Nonalcohol substance use disorder (SUD) was 2.5 times more common in people who had gastric bypass surgery compared with a control group who received usual obesity care, a new prospective study has found.
The findings suggest that the risk for nonalcohol SUD should be carefully explained to patients getting a gastric bypass and that the risk should be considered in care before and after the surgery, say the study authors and editorialists.
Though alcohol use disorder is a well-known side effect for some bariatric procedures, little is known about the link between the procedures and other substance abuse, write the study authors, led by Per-Arne Svensson, PhD, with the Department of Molecular and Clinical Medicine, Institute of Medicine at the University of Gothenburg in Sweden.
The study was published online in Obesity.
The researchers analyzed data from the SOS study. It was originally designed to compare bariatric surgery with usual obesity care, with overall mortality as the primary outcome. The protocol also called for reporting negative effects of included treatments.
The study was conducted throughout Sweden at 25 public surgical departments and 480 primary health centers. Participants were between ages 37 and 60 years and had a body mass index of at least 34 for men and 38 for women.
After people with previous nonalcoholic SUD were excluded, the study population included 1990 patients who had undergone bariatric surgery between September 1987 and January 2001, as well as 2030 matched controls who received usual obesity care. The three types of bariatric surgery were gastric bypass (264 patients), vertical banded gastroplasty (1353), and gastric banding (373), as chosen by the surgeons.
The follow-up was nearly 24 years.
Link Found Only With Gastric Bypass
The researchers identified participants who had nonalcoholic SUDs using the International Statistical Classification of Diseases (ICD) from the Swedish National Patient Register covering hospital treatment (hospital stays or hospital-based outpatient care) but not primary care.
Only gastric bypass was associated with an increased incidence of nonalcoholic SUD (adjusted hazard ratio, 2.54; 95% CI, 1.14-5.65) compared with controls during the follow-up period.
Among those who had gastric bypass surgery, three developed opioid-related disorders; three had sedative, hypnotic, or anxiolytic related disorders; and three had other psychoactive substance related disorders, the study authors write.
The researchers found no statistical difference in the incidence of nonalcoholic SUD when the groups who had undergone different surgical procedures were compared with each other.
“It is important to acknowledge that the number of affected patients was relatively low, in the single digits,” Jihad Kudsi, MD, a bariatric surgeon and chairman of surgery at Duly Health and Care, Oak Brook, Illinois, said in a press release.
The findings “highlight the critical role of bariatric behavioral health clinicians in the comprehensive evaluation and care of patients both before and after weight-loss surgery,” added Kudsi, who was not associated with the research.
Bariatric Surgery Candidates Should Be Warned, Monitored
The data indicate that patients who are candidates for bariatric surgery should be “carefully warned” about risks for nonalcoholic SUD and be monitored after the procedure, write James E. Mitchell, MD, a psychiatrist with the Department of Psychiatry and Behavioral Science, University of North Dakota in Fargo, and Devika Umashanker, MD, with Obesity Medicine, Hartford Health Care in Hartford, Connecticut, in an accompanying editorial.
They acknowledge, however, that monitoring can be difficult given the typical low rate of follow-up of these patients.
Though the reasons for the rise in nonalcoholic SUD are not clear, Mitchell and Umashanker say biologic and psychosocial issues may be contributors to the increase.
The persistence of medical comorbidities and a lack of noted improvement in quality of life or physical mobility after the surgery has been addressed in a paper on suicide risk after bariatric surgery, the study authors also note.
Svensson told Medscape Medical News that a mechanism for alcohol abuse after gastric bypass surgery is more evident, as measured by “increased blood alcohol levels after the surgery for a given amount of alcohol.” However, for other addictive substances, the mechanism is not obvious and needs further study.
The editorialists remind clinicians that measuring phosphatidylethanol can be very useful in identifying and quantifying recent alcohol intake, suggesting that all clinicians, not just those in bariatric surgery clinics, should be aware of the connection between the procedures and subsequent alcohol abuse and monitor those patients carefully.
Both the study authors and the editorialists point out that the SOS cohort was recruited when vertical banded gastroplasty and banding were commonly used, and both methods are now rarely, if ever, used. Gastric sleeve procedures are now the most common approach, and those patients were not included in the study.
“However, gastric bypass surgery patients were included, albeit in a minority of the sample,” the editorialists write.
In addition, the sample size of patients with SUD was too small to determine the drugs that were being abused, the editorialists note.
Svensson told Medscape Medical News the main limitation is that SUD events were identified in the Swedish National Patient Register, which misses nonhospitalized patients.
“This register is very complete for hospitals, but it does not include SUD events detected in the primary health care setting,” he said. “Hence, the absolute number of events is probably a clear underestimation. However, it is unlikely that this limitation would affect the study groups (control group vs groups with different surgical procedures) in different ways and hence the conclusions from this study are most likely valid.”
The study authors and the editorialists report no relevant financial relationships.
Obesity. Published online July 21, 2023. Article; Editorial
Marcia Frellick is a freelance journalist based in Chicago. She has previously written for the Chicago Tribune, Science News, and Nurse.com, and was an editor at the Chicago Sun-Times, the Cincinnati Enquirer, and the St. Cloud (Minnesota) Times. Follow her on Twitter at @MLfrellick
For more news, follow Medscape on Facebook, Twitter, Instagram, and YouTube
Source: Read Full Article