PALM BEACH, FLA. – Add another notch to the evidence base for bariatric surgery as effective treatment for type 2 diabetes in obese patients.
Patients with type 2 diabetes who underwent any type of bariatric surgery had a 61%-78% relative risk reduction in their rate of macrovascular, microvascular, or vascular events during an average 20-month follow-up in a review of more than 15,000 cases in South Carolina.
"We are trying to get primary care physicians to spread the word [to patients] that bariatric surgery has come a long way over the past 30 or 40 years; the risk-to-reward ratio is much more beneficial to patients," Dr. John D. Scott said at the annual meeting of the Southern Surgical Association.
The new finding "adds to the extensive list of papers that show bariatric surgery mitigates the long-term effects of type 2 diabetes," Dr. Scott added in an interview. "Some front-line medical providers still see bariatric surgery as a procedure of last resort, but findings like ours show that a discussion [with patients on whether they should consider bariatric surgery] should happen a lot sooner."
Dr. Scott, a surgeon at University Medical Center in Greenville, S.C., recommended that patients with a body mass index of at least 35 kg/m2 and two or more comorbidities be told that they have the option of undergoing bariatric surgery and reducing their risk.
"We have an epidemic [of obesity and type 2 diabetes], and for the first time since tuberculosis, this is an epidemic where surgery has a real opportunity to positively intervene," commented Dr. Josef E. Fischer, a professor of surgery at Harvard Medical School in Boston.
The study used hospital billing data collected by the South Carolina Office of Research and Statistics as well as state vital records data for 1995-2009. The analysis included 2,580 obese patients who underwent any type of bariatric surgery and 13,371 obese patients who did not have surgery. The researchers extracted the data from records of nearly 34,000 obese patients, but excluded patients with type 1 diabetes, patients with incomplete data, and patients with advanced cardiovascular or microvascular disease at the time of their surgery or entry into the state records during this period.
During a median follow-up of about 20 months, the rate of new-onset macro- or microvascular events was 2% in the bariatric surgery patients and 11% in the patients who did not undergo surgery. The rate of an incident vascular disease event was 2% in the patients who had surgery and 13% in those who did not. Macrovascular events included myocardial infarction, stroke, and all-cause death. Microvascular events included blindness in at least one eye, laser eye surgery, nontraumatic amputation, or placement of access for dialysis. Other vascular events included new-onset heart failure or angina, or revascularization of a coronary, carotid, or peripheral artery.
In a multivariate-adjusted analysis, patients who underwent bariatric surgery had a 61% reduction in macrovascular events, a 78% reduction in microvascular events, a 75% reduction in vascular events, and a 64% reduction in combined macro- and microvascular events, compared with patients who did not have this surgery – all statistically significant differences, reported Dr. Spence M. Taylor, a coinvestigator with Dr. Scott on the study. A propensity-score matched analysis that compared the bariatric surgery patients and matched nonsurgical patients showed very similar reductions in all three event categories.
"Bariatric surgery has a substantial and lasting mitigating association on major complications associated with type 2 diabetes in the obese population," concluded Dr. Taylor, chairman of surgery at the University Medical Center in Greenville.
Dr. Scott, Dr. Fischer, and Dr. Taylor had no relevant disclosures.