A longitudinal observational study of insulin therapy and glycaemic control in Scottish children with Type 1 diabetes: DIABAUD 3

Objective/background Our objective was to investigate glycaemic control in children with Type 1 diabetes in Scotland and to analyse the effect of changing 'conventional' insulin regimen strategies on outcome. DIABAUD 2 ( 1997 - 1998) (D2) demonstrated that average glycaemic control in young people with Type 1 diabetes in Scotland was poor, with mean HbA(1c) of 9.0%. Over 90% were then treated with a twice-daily insulin regimen. The aim of DIABAUD 3 ( 2002 2004) (D3) was to determine if control had improved, and to examine changes in insulin regimen and effects on glycaemic control.

Methods In DIABAUD 3, data were collected prospectively on children aged < 15 years. in nine out of 15 centres throughout Scotland. HbA(1c) on 986 subjects was measured in a single Diabetes Control and Complications Trial-aligned laboratory. The results were compared with those from DIABAUD 2, for the same nine centres. Multiple regression comparison was performed to adjust for imbalance in relevant confounders ( e. g. age, duration, height and weight, insulin dose and centre).

Results For D3, the age range was 1.1 - 14.9 years (62% aged 10 - 14 years), mean ( +/- SD) HbA(1c) 9.2% +/- 1.5 ( compared with D2, 9.0% +/- 1.5). Only 9.7% achieved the target of HbA(1c) < 7.5%. The number of subjects in D3 on twice-daily injections was 51% ( compared with 94% in D2), 43% on three-times-daily injections (2% in D2) and 2.3% on four or more (1.9% in D2): HbA(1c) did not differ in these groups. In both the D2 and D3 cohorts, HbA(1c) rose with age. After adjustment for other variables in the combined datasets, insulin regimen was not a significant predictor of HbA(1c) ( F = 0.19, d. f. = 3, 1774; P = 0.90).

Conclusion The glycaemic control in young people in Scotland remains poor and above the national target. Over 4 years, moderate intensification of insulin therapy (i.e. from two to three injections each day, usually reflecting splitting of the evening dose) across the population failed to improve the average HbA(1c) and reduce the increase seen with age. A national programme away from 'conventional' to an 'intensive' regimen of insulin therapy is required.