Glycemic Control and Blood Glucose Monitoring Over Time in a Sample of Young Australians With Type 1 Diabetes: The role of personality

OBJECTIVE

To determine whether personality traits (conscientiousness, agreeableness, emotional regulation, extraversion, and openness to experience) are associated with glycemic control and blood glucose monitoring behavior, and change or stability of these outcomes over time, in young people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

A 3-year longitudinal study was conducted using data from 142 individuals with type 1 diabetes, 8–19 years of age. Personality was assessed at baseline using the Five-Factor Personality Inventory for Children. Data relating to glycemic control (HbA_1c) and frequency of blood glucose monitoring (based on meter memory) were collected annually. Relationships between personality traits and HbA_1c and monitoring frequency were examined using regression models and mixed-design ANOVA.

RESULTS

Three of the Five-Factor domains were independently associated with glycemic control. Individuals high in conscientiousness and agreeableness had a lower and more stable HbA_1c across the 3-year study period. In contrast, the HbA_1c of individuals scoring low on these traits was either consistently worse or deteriorated over time. Low or high emotional regulation scores were also associated with worse glycemic control. By the third year, these domains, together with initial HbA_1c, accounted for 39% of HbA_1c variance. Conscientiousness was the only personality factor associated with blood glucose monitoring behavior.

CONCLUSIONS

Results of this study underline the importance of personality in contributing to diabetes outcomes. Attention to a young person’s personality, and appropriate tailoring of diabetes management to ensure an individualized approach, may help to optimize diabetes outcomes.In Australia, and many other countries, a large proportion of young people with diabetes are not reaching glycemic targets (1–6). This is likely to have life-long consequences. Indeed, those subjects who were randomized to the conventional treatment arm of the Diabetes Control and Complications Trial (7) and who had an average HbA_1c of 9.1% during the course of the study continued to develop significantly more micro- and macrovascular complications compared with the intensive group when followed up in the Epidemiology of Diabetes Interventions and Complications study. This occurred despite the rapid convergence of mean HbA_1c between the groups at the end of the active study phase (8).While there are many factors that contribute to suboptimal control, there is mounting evidence that an individual’s personality may play an important role. Several studies in the late 1980s showed that personality traits could account for substantial variability in glycemic control in school-aged children (9,10). However, there has been increasing complexity in treatment regimens since that time. For example, current treatment now involves multiple daily injections or insulin pump therapy. Today, therefore, young people and their families are required to make more complex medical decisions on a daily basis.The role of personality in these new treatment contexts is not well-understood. Personality can be understood in terms of the Five-Factor model. The Five-Factor model states that there are five broad, independent, and stable dimensions that make up an individual’s personality (11). These factors are termed conscientiousness, agreeableness, emotional regulation, extraversion, and openness to experience. Conscientiousness refers to an individual’s tendency to be reliable, perseverant, and self-disciplined. Agreeableness refers to one’s tendency to be empathetic, considerate, friendly, and helpful. Emotional regulation refers to a person’s capability to regulate their emotional responses to their environment and others. Extraversion refers to an individual’s tendency to be gregarious, assertive, and seek out social situations. Openness refers to one’s tendency to be imaginative, sensitive, and have intellectual curiosity.Recent work by Vollrath et al. (12) suggests that personality, as measured using the Five-Factor model, influences glycemic control in the first 2 years following diagnosis of type 1 diabetes. In particular, higher levels of conscientiousness and agreeableness appear to have a positive influence on management of blood glucose values, while moderate levels of emotional regulation also appear to be protective (12). Further studies are needed to confirm these relationships between personality and glycemic control and to determine whether this is ameliorated by duration of diabetes. Studies are also needed to examine the role of personality in terms of self-care behavior.Accordingly, this study was designed to answer two research questions. 1) Are Five-Factor model personality traits associated with a young person’s glycemic control, as measured by HbA_1c, and their frequency of self-monitoring of blood glucose (SMBG)? 2) Are these traits associated with change or stability in HbA_1c and SMBG over time?