Summary: New research shows that signs of Alzheimer’s disease can already be detected in the blood of people as young as their 40s. Finnish scientists found elevated Alzheimer’s-related biomarkers in middle-aged adults, especially among those with maternal history or kidney disease.
These findings suggest that blood-based testing could one day allow earlier, more targeted prevention while symptoms are still mild. However, more research is needed to set standards and avoid misdiagnosis before blood tests become routine.
Key Facts:
- Alzheimer’s-related biomarkers appear in some people as early as ages 41–56.
- High maternal biomarker levels and kidney disease were linked to higher risk in offspring.
- Blood-based biomarker tests could become a cost-effective screening tool, pending further validation.
Source: University of Turku
A Finnish population study shows that signs related to Alzheimer’s disease may already be found in the brain in middle age. In the future, blood-based biomarkers associated with Alzheimer’s disease could allow earlier detection of the disease. This would allow preventive treatment to be targeted at the right individuals while the disease is still at the mild stage.
As the population ages, Alzheimer’s disease and other dementing diseases are becoming more common. The disease processes leading to symptoms begin years or even decades before any decline in cognitive functions, such as memory, becomes apparent.
A study conducted at the University of Turku in Finland found that even middle-aged individuals may have high levels of blood-based biomarkers associated with Alzheimer’s disease, and the levels are higher with increasing age.
A novel finding was that a high biomarker concentration in the parent, particularly mother, may be associated with higher biomarker levels in the middle-aged offspring. In addition, the researchers found that kidney disease may be linked to higher levels of biomarkers already in middle-age.
The APOE ε4 gene, which increases the risk of Alzheimer’s disease, was associated with higher blood-based biomarker levels in older age, but not yet in middle age.
A blood sample will help diagnose Alzheimer’s disease in the future
Recently, it has become possible to identify biomarkers associated with Alzheimer’s disease through a blood sample. In the future, this offers a cost-effective method for identifying those at greatest risk of developing Alzheimer’s disease and prioritising them for preventive treatments.
“In clinical practice, detecting beta-amyloid pathology associated with Alzheimer’s disease currently requires imaging studies or cerebrospinal fluid sampling. However, recently developed ultrasensitive measurement technologies now allow the detection of Alzheimer’s disease-related brain biomarkers from blood samples,” says Suvi Rovio, Senior Researcher at the Research Centre of Applied and Preventive Cardiovascular Medicine at the University of Turku, who led the study.
It is not yet possible to definitively diagnose Alzheimer’s disease with a blood sample, as the method is still limited by the lack of well-known reference values. Additionally, it remains unclear which confounding factors influence biomarker concentrations in blood related to Alzheimer’s disease. Therefore, the interpretations of the biomarkers obtained from blood sample could lead to misdiagnosis.
“In order to reliably use blood-based biomarkers for Alzheimer’s disease diagnosis in the future, more research is needed across different population and age groups to standardize reference values,” highlights Rovio.
In the study, biomarkers associated with Alzheimer’s disease were measured from blood samples of middle-aged participants (aged 41–56) and their parents (aged 59–90), with a total sample size of 2,051 individuals.
“Until now, brain biomarkers associated with Alzheimer’s disease have mainly been studied in older individuals. Our study provides new insights into biomarker levels and associated factors starting from middle age,” says Marja Heiskanen, Senior Researcher at the Research Centre of Applied and Preventive Cardiovascular Medicine at the University of Turku.
The study is part of the national Cardiovascular Risk in Young Finns Study coordinated by the Research Centre of Applied and Preventive Cardiovascular Medicine at the University of Turku in Finland.
The research results have been published in the Lancet Healthy Longevity.
About this Alzheimer’s disease research news
Author: Tuomas Koivula
Source: University of Turku
Contact: Tuomas Koivula – University of Turku
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Factors related to blood-based biomarkers for neurodegenerative diseases and their intergenerational associations in the Young Finns Study: a cohort study” by Suvi Rovio et al. Lancet Healthy Longevity
Abstract
Factors related to blood-based biomarkers for neurodegenerative diseases and their intergenerational associations in the Young Finns Study: a cohort study
Background
Blood-based biomarkers (BBM) of neurodegenerative diseases are emerging as cost-effective tools in the differential diagnostics of Alzheimer’s disease and other dementias. Scarce data exist about factors explaining BBM variation in population-based cohorts, and their intergenerational associations are unknown.
This study aimed to characterise BBM distributions among a population-based cohort, investigate the association of a wide array of factors with BBM both in midlife and old age, and investigate intergenerational associations of BBM.
Methods
We measured BBM detecting amyloid β and tau pathologies, including amyloid β42, amyloid β40, and phosphorylated Tau (pTau)-217, as well as glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) in the multigenerational Young Finns Study participants (n=1237, age 41–56 years) and their parents (n=814, age 59–90 years) using the Quanterix Simoa HD-X analyser.
Standard statistical methods were used to examine the associations between BBM and age, sex, genetic factors, a plethora of cardiometabolic markers, liver and kidney function, and lifestyle factors, as well as their intergenerational associations.
Findings
Increased age was associated with adverse BBM concentrations. Of the various investigated factors, the most robust associations towards adverse BBM concentration were found for APOE ε4 carrier status among parents (amyloid β42:40 ratio, pTau-217, and GFAP) and high serum creatinine concentration in both generations (pTau-217, GFAP, and NfL).
Several factors related to glucose metabolism and dyslipidaemia were negatively associated with all BBM, but adjusting for BMI diluted many of these associations. Statistically significant intergenerational correlations ranged from 0·20 to 0·33 and were mostly observed between mothers and offspring in pTau-217, GFAP, and NfL. No intergenerational correlations existed in amyloid β42:40 ratio.
Interpretation
We identified several factors that might influence BBM concentrations, parental transmission being one of them. For reliable use of BBM in clinical practice, it is important to identify which factors directly link to amyloid β and tau pathology and which factors influence BBM concentrations due to other physiological processes.
Funding
Research Council of Finland, Social Insurance Institution of Finland, Competitive State Research Financing of the Expert Responsibility area of the Kuopio, Tampere and Turku University Hospitals, Juho Vainio Foundation, Paavo Nurmi Foundation, Finnish Foundation for Cardiovascular Research, Finnish Cultural Foundation, The Sigrid Juselius Foundation, Tampere Tuberculosis Foundation, Emil Aaltonen Foundation, Yrjö Jahnsson Foundation, Signe and Ane Gyllenberg Foundation, Jenny and Antti Wihuri Foundation, Diabetes Research Foundation of the Finnish Diabetes Association, EU Horizon 2020, European Research Council, Tampere University Hospital Supporting Foundation, Finnish Society of Clinical Chemistry, the Jane and Aatos Erkko Foundation, and the Finnish Brain Foundation.
