Resting heart rate, heart rate variability and functional decline in old age

Area of Science:

• Gerontology
• Cardiology
• Autonomic Nervous System

Background:

• Heart rate and heart rate variability are key indicators of cardiac autonomic function.
• These markers have previously been associated with cardiovascular disease.
• Their independent association with functional status in older adults requires investigation.

Purpose of the Study:

• To examine the relationship between heart rate, heart rate variability, and functional status in older adults.
• To determine if these associations persist independently of cardiovascular disease.

Main Methods:

• Utilized data from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) with 5042 participants.
• Assessed heart rate and heart rate variability (standard deviation of normal-to-normal RR intervals - SDNN) from baseline electrocardiograms.
• Measured functional status using Barthel (basic ADL) and Lawton (instrumental ADL) scales over a mean follow-up of 3.2 years.

Main Results:

• Higher baseline heart rate correlated with worse basic and instrumental activities of daily living (ADL and IADL).
• Lower SDNN was associated with poorer IADL.
• Elevated heart rate and reduced SDNN significantly predicted future decline in both ADL and IADL, independent of cardiovascular risk factors and comorbidities.

Conclusions:

• Increased resting heart rate and diminished heart rate variability are linked to poorer functional status in older adults.
• These cardiac autonomic markers predict an increased risk of future functional decline.
• Cardiac autonomic function plays a significant role in the development of functional decline in aging populations.