Mental disorders. It seems like everyone knows someone who suffers from one affliction or another. Some worse than others, though one can attest that dementia associated with brain aging is one of the most painful afflictions to witness. Most frequently characterized by memory loss, personality changes and impaired mental reasoning. Resulting in suffering individuals completely forgetting decades worth of their lives. It can be terrifying to witness a loved one afflicted by dementia, so studies into the causes of dementia can help improve available treatments are vital.
A study performed by Lane and colleagues looks for associations between high blood pressure and later-life brain pathologies, or illnesses. Previous studies have indicated a correlation between hypertension (high blood pressure) and dementia later in life. They follow something called a cohort of British individuals. A cohort study involves making observations and recording data about individuals born around the same time (in this case, individuals born for one week in the year 1946) and recording information throughout their lives. High blood pressure is frequently associated with negative health effects, but the long-term effects of it with regards to brain pathologies like dementia aren’t very well understood. As such, a cohort study looking for correlations between these two factors could be vital in research for dementia (and other) treatments. In the study performed by Lane and colleagues, blood pressure recordings were performed at set ages (36, 43, 53, 60–64, and 69 years) with the hope to identify correlations between blood pressure and various brain factors. Blood pressure changes between these ages were also noted, the scientists developing the study decided that the primary outcome measure (the most important outcome variable) was to be white matter hyperintensity volume (WMHV, greater volume associated with brain aging and damage) and the presence of amyloid-? proteins (higher levels associated with Alzheimers disease) as well as overall brain and hippocampal volume. A composite cognitive score was also performed, the Preclinical Alzheimer Cognitive Composite (PACC), to measure brain function at each interval.
What they found was that higher blood pressure between the ages of 43 and 53 years was positively correlated with WMHV at ages 69-71. Higher blood pressure during this period was associated with more white matter hyperintensities (associated with aging and brain damage) in old age. Individuals that expressed higher diastolic blood pressure (pressure in arteries when heart ventricles refill) at ages 36-43 had lower overall brain volume at ages 69-71. Greater increases in systolic blood pressure (pressure in arteries when the heart contracts) between ages 36-43 were also associated with lower hippocampal volumes at ages 69-71. However, overall blood pressure was not correlated with the presence of amyloid-? proteins or with scores on the PACC test at ages 69-71.
To sum up their findings, midlife seems to be the age at which blood pressure has an impact on brain structure and function in old age (69-71). As such, any interventions to help improve later life brain function would ideally need to be executed before or around ages 36-43. While marked improvements could theoretically be achieved with regards to brain structure if efforts are made to improve blood pressure earlier on in life, this isn’t a be-all-end-all solution to brain aging disorders such as dementia and Alzheimers. We still have a long way to go with regards to finding highly effective treatments or eventually a cure. Every study and every piece of information will be vital in understanding this distressing illness.
Lane, C. A., Barnes, J., Nicholas, J. M., Sudre, C. H., Cash, D. M., Parker, T. D., … & Murray-Smith, H. (2019). Associations between blood pressure across adulthood and late-life brain structure and pathology in the neuroscience substudy of the 1946 British birth cohort (Insight 46): an epidemiological study. The Lancet Neurology, 18(10), 942-952.