OBJECTIVES: The goal of the study was an evaluation of differences in working memory effectiveness between patients with type 1 and type 2DM. It was also attempted to ascertain whether the level of diabetes control is associated with working memory effectiveness.
METHODS: 62 subjects were enrolled into the study. All patients were divided into two groups: patients with type 1DM (n=31) and with type 2DM (n=31). The Trail Making Test (TMT) and the Stroop Test were used for evaluation of working memory effectiveness. Diabetes control indicators included: glycated haemoglobin (HbA1C) level, total cholesterol concentration, HDL and LDL cholesterol concentration and body mass index (BMI).
RESULTS: The patients with type 1DM obtained a significantly lower time in the execution of TMT, part B (p=0.01) and of RCNb (p=0.01) and NCWd (p=0.01) versions of the Stroop Test, while making significantly less errors in NCWd version (p=0.01). Significant correlations were demonstrated between BMI values and the rate of execution of TMT, part B (p=0.03), as well as the rate of execution of RCNb (p=0.04) and NCWd (p=0.01) versions of the Stroop Test. Total cholesterol level was significantly correlated with the rate of execution of TMT, part A (p=0.04) and B (p=0.01). No significant correlations were found between cholesterol fraction levels in blood of the studied patients and the results of performed tests, with one exception, regarding the relationship between LDL cholesterol fraction and the rate of the Stroop Test execution in RCNb version (p=0.04).
CONCLUSIONS: 1). Higher working memory efficacy was demonstrated among the patients with type 1DM vs. those with type 2DM. 2). The level of diabetes control is an influential factor for working memory effectiveness in diabetic patients.