Findings from the multisite IGNITE clinical trial indicate that arterial stiffness — a condition in which large blood vessels lose their natural elasticity — may heighten the impact of nerve fibre injury in the brains of older adults who are not yet showing signs of cognitive impairment. This relationship is drawing growing attention because it may help clinicians recognise individuals who are more vulnerable to future memory and thinking problems long before symptoms appear. As researchers increasingly investigate how vascular health influences brain ageing, the interplay between stiffened arteries and subtle neurological changes is emerging as a key area of interest.
The study, published in Alzheimer’s & Dementia, followed 570 cognitively unimpaired older adults. It focused on neurofilament light chain (NfL), a blood biomarker that reflects damage to nerve fibres in the brain. Although NfL levels rise naturally with age, unusually elevated levels can signal accelerated neural ageing or increased risk of cognitive decline. By measuring plasma NfL, the researchers aimed to detect biological signs of brain vulnerability that might not yet be evident through behaviour or clinical assessment.
To assess vascular health, the team used carotid–femoral pulse wave velocity, a widely accepted measure of arterial stiffness. Healthy arteries expand and contract with each heartbeat, cushioning pressure and ensuring stable blood flow. Stiff arteries, however, lose this capacity and transmit greater force to the organs they supply. Because the brain relies on exceptionally steady blood circulation, even modest disruptions can gradually contribute to injury. Over time, these changes may influence how effectively the brain processes and stores information.
The results showed that greater arterial stiffness was associated with poorer cognitive performance, particularly in episodic memory, working memory and processing speed. These domains are crucial for daily functioning, and even slight declines can signal broader vulnerabilities. The most striking finding was that individuals with both high arterial stiffness and elevated NfL showed the strongest association with memory difficulties. In this subgroup, higher NfL was associated with significantly worse memory outcomes, suggesting that stiffened arteries may amplify the effects of nerve fibre injury on the brain.
Although these findings highlight a potentially significant interaction, the study’s cross-sectional design does not establish cause and effect. Longitudinal research will be necessary to determine whether improving vascular health — for example, by treating hypertension or high cholesterol — can modify the relationship between nerve fibre damage and cognitive performance. Nonetheless, the results offer a valuable early indication that vascular and neurological factors may work together to influence cognitive ageing.
Several investigators emphasised the broader implications. Lewis A. Lipsitz, MD, noted that healthy brain ageing depends not only on preventing nerve fibre damage, but also on maintaining the condition of the blood vessels that nourish the brain. Lead author Amani M. Norling, PhD, stressed that dual monitoring of NfL and vascular health may help identify individuals at elevated risk. Senior author Kirk Erickson, PhD, added that understanding why some people decline faster than others remains a central challenge in ageing research, and studies like IGNITE bring the field closer to targeted therapies.
For many older adults, early cognitive changes are challenging to detect, yet the groundwork for decline may form long beforehand. This study offers promising evidence that protecting vascular health could play a meaningful role in preserving memory and cognitive function as people age.
More information: Amani M. Norling et al, Arterial stiffness moderates the link between NfL and cognition: The IGNITE study, Alzheimer’s & Dementia. DOI: 10.1002/alz.70554
Journal information: Alzheimer’s & Dementia Provided by Hebrew SeniorLife Hinda and Arthur Marcus Institute for Aging Research
