Weight and glycaemic control in type 2 diabetes : what is the outcome of insulin initiation?

Aims: Little information is available on the association between obesity at time of insulin initiation and attainment of glycaemic targets in type 2 diabetic (T2DM) patients. This study describes changes in HbA1c, weight and body mass index (BM) over 24 months postinsulin initiation. Methods: First-time insulin users with T2DM were selected from the UK General Practice Research Database for the period 1st January 2002 to 31st March 2008. The cohort was stratified into BMI categories (kg/m(2)) at the time of insulin initiation. Data were reviewed at 6 monthly intervals. A multivariate repeated measures linear model was fitted assessing weight change over 12 months. Results: 3783 patients were included (normal weight, n = 672; overweight, n = 1259; obese, n = 1070; clinically obese, n = 480; morbidly obese, n = 302). The largest reductions in HbA1c were observed 6 months postinsulin initiation and were greatest in lower BMI categories: median observed HbA1c at initiation and 6 months yeas 9.7 and 7.9% in normal weight patients and 9.6 and 8.2% in the clinically obese, respectively. A minority of patients achieved HbA1c = 12.1%-5.55 kg (950 Cl: 3.81, 7.28). Conclusion: Obesity is associated with a poorer response to insulin illustrated by higher HbA1c values and lower achievement of targets