A new 24-year follow-up study of patients who received bariatric surgery published Friday has found that while the procedure is generally safe and effective, it presents a clear increased risk the patient will go on to develop a drug use disorder. File Photo by Alexis C. Glenn/UPI | License Photo
July 21 (UPI) -- A major study by Swedish medical researchers of more 4,000 patients with obesity has found that those who underwent weight loss surgery were 2.5 times more likely to go on to develop a non alcohol-related substance use disorder than those who receive standard obesity care.
The Swedish Obese Subjects prospective study published in the journal Obesity on Friday compared 2,010 patients who underwent one of the three types of appetite-suppressing bariatric surgeries -- gastric bypass, vertical banded gastroplasty or gastric banding -- with a match control group of 2,037 subjects.
A link between increased risk of alcohol intoxication and alcohol use disorder is already well understood but the SOS study, involving 25 Swedish public surgical departments and 480 primary health care centers, compared the outcomes of the two groups over 24 years to investigate evidence the treatment is linked to both prescription and illicit drug misuse.
"The current study shows that non-alcohol substance use disorder was 2.5 times more common after gastric bypass surgery compared with controls receiving usual obesity care, but the total number of patients having non-alcohol substance use disorder was overall low," said lead author Professor Per-Arne Svensson of Gothenburg University's Department of Molecular and Clinical Medicine.
"Healthcare professionals should consider the risk of non-alcohol substance use disorder in the care of patients treated with gastric bypass surgery."
The authors acknowledged limitations in the studies' utility in the fact that subjects received their surgeries between 1987 and 2001, that these procedures are far less common today and that the surgery cohort was at higher risk than the control group because they were younger, heavier, more likely to smoke or have smoked and less likely to have a university education.
The control group had fewer men and subjects had an average Body Mass Index of 40.1 kg/m2 compared with a BMI of 43.8 kg/m2 for the surgery group.
Candidates were excluded from the study if they had a gastric or duodenal ulcer, earlier bariatric surgery, gastric ulcer during the past six months, myocardial infarction during the past six months, ongoing or active cancer in the past five years, bulimia, psychiatric or cooperative problems precluding bariatric surgery, or high drug or alcohol blood levels.
Follow-ups of patients in the three surgery groups saw a rapid reduction in their BMI in the first year after surgery, followed by weight regain -- but BMI then stabilized after between eight and 10 years. However, changes in BMI among the control group during the follow-ups were only slight.
A follow-up commentary from Professor James Mitchell at the University of North Dakota cautioned that both biological and psychosocial issues needed to be considered given the persistence of post-surgery medical comorbidities and lack of adequate improvement in quality of life or physical mobility, which could be the mechanism for SUD, rather than the surgery itself.
Mitchell concluded that the study shows candidates for bariatric surgery "need to be carefully warned regarding these risks and monitored for their development," although he said he was skeptical of this occurring due to the due poor follow-up care that many of these patients receive.