Blood Pressure Changes Linked to Poor Brain Health in Late Adulthood
AUGUST 20, 2019
Professor Jonathan Schott
Insight 46, which is the oldest running birth cohort study in Britain, revealed high and increasing blood pressure from early adulthood into midlife appeared to be associated with increases in white matter hyperintensity volume (WMHV) and smaller brain volumes between the ages of 69 and 71 years old.
"We now know that damage caused by high blood pressure is unlikely to be driven through the hallmark Alzheimer's protein amyloid, but through changes in blood vessels and the brain's architecture,” said Jonathan Schott, professor at University College London. “The findings show that blood pressure monitoring and interventions aimed at maximizing brain health later in life need to be targeted at least by early midlife."
Insight 46, which was a substudy of the Medical Research Council National Survey of Health and Development, contained 502 participants who were followed from their birth in during the same week 1946. All participants had their blood pressure assessed at the ages of 36, 43, 53, 60 to 64, and 69 years old.
Additionally, 465 participants in the study underwent brain scans to assess their brain health. Of the 465 who underwent brain scans, 238 were men, the mean age of the group was 70.7 years, and 18% (83) were amyloid-β-positive.
Upon analyses, investigators found that higher systolic blood pressure and diastolic blood pressure at all timepoints were associated with greater WMHV but the association only reached significance after the age of 53.
In a fully-adjusted model, investigators found a 10 mm Hg increase in systolic blood pressure at 53 years of age was associated with a relative increase in mean WMHV of 7% (relative increase 1.07, 95% CI 1.01–1.24, P = 0.024). Additionally, a 10 mm Hg in tease in diastolic blood pressure at 53 years of age was associated with a 15% increase (1.15, 1.04 – 1.27, P = 0.0057) in mean WMHV.
Higher diastolic blood pressure at age 43 was associated with smaller whole-brain volume at 69 to 71 years (–6.9 mL per 10 mm Hg increase, –11.9 to –1.9, P = 0.0068). Investigators noted that greater increases in Diastolic blood pressure between 36 and 43 years of age were also associated with smaller whole-brain volume (–6.5 mL per 1 SD change, –11.1 to –1.9, P = 0.0054). Investigators also added that absolute blood pressure nor change in blood pressure predicted amyloid-β status at 69 to 71 years.
“The Insight 46 study has allowed us to reveal more about the complex relationship between blood pressure and brain health,” Schott said. “The findings suggest that blood pressure even in our 30s could have a knock-on effect on brain health four decades later.”
This study, “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,” was published online in The Lancet Neurology.