obesity

Background: Obesity is a global health challenge with few pharmacologic options. Whether adults with obesity can achieve weight loss with once-weekly semaglutide at a dose of 2.4 mg as an adjunct to lifestyle intervention has not been confirmed.

Methods: In this double-blind trial, we enrolled 1961 adults with a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or greater (≥27 in persons with ≥1 weight-related coexisting condition), who did not have diabetes, and randomly assigned them, in a 2:1 ratio, to 68 weeks of treatment with once-weekly subcutaneous semaglutide (at a dose of 2.4 mg) or placebo, plus lifestyle intervention. The coprimary end points were the percentage change in body weight and weight reduction of at least 5%. The primary estimand (a precise description of the treatment effect reflecting the objective of the clinical trial) assessed effects regardless of treatment discontinuation or rescue interventions.

Results: The mean change in body weight from baseline to week 68 was -14.9% in the semaglutide group as compared with -2.4% with placebo, for an estimated treatment difference of -12.4 percentage points (95% confidence interval [CI], -13.4 to -11.5; P<0.001). More participants in the semaglutide group than in the placebo group achieved weight reductions of 5% or more (1047 participants [86.4%] vs. 182 [31.5%]), 10% or more (838 [69.1%] vs. 69 [12.0%]), and 15% or more (612 [50.5%] vs. 28 [4.9%]) at week 68 (P<0.001 for all three comparisons of odds). The change in body weight from baseline to week 68 was -15.3 kg in the semaglutide group as compared with -2.6 kg in the placebo group (estimated treatment difference, -12.7 kg; 95% CI, -13.7 to -11.7). Participants who received semaglutide had a greater improvement with respect to cardiometabolic risk factors and a greater increase in participant-reported physical functioning from baseline than those who received placebo. Nausea and diarrhea were the most common adverse events with semaglutide; they were typically transient and mild-to-moderate in severity and subsided with time. More participants in the semaglutide group than in the placebo group discontinued treatment owing to gastrointestinal events (59 [4.5%] vs. 5 [0.8%]).

Conclusions: In participants with overweight or obesity, 2.4 mg of semaglutide once weekly plus lifestyle intervention was associated with sustained, clinically relevant reduction in body weight. (Funded by Novo Nordisk; STEP 1 ClinicalTrials.gov number, NCT03548935).

• Obesity is a prevalent, complex, progressive and relapsing chronic disease, characterized by abnormal or excessive body fat (adiposity), that impairs health.

• People living with obesity face substantial bias and stigma, which contribute to increased morbidity and mortality independent of weight or body mass index.

• This guideline update reflects substantial advances in the epidemiology, determinants, pathophysiology, assessment, prevention and treatment of obesity, and shifts the focus of obesity management toward improving patient-centred health outcomes, rather than weight loss alone.

• Obesity care should be based on evidence-based principles of chronic disease management, must validate patients’ lived experiences, move beyond simplistic approaches of “eat less, move more,” and address the root drivers of obesity.

• People living with obesity should have access to evidence-informed interventions, including medical nutrition therapy, physical activity, psychological interventions, pharmacotherapy and surgery.

BACKGROUND

Obesity shortens life expectancy. Bariatric surgery is known to reduce the long-term relative risk of death, but its effect on life expectancy is unclear.

METHODS

We used the Gompertz proportional hazards regression model to compare mortality and life expectancy among patients treated with either bariatric surgery (surgery group) or usual obesity care (control group) in the prospective, controlled Swedish Obese Subjects (SOS) study and participants in the SOS reference study (reference cohort), a random sample from the general population.

RESULTS

In total, 2007 and 2040 patients were included in the surgery group and the control group, respectively, and 1135 participants were included in the reference cohort. At the time of the analysis (December 31, 2018), the median duration of follow-up for mortality was 24 years (interquartile range, 22 to 27) in the surgery group and 22 years (interquartile range, 21 to 27) in the control group; data on mortality were available for 99.9% of patients in the study. In the SOS reference cohort, the median duration of follow-up was 20 years (interquartile range, 19 to 21), and data on mortality were available for 100% of participants. In total, 457 patients (22.8%) in the surgery group and 539 patients (26.4%) in the control group died (hazard ratio, 0.77; 95% confidence interval [CI], 0.68 to 0.87; P<0.001). The corresponding hazard ratio was 0.70 (95% CI, 0.57 to 0.85) for death from cardiovascular disease and 0.77 (95% CI, 0.61 to 0.96) for death from cancer. The adjusted median life expectancy in the surgery group was 3.0 years (95% CI, 1.8 to 4.2) longer than in the control group but 5.5 years shorter than in the general population. The 90-day postoperative mortality was 0.2%, and 2.9% of the patients in the surgery group underwent repeat surgery.

CONCLUSIONS

Among patients with obesity, bariatric surgery was associated with longer life expectancy than usual obesity care. Mortality remained higher in both groups than in the general population. 

BACKGROUND:

Mental health problems are prevalent among adolescents with severe obesity, but long-term mental health outcomes after adolescent bariatric surgery are not well known. We aimed to assess mental health outcomes over 5 years of follow-up after Roux-en-Y gastric bypass surgery in adolescents who participated in the Adolescent Morbid Obesity Surgery (AMOS) study.

METHODS:

This was a non-randomised matched-control study in adolescents aged 13-18 years who had a BMI of 40 kg/m2 or higher, or 35 kg/m2 or higher in addition to obesity-related comorbidity; who had previously undergone failed comprehensive conservative treatment; and were of pubertal Tanner stage III or higher, with height growth velocity beyond peak. A contemporary control group, matched for BMI, age, and sex, who underwent conventional obesity treatment, was obtained from the Swedish Childhood Obesity Treatment Register. Data on dispensed psychiatric drugs and specialist treatment for mental disorders were retrieved from national registers with complete coverage. In the surgical group only, questionnaires were used to assess self-esteem (Rosenberg Self-Esteem [RSE] score), mood (Mood Adjective Checklist [MACL]), and eating patterns (Binge Eating Scale [BES] and Three-Factor Eating Questionnaire-R21 [TFEQ]). This study is registered with ClinicalTrials.gov (NCT00289705).

FINDINGS:

Between April 10, 2006, and May 20, 2009, 81 adolescents (53 [65%] female) underwent Roux-en-Y gastric bypass surgery, and 80 control participants received conventional treatment. The proportion of participants prescribed psychiatric drugs did not differ between groups in the years before study inclusion (pre-baseline; absolute risk difference 5% [95% CI -7 to 16], p=0·4263) or after intervention (10% [-6 to 24], p=0·2175). Treatment for mental and behavioural disorders did not differ between groups before baseline (2% [-10 to 14], p=0·7135); however, adolescents in the surgical group had more specialised psychiatric treatment in the 5 years after obesity treatment than did the control group (15% [1 to 28], p=0·0410). There were few patients who discontinued psychiatric treatment post-surgery (three [4%] receiving psychiatric drug treatment and six [7%] receiving specialised care for a mental disorder before surgery). In the surgical group, self-esteem (RSE score) was improved after 5 years (mixed model mean 21·6 [95% CI 19·9 to 23·4]) relative to baseline (18·9 [17·4 to 20·4], p=0·0059), but overall mood (MACL score) was not (2·8 [2·7 to 2·9] at 5 years vs 2·7 [2·6 to 2·8] at baseline, p=0·0737). Binge eating was improved at 5 years (9·3 [7·4 to 11·2]) relative to baseline (15·0 [13·5 to 16·5], p<0·0001). Relative changes in BMI were not associated with the presence or absence of binge eating at baseline.

INTERPRETATION:

Mental health problems persist in adolescents 5 years after bariatric surgery despite substantial weight loss. Although bariatric surgery can improve many aspects of health, alleviation of mental health problems should not be expected, and a multidisciplinary bariatric team should offer long-term mental health support after surgery.

FUNDING:

Swedish Research Council, VINNOVA, Västra Götalandsregionen, ALF VG-region, Region Stockholm, Swedish Child Diabetes Foundation, Swedish Heart and Lung Foundation, Tore Nilsson's Foundation, SUS Foundations and Donations, Capio Research Foundation, and Mary von Sydow's Foundation.