Elevated Metabolic Marker May Correlate to Cognitive Decline

A number of previous studies have linked blood pressure glucose with cognitive performance, among men and women who have dysregulated glucose metabolism. Agnes Floel, from Charite-University Medicine (Germany), and colleagues studied data collected on 141 healthy middle age and elderly community-living adults, average age 63 years. Standardize assessment was utilized to measure memory; peripheral levels of fasting hemoglobin A1C, glucose, and insulin will measured; and an MRI scan was utilized to assess hippocampal volume and microstructure.  The participants' mean glycated hemoglobin (HbA1c) levels was 5.8%. The team observed that each standard deviation increase in HbA1c was associated with decreases of 0.18 to 0.27 standard deviations in measures of delayed recall, learning ability, and memory consolidation. In turn, these changes were correlated to reductions in hippocampal volume and increased mean diffusivity within the hippocampus.  The study authors observe that: "chronically higher blood glucose levels exert a negative influence on cognition, possibly mediated by structural changes in learning-relevant brain areas."