TOPLINE:
Gastric bypass surgery for obesity is associated with a reduced risk of developing type 2 diabetes (T2D) similar to that in the general population for up to 6 years after surgery, but the risk increases again thereafter.
METHODOLOGY:
- The study included 55,534 patients (age, 20-65 years) with a principal diagnosis of obesity between 2001 and 2013 from the National Swedish Patient Registry, of whom 23,099 had and 32,435 had not undergone gastric bypass surgery.
- Each patient was matched by age, sex, and geographic region with two control individuals from the general population without obesity diagnosis (ie, n = 44,735 and n = 62,522, respectively).
TAKEAWAY:
- Over the maximum 10 years (median, 4.3 years) of follow-up, 3.9% of all participants developed T2D.
- During the first 6 years of follow-up, the T2D incidence per 1000 person-years was similar among those who had undergone gastric bypass and their matched control individuals (4.0 and 3.5, respectively).
- However, during the subsequent 6-10 years, the incidence was 7.6 (9.5% CI, 6.1-11.0) vs 4.3 (3.3-6.2), respectively.
- After adjustment for age, education, and sex, the risk of developing T2D among the operated vs non-operated patients with obesity was 85% lower during the first 6 years of follow-up (hazard ratio, 0.15; 95% CI, 0.13-0.17) and 51% lower during 6-10 years of follow-up (0.49; 0.37-0.66).
- Compared with the general population, the T2D risk in the operated group was 22% lower up to 6 years (0.78, 0.66-0.93) but was twofold higher after 6 years (2.19, 1.61-2.98).