Type 2 diabetes mellitus--guidelines for initiating insulin therapy

Insulin is often indicated for patients with suboptimally controlled type 2 diabetes mellitus, despite lifestyle modification and oral antidiabetic agents.

This article outlines the initiation of insulin therapy for patients with type 2 diabetes in the general practice context.

Insulin initiation options are bed time basal insulin (NPH, glargine) 10 U for patients with fasting hyperglycaemia, or twice daily premixed insulin (eg. aspart 30%/NPH 70%) 6-10 U twice per day targeting day time or postprandial hyperglycaemia. Basal insulin should be titrated regularly on a prophylactic basis (eg. fasting glucose <4.4 mmol/L: -2U, 4.4-7.0: +0 U, 7.1-10.0: +2 U, >10.0: +4 U) or increased by 1 U/day until fasting glucose of 5.5 mmol/L is reached. HbA1c changes of -1.5 to -2.5% are achievable with potential weight gain around 3 kg over 6 months. Approximately 50% of patients can achieve HbA1c or=9.5% insulin results in greater improvement in fasting glucose and HbA1c. Patients require education for blood glucose monitoring, healthy diet, exercise and identifying and responding to hypoglycaemia.