Refractory and new-onset diabetes more than 5 years after gastric bypass for morbid obesity.

BACKGROUND: Few studies about long-term glucose homeostasis in bariatric patients are available. In a prospective protocol that included retrospective information, outcome of patients with both impaired and normal fasting blood glucose (FBG) was monitored to assess frequencies and correlates.
METHODS: Patients submitted to Roux-en-Y gastric bypass were classified as group I, elevated FBG, and group II, normal controls. Those in group I with improvement in FBG were defined as responsive and the others as refractory. Group II participants progressing to new-onset diabetes (NOD) or prediabetes represented NOD cases; the remaining were listed as stable controls. FBG was the main endpoint, but HbA1c results were considered, along with diet composition and general biochemical profile.
RESULTS: Among 97 selected patients, 51 belonged to group I (52.4 ± 10.5 years, 29.6 % males, initial body mass index (BMI) 58.4 ± 13.4, current BMI 35.1 ± 8.4 kg/m(2)) and 46 to group II (48.2 ± 10.5 years, 19.6 % males, initial BMI 55.5 ± 8.8, current BMI 33.9 ± 6.9 kg/m(2)). Follow-up was 7-9 years, and 31.4 % (16/51) of group I were classified as refractory, whereas 15.2 % (7/46) of the controls converted to NOD. Multivariate analysis pointed out higher current BMI, older age, consumption of antidiabetic drugs, and male gender as features of refractory cases, whereas NOD participants were not significantly different from non-progressing controls.
CONCLUSIONS: This is the first investigation, to the best of our knowledge, to underscore the correlates of refractory and NOD within the bariatric context. Further studies are recommended as such information could be valuable for patient selection, prognostic scoring, and outcome monitoring.