Even ‘Elevated’ Blood Pressure Raises Dementia Risk: Insights from 2.8 Million Adults Over 8 Years

Highlights

This nationwide cohort study provides compelling evidence that even blood pressure levels previously considered “borderline”—now classified as elevated blood pressure by the 2024 European Society of Cardiology guidelines—carry significant implications for long-term brain health.

The investigation of 2.8 million South Korean adults tracked over 8.1 years revealed several critical findings: Hypertension was associated with a 3% increased risk of all-cause dementia, while elevated blood pressure showed a 16% increased risk specifically for vascular dementia. Women and middle-aged individuals demonstrated particularly pronounced vulnerability to these cognitive risks.

The absence of significant associations with Alzheimer’s disease dementia suggests that blood pressure management may be most consequential for vascular pathways leading to cognitive decline.

Background: Reframing Blood Pressure Categories

The relationship between cardiovascular health and cognitive decline has long been recognized in clinical medicine. Hypertension stands as one of the most modifiable risk factors for dementia, yet the precise thresholds at which blood pressure begins to confer neurological risk have remained subjects of ongoing debate.

In 2024, the European Society of Cardiology introduced a refined blood pressure classification system that created a new intermediate category: elevated blood pressure, defined as systolic blood pressure of 120-139 mmHg or diastolic blood pressure of 70-89 mmHg. This category sits between non-elevated blood pressure and hypertension, challenging previous binary conceptualizations of cardiovascular risk.

The clinical significance of this reclassification extends beyond theoretical categorization. If elevated blood pressure—previously often dismissed as within normal limits—indeed carries meaningful risk for adverse neurological outcomes, the implications for preventive strategies would be substantial.

Dementia represents one of the most pressing global health challenges, with the World Health Organization estimating that over 55 million people worldwide currently live with this condition. As populations age, identifying modifiable risk factors that can be addressed early in the disease trajectory becomes increasingly urgent.

Study Design: A Nationwide Investigation

Researchers from South Korean institutions conducted a retrospective cohort study utilizing the Korean National Health Insurance Service database, one of the most comprehensive population health datasets globally. The analysis included 2,802,364 adults aged 40 years and older who underwent national health screening examinations in 2009.

Several exclusion criteria ensured the study captured incident dementia rather than pre-existing or recently diagnosed cases. Participants with prior dementia diagnoses or those receiving dementia diagnoses within the first year of follow-up were excluded, minimizing the potential for reverse causation where preclinical cognitive changes might influence blood pressure measurements.

Blood pressure classification followed the 2024 ESC guidelines precisely:

Non-elevated blood pressure was defined as systolic blood pressure below 120 mmHg and diastolic blood pressure below 70 mmHg. Elevated blood pressure encompassed systolic readings of 120-139 mmHg or diastolic readings of 70-89 mmHg. Hypertension was classified as systolic blood pressure of 140 mmHg or higher, diastolic blood pressure of 90 mmHg or higher, or current antihypertensive medication use.

The study population was then stratified into three groups based on these definitions. Incident dementia—including Alzheimer’s disease dementia, vascular dementia, and all-cause dementia—was tracked through December 2018, providing a mean follow-up period of 8.1 years.

Cox proportional hazards models calculated adjusted hazard ratios, controlling for potential confounders including age, sex, socioeconomic factors, baseline health conditions, and lifestyle variables.

Key Findings: Elevated Blood Pressure and Dementia Risk

During the observation period, 121,223 incident dementia cases were identified among the study population. The findings revealed nuanced patterns of risk that varied by blood pressure category, dementia subtype, age group, and sex.

All-Cause Dementia

Compared with the non-elevated blood pressure reference group, participants with elevated blood pressure demonstrated a modest but directionally consistent increase in dementia risk, with an adjusted hazard ratio of 1.016 and a 95% confidence interval spanning from 0.996 to 1.037. While the confidence interval marginally crossed unity, suggesting statistical uncertainty, this trend warrants clinical attention.

The hypertension group showed statistically significant elevated risk, with an adjusted hazard ratio of 1.029 (95% CI 1.006-1.051), representing approximately a 3% increase in dementia risk compared to those with non-elevated blood pressure.

Vascular Dementia: The Strongest Signal

The most striking associations emerged for vascular dementia, a form of cognitive impairment directly attributable to cerebrovascular pathology. Among individuals with elevated blood pressure, the adjusted hazard ratio for vascular dementia reached 1.159 (95% CI 1.046-1.285), indicating a 16% increased risk.

Those with hypertension demonstrated even more pronounced vulnerability, with an adjusted hazard ratio of 1.372 (95% CI 1.245-1.512) for vascular dementia—representing a 37% increase in risk compared to the non-elevated blood pressure group.

These findings align with established pathophysiological understanding: chronic elevation in blood pressure damages cerebral microvasculature, promotes small vessel disease, and creates conditions conducive to ischemic brain injury.

Alzheimer’s Disease Dementia: No Significant Association

Perhaps unexpectedly, neither elevated blood pressure nor hypertension showed statistically significant associations with Alzheimer’s disease dementia in this study. The adjusted hazard ratios for elevated blood pressure and hypertension in relation to Alzheimer’s disease were 1.013 (95% CI 0.984-1.042) and 1.004 (95% CI 0.974-1.035) respectively.

This differential pattern suggests that blood pressure-mediated dementia risk operates primarily through vascular mechanisms rather than through pathways traditionally associated with Alzheimer’s pathology, such as amyloid accumulation.

Effect Modification by Age and Sex

The study identified important heterogeneities in risk across demographic subgroups. The associations between blood pressure categories and dementia outcomes were more pronounced among middle-aged adults compared to older participants, highlighting midlife as a critical window for intervention.

Women also demonstrated stronger blood pressure-dementia associations compared to men, suggesting potential sex-specific vulnerabilities that may relate to hormonal factors, differential healthcare utilization, or biological differences in vascular aging.

Expert Commentary: Interpreting the Clinical Implications

These findings carry substantial weight for clinical practice and public health policy. The validation of the 2024 ESC blood pressure classification system through this large-scale investigation provides empirical support for the guideline committee’s decision to recognize elevated blood pressure as a distinct risk category.

The magnitude of association for vascular dementia is particularly noteworthy. A 37% increased risk with hypertension and a 16% increased risk with elevated blood pressure represent clinically meaningful effect sizes that should prompt consideration of more aggressive preventive strategies.

Several mechanisms may explain the observed associations. Chronic hypertension promotes atherosclerosis in large and medium-sized cerebral arteries, damages the blood-brain barrier, and leads to white matter hyperintensities visible on magnetic resonance imaging. These structural changes accumulate over years, explaining why midlife blood pressure may be especially predictive of late-life cognitive outcomes.

The absence of significant associations with Alzheimer’s disease dementia is consistent with some but not all prior literature. While midlife hypertension has been linked to Alzheimer’s disease risk in several cohort studies, the relationship appears weaker and less consistent than that observed for vascular dementia.

Limitations of this study warrant acknowledgment. The use of single baseline blood pressure measurements may not capture long-term blood pressure trajectories or temporal variations. The observational design precludes causal inference, and residual confounding by unmeasured factors remains possible. Additionally, the Korean population may not be directly generalizable to other ethnic and geographic contexts.

Despite these limitations, the study’s major strengths—its enormous sample size, lengthy follow-up period, and comprehensive adjustment for confounding variables—provide robust evidence that should inform clinical decision-making.

Conclusion: Implications for Prevention

This landmark investigation establishes that blood pressure categories as defined by the 2024 ESC guidelines carry differential implications for dementia risk. Both elevated blood pressure and hypertension increase the likelihood of cognitive decline, with effects most pronounced for vascular dementia.

The findings reinforce the importance of blood pressure monitoring and management across the adult lifespan, with particular attention warranted during midlife. Women and middle-aged individuals emerge as priority populations for early intervention strategies.

From a public health perspective, these results support broader screening initiatives targeting blood pressure elevation before it progresses to hypertension. Lifestyle modifications including dietary changes, regular physical activity, and stress management may provide benefit even at the elevated blood pressure stage.

The separation of dementia subtypes by vascular and Alzheimer’s pathways provides mechanistic clarity that can guide both clinical practice and future research directions. As the global burden of dementia continues to grow, identifying and addressing modifiable risk factors such as blood pressure represents one of the most promising avenues for reducing this burden.

Further research is needed to determine whether early intervention at the elevated blood pressure stage can reverse or mitigate cognitive risk, and whether sex-specific approaches to blood pressure management may optimize outcomes for women.

References

Jung YH, Kim J, Han KD, Lee JY, Cheon DY, Lim JS, Lee M. Dementia risk across blood pressure categories: a South Korean nationwide study. European Heart Journal. 2026 Apr 7;47(14):1688-1698. PMID: 41165161.

Williams B, Mancia G, Spiering W, et al. 2018 ESC/ESH Guidelines for the management of arterial hypertension. European Heart Journal. 2018;39(33):3021-3104.

Livingston G, Huntley J, Sommerlad A, et al. Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. Lancet. 2020;396(10248):413-446.

Iadecola C, Yaffe K, Biller J, et al. Impact of hypertension on cognitive function: a scientific statement from the American Heart Association. Hypertension. 2016;68(6):e67-e94.