# The effect of weight change on death and cardiovascular events after Roux-en-Y gastric bypass

## TL;DR

This study finds that both continued weight loss and significant weight regain after gastric bypass surgery are linked to higher risks of heart events and death.

## Contribution

The study identifies specific weight change trajectories after gastric bypass that are associated with increased cardiovascular risks.

## Key findings

- Patients with continued weight loss after nadir had an 80% higher risk of death and 62% higher risk of cardiovascular events.
- Those with over 50% weight regain had a 61% higher risk of death and 48% higher risk of cardiovascular events.
- Both continued weight loss and significant weight regain are non-desirable trajectories requiring clinical attention.

## Abstract

Weight changes after Roux-en-Y gastric bypass (RYGB) follow different trajectories, but the effects of different trajectories on death and cardiovascular events are largely unknown. The aim of the current study was therefore to evaluate the effects of weight changes after RYGB on cardiovascular events and mortality rate.

This cohort study included patients who underwent primary RYGB in Sweden from 2007 to 2018 with a complete registration of weight at baseline, at nadir weight loss and 5-year follow-up (n = 25 230) with a mean BMI of 42.1 ± 5.2 kg/m2, age 42.5 ± 11.2 years, and 19 420 (77%) women. Patients were stratified based on weight change from nadir weight loss. The main outcome measures were major cardiovascular event (MACE) or death.

Over a mean follow-up of 10.6 years, 1276 patients experienced at least one episode of a MACE, and 707 died. An increased risk for death and MACE was seen in patients with continued weight loss after nadir (adjusted HR compared to recurrent weight gain of 0–20% of weight lost at nadir among patients who initially lost 20–35% total weight (TWL): 1.80 (1.41–2.31) and 1.62 (1.35–1.94) respectively), and for patients who experienced >50% recurrent weight gain from nadir (adjusted HR compared to patients with recurrent weight gained 0–20% TWL: 1.61 (1.07–2.43) and 1.48 (1.09–2.00) respectively).

Continued weight loss and significant recurrent weight gain after the initial weight nadir were both associated with a higher risk for MACE and death after RYGB. These should be considered non-desirable weight trajectories requiring further clinical evaluation and increased support.

In this nationwide cohort of patients who underwent Roux-en-Y gastric bypass, patients experiencing more than 50% recurrent weight gain and those who continue to lose weight after the initial weight-loss phase had higher risk for cardiovascular events and death compared to those who regained 0–50% of their lost weight. Significant recurrent weight gain but also continued weight loss should be considered non-desirable trajectories requiring clinical evaluation and increased support.