Biomarkers

There is substantial experimental evidence for dysregulation of several microRNA (miRNA) expression levels in Alzheimer’s disease (AD). The authors identified a set of brain-enriched miRNAs in a monocentric cohort of cognitively normal individuals with subjective memory complaints, a condition associated with increased risk of AD. They then investigated the association of clinical markers on miRNA plasma concentrations. In addition, they explored the cross-sectional and longitudinal association of the miRNAs plasma concentrations with regional brain metabolic uptake using PET imaging. The results, coupled with existing experimental evidence, suggest a potential protective anti-Aβ effect of miRNA-15b and a biological link between miRNA-125b and Aβ-independent neurotoxic pathways.

It is not clear if changes in ABeta42 are specific to Alzheimer’s disease dementia or if they are also seen in other types of dementia. It is possible that ABeta42 could help differentiate Alzheimer’s disease dementia from other dementia subtypes. In this systematic review, applying ABeta42 thresholds, specificity and sensitivity values were calculated where Alzheimer’s disease dementia may be distinguished from other dementia subtypes. The review indicated that measuring ABeta42 levels in CSF may help differentiate Alzheimer’s disease dementia from other dementia subtypes, but can misdiagnose. The authors caution against the use of CSF ABeta42 alone for dementia classification but suggest using it as an adjunct to a full clinical assessment.

This study evaluated the influence of insulin resistance on brain glucose metabolism, grey matter volume and white matter lesions in non-diabetic Alzheimer’s disease subjects. In non-diabetic Alzheimer’s disease, peripheral insulin resistance is independently associated with reduced hippocampal glucose metabolism and with lower grey matter volume, suggesting that peripheral insulin resistance might influence Alzheimer’s disease pathology by its action on cerebral glucose metabolism and on neurodegeneration.

The aim of the study was to investigate the effect of amyloid/tau/neurodegeneration (ATN) staging on neuropsychological profiles and atrophy patterns within the European Prevention of Alzheimer’s Dementia (EPAD) cohort. A description of the cohort and related biomarkers according to ATN staging is given.

Multiple chronic health conditions commonly coexist simultaneously, this is referred to as multimorbidity. Cases of multimorbidity have been increasing in recent years, partially due to an ageing population. In light of this, research has begun to focus on ways of better understanding multimorbidity. Measuring multimorbidity is tricky, as a simple count of the number of conditions proves to be too simplistic and does not account for factors such as the severity of the conditions. Accordingly, some measurement indices combine a count of chronic conditions with more informative information.

This systematic review identified multimorbidity indices which include more than a simple disease count, with a particular focus on those which included information on mental health. After reviewing more than 5000 research papers, 35 measures were identified which fit the description. Each of these measurement indices measure multimorbidity in slightly different, but equally valid ways. This review’s outcomes provide valuable information for clinicians and researchers who require an effective measure of multimorbidity.