Cardiovascular reflex tests. Assessment of age-adjusted normal range

Area of Science:

• Cardiovascular Physiology
• Autonomic Nervous System Function
• Gerontology

Background:

• Autonomic control of heart rate and blood pressure is crucial for maintaining homeostasis.
• Aging is associated with various physiological changes, including potential alterations in autonomic function.
• Understanding age-related changes in cardiovascular reflexes is essential for accurate health assessments.

Purpose of the Study:

• To investigate the relationship between chronological age and the performance of cardiovascular reflex tests.
• To identify which specific autonomic functions are affected by aging.
• To establish age-adjusted reference values for autonomic function tests.

Main Methods:

• Cardiovascular reflex tests were administered to 70 healthy volunteers aged 25-71 years.
• Tests included R-R interval variation, heart rate change with deep breathing, 30/15 ratio, blood pressure response to standing, Valsalva ratio, and blood pressure response to sustained handgrip.
• Statistical analysis was performed to assess the correlation between age and test results, including calculation of confidence limits.

Main Results:

• Significant age-dependent declines were observed in R-R interval variation, heart rate change with deep breathing, 30/15 ratio, and blood pressure response to standing.
• The Valsalva ratio and blood pressure response to sustained handgrip showed no significant relationship with age.
• These findings indicate an age-related degradation in specific cardiovascular reflex mechanisms.

Conclusions:

• Cardiovascular reflex function, particularly related to heart rate variability and baroreflex sensitivity, deteriorates with advancing age.
• Certain autonomic tests are more sensitive to age-related changes than others.
• Implementing age-adjusted normal values is crucial for accurate interpretation of autonomic function tests in clinical practice.