HRV & Aging

Methods

UK Whitehall II cohort longitudinal follow-up with cognitive testing

Key Findings

• Low RMSSD: cognitive decline 3 years faster per decade
• Low HF-HRV: cognitive decline 3.5 years faster per decade
• Low RMSSD: 37% higher odds of low cognitive function
• HRV in midlife predicts long-term cognitive trajectory

Limitations

Observational study, predominantly white-collar workers

Methods

Cross-sectional analysis of older adults in Einstein Aging Study

Key Findings

• Higher HF-HRV associated with better global cognition
• Lower HF-HRV associated with mild cognitive impairment
• Extends prior findings on HRV as early dementia indicator
• Community-based cohort increases generalizability

Limitations

Cross-sectional design

Methods

Longitudinal follow-up of 14 centenarians with HRV measurements until death

Key Findings

• SDNN correlated with survival prognosis in centenarians (ρ = 0.536)
• SDNN < 19ms associated with death within 1 year
• Low-HRV group survived 0.6 years vs 1.6 years for high-HRV group
• Mortality risk 5x higher in low-HRV centenarians
• HRV remains predictive even at extreme ages

Limitations

Small sample size, observational design

Methods

Prospective study with 7-year median follow-up comparing phenotypic HRV to genetic risk scores

Key Findings

• Lower phenotypic HRV associated with higher mortality risk
• Genetically predicted HRV not associated with mortality
• Suggests lifestyle factors more important than genetics
• HRV is modifiable and modification may impact longevity

Limitations

Genetic scores may not capture all HRV-related variants

Methods

Literature review of HRV and cognitive function studies

Key Findings

• Higher HRV associated with better executive function
• Vagal tone supports prefrontal cortex activity
• Low HRV linked to cognitive impairment and dementia risk
• Relationship holds across age groups
• Interventions improving HRV may support cognition

Limitations

Bidirectional relationship, causation unclear

Methods

Cross-sectional analysis of HRV data from 296,000+ participants

Key Findings

• Steepest HRV decline occurs between ages 20-40
• Men have higher RMSSD than women until approximately age 50
• Decline rate slows after age 50 in both sexes
• HRV coefficient of variation increases with age in males after 40

Limitations

Cross-sectional design cannot establish individual trajectories

Methods

Review of long-term studies on HRV and health outcomes

Key Findings

• 24-hour SDNN < 50ms associated with higher mortality
• Low HRV predicts cardiovascular events independently of other risk factors
• Association holds across age groups
• Short-term RMSSD also predictive but less studied for mortality

Limitations

Most studies in populations with existing heart disease

Methods

Prospective study of 501 twins with 24-hour Holter ECG monitoring

Key Findings

• HRV predicted mortality independent of genetic factors
• Deceleration capacity showed strongest mortality association
• Effect persisted after controlling for traditional CVD risk factors
• Suggests HRV reflects brain-heart-autonomic network health

Limitations

All-male veteran population