Evaluation of current eligibility criteria for bariatric surgery: diabetes prevention and risk factor changes in the Swedish obese subjects (SOS) study.

OBJECTIVE

Patients with a BMI <35 kg/m(2) and patients with a BMI between 35 and 40 kg/m(2) without comorbidities are noneligible by current eligibility criteria for bariatric surgery. We used Swedish obese subjects (SOS) to explore long-term outcomes in noneligible versus eligible patients.

RESEARCH DESIGN AND METHODS

The SOS study involved 2,010 obese patients who underwent bariatric surgery (68% vertical-banded gastroplasty, 19% banding, and 13% gastric bypass) and 2,037 contemporaneously matched obese controls receiving usual care. At inclusion, the participant age was 37-60 years and BMI was ≥34 kg/m(2) in men and ≥38 kg/m(2) in women. The effect of surgery was assessed in patients that do (n = 3,814) and do not (n = 233) meet current eligibility criteria. The date of analysis was 1 January 2012. The follow-up time was up to 20 years, with a median of 10 years.

RESULTS

Cardiovascular risk factors were significantly improved both in noneligible and eligible individuals after 10 years of follow-up. Surgery reduced the diabetes incidence in both the noneligible (adjusted hazard ratio 0.33 [95% CI 0.13-0.82], P = 0.017) and eligible (0.27 [0.22-0.33], P < 0.001) groups. We could not detect a difference in the effect of surgery between the groups (adjusted interaction P value = 0.713).

CONCLUSIONS

Bariatric surgery drastically reduced the incidence of type 2 diabetes both in noneligible and eligible patients and improved cardiovascular risk factors in both groups. Our results show that strict BMI cutoffs are of limited use for bariatric surgery prioritization if the aim is to prevent diabetes and improve cardiovascular risk factors.