This longitudinal study appears to be a little strange! E.g. it appears they tested only for two risk factors and they did not exclude any other potential or presumed risk factors.
"Johns Hopkins University-led researchers, working with the Biomarkers for Older Controls at Risk for Dementia (BIOCARD) cohort, have found that certain factors are linked to faster brain shrinkage and quicker progression from normal thinking abilities to mild cognitive impairment (MCI). People with type 2 diabetes and low levels of specific proteins in their cerebrospinal fluid showed more rapid brain changes and developed MCI sooner than others. ...
BIOCARD was initiated at the National Institutes of Health in 1995 and continued at Johns Hopkins University from 2015 to 2023. A total of 185 participants, averaging 55 years old at the start and all cognitively normal, were selected. They underwent brain scans and tests of their cerebrospinal fluid over 20 years, measuring changes in brain structures and levels of proteins associated with Alzheimer's disease.
Findings showed that high rates of white matter shrinkage and enlargement of the brain's ventricles (fluid-filled spaces) were significant predictors of earlier MCI onset. Specifically, white matter atrophy was associated with an 86% higher risk and ventricular enlargement with a 71% higher risk of progressing to MCI. ..."
From the key points and abstract:
"Key Points
Question What factors are associated with the acceleration of brain atrophy and progression to mild cognitive impairment (MCI) based on long-term longitudinal data for individuals with normal cognition at baseline?
Findings In the cohort study, 185 participants with normal cognition underwent a mean follow-up of 20 years with brain magnetic resonance imaging scans. Type 2 diabetes and abnormal amyloid-β concentration in the cerebrospinal fluid were associated with accelerated brain atrophy and an earlier progression to MCI.
Meaning These results support the importance of identifying individuals who have accelerated brain atrophy to optimize strategies to prevent MCI.
Abstract
Importance It remains unclear which risk factors accelerate brain atrophy along with a progression from normal cognition to mild cognitive impairment (MCI).
Objective To examine risk factors associated with the acceleration of brain atrophy and progression from normal cognition to MCI based on long-term longitudinal data for middle-aged and older adults.
Design, Setting, and Participants Data for this cohort study were extracted from the Biomarkers for Older Controls at Risk for Dementia (BIOCARD) cohort, initiated at the National Institutes of Health from January 1, 1995, to December 31, 2005, and continued at Johns Hopkins University from January 1, 2015, to October 31, 2023. All participants were cognitively normal at baseline. The participants whose structural magnetic brain imaging (MRI) of the brain and cerebrospinal fluid (CSF) measures were available for over 10 years were included.
Exposures Longitudinal structural MRI of the brain and measurement of CSF biomarkers for Alzheimer disease pathology (ratio of amyloid β peptide 42 [Aβ42] to Aβ40, tau phosphorylated at threonine 181, and total tau).
Main Outcomes and Measures Annual change rates of segmental brain volumes, Kaplan-Meier survival curves plotting time to event for progression to MCI symptom onset, and hazard ratios (HRs) determined by Cox proportional hazards regression models.
Results A total of 185 participants (mean [SD] age, 55.4 [8.4] years; 116 women [63%]) were included and followed up for a maximum of 27 years (median, 20 [IQR, 18-22] years). The groups with high levels of atrophy in the white matter and enlargement in the ventricles had an earlier progression from normal cognition to MCI symptom onset (HR for white matter, 1.86 [95% CI, 1.24-2.49]; P = .001; HR for ventricles, 1.71 [95% CI, 1.19-2.24]; P = .009). Diabetes was associated with progression to MCI (HR, 1.41 [95% CI, 1.06-1.76]; P = .04), as was a low CSF Aβ42:Aβ40 ratio (HR, 1.48 [95% CI, 1.09-1.88]; P = .04), and their combination had a higher HR of 1.55 (95% CI, 1.13-1.98]; P = .03), indicating a synergic association of diabetes and amyloid pathology with MCI progression.
Conclusions and Relevance In this cohort study of middle-aged and older adults, higher rates of volume change in the white matter and ventricles, along with the presence of diabetes and a low CSF Aβ42:Aβ40 ratio, were identified as important risk factors for the progression to MCI. These results support the importance of identifying individuals who have accelerated brain atrophy to optimize preventive strategies for progression to MCI."
Acceleration of Brain Atrophy and Progression From Normal Cognition to Mild Cognitive Impairment (open access)
Figure 1. Longitudinal Changes in Brain Volumes Across Ages
No comments:
Post a Comment