Expanding Our Understanding of Age-Related Mortality After Gastric Bypass Surgery.

Abstract

Young adults are generally thought to be the least risky operative candidates for elective surgery, whereas older individualsmaybe considered too risky. In this issueof JAMASurgery, Davidson et al1 challenge these notions for patients undergoing gastric bypass surgery. At least 1 recent study2 inpatientsundergoingbariatric surgery has identified older age as a risk factor for poor outcome. These data combined with the belief that older patients may die before any health benefitsofweight loss surgeryare realized have led to physician reluctance to offer bariatric surgery to this population. However,Davidsonet al1 report ahazard ratio of only0.34, indicating a 66% reduction inmortality for the 65through 74year-old patientswhohave undergone gastric bypass surgery comparedwith their obese counterpartswhohavenot undergone gastric bypass surgery. This finding is a powerful argument for keeping bariatric surgery in the armamentarium for treating obesity in older individuals. These results should be interpreted with some caution, however. Bariatric surgeons exclude high-risk patients from surgery, which represents the major flaw in this study. The group not undergoing surgery had no such exclusion criteria and in all likelihood was not comparable in terms of disease burden and severity to the group undergoing surgery. Thus, the study by Davidson et al1 may be biased in favor of the patientsundergoingsurgery.That said, themagnitudeof thebeneficial effect of gastric bypass surgery onmortality is so stark that it is hard to solely attribute the authors’ findings to a selection bias alone. In addition,Davidsonet al1 found that theobese individuals not undergoing gastric bypass surgery had a faster increase in mortality as they aged compared with those undergoing the surgery. This finding indicates that patients should resist theurge to enjoy excess food intakewhile young, thinking that theyhavebariatric surgery tobail themoutwhen they areold.Obesepatientsmaybecomeprohibitively risky for surgery—or die—before the bariatric surgeon can intervene. Paradoxically, the data from the study by Davidson et al1 did not reveal improved outcome in patients younger than 35 years. The authors attribute this finding to the fact that young womenwere at a 3-fold increased risk of death from external causes (eg, unintentional or undetermined injuries or poisonings),whichappears tohaveoffset theprotectiveeffectsof surgery. A previous study3 reported on the increased incidence of external causes of death after bariatric surgery. The current study suggests that youngwomen in particular are a vulnerable population who may need additional preoperative preparation and postoperative follow-up to limit potentially avoidable causes of death. In conclusion, the study by Davidson et al1 suggests that mortality is drastically reduced for obese patients who undergo gastric bypass surgery across a broad age range. However, one should be judicious in the workup, selection, and postoperative support of both young and old patients before offering this powerful tool for treating obesity.