To Örebro University

Importance: There is a lack of studies evaluating sleeve gastrectomy compared with intensive lifestyle treatment in patients with class 1 obesity (body mass index [BMI] 30 to <35 [calculated as weight in kilograms divided by height in meters squared]).

Objective: To compare outcomes and safety of sleeve gastrectomy compared with intensive nonoperative obesity treatment in patients with class 1 obesity.

Design, Setting, and Participants: This matched, nationwide cohort study included patients with class 1 obesity who underwent a sleeve gastrectomy or intensive lifestyle treatment between January 1, 2012, and December 31, 2017, and who were registered in the Scandinavian Obesity Surgery Registry or the Itrim health database. Participants with class 1 obesity were matched 1:2 using a propensity score including age, sex, BMI, treatment year, education level, income, cardiovascular disease, and use of antibiotic drugs, antidepressants, and anxiolytics.

Interventions: Sleeve gastrectomy or intensive lifestyle treatment.

Main Outcomes and Measures: Outcomes included weight loss after intervention, changes in metabolic comorbidities, substance use disorders, self-harm, and major cardiovascular events retrieved from the National Patient Register, Prescribed Drug Register, and Cause of Death Register as well as the Scandinavian Obesity Surgery Registry and the Itrim health database. Data were analyzed from December 1, 2021 until May 31, 2022.

Results: The study included 1216 surgery patients and 2432 lifestyle participants with similar mean (SD) BMI (32.8 [1.4] vs 32.9 [1.4]), mean (SD) age (42.4 [9.7] vs 42.6 [12.7] years), and sex (1091 [89.7%] vs 2191 [90.1%] women). Surgery patients had greater 1-year weight loss compared with controls (22.9 kg vs 11.9 kg; mean difference, 10.7 kg; 95% CI, 10.0-11.5 kg; P < .001). Over a median follow-up of 5.1 years (IQR, 3.9-6.2 years), surgery patients had a lower risk of incident use of diabetes drugs (59.7 vs 100.4 events per 10 000 person-years; hazard ratio [HR], 0.60; 95% CI, 0.39-0.92; P = .02) and greater 2-year diabetes drug remission (48.4% vs 22.0%; risk difference 26.4%; 95% CI, 11.7%-41.0%; P < .001), but higher risk for substance use disorder (94 vs 50 events per 10 000 person-years; HR, 1.86; 95% CI, 1.30-2.67; P < .001) and self-harm (45 vs 25 events per 10 000 person-years; HR, 1.81; 95% CI, 1.09-3.01; P = .02). No between-group difference in occurrence of major cardiovascular events was observed (23.4 vs 24.8 events per 10 000 person-years; HR, 0.96; 95% CI, 0.49-1.91; P = .92).

Conclusions and Relevance: In this cohort study, compared with intensive nonoperative obesity treatment, sleeve gastrectomy in patients with class 1 obesity was associated with greater weight loss, diabetes prevention, and diabetes remission but a higher incidence of substance use disorder and self-harm.