June 16, 2011 Bariatric surgery and the significant weight loss it achieves can significantly reduce the incidence of myocardial infarction (MI), stroke, and premature death, according to a study presented at the American Society for Metabolic and Bariatric Surgery (ASMBS) 28th Annual Meeting in Orlando, Florida.
“In addition to weight loss, bariatric surgery offers patients a whole host of health benefits, including a reduction in the risk of major cardiovascular problems,” study presenter John David Scott, MD, a bariatric surgeon at Greenville Hospital System University Medical Center in South Carolina, noted in an interview with Medscape Medical News.
“There is a long line of studies showing that bariatric surgery affects cardiovascular outcomes,” Dr. Scott noted. “The difference between our study and other studies is that we looked at major cardiovascular events (heart attack and stroke), whereas a lot of other studies have looked at risk for these events.”
The researchers reviewed data on 9140 morbidly obese individuals, 40 to 79 years of age, who had undergone bariatric surgery (nÂ = 4747), gastrointestinal (GI) surgery (nÂ = 3066), or orthopedic surgery (nÂ = 1327) in South Carolina between 1996 and 2008.
The GI group (hernia or gallbladder) and the orthopedic group (joint replacement) served as control groups because of their similar health and risk profiles, the authors note.
All patients had similar a health status before surgery and no history of MI or stroke. The patients were followed to the end points of first MI, stroke, transient ischemic attack, or death.
“Life-table analysis demonstrated significantly improved event-free survival in the bariatric patients within 6 months of surgery, and it was sustained over time,” the authors note in the meeting abstract.
Five years after surgery, an estimated 85% of bariatric surgery patients were free of MI and stroke, compared with 73% of orthopedic patients and 66% of GI patients, the researchers say.
At 10 years, event-free survival was 77% in the bariatric group, 64% in the orthopedic group, and 62% in the GI group (PÂ < .05).
After adjustment for differences in age and relevant co morbidities, bariatric surgery was an independent predictor of event-free survival. Compared with orthopedic surgery, the hazard ratio (HR) was 0.57 (95% confidence interval [CI], 0.47 to 0.69); compared with GI surgery, the HR was 0.35 (95% CI, 0.29 to 0.43).
“Important Area of Emerging Study”
In a statement from the ASMBS, Anita Courcoulas, MD, MPH, director of minimally invasive bariatric and general surgery at the University of Pittsburgh Medical Center, Pennsylvania, who was not involved in the study, said: “The impact of bariatric surgery on both cardiovascular risk factors and events is an important area of emerging study.”
The findings, she said, are “suggestive of an association between undergoing bariatric surgery and improved event-free survival. This relationship needs to be further explored with prospective clinical data, but still highlights the importance of understanding the broader impact of bariatric surgery on long-term outcomes.”
In an interview with Medscape Medical News, John Morton, MD, director of bariatric surgery at Stanford Hospitals & Clinics at Stanford University in Palo Alto, California, who was also not involved in the study, made the point that “obesity affects every single body part and if you are able to affect the weight, you’re going to help other medical problems â€” particularly the ones that are inflammatory-mediated.”
“Obesity is really an inflammatory-mediated disease, and stroke, cardiac risk, and even diabetes are now being recognized as inflammatory-related. With weight-loss surgery, direct markers of inflammation go down and, more importantly, these diseases get better,” Dr. Morton explained.
Studies have shown that morbidly obese patients can lose 30% to 50% of their excess weight in the first 6 months after surgery, and 77% as early as 1 year after surgery.
American Society for Metabolic and Bariatric Surgery (ASMBS) 28th Annual Meeting. AbstractÂ PL-105. Presented June 15, 2011.