Carbohydrate restricted diet in conjunction with metformin and liraglutide is an effective treatment in patients with deteriorated type 2 diabetes mellitus: Proof-of-concept study

BACKGROUND: Type 2 diabetes mellitus is a chronic progressive disease. During the course of the disease intensive treatment is often necessary resulting in multiple interventions including administration of insulin. Although dietary intervention is highly recommended, the clinical results of the widely prescribed diets with low fat content and high carbohydrates are disappointing. In this proof-of-concept study, we tested the effect of dietary carbohydrate-restriction in conjunction with metformin and liraglutide on metabolic control in patients with type 2 diabetes. METHODS: Forty patients with type 2 diabetes already being treated with two oral anti-diabetic drugs or insulin treatment and who showed deterioration of their glucose metabolism (i.e. HbA1c >7.5), were treated. A carbohydrate-restricted diet and a combination of metformin and liraglutide were instituted, after stopping either insulin or oral anti-diabetic drugs (excluding metformin). After enrollment, the study patients were scheduled for follow-up visits at one, two, three and six months. Primary outcome was glycemic control, measured by HbA1c at six months. Secondary outcomes were body weight, lipid-profile and treatment satisfaction. RESULTS: Thirty-five (88%) participants completed the study. Nearly all participating patients experienced a drop in HbA1c and body weight during the first three months, an effect which was maintained until the end of the study at six months. Seventy-one percent of the patients reached HbA1c values below 7.0%. The range of body weight at enrollment was extreme, reaching 165 kg as the highest initial value. The average weight loss after 6 months was 10%. Most patients were satisfied with this treatment. During the intervention no significant change of lipids was observed. Most patients who were on insulin could maintain the treatment without insulin with far better metabolic control. CONCLUSIONS: Carbohydrate restriction in conjunction with metformin and liraglutide is an effective treatment option for patients with advanced diabetes who are candidates for instituting insulin or who are in need of intensified insulin treatment. This proof-of-principle study showed a significant treatment effect on metabolic control.