While gastric bypass surgery has emerged as an effective way to treat severe obesity, there is a dark and dangerous side to the procedure, according to a new report.

Dr. Bennet Omalu and colleagues at the University of Pittsburgh looked at nearly 17,000 Pennsylvania residents who underwent bariatric surgery, between 1995 and 2004. What they found was startling. The patients had a higher death rate, including more suicides and heart-disease-related-deaths, than the regular population.

"It is likely that this continued excess mortality after bariatric surgery could be reduced by better coordination of follow-up after the surgery, especially control of high risk factors such as hypertension, diabetes mellitus, hyperlipidemia [high cholesterol] and smoking, as well as efforts to prevent weight regain by diet and exercise and psychological support to prevent and treat depression and suicide", said Omalu's team in their report.

Approximately 1 percent of patients died within one year of surgery and nearly 6 percent died within five years.

The researchers also found that:

— Death rates increased with age, especially among patients older than 65; the average age at the time of surgery was 48.

— Heart disease was the leading cause of death, cited for 76 patients (19.2 percent). Rates of death from heart disease were higher among bariatric surgery patients than the general population.

— Of 45 deaths from traumatic causes, 16 (4 percent of all deaths) were suicides and 14 (3 percent) were drug overdoses not classified as suicides.

The full report can be found in this month's issue of Archives of Surgery