Summary: New research links high blood pressure beginning in a person’s thirties and early forties with smaller overall brain volume and a higher risk of developing dementia later in life.
Source: American Heart Association
People diagnosed with hypertension between ages 35 and 44 had smaller brain volumes and a greater likelihood of developing dementia than matched peers with normal blood pressure, according to a study published in Hypertension.
The findings suggest that preventing or delaying the onset of high blood pressure in young adulthood could be a strategy to reduce dementia risk decades later.
“Hypertension is common in middle age, and early-onset high blood pressure appears to be increasing. While prior work has linked hypertension with poorer brain health and higher dementia risk, the impact of the age when hypertension begins was unclear. If earlier onset proves harmful, it supports more aggressive prevention or treatment earlier in life,” said Mingguang He, M.D., Ph.D., senior author of the study and professor of ophthalmic epidemiology at the University of Melbourne.
Researchers used data from the UK Biobank, a large health database of roughly half a million volunteers in the United Kingdom, to examine the relationship between age at hypertension diagnosis, brain structure on MRI, and later dementia diagnoses.
For the brain-imaging portion, investigators compared MRI measures of brain volume across two matched groups: 11,399 adults diagnosed with high blood pressure at different age ranges (younger than 35; 35–44; and 45–54) and 11,399 adults without a hypertension diagnosis, matched for age and other health factors. Participants entered the biobank between 2006 and 2010 and underwent brain MRI between 2014 and 2019. Hypertension was defined by a reported medical diagnosis or inpatient records using diagnostic codes. The analysis controlled for measured blood pressure at the time of the MRI scans.
Key MRI findings included:
- Across the diagnostic age categories from 35 to 54, individuals with a history of hypertension had smaller total brain volumes and reduced volume in several brain regions compared with participants without hypertension;
- The largest reductions in brain volume were observed in those diagnosed before age 35 compared with matched controls; and
- Even among participants with normal blood pressure at the time of imaging, those previously diagnosed with hypertension before age 35 showed smaller total brain volume than never-diagnosed peers with normal blood pressure.
“Those diagnosed with hypertension at younger ages already showed smaller brain volumes on these single-timepoint scans. Longitudinal imaging that tracks brain volume over time will be needed to determine whether early-onset hypertension is linked to faster brain volume decline,” said Xianwen Shang, Ph.D., M.P.H., lead author and research fellow at Guangdong Provincial People’s Hospital in Guangzhou, China.
To assess dementia outcomes, the team followed 124,053 people with hypertension and 124,053 matched adults without hypertension for up to 14 years (median follow-up 11.9 years). During that period, 4,626 participants developed dementia from any cause. The researchers analyzed dementia incidence by age at hypertension diagnosis and reported the following:
- Individuals diagnosed with hypertension between ages 35 and 44 had a 61% higher risk of dementia from any cause compared with participants without hypertension;
- The risk of vascular dementia was 69% higher for those diagnosed with hypertension at 35–44 and 45% higher for diagnoses at 45–54, compared with same-age participants without hypertension;
- Although vascular dementia risk appeared 80% higher for hypertension diagnosed before age 35, fewer dementia cases occurred in that youngest group and the association did not reach statistical significance in this sample; and
- No association was found between age at hypertension diagnosis and risk of Alzheimer’s disease in this analysis.
“Our results link an earlier age at hypertension onset with later dementia and support this association with structural brain changes,” said Shang. “These findings highlight the potential value of preventing or controlling high blood pressure early in adulthood to reduce dementia risk.”
Mingguang He added, “Screening to identify early hypertension and offering earlier, more intensive blood pressure management could help lower the future burden of dementia.”
The investigators plan further work to review medical records and determine whether dementia onset in people with early- or midlife hypertension was preceded by other conditions known to raise dementia risk, such as diabetes or stroke. The study population was predominantly White, and the authors caution that results may not generalize to all racial or ethnic groups.
Co-authors include Edward Hill, Ph.D.; Zhuoting Zhu, M.D., Ph.D.; Jiahao Liu, B.Sc.; Zongyuan Ge, Ph.D.; and Wei Wang, M.D., Ph.D. Authors’ disclosures are available in the published manuscript.
Funding: The research was supported by the Fundamental Research Funds of the State Key Laboratory of Ophthalmology, the Project of Investigation of Health Status of Employees of Financial Industry in Guangzhou, China, and the Science and Technology Program of Guangzhou, China.
About this neurology research news
Author: William Westmoreland
Source: American Heart Association
Contact: William Westmoreland – American Heart Association
Image: The image is in the public domain
Original Research: The study will appear in Hypertension