The Effect of Diabetes Type 2, the Metabolic Syndrome and Co-existing Risk Factors on Cognitive Functioning within the Elderly Population

Abstract

BACKGROUND: Type 2 diabetes mellitus is a metabolic disease with a rapidly rising prevalence. Recently, diabetes mellitus type 2 has been associated with cognitive decrement. The onset and the course of the development of the cognitive decrement within the diabetic population is still unknown. The influence of co-existing risk factors on cognition within a diabetic population has not been examined before. METHODS: In this study participants with diabetes mellitus type 2 (n=74), participants with the metabolic syndrome (n=99), a pre-diabetic stage, and control subjects (n=115) underwent neuropsychological and medical tests. The performance of the groups are compared on 5 cognitive domains; abstract reasoning, attention executive functioning, information processing speed, memory and visuo-construction. In the second part of the study the independent impact of vascular and metabolic risk factors associated with diabetes mellitus type 2 on cognition in a population sample (n=377) study will be examined. RESULTS: The group with diabetics performed worse than control subjects on several cognitive domains. The metabolic syndrome group also performed worse than healthy subjects, but performed better than the diabetics. The risk factors HbA1c and blood pressure were negatively related to performance on several cognitive domains. CONCLUSION: The decay in cognitive functioning already commences in the pre-diabetic stage, when mainly vascular risk factors are present. Not one risk factor can be held responsible for the cognitive decrement. Both vascular and metabolic risk factors seem to have a part in this process.