Type 1 diabetes mellitus in a routine diabetes clinic: the association of psycho-social factors, diabetes knowledge and glycaemic control to insulin regime

Abstract

In controlled trials intensified diabetes therapy including multiple insulin injection regimes has been shown to improve glycaemic and microvascular disease outcomes in insulin dependent diabetes but this is not clear in routine outpatient practice. We undertook a pragmatic cross sectional study of 200 patients with Type 1 diabetes aged 18–50 years. There were 108 on two insulin injections/day (conventional) and 92 on four injections/day (multiple) with no significant difference for age, sex, social class, body mass index, diabetes duration, hypoglycaemia rate or complications prevalence. The relationship of insulin injection regime used with diabetes knowledge, psychological factors and glycaemic control outcomes was evaluated. Percent glycated HbA 1c concentrations (normal range <5.5%) were worse in the multiple injection group (7.5±1.7 vs. 6.8±1.4%, P<0.001) (mean±SD). Their scores for diabetes knowledge (72.5±8.2 vs. 69.0±9.8, P<0.01) were better but treatment satisfaction (29.9±5.1 vs. 28.5±6.1, ns) and well-being (49.1±10.7 vs. 46.5±12.7, ns) scores were not. Parameters of perceived locus of control were (multiple v conventional): personal (self), 24.5±5.0 vs. 22.3±5.9, P<0.05; medical (doctor), 11.8±5.1 vs. 10.8±5.8, ns; situational (chance), 7.9±5.1 vs. 8.9±5.9, ns. In multiple regression of HbA 1c versus multiple variables only insulin regime ( P<0.001) was significant. We conclude that in routine clinical practice the use of intensive insulin regimes are associated with worse glycaemic control despite patients being marginally more knowledgeable and self directed.