Liraglutide normalised glucose tolerance and the response of insulin to glucose in a non-obese patient with newly diagnosed type-2 diabetes mellitus

Medical examination of a 60-year-old non-obese female revealed a fasting plasma glucose concentration of 220 mg/dl and a glycated haemoglobin (HbA1c) level of 7.6 %. Because a 75-g oral glucose tolerance test (75-g OGTT) demonstrated fasting and post-prandial hyperglycaemia (>200 mg/dl), she was diagnosed with type-2 diabetes mellitus. Four days after hospitalisation, treatment with the glucagon-like peptide-1 analogue liraglutide was started. The M value, which reflects daily variations in plasma glucose levels, was markedly improved on days 3 and 14 of treatment (12.8 and 0.43, respectively). Her HbA1c level was consistently ≤5.8 % after discharge. OGTT revealed normal glucose levels (<140 mg/dl at 120 min) at 3, 14, and 24 months of liraglutide treatment. The insulinogenic index (μU/ml/mg/dl) increased from 0.067 before treatment to 0.20, 0.44, and 0.48 at 3, 14, and 24 months of treatment, respectively. The proinsulin/C-peptide immunoreactivity ratio, which reflects pancreatic β-cell failure, decreased from 0.03 before treatment to 0.025, 0.016, and <0.01 at 3, 14, and 24 months of treatment, respectively. The woman reported no side effects during liraglutide treatment. In conclusion, early administration of liraglutide was beneficial in our patient in terms of improving glycaemic control and protecting pancreatic β cells from glucotoxicity.