Objective: The efficacy of various regimens of initial insulin treatment in poorly controlled type 2 diabetes was compared with regard to diurnal glucose variation.
Design: Randomized controlled trial. Setting. Insulin therapy initiated on hospital wards, follow-up as outpatients for 12 months.
Subjects: Fifty-two type 2 diabetic patients (HbA1c >7.5%, mean 9.8%) on maximal oral therapy. Interventions. Insulin only (IO), bedtime insulin with sulphonylurea (glipizide) (IS), or bedtime insulin with metformin (IM).
Main outcome measures: HbA1c and body weight.
Results: HbA1c decreased on average by 1.8, 1.0 and 1.5 percentage points in the IO, IS, and IM groups, respectively (p always <0.025). Body weight increased, most in the IO patients (+6.2 kg), least in the IM patients (+3.4 kg). Analysing all treatment groups combined, a similar HbA1c reduction was observed in patients with overall hyperglycaemia (low fasting plasma glucose/HbA1c ratio) and in patients with fasting hyperglycaemia (high fasting plasma glucose/HbA1c ratio). Within the overall hyperglycaemia group, the IS and IM patients had smaller decreases in HbA1c (-1.5 and -1.3 percentage points, respectively) than the IO patients (-2.7 percentage points). On the other hand, within the fasting hyperglycaemia group HbA1c reductions were -1.2, -0.8 and -1.5 percentage points, in the IO, IS, and IM groups, respectively.
Conclusion: Not all poorly controlled type 2 diabetic patients should automatically be treated with an oral agent and bedtime insulin. Two daily insulin injections is a valid choice, particularly if the patient has overall hyperglycaemia.