Dan Eisenberg, MD, MS, of the Palo Alto VAMC and Stanford School of Medicine led the research.

PALO ALTO, CA—Roux-en-Y gastric bypass (RYGB) is the criterion standard operation for weight loss, but it also increases the risk of adverse outcomes such as mineral and/or vitamin deficiency.

Noting that few studies have described long-term outcomes in a veteran population, a research letter published in JAMA Surgery sought to evaluate the prevalence of anemia 10 years after RYGB and assesses whether postoperative bariatric follow-up affects that outcome.1

Researchers from the Palo Alto VA Healthcare System and Stanford University School of Medicine performed a retrospective review of a prospective, 10-year database of RYGB at a single VAMC. Patients who did not have follow-up with a bariatric specialist more than five years postoperatively were compared with patients who had at least one visit with a bariatric specialist after five years. For purposes of the study, anemia was defined as a hemoglobin concentration of less than 13.5 g/dL for men and less than 12.0 g/dL for women.

The study looked at 102 patients who underwent RYGB from 2002 through 2006, ultimately focusing on 74 patients, 78% male, with an average age of 51 and a preoperative body mass index of 46.2. After 10 years, the mean BMI was 33.7, representing 60% excess BMI loss.

With an initial mean rate of preoperative anemia of 20%, the rate increased after RYGB to 28% at one year, 31% at five years and 47% at 10 years. The rate varied based on bariatric specialist follow-up, according to the report. While, at 10 years after surgery, the anemia rate in the cohort without follow-up increased to 57% from 22% before surgery, the rate among participants with follow-up did not increase—19% vs. 13%.

“Compared with patients with bariatric specialist follow-up, patients without bariatric specialist follow-up had significantly higher odds of anemia at 10 years (odds ratio, 6.1; 95% CI, 1.4-27.6; P = .02) after adjusting for preoperative anemia,” study authors concluded.

“Long-term complications of RYGB, such as anemia, may go unrecognized by non-bariatric specialists,” the researchers pointed out. “Causes include iron, vitamin B12, and folate deficiency; less common causes include copper, vitamin A, and selenium deficiency and bleeding marginal ulcers. We found high anemia rates 10 years after RYGB; these rates may reflect a mixed vitamin and mineral deficiency, because patients had normocytic anemia.

“Our study suggests that follow-up with bariatric specialists more than 5 years after surgery, rather than with specialists with no bariatric expertise, can decrease long-term anemia risk. This finding may demonstrate the bariatric specialist’s specific understanding of the long-term risk for nutritional deficiency after RYGB and the importance of vitamin and mineral supplementation.”

Chen GL, Kubat E, Eisenberg D. Prevalence of Anemia 10 Years After Roux-en-Y Gastric Bypass in a Single Veterans Affairs Medical Center. JAMA Surg. 2017 Sep 20. doi: 10.1001/jamasurg.2017.3158. [Epub ahead of print] PubMed PMID: 28975250. Cancer. 2017 Apr 1;123(7):1174-1183. doi: 10.1002/cncr.30416. Epub 2016 Dec 2.