Metabolic and cardiovascular effects of very-low-calorie diet therapy in obese patients with Type 2 diabetes in secondary failure: outcomes after 1 year

Abstract

Aims: To evaluate the short-term and 1-year outcomes of an intensive very-low-calorie diet (VLCD) on metabolic and cardiovascular variables in obese patients with Type 2 diabetes (T2DM) and symptomatic hyperglycaemia despite combination oral anti-diabetic therapy +/- insulin, and to assess patient acceptability and the feasibility of administering VLCD treatment to this subgroup of patients in a routine practice setting.

Methods: Forty obese patients with T2DM (22 M, mean age 52 years, body mass index (BMI) 40 kg/m2, duration of T2DM 6.1 years) and symptomatic hyperglycaemia despite combination oral therapy (n = 26) or insulin + metformin (n = 14) received 8 weeks of VLCD therapy (750 kcal/day) followed by standard diet and exercise advice at 2-3-month intervals up to 1 year. Insulin was discontinued at the start of the VLCD, and anti-diabetic therapy was adjusted individually throughout the study, including (re)commencement of insulin as required.

Results: Immediate improvements in symptoms and early weight loss reinforced good compliance and patient satisfaction. After 8 weeks of VLCD, body weight and BMI had fallen significantly: 119 +/- 19-107 +/- 18 kg and 40.6-36.6 kg/m2, respectively, with favourable reductions in serum total cholesterol (5.9-4.9 mm), blood pressure (10/6 mmHg) and fructosamine (386 +/- 73-346 +/- 49 microm) (equates to an HbA1c reduction of approximately 1%). Sustained improvements were evident after 1 year, with minimal weight regain, e.g. mean body weight 109 +/- 18 kg and BMI 37 +/- 4 kg/m2. Glycaemic control tended to deteriorate after 1 year.

Conclusions: The absence of a control group is a major limitation, but the results indicate that 8 weeks of VLCD treatment may be effective and well tolerated in symptomatic obese patients with T2DM in secondary failure, producing sustained cardiovascular and metabolic improvements after 1 year. VLCD therapy is a treatment option that deserves greater consideration in this difficult-to-treat patient population.