Metabolic response 4 years after gastric bypass in a complete cohort with type 2 diabetes mellitus

To evaluate the long-term remission rates of type 2 diabetes mellitus and associated comorbidities after gastric bypass surgery in a complete cohort, in a real-life clinic setting.

A retrospective study of all consecutive patients with type 2 diabetes mellitus who underwent gastric bypass at a Veterans Affairs Medical Center from 2003 to 2010. The main outcome was remission of type 2 diabetes mellitus defined as HbA1c <6.5% (49 mmol/mol) without diabetic medication usage. Secondary outcomes were remission of hypertension and hyperlipidemia, weight loss, and long-term complications four years post-gastric bypass.

Eighty-four patients with type 2 diabetes mellitus underwent gastric bypass. Four-year follow-up data were available for 92% (77/84) of patients. The patients (73% male; mean age 54 years) had a mean body mass index of 49 kg/m² ± 8.3. Hypertension and hyperlipidemia prevalence were 92% and 85%, respectively. The mean total body weight decrease over four years was 35 kg ± 21. Remission of type 2 diabetes mellitus occurred in 15% at 6 months and 49% four years after surgery. Diabetes remission was more likely (OR 3.2; 95% confidence interval 1.2-9.7) in patients not using insulin at baseline. Remission rates were 12% (9/74) for hypertension and 16% (11/68) for hyperlipidemia. Long-term surgical complications included reoperation (11%), incisional hernia (10%) and anastomotic ulcer (10%). Forty-four percent of patients had one or more nutritional complications.

The metabolic effects of gastric bypass are significant and durable for at least four years, even in a predominantly male cohort and real-life clinical setting.