Higher-Than-Expected Suicide Rate Following Bariatric Surgery

October 29, 2007 — Extremely obese Pennsylvania residents undergoing weight loss surgery over a 10-year period had a higher-than-expected mortality rate from suicide, according to a new study appearing in the October issue of Archives of Surgery. The study also uncovered an excess of deaths due to coronary heart disease among these surgery patients.
The large number of deaths from suicides and drug overdoses is "a cause for concern," the authors, led by Bennet I. Omalu, MD, from the University of Pittsburgh, in Pennsylvania, write. The fact that most of these deaths occurred at least 1 year after surgery suggests that "careful follow-up, especially the need to recognize and treat depression, should be provided for patients who have undergone bariatric surgery," they write.
Substantial Excess of Suicide Deaths
Bariatric surgery is the most effective treatment for morbidly obese patients (those with a body mass index [BMI] of 40 kg/m2 or more), the authors write. Patients typically lose up to 80% of their excess body weight 1 to 2 years following the operation.
In this study, Dr. Omalu and colleagues examined data from the Pennsylvania Health Care Cost and Containment Council on 16,683 Pennsylvania residents who underwent bariatric surgery (gastric bypass) between January 1, 1995, and December 31, 2004. There were 440 deaths among these patients, or 2.6% of the total. Death rates increased with age, especially after the age of 65 years. The mean age of the surgery patients was 48 years. The study also looked at comparable death rates among Pennsylvania residents from the Division of Vital Records at the Pennsylvania State Department of Health.
In the study, less than 1% of the deaths occurred within the first 30 days. Therapeutic complications accounted for 38 of 150 natural deaths within 30 days, including pulmonary embolism in 31 (20.7%), coronary heart disease in 26 (17.3%), and sepsis in 17 (11.3%).
The 1-year case fatality rate was 1% and rose to almost 6% by the 5-year mark. The percentage of men dying was almost 3 times that of women.
There were 16 deaths listed as suicides, but the actual suicide rate was likely higher, since some of the 14 deaths listed as drug overdoses on death certificates may have been suicides as well. Based on statistics for the general US population, only 2 suicides would have been expected in this number of people. "There was a substantial excess of suicide deaths, even excluding those listed only as drug overdose," the authors write.
Overall, coronary heart disease was the leading cause of death in the study, listed as the cause of death in 76 patients, or 19.2%. "A more thorough examination of cardiac morbidity and mortality, including more detailed clinical evaluation of cardiac pathophysiological characteristics before and after surgery, is indicated because of the continuing high mortality due to cardiovascular disease in this population," write the study authors.
This high death rate could be reduced by better coordination of follow-up after the surgery, they write, "especially control of high risk factors such as hypertension, diabetes mellitus, hyperlipidemia, and smoking, as well as efforts to prevent weight regain by diet and exercise."
View the Deaths in Context
Asked for comment on these findings, Anita Courcoulas, MD, who did not take part in the study but is an associate professor of surgery and chief of the section of minimally invasive bariatric and general surgery at the University of Pittsburgh School of Medicine, agrees that bariatric-surgery patients "need to be followed carefully." She adds that they need social and psychological support and follow-up as well as medical follow-up.
Dr. Courcoulas noted that there is a high rate of depression among obese people, especially those seeking surgery. "There is a subset in this population that doesn't get better with respect to depression, and it could actually get worse," she told Medscape Psychiatry, adding that this group seems to be particularly at risk for suicide. "I think we have to identify who these people are."
However, the deaths in the study should be viewed in context, said Dr. Courcoulas who, as an epidemiologist, says she is familiar with studies such as this one and their limitations. She noted that it might not be so much the surgery that is killing these patients but their obesity. She points out that the study compared death rates of obese patients undergoing bariatric surgery with an age- and sex-matched population — that is, with people who do not have the same comorbid medical conditions — and not with obese people in the state who did not undergo surgery.
The 1%-per-year mortality rate is "not widely different from what bariatric surgeons know to be the expected mortality of a group of patients who are otherwise quite ill," she said. She pointed to 2 recent studies that compared mortality among bariatric-surgery patients with obese, nonsurgery patients in the population using drivers' licenses, which document age as well as BMI. Those studies, she said, found "a much reduced incidence of mortality when you compared the surgery patients with equally obese patients" who did not undergo surgery.
The study authors have disclosed no relevant financial relationships.
Arch Surg. 2007;142;923-928.