Which aspects of executive dysfunction influence ability to manage diabetes in older adults?

To examine whether different aspects of executive function as measured by different assessment tools are associated with glycaemic control and other clinical characteristics in older adults with Type 2 diabetes.

We performed a cross-sectional study of older adults aged ≥ 70 years with Type 2 diabetes at a tertiary care diabetes centre. The Dysexecutive Questionnaire was used to measure self-reported executive dysfunction. Objective tests of executive functions included a modified clock drawing test (Clock-in-a-Box), Trail Making Tests (parts A and B) and verbal fluency. Demographic and clinical information was collected using questionnaires and surveys. Glycaemic control was measured by HbA(1c).

We evaluated 145 patients [average age 77 ± 5 years, diabetes duration 15 ± 11 years, mean HbA(1c) 56 ± 11 mmol/mol (7.3 ± 1.1%)]. Poor performances on objective tests (low scores on Clock-in-a-Box and verbal fluency; and high scores on Trail Making Tests A and B) but not on the subjective test (the Dysexecutive Questionnaire), were associated with poor glycaemic control (r = -0.23, P < 0.005; r = -0.17, P < 0.04; r = 0.20, P < 0.01, r = 0.22, P < 0.008, r = -0.07, P < 0.42, respectively). In a multiple regression model (r(2) = 0.39), high Dysexecutive Questionnaire scores were associated with higher diabetes-related distress (P < 0.0004), depressive symptoms (P < 0.004), number of falls (P < 0.009), fear of falling (P < 0.01), less years of education (P < 0.0007) and fewer medications (P < 0.001).

On the one hand, in older adults, executive dysfunction detected by objective tests is associated with poor glycaemic control and may be considered before prescribing complex treatment regimens. On the other hand, self-reported executive dysfunction is associated with risk and fear of falls, and more affective symptoms, which may indicate higher awareness of subtle deficits.