Assessment of Executive Function in Type 2 Diabetes Mellitus – A Case Control Study

Abstract

INTRODUCTION: Type2 Diabetes Mellitus is associated with inherent micro-vascular disease affecting frontal sub-cortical function. Executive Dysfunctions are implicated in decreased self-care capacity, poor adherence to diabetic medication, decreased levels of autonomy and a decrease in ability to make essential decision, for instrumental activities of daily living, as well as resistance to proper medical care. Isolated executive impairment falls within the category of mild cognitive impairment. Studies have shown that patients with Type 2 DM performs significantly poorer in Executive Function compared to normal subjects .Hence this study was proposed to assess the executive Function of Type 2 DM patients. AIM AND OBJECTIVE: To assess executive functioning in type 2 diabetic patients compared to normal subjects. METHODS: The study is a cross sectional observational case control study,conducted at the Rajiv Gandhi Government General Hospital (RGGGH), Chennai. 50 patients attending outpatient department of Diabetology, fulfilling the inclusion criteria were randomly chosen and included in the study. Fifty consenting age, sex, education matched normal people who were relatives of patients attending RGGGH OPD were taken as controls. Both the study population and controls were administered the semi structured proforma. Then GHQ and HAM D was administered to screen for psychiatric symptoms. Those who scored positively were excluded from the study. MMSE was administered as a screening tool for cognition. All diabetes mellitus patients were tested for their blood glucose level before administering the evaluation tests. This was done to avoid hypoglycemia /severe hyperglycemiaaffecting the executive function assessment. The following parameters were assessed - Proforma for socio demographic data of study cases and control group, Proforma for Diabetes Status, Mini Mental State Examination (MMSE), Test for Executive Function namely Digit Span Test,Verbal fluency , Trail making test, Stroop Test, Wisconsin Card Sorting Test. The data collected were analysed using Chi square test and Wilcoxon – Mann-Whitney U test. RESULT: Comparison of socio-demographic data of cases and controls shows no significant difference. The mean age of onset of diabetesmellitus is 41.40 years and the duration of illness was < 5 years. There was no major macro / micro vascular complication. Comparison of neuropsychological scores between cases(study group) and controls with Digit Span Test,Verbal fluency , Trail making test, Stroop Test, Wisconsin Card Sorting Test was done.In Digit Span Test,Verbal fluency, Stroop Test& Wisconsin Card Sorting Test did not show statistical significance. Trail making test showed statistical significance. CONCLUSION: Executive functioning in diabetics was comparable to that of control group. Though Trail making test, showed a statistical difference between diabetics and non-diabetic, it was still within the normative Range for the particular age group. Validation of this conclusion requires a larger group and prospective longitudinal study.