Comparing outcome of diabetes mellitus in cases under bariatric surgery or medical treatment

Background: Diabetes mellitus (DM) type 2 is one of the most comorbidities in obese patients. Uncontrolled DM can cause life threatening complications. There is some studies suggested that bariatric surgery has positive effect on DM type 2 remission but it is still controversial. The aim of this study is to investigate the effect of bariatric surgery on DM type 2 in obese patients. Methods: This prospective study was performed on 518 adult patients with BMI ≥ 30 between 2009 and 2017. All data were extracted from the National Database of Bariatric Surgery of Iran. Patients with congenital metabolic disease, DM type 1 and women who became pregnant during the first 6 months after treatment, were excluded from the study. Patients were divided into two groups, 306 patients were in surgical treatment group and the others were in non-surgical procedures group (contains psychological consultation, physical activity and changing in diet). Outcome in this study considered as DM incidence (FBS > 126 mg/dl) and remission (FBS ≤ 126 mg/dl). Patients were followed for one year. National data registry is ethically confirmed by Iran University of Medical Sciences (ethic code: IR.IUMS.REC.1397.134) Results: Among 518 patients enrolled in this study 419 (80.88%) were female. Mean age was 44.963 ± 10.74 and, mean BMI at baseline was 45.51 ± 7.24. Among the 303 patients in surgical treatment group who had DM type 2, DM remission occurred in 268 (88.4%) of them; also, among the 212 patients in non-surgical procedure group 74 patients had DM type 2, DM improved in 24 (32.4%) of them after one year. On the other hand, in the surgical treatment group 3 patients did not have DM but, after surgery 1 (33.3%) of them took diabetes and in the non-surgical group among 138 patients without DM, there was 2 (1.4%) patients who took DM after one year (p-value < 0.001). Relative risk for incidence of DM was 9.41 (95% CI: 3.070, 28.870) and for remission of DM was 0.703 (95% CI: 0.652, 0.758). Multivariable logistic regression by forward stepwise method after adjusting model for age, BMI before surgery and sex, indicated that having DM at baseline (odds ratio: 87.055) and non-surgical therapy (odds ratio: 14.543) have significance effects on DM remission after 1 year. (nagelkerke R2=0.36; p<0.001) Conclusion: In comparison between surgical treatment and non-surgical procedures frequencies of DM remission was higher in surgical treatment. The incidence of DM was also higher in surgical group although, it was not reliable due to small sample size. Finally after adjustment for confounding factors type of treatment remain as independent factor for predicting DM status one year after treatment.

Keywords:

Diabetes mellitus type 2 , bariatric surgery , obesity.