We assessed the advantages of bariatric operation in non-diabetic individuals with class I obesity compared to those with class II obesity. No significant difference was detected in weight loss, improvement of cardiovascular risk factors, and obesity-related health conditions between individuals with class I and class II obesity three years after undergoing bariatric operation. Additionally, the incidence of adverse outcomes and surgical complications was found to be similar between the two groups. Therefore, bariatric operation is considered a safe and effective intervention for both non-diabetic cases with class I and II obesity.
Class I patients with obesity are at increased risk for obesity-related comorbidities, non-alcoholic fatty liver disease, and cancers(19). Recent updates from the ASMBS and the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) have led to alterations in the indications for metabolic surgery compared to the criteria outlined by the NIH (2, 20). This emphasized that it is not only the BMI but also various conditions such as cardiovascular comorbidities which make individuals appropriate candidates for bariatric surgeries.
Our study results demonstrate improvements in anthropometric measurements and body composition indices, as well as similar enhancements in cardiovascular risk factors among patients with class I and class II obesity three years post-surgery. There are several previous papers demonstrating the positive effects of bariatric surgery on patients with class II obesity, in terms of anthropometric, body composition, and cardiovascular improvement. Moreover, a meta-analysis of 11 studies revealed that bariatric surgery had the potential to notably improve the concentration of oxidized LDL-C (ox LDL-C), with this enhancement being linked to changes in BMI among patients with class II obesity (21). Consistent with this finding, a recent prospective study observed significant enhancements in anthropometric measurements and improvements in all cholesterol indices in 443 patients with class II obesity who underwent SG, Roux-en-Y gastric bypass (RYGB), or OAGB one-year post-surgery (22). Julve et al. demonstrated an increase in atherogenicity over 12 months following bariatric surgery attributed to reductions in apo B-containing lipoproteins and lipoprotein-associated phospholipase A2 activity, ox LDL-C, and an increase in HDL-2 concentration (23). We observed a parallel reduction in dyslipidemia, hypertension, LDL-C, TG, SBP, and DBP, accompanied by an increase in HDL-C, with no significant differences between the two groups. Thus, while weight loss remains the primary factor in improving comorbidities after bariatric surgery, other factors may also play a crucial role (24).
In the current study, we addressed the benefits and safety of bariatric operation in non-diabetic cases with class I obesity. Similar to our study, Mark. Maiz et al presented their findings in a retrospective cohort of 1119 patients diagnosed with class I obesity. Among these individuals, 283 underwent RYGB while 836 operated for SG. After 1 year, the patients achieved a BMI of 24.5 and a mean EWL of 107.9%. DM, HTN, dyslipidemia, and insulin resistance or remission rates were 54.39, 58.29, 54.30, and 72.17%, respectively. Maiz et al. reported high rates of HTN and dyslipidemia improvement (58 and 54%, respectively) in patients with class I obesity, one year after surgery. However, the extensive nature of this study was hindered by its limited duration of follow-up (25). In line with our findings, a retrospective analysis of the impact of bariatric operation on class I obesity revealed that H and dyslipidemia remission was observed in 42% and 64% of the population for a follow-up of 5 years, respectively (26). Recent research by Kermansarvi et al. believed that bariatric operation is an effective and safe method in patients with class I obesity, which can significantly improve cardiovascular complications (27). Three randomized controlled trials (RCTs) also evaluated the impact of bariatric operation in cases with class I obesity. These studies observed favorable outcomes in terms of BP progression, which were almost comparable to the results achieved in patients with a BMI exceeding 35 kg/m2 (28–30). Although all these studies were evaluations of diabetic patients. Therefore, various RCTs are needed to assess the impact of metabolic surgery on non-diabetic patients with class I obesity.
Our study demonstrated that calcium, iron, ferritin, hemoglobin, and vitamins B-12 and D, increased and albumin reduced in both groups, despite supplement therapy. Mohapatra et al. reported that iron, calcium, folate, and vitamins D and B12 are the most common micronutrient deficiencies in post-bariatric operation. The specific type of bariatric operation decides the mechanism of malabsorption (31). In line with our study, Eva-Christina Krzizek et al. (32) established a prevalence of deficiency in ferritin and a decrease in hemoglobin one-year post-operation in cases with a mean BMI of 33.9 ± 19.2. Overall, these findings emphasize the significance of continuous monitoring after surgical procedures and propose that, through the appropriate utilization of vitamin and mineral supplements in the postoperative phase, patients may not face an elevated susceptibility to micronutrient insufficiency after bariatric operation. However, there are not enough studies to compare the effect of bariatric operation on micronutrient deficiency in cases with class I and class II obesity.
To our knowledge, there are not enough studies on the effect of bariatric operation comparing class I and II obesity. Choi et al. explored the utilization of Laparoscopic Adjustable Gastric Banding (LAGB) in 66 cases (with BMI 30 to 35 kg/m2 and co-morbidity or 35 to 40 kg/m2 without comorbidities) and compared to 438 patients classified as severely obese. The average percentage of EWL observed at 3, 6, 12, and 18 months were 20.3, 28.5, 44.7, and 42.2%, respectively(33). More studies should investigate the safety and necessity of bariatric operation in cases with obesity class I and compare it to class II.
Certain limitations must be acknowledged with our study. Firstly, the duration of follow-up was relatively brief in some analyses, amounting to one year. Secondly, the control group did not encompass any nonsurgical class I or II obesity. Thirdly, no comparisons were made between the groups regarding other factors that could potentially contribute to weight loss and metabolic improvements, such as physical activity, dietary intake, quality of life, and psychological state. The present study also had some strengths. This is the first prospective research to compare body composition indices, micronutrient deficiency, and comorbidity outcomes in matched patients with class II obesity undergoing bariatric operation with a control group of non-diabetic patients with class I obesity.