When is bariatric surgery considered for individuals with obesity?

Indications for Bariatric Surgery

Bariatric surgery should be considered for individuals with a BMI ≥40 kg/m² or BMI ≥35 kg/m² with at least one obesity-related comorbidity, including type 2 diabetes, hypertension, obstructive sleep apnea, and non-alcoholic steatohepatitis. 1

Primary Indications Based on BMI

Bariatric surgery is indicated in the following scenarios:

• BMI ≥40 kg/m² (severe obesity) regardless of comorbidities 2, 1
• BMI ≥35 kg/m² with at least one obesity-related comorbidity 2, 1
• BMI ≥30 kg/m² with type 2 diabetes that could potentially go into remission (metabolic surgery) 2
• BMI >25 kg/m² for Asian populations due to different body composition and risk profiles 1

Qualifying Comorbidities

The presence of these obesity-related conditions strengthens the indication for bariatric surgery:

• Metabolic conditions:

  • Type 2 diabetes, especially if poorly controlled despite optimal medical therapy 1
  • Metabolic dysfunction-associated steatotic liver disease (MASLD/MASH) 1
  • Dyslipidemia 1

• Cardiovascular conditions:

  • Hypertension, particularly if poorly controlled 1
  • Cardiovascular disease 1

• Respiratory conditions:

  • Obstructive sleep apnea 2, 1
  • The American Academy of Sleep Medicine strongly recommends discussing referral to a bariatric surgeon for adults with OSA and obesity (BMI ≥35) who are intolerant or unaccepting of PAP therapy 2

• Other qualifying conditions:

  • Polycystic ovary syndrome
  • Pseudotumor cerebri
  • Gastroesophageal reflux disease (GERD) 1

Special Considerations

Liver Disease

• Patients with compensated advanced chronic liver disease/compensated cirrhosis may be considered for bariatric surgery but require careful evaluation by a multidisciplinary team 1
• For patients with advanced fibrosis, improvement may be limited even with significant weight loss 1
• Bariatric surgery is not recommended as a primary surgery for NASH treatment 2
• The effectiveness and safety of bariatric surgery have not been established in patients with severe liver fibrosis or cirrhosis 2

Obesity with Decompensated Cirrhosis

• In patients with obesity with decompensated cirrhosis and BMI >35, bariatric surgery should be considered only at the time of liver transplantation or thereafter 2
• Sleeve gastrectomy is the technique of choice in selected patients with obesity with well-compensated cirrhosis or in the setting of liver transplantation 2

Benefits of Bariatric Surgery

Bariatric surgery provides significant benefits beyond weight loss:

• Substantial and sustained weight loss (approximately 25-30% at 1-2 years) 2, 3
• Improvement or resolution of obesity-related comorbidities:
  • Type 2 diabetes remission or improvement
  • Hypertension improvement
  • Sleep apnea reduction
  • Dyslipidemia improvement 2, 3
• Reduced risk of malignant tumors, acute cerebrovascular events, and all-cause mortality 2
• Enhanced quality of life and increased longevity 2

Limitations and Risks

Despite its benefits, bariatric surgery has important limitations:

• 20-30% of patients may experience suboptimal clinical response (less than 20% total weight loss) or recurrent weight gain 2
• Potential risks include surgical complications and nutritional deficiencies 2
• Perioperative mortality rates range from 0.03% to 0.2% 3
• Long-term success depends on adherence to adjunctive interventions (nutrition therapy, physical activity, behavioral interventions) 2

Referral Process

Healthcare professionals should:

• Refer potentially eligible individuals to specialized centers with multidisciplinary teams capable of providing long-term follow-up and support 2
• Ensure patients undergo comprehensive preoperative evaluation, including assessment for type 2 diabetes and related complications 2
• Consider prediction scales to identify patients who may benefit most from metabolic and bariatric surgery 2

Conclusion

Bariatric surgery represents the most effective treatment for morbid obesity and its related comorbidities when non-surgical approaches have failed. The decision to proceed should be based on a careful assessment of the individual's BMI, comorbidities, and risk factors, with referral to specialized centers that can provide comprehensive multidisciplinary care and long-term follow-up.