TOPLINE:
Excessive total weight loss and a high proportion of fat-free mass loss at 12 months after metabolic-bariatric surgery are associated with an increased risk for major adverse cardiovascular events and mortality in patients aged ≥ 45 years.
METHODOLOGY:
- Although metabolic-bariatric surgery produces durable total weight loss of approximately 30% and lowers many complications, it is unclear whether these benefits persist when a large share of the weight lost is fat-free mass.
- Researchers in the Netherlands conducted a retrospective study (2012-2020) to examine whether the composition of weight loss after either Roux-en-Y gastric bypass surgery or sleeve gastrectomy is associated with major adverse cardiovascular events and all-cause mortality.
- Analyses focused on the 12-month total weight loss, fat mass loss, fat-free mass loss, and the proportion of fat-free mass loss within total weight loss.
- The primary outcome was a composite endpoint of incident major adverse cardiovascular events and all-cause mortality.
TAKEAWAY:
- Of 5889 patients (21% male; mean age, 44.3 years) followed for a mean of 4.9 years, 106 (1.8%) experienced the composite endpoint of major adverse cardiovascular events or all-cause mortality.
- In the overall cohort, total weight loss, fat-free mass loss, fat mass loss, and the proportion of fat-free mass loss were not significantly associated with the composite endpoint after adjusting for confounders.
- Among patients aged ≥ 45 years, high total weight loss (fully adjusted hazard ratio [HR], 1.68) and proportional fat-free mass loss ≥ 30% (fully adjusted HR, 1.78) were associated with an increased risk for major adverse cardiovascular events or death.
IN PRACTICE:
“[The findings] contradict current beliefs that ‘more weight loss is better,’” the authors of the study wrote. “Post-[metabolic-bariatric surgery] care should therefore routinely monitor the composition of weight loss and implement countermeasures to limit disproportional [fat-free mass loss].”
SOURCE:
The study was led by Malou A.H. Nuijten, Department of Medical Biosciences, Radboudumc Graduate School, Radboud University Medical Center, Nijmegen, Netherlands. It was published online in Clinical Obesity.
LIMITATIONS:
The study lacked data on weight regain and body composition during follow-up. Use of bioelectrical impedance analysis for body composition assessment also limited accuracy because this method assumes stable hydration and body fluid distribution, which may be affected in individuals with severe obesity. The low incidence of adverse events reduced the statistical power for separate outcome analyses.
DISCLOSURES:
The authors reported having no relevant conflicts of interest.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.