The effects of glucagon like peptide-1 (GLP-1) on cardiac remodeling: exploring the role of medication and physiological modulation after metabolic surgery

Obesity and associated comorbidities reach epidemic proportions nowadays. Several treatment strategies exist, but bariatric surgery has the only longstanding effects. Since a few years, there is increasing interest in the effects of gastro-intestinal hormones, in particular Glucagon-Like Peptide-1 (GLP-1) on the remission of Type 2 Diabetes (T2DM) and its effects on cardiac cardiovascular morbidity, cardiac remodelling and mortality. In the past years several high quality multicentre randomised controlled trials were developed to assess the effects of GLP-1 receptor agonist therapy on cardiovascular morbidity and mortality. Most of the trials were designed and powered as non-inferiority trials to demonstrate cardiovascular safety. The majority of these trials show a reduction in cardiovascular morbidity in patients with T2DM. Some follow-up studies indicate potential beneficial effects of GLP-1 receptor agonists on cardiovascular function in patients with heart failure, however the results are contradictory and we are in need of long-term studies to make firm conclusions about the pleiotropic properties of incretin-based therapies. However it seems that GLP-1 receptor agonists have different effects than the increased GLP-1 production after bariatric surgery on cardiovascular remodelling. One of the hypothesis is that the blood concentrations of GLP-1 receptor agonists are three times higher compared to GLP-1 increase after bariatric and metabolic surgery. The purpose of this narrative review is to summarise the effects of GLP-1 on cardiovascular morbidity, mortality and remodelling due to medication but also due to bariatric and metabolic surgery. The second objective is to explain the possible differences in effects of GLP-1 agonists and bariatric and metabolic surgery.