From 1988 to 2000, the average age at diagnosis for type 2 diabetes decreased from 52 to 46 years in the Unites States, and the trend indicates that even younger mean ages of diagnosis will occur in the future [1
]. Furthermore, the number of adults diagnosed with type 2 diabetes under the age of 44 doubled from 1996 to 2006 [2
], and in 2007 it was estimated that almost 1 in 5 newly diagnosed patients with diabetes were between 20 and 39 years of age [3
]. This means that type 2 diabetes may no longer be a disease primarily of the elderly and that patients will reflect a much broader adult age range than in the past. Little work has focused on how age or stage of adult life may be associated with important aspects of diabetes and its management. Developmentally linked aspects of work, family and parenting may influence disease distress, depressive affect, disease management, and glycemic control in different ways. With a growing population of younger adult patients diagnosed with type 2 diabetes, patient age will increasingly need to be considered in the design and implementation of programs of education, support and clinical care. To date, however, little information is available about how programs tailored on the basis of age should be developed, and which age-related factors should be addressed.
The overwhelming majority of published studies have either controlled or matched for adult age, thus essentially eliminating age from analysis. Where age effects are reported in studies of type 2 patients, younger adult age has been associated with: a higher likelihood of being an ethnic minority, higher BMI, both higher and lower prevalence of depression, greater stress, poorer diet, and lower diabetes self-efficacy (e.g., [4
]). Findings regarding the relationship between age and glycemic control have been mixed, with some studies showing higher or lower HbA1c among younger than older patients (e.g., [8
]). It remains unclear whether age differences in glycemic control are due to biological factors, psychosocial factors, or both, and for which patients. However, very few of these studies have examined age effects while controlling for potentially confounding patient characteristics, such as time since diagnosis. Furthermore, little work has explored to what extent age may interact with other variables, such as patient demographics and psychosocial contextual variables, to predict glycemic control and disease management.
We examined age differences in key aspects of diabetes management, controlling for potentially confounding patient characteristics. Building on previous literature, we asked whether patient age is significantly associated with patient characteristics (behavioral self-management, stress, depressed affect, self-efficacy) and HbA1c. In exploratory analyses, we also asked if age qualifies the relation between these variables and HbA1c. Our goal was to identify patient characteristics that need to be addressed when designing and implementing programs of education and care for adult patients with type 2 diabetes of different ages.