Disturbances in carbohydrate metabolism in dementia

Several authors observed a diminished insulin sensitivity in dementia. It was proposed that dementia could be treated as a kind of diabetes type 2 expressed mainly in the brain. In insulin resistance states insulin levels in blood serum are usually elevated. In this work a group of 140 demented patients was investigated: 63 of them were diagnosed as probable Alzheimer disease (AD), 33 as dementia of vascular origin (VaD) and 44 as mixed dementia (MD) and compared with 59 individuals without dementia. Dementia was diagnosed according to DSM-IV and the kind of dementia by NINCDS-ADRDA criteria. Fasting glucose and glucose after glucose load level was determined by enzymatic method. Fasting insulin concentration was assayed using ELISA using DRG kits. Homeostasis Model Assessment (HOMA-IR) - the most frequently used index of insulin resistance was calculated. Statistically significant higher glucose levels after glucose load (impaired glucose tolerance IGT) were stated in the group of dementia as compared with controls. Elevated HOMA-IR values were more frequently observed in patients with dementia as compared with controls borderline significantly in the VaD and MD groups. The results indicate abnormal glucose metabolism expressed as IGT as well as probable glucose resistance in dementia.