Severely obese individuals who opt to have gastric bypass surgery not only reduce their waistlines, they reduce their long-term total mortality as well, Utah researchers have reported.
Rates of death from diabetes, coronary artery disease, and cancer were all significantly lower in 7,925 patients who underwent gastric bypass between 1984 and 2002, Ted D. Adams, Ph.D., and his associates wrote.
Compared with a group of similarly obese control subjects who did not have the surgery, the gastric bypass group had a statistically significant, 40% decrease in adjusted long-term mortality from any cause during the mean follow-up of 7.1 years (37.6 vs. 57.1 deaths/10,000 person-years, P less than .001).
Deaths from coronary artery disease decreased by 56% (2.6 vs. 5.9/10,000 person-years, P = .006); deaths from diabetes were reduced by 92% (0.4 vs. 3.4/10,000 person-years, P = .005), and deaths from cancer dropped by 60% (5.5 vs. 13.3/10,000 person-years, P less than .001).
However, the rate of death from all nondisease causes, such as accidents and suicides, was 58% higher in the surgery group than in the control group, wrote Dr. Adams, professor in the division of cardiovascular genetics at the University of Utah, Salt Lake City, and his associates (N. Engl. J. Med. 2007;357:753–61).
The retrospective cohort study compared long-term mortality among severely obese men and women who had chosen gastric bypass surgery with that of an equal number (7,925) of severely obese persons who had applied for driver's licenses in the state of Utah. The two groups were matched for age, gender, and body mass index. The rates of death from any cause and from specific causes were determined with the use of the National Death Index.
Dr. Adams said that the reduced mortality from disease likely is related to the improvements in health that follow significant weight loss, such as reduced blood pressure, lower diabetes and coronary artery disease risk, and reduced sleep apnea. Dr. Adams also is a program director at the Health and Fitness Institute at Latter Day Saints Hospital, Salt Lake City.
When asked what he thought might be the reason for the higher rate of nondisease deaths in the bariatric surgery group, he commented that it was difficult to know. “We don't have any information about patients' psychosocial makeup or anything like that. There have been suggestions that some individuals who have undergone gastric bypass surgery may go on to increase their intake of alcohol.”
He also suggested that the significant weight loss associated with bariatric surgery may lead patients to become more physically active, and thus at greater exposure to accidents. “Patients lose, on average, more than 100 pounds.”
The finding that cancer deaths were lower after bypass surgery was a surprise, especially because this occurred within the relatively short time frame of 7.1 years, Dr. Adams said.
“This reduction persisted even after we excluded prevalent cancers and deaths from cancer occurring within 5 years after baseline. It really interested us that in such a short period of time we would see such a dramatic reduction in cancer.”
ELSEVIER GLOBAL MEDICAL NEWS