Metabolic outcomes after bariatric surgery for Indigenous patients in Ontario

In 2013, 18% of Canadian adults had obesity (body mass index [BMI] >30 kg/m²), compared with 25.7% of Canada's Indigenous population. Bariatric surgery is an effective treatment for obesity, but has not been studied in Canadian Indigenous populations.

To determine the effects of bariatric surgery in the Indigenous Ontario population.

Multicenter data from the publicly funded Ontario bariatric program and registry.

Prospectively collected data using all surgical patients between March 2010 and 2018 was included in initial analysis and included the following postoperative outcomes: diabetes, hypertension, and gastroesophageal reflux disease. Demographic characteristics, baseline characteristics, and univariate outcomes were assessed using Pearson Χ² or t tests. Multivariable regression for BMI change was used with complete case analysis and multiple imputation.

Of 16,629 individuals initially identified, 338 self-identified as Indigenous, 13,502 as Non-Indigenous, and 2789 omitted ethnicity and were excluded. Baseline demographic characteristics were not statistically different; rates of hypertension (P = .03) and diabetes (P < .001) were higher in the Indigenous population. Univariable analysis showed similar 1-year BMI change (Indigenous: 15.8 ± 6.0 kg/m²; Non-Indigenous: 16.1 ± 5.6 kg/m², P = .362). After adjustment, BMI change was not different between groups at 6 months (effect size = .07, 95% confidence interval -.45 to .58, P = .803) and 1 year (effect size = -.24, 95% confidence interval -.93 to .45, P = .489). Rates of co-morbidities were similar at 1 year between the 2 populations, despite differences at baseline. Six-month and 1-year follow-up rates were higher in the Non-Indigenous population (P < .001, P = .005, respectively).

Weight loss and resolution of obesity-related co-morbidities are similar in Indigenous and Non-Indigenous patients. Access to surgery, patient selection, and long-term results merit further investigation.