Predictors of type 2 diabetes remission in the Diabetes Remission Clinical Trial (DiRECT).

AIM: To identify predictors of type 2 diabetes remission in the intervention arm of DiRECT (Diabetes Remission Clinical Trial). METHODS: Participants were aged 20-65 years, with type 2 diabetes duration of <6 years and BMI 27-45 kg/m2 , and were not receiving insulin. Weight loss was initiated by total diet replacement (825-853 kcal/day, 3-5 months, shakes/soups), and weight loss maintenance support was provided for 2 years. Remissions (HbA1c <48 mmol/mol [<6.5%], without antidiabetes medications) in the intervention group (n = 149, mean age 53 years, BMI 35 kg/m2 ) were achieved by 68/149 participants (46%) at 12 months and by 53/149 participants (36%) at 24 months. Potential predictors were examined by logistic regression analyses, with adjustments for weight loss and effects independent of weight loss. RESULTS: Baseline predictors of remission at 12 and 24 months included being prescribed fewer antidiabetes medications, having lower triglyceride and gamma-glutamyl transferase levels, and reporting better quality of life with less anxiety/depression. Lower baseline HbA1c was a predictor at 12 months, and older age and male sex were predictors at 24 months. Being prescribed antidepressants predicted non-remission. Some, but not all effects were explained by weight loss. Weight loss was the strongest predictor of remission at 12 months (adjusted odds ratio per kg weight loss 1.24, 95% CI 1.14, 1.34; P < 0.0001) and 24 months (adjusted odds ratio 1.23, 95% CI 1.13, 1.35; P <0.0001). Weight loss in kilograms and percentage weight loss were equally good predictors. Early weight loss and higher programme attendance predicted more remissions. Baseline BMI, fasting insulin, fasting C-peptide and diabetes duration did not predict remission. CONCLUSIONS: Other than weight loss, most predictors were modest, and not sufficient to identify subgroups for which remission was not a worthwhile target.

Calorie restriction and not glucagon-like peptide-1 explains the acute improvement in glucose control after gastric bypass in Type 2 diabetes.

AIMS: To compare directly the impact of glucagon-like peptide-1 secretion on glucose metabolism in individuals with Type 2 diabetes listed for Roux-en-Y gastric bypass surgery, randomized to be studied before and 7 days after undergoing Roux-en-Y gastric bypass or after following a very-low-calorie diet. METHODS: A semi-solid meal test was used to investigate glucose, insulin and glucagon-like peptide-1 response. Insulin secretion in response to intravenous glucose and arginine stimulus was measured. Hepatic and pancreatic fat content was quantified using magnetic resonance imaging. RESULTS: The decrease in fat mass was almost identical in the Roux-en-Y gastric bypass and the very-low-calorie diet groups (3.0±0.3 and 3.0±0.7kg). The early rise in plasma glucose level and in acute insulin secretion were greater after Roux-en-Y gastric bypass than after a very-low-calorie diet; however, the early rise in glucagon-like peptide-1 was disproportionately greater (sevenfold) after Roux-en-Y gastric bypass than after a very-low-calorie diet. This did not translate into a greater improvement in fasting glucose level or area under the curve for glucose. The reduction in liver fat was greater after Roux-en-Y gastric bypass (29.8±3.7 vs 18.6±4.0%) and the relationships between weight loss and reduction in liver fat differed between the Roux-en-Y gastric bypass group and the very-low-calorie diet group. CONCLUSIONS: This study shows that gastroenterostomy increases the rate of nutrient absorption, bringing about a commensurately rapid rise in insulin level; however, there was no association with the large post-meal rise in glucagon-like peptide-1, and post-meal glucose homeostasis was similar in the Roux-en-Y gastric bypass and very-low-calorie diet groups. (Clinical trials registry number: ISRCTN11969319.).