and they were not modified after metformin treatment. Metformin induced a significant (P < 0.05) increase of GLP-1(7–36)amide/(7–37) at 30 and 60 min after the oral glucose load (63.8 ± 29.0 vs. 50.3 ± 15.6 pmol/l and 75.8 ± 35.4 vs. 46.9 ± 20.0 pmol/l, respectively), without affecting baseline GLP-1 levels. No variations of GLP-1 levels were observed in the control group. In pooled human plasma, metformin (0.1–0.5 μg/ml) significantly inhibited degradation of GLP-1(7–36)amide after a 30-min incubation at 37°C; similar results were obtained in a buffer solution containing DPP-IV. CONCLUSIONS—Metformin significantly increases GLP-1 levels after an oral glucose load in obese nondiabetic subjects; this effect could be due to an inhibition of GLP-1 degradation

Clinical and psychological correlates of health-related quality of life in obese patients

<p>Abstract</p> <p>Background</p> <p>Health-related quality of life (HRQL) is poor in obese subjects and is a relevant outcome in intervention studies. We aimed to determine factors associated with poor HRQL in obese patients seeking weight loss in medical units, outside specific research projects.</p> <p>Methods</p> <p>HRQL, together with a number of demographic and clinical parameters, was studied with generic (SF-36, PGWB) and disease-specific (ORWELL-97) questionnaires in an unselected sample of 1,886 (1,494 women; 392 men) obese (BMI > 30 kg/m²) patients aged 20-65 years attending 25 medical units scattered throughout Italy. The clinics provide weight loss treatment using different programs. General psychopathology (SCL-90 questionnaire), the presence of binge eating (Binge Eating scale), previous weight cycling and somatic comorbidity (Charlson's index) were also determined. Scores on SF-36 and PGWB were compared with Italian population norms, and their association with putative determinants of HRQL after adjustment for confounders was assessed through logistic regression analysis.</p> <p>Results</p> <p>HRQL scores were significantly lower in women than in men. A greater impairment of quality of life was observed in relation to increasing BMI class, concurrent psychopathology, associated somatic diseases, binge eating, and weight cycling. In multivariate analysis, psychopathology (presence of previously-diagnosed mental disorders and/or elevated scores on SCL-90) was associated with lower HRQL scores on both psychosocial and somatic domains; somatic diseases and higher BMI, after adjustment for confounders, were associated with impairment of physical domains, while binge eating and weight cycling appeared to affect psychosocial domains only.</p> <p>Conclusions</p> <p>Psychopathological disturbances are the most relevant factors associated with poor HRQL in obese patients, affecting not only psychosocial, but also physical domains, largely independent of the severity of obesity. Psychological/psychiatric interventions are essential for a comprehensive treatment of obesity, and to improve treatment outcome and to reduce the burden of disease.</p

3 years of liraglutide versus placebo for type 2 diabetes risk reduction and weight management in individuals with prediabetes: a randomised, double-blind trial

Background: Liraglutide 3·0 mg was shown to reduce bodyweight and improve glucose metabolism after the 56-week period of this trial, one of four trials in the SCALE programme. In the 3-year assessment of the SCALE Obesity and Prediabetes trial we aimed to evaluate the proportion of individuals with prediabetes who were diagnosed with type 2 diabetes. Methods: In this randomised, double-blind, placebo-controlled trial, adults with prediabetes and a body-mass index of at least 30 kg/m2, or at least 27 kg/m2 with comorbidities, were randomised 2:1, using a telephone or web-based system, to once-daily subcutaneous liraglutide 3·0 mg or matched placebo, as an adjunct to a reduced-calorie diet and increased physical activity. Time to diabetes onset by 160 weeks was the primary outcome, evaluated in all randomised treated individuals with at least one post-baseline assessment. The trial was conducted at 191 clinical research sites in 27 countries and is registered with ClinicalTrials.gov, number NCT01272219. Findings: The study ran between June 1, 2011, and March 2, 2015. We randomly assigned 2254 patients to receive liraglutide (n=1505) or placebo (n=749). 1128 (50%) participants completed the study up to week 160, after withdrawal of 714 (47%) participants in the liraglutide group and 412 (55%) participants in the placebo group. By week 160, 26 (2%) of 1472 individuals in the liraglutide group versus 46 (6%) of 738 in the placebo group were diagnosed with diabetes while on treatment. The mean time from randomisation to diagnosis was 99 (SD 47) weeks for the 26 individuals in the liraglutide group versus 87 (47) weeks for the 46 individuals in the placebo group. Taking the different diagnosis frequencies between the treatment groups into account, the time to onset of diabetes over 160 weeks among all randomised individuals was 2·7 times longer with liraglutide than with placebo (95% CI 1·9 to 3·9, p&lt;0·0001), corresponding with a hazard ratio of 0·21 (95% CI 0·13–0·34). Liraglutide induced greater weight loss than placebo at week 160 (–6·1 [SD 7·3] vs −1·9% [6·3]; estimated treatment difference −4·3%, 95% CI −4·9 to −3·7, p&lt;0·0001). Serious adverse events were reported by 227 (15%) of 1501 randomised treated individuals in the liraglutide group versus 96 (13%) of 747 individuals in the placebo group. Interpretation: In this trial, we provide results for 3 years of treatment, with the limitation that withdrawn individuals were not followed up after discontinuation. Liraglutide 3·0 mg might provide health benefits in terms of reduced risk of diabetes in individuals with obesity and prediabetes. Funding: Novo Nordisk, Denmark