Men had more health conditions before MBS and lost less weight after MBS

Researchers from the Netherlands and Yale School of Medicine - who evaluated sex differences in health status before and outcomes after metabolic and bariatric surgery (MBS) among men, premenopausal women, and postmenopausal women - have reported that men had more health conditions before MBS and lost less weight after surgery. Postmenopausal women showed a similar pattern but to a lesser extent.

For the study, the researchers analysed data from the National Bariatric Surgery Registry in the Netherlands, which included more than 17,000 participants who underwent one of two types of bariatric surgery, gastric bypass or sleeve gastrectomy. Among 17,567 patients, nearly two-thirds of the participants were premenopausal women, 22% were men and 16% were postmenopausal women. Historically, studies on bariatric surgery comprised mostly female patients in their 40s, which may not be representative of the overall population with obesity.

Prior to the procedure, men and postmenopausal women had more health conditions, such as hypertension, type 2 diabetes and dyslipidaemia, than premenopausal women. Notably, the men were younger than the postmenopausal women and closer in age to the premenopausal group yet carried a comparable disease burden.

Postmenopausal women experienced more severe complications than both premenopausal women and men (6.2 % vs. 1.7 % and 2.7 %, p < 0.001), and men and postmenopausal women had higher postoperative bleeding rates (1.9 % and 1.6 % vs. 1.0 %, p < 0.001). MBS-induced total weight loss (TWL) was lower in men (TWL 28.2 ± 8.5 % and 27.9 ± 9.4 % at respectively 12 and 24 months). The observed differences between men, premenopausal, and postmenopausal women were largely consistent across surgery types.

Two years after surgery, about 1 in 5 men had not reached a commonly used benchmark for successful weight loss, a loss of at least 20% of total body weight, compared with roughly 1 in 11 premenopausal women.

One plausible explanation for the higher prevalence of cardiometabolic disease in men and postmenopausal women undergoing MBS is increased visceral fat, the researchers noted. Visceral fat distribution is associated with a higher risk for developing conditions such as cardiovascular disease or diabetes, as opposed to subcutaneous fat, which is directly under the skin.

Surgery eligibility is primarily driven by BMI; however, there is a movement to consider waist circumference because of the associated risks. While men with larger waist circumferences may not have as high of a BMI, clinicians consider weight loss interventions sooner in men before obesity-related health conditions develop.

“This is the first study providing insights in preoperative and postoperative differences between men and premenopausal and postmenopausal women,” they concluded. “Our findings underscore the potential benefit of earlier obesity treatment and referral of men and postmenopausal women, and create awareness that these groups more often present with unfavourable body composition and a significant disease burden... These observations underscore the potential benefit of earlier obesity treatment and referral in these populations, including greater consideration of waist circumference as a marker of metabolic risk, and increased awareness among healthcare providers of the distinct clinical profiles and risks associated with men and postmenopausal women.”

The findings were featured in the paper, ‘Sex disparities in patients undergoing metabolic bariatric surgery: Data from a national registry’, published in Clinical Nutrition. To access this paper, please click here