Research in Older, Male Patients with Comorbidities
By Brenda L. Mooney
DURHAM, NC – While evidence is growing that bariatric surgery can improve survival among the severely obese, past research hasn’t been as useful for some of the patients who would benefit most from weight loss.
Earlier long-term studies have tended to focus on lower-risk, predominantly female patients. But how safe and effective is bariatric surgery in older men with myriad health issues?
That’s what a group of researchers set out to determine, using the VA’s database — the only one with extensive information on such a population. Comparing 2,500 veterans, 74% male, who underwent bariatric surgery at the VA from 2000-2011 with 7,462 control patients who did not undergo bariatric surgery, the study found a 53% lower risk of dying from any cause at five to 14 years after the procedure.
More than half, 55%, of the study subjects had diabetes as well as a variety of other comorbidities, including high blood pressure, arthritis, heart disease and depression, according to the report published recently in the Journal of the American Medical Association.1
“We examined this question for several reasons,” said Matthew L. Maciejewski, PhD, of the Center for Health Services Research in Primary Care at the Durham, NC, VAMC. “First, complications and death during and soon after bariatric surgery have progressively declined over the past several decades, but there is simply very little long-term evidence of the survival benefits of bariatric surgery, particularly in Americans having surgical procedures being used today in routine practice. Secondly, we thought it was important to look at the impact of bariatric surgery among veterans, because they are typically older males and they typically have multiple medical comorbidities, which is fairly different than the typical bariatric patient in the United States who is often younger and female.”
In an interview made available by JAMA, Maciejewski noted that, despite past safety concerns, the study’s adjusted analyses showed no significant association between bariatric surgery and death from all causes in the first year of follow-up. The study found that the risk of dying during and soon after bariatric surgery was lower in 2006-2011 than in 2000-2005, he said.
“In other words,” Maciejewski pointed out, “having bariatric surgery was not significantly related to a veteran’s chance of dying in the first year, compared with not having had surgery at all.”
Over the longer term, veterans who had surgery showed significantly lower mortality, he said. “So this means bariatric surgery is associated with lower long term mortality — that is, better long-term survival among veterans, and this finding is consistent with the limited non-VA research that addressed the same question.”
In fact, the relationship between surgery and survival was similar when comparisons were made between men and women, patients with and without diagnosed diabetes and patients who had bariatric surgery before 2006, compared with patients who had surgery on or after 2006, added Maciejewski, who also is on the faculty of Duke University.
For the study, researchers looked at the effects of a range of bariatric-surgery procedures including gastric bypass (undergone by 74% of the patients receiving surgery), sleeve gastrectomy (15%), adjustable gastric banding (10%) and other (1%). The surgical group and control patients were of similar age — early 50s and body mass index (BMI) 46-47.
At the end of the 14-year study period, 263 patients in the surgical group had died, with 1,277 deaths in the control group. Estimated mortality rates for surgical patients were 2.4% at one year, 6.4% at five years and 13.8% at 10 years. For control patients, however, estimated mortality rates were 1.7% after the first year, 10.4% at five years and 23.9% after a decade.
“Previous studies of long-term survival after bariatric surgery involved younger, mostly female, populations who tended to have few obesity-related diseases,” noted lead author David Arterburn, MD, MPH, a Group Health Research Institute associate investigator and an affiliate associate professor of medicine at the University of Washington School of Medicine. “In contrast, our study’s population was older — with a mean age of 52 — and 74% male.”
The study’s extended follow-up was one of its key advantages, Arterburn emphasized.
“We have tracked a large group of patients for a long enough time that we can clearly see a strong link between bariatric surgery and long-term survival,” he said. “As time passes, the risk of dying among the patients who’ve had surgery appears to be diverging from those of the matched controls who haven’t had surgery.”
A 2011 VA study led by Maciejewski and Arterburn found that bariatric surgery in older males was not significantly associated with a decrease in mortality; however, the follow-up period was only 6.7 years. 2
A study the next year compared VA inpatient, outpatient and total expenditures between the surgical and nonsurgical patients for a six-year period: three years before the surgery took place and three years afterward. Previous studies found that healthcare expenditures decreased after bariatric surgery, two to five years after the procedure took place in younger, primarily white, and female populations. 3
The results of the VA research, however, indicated that, in the months before the procedure took place, both inpatient and outpatient costs increased significantly for the patients undergoing bariatric surgery and decreased after surgery until the last six-month period, 31 to 36 months after surgery. At that point, VA healthcare costs were essentially the same for those who did and did not have surgery.
At the time, Maciejewski said the difference in results from the VA study and research on younger, female patients could “be explained by important differences in the populations examined and the methods of analysis.”
In light of the results of the latest research, the two researchers said they still plan to explore the following questions:
- Does bariatric surgery help certain subgroups of patients more or less?
- How long does weight loss last after surgery, and at what level?
- Is the course of associated diseases, such as diabetes, changed?
- Do total costs of healthcare decrease in the long run?
Arterburn also suggested the recent study’s results could have broader implications for encouraging weight loss in general. “Despite the studies showing that patients with lower BMIs live longer, not much evidence has linked intentional weight loss (from surgery, medication, or diet and exercise) with longer survival,” he noted. “But our results, combined with other studies of bariatric surgery, may help to make that case.”
1 Arterburn DE, Olsen MK, Smith VA, Livingston EH, Van Scoyoc L, Yancy WS Jr, Eid G, Weidenbacher H, Maciejewski ML. Association between bariatric surgery and long-term survival. JAMA. 2015 Jan 6;313(1):62-70. doi: 10.1001/jama.2014.16968. PubMed PMID: 25562267.
2 Maciejewski ML, Livingston EH, Smith VA, Kavee AL, Kahwati LC, Henderson WG, Arterburn DE. Survival among high-risk patients after bariatric surgery. JAMA. 2011 Jun 15;305(23):2419-26. doi: 10.1001/jama.2011.817. Epub 2011 Jun 12. PubMedPMID: 21666276.
3 ML Maciejewski, EH Livingston, VA Smith, LC Kahwati, WG Henderson, DE Arterburn, “Health Expenditures Among High-Risk Patients After Gastric Bypass and Matched Controls.” Arch Surg. 2012;147(7):633-640. Doi:10.1001/archsurg.2012.818