A wearable-based aging clock associates with disease and behavior.

Area of Science:

• Biomarkers of aging
• Longevity research
• Digital health

Background:

• Aging clocks are crucial for understanding longevity and improving clinical interventions.
• Current aging clocks rely on clinical data (blood, vitals, imaging).
• Wearable devices offer frequent, low-cost, real-world measurements.

Purpose of the Study:

• To develop and validate PpgAge, a novel aging clock utilizing wrist-based photoplethysmography (PPG) from consumer wearables.
• To assess PpgAge's accuracy in predicting chronological age and its association with healthy aging indicators.

Main Methods:

• Development of PpgAge using PPG data from a large-scale observational study (Apple Heart & Movement Study, n=213,593).
• Analysis of the PpgAge gap (predicted age - chronological age) in relation to health outcomes and behaviors.
• Longitudinal assessment of PpgAge changes.

Main Results:

• PpgAge accurately predicts chronological age and reflects healthy aging.
• An elevated PpgAge gap correlates with increased diagnoses of heart disease, heart failure, and diabetes.
• The PpgAge gap predicts incident heart disease events, even after controlling for risk factors.
• PpgAge associates with lifestyle behaviors (smoking, exercise, sleep).
• PpgAge shows sharp increases during pregnancy and with cardiac events.

Conclusions:

• PpgAge is a non-invasive, passively collected aging clock with significant clinical potential.
• Wrist-based PPG aging clocks can identify individuals at elevated risk for chronic diseases.
• PpgAge offers a new tool for monitoring health and aging trajectories using wearable technology.