Association of Sex Differences on Weight Loss and Complications Following Bariatric Surgery

Abstract

Introduction: Sex as a biologic variable remains largely understudied, even for the most commonly performed operations. The most effective treatment for obesity and obesity-associated comorbidities is bariatric surgery. There are limited data to describe potential differences in outcomes between male and female patients, particularly with regards to weight loss. Within this context, we examined weight loss and complications up to 1 y following sleeve gastrectomy or gastric bypass within a statewide bariatric quality improvement collaborative.

Methods: We performed a retrospective cohort study among patients who had bariatric surgery. Using a state-wide bariatric-specific data registry, all patients who underwent gastric bypass or sleeve gastrectomy between June 2006 and June 2022 were identified. The primary outcome was percent excess body weight loss and change in body mass index (BMI) at 1 y. The secondary outcome was 30-d risk-adjusted complications.

Results: Among 107,504 patients, the majority (n = 85,135; 79.2%) were female and most patients (n = 49,731; 58%) underwent sleeve gastrectomy. Compared to female patients, male patients were older (47.6 y versus 44.8 y; P < 0.0001), had higher baseline weight (346.6 lbs versus 279.9 lbs; P < 0.0001), had higher preoperative BMI (49.9 kg/m²versus 47.2 kg/m²; P < 0.0001), and higher prevalence of most comorbid conditions including hypertension, hyperlipidemia, diabetes, and sleep apnea (P < 0.0001). Compared to female patients, male patients experienced greater total body weight loss (105.1 lbs versus 84.9 lbs; P < 0.0001) and higher excess body weight loss (60.0% versus 58.8%; P < 0.0001) but had higher BMI overall (34.0 kg/m²versus 32.8 kg/m²; P < 0.0001) at 1-y follow-up. Males had higher rates of serious complications (2.5% versus 1.9%; P < 0.0001), leak and perforation (0.5% versus 0.4%; P < 0.0001), venous thromboembolism (0.7% versus 0.4%; P < 0.0001), and medical complications (1.5% versus 1%; P < 0.0001).

Conclusions: In this study we found that both males and females experienced excellent weight loss with a low risk of complications following bariatric surgery. Male sex was associated with slightly greater weight loss and slightly higher incidence of complications. However, although statistically significant, clinically, the differences in weight loss was not. Due to males having higher prevalence of comorbidities, providers should consider referring males earlier for bariatric surgery which may improve outcomes for this population.

Keywords: Bariatrics; Roux-en-Y bypass; Sex differences; Sleeve gastrectomy; Weight loss.