The role of age-associated autonomic dysfunction in inflammation and endothelial dysfunction

Area of Science:

• Gerontology
• Cardiovascular Physiology
• Neuroimmunology

Background:

• Aging leads to autonomic nervous system (ANS) imbalance, characterized by sympathetic overdrive and unclear changes in parasympathetic (vagal) activity.
• Reduced vagal tone with age may diminish the cholinergic anti-inflammatory reflex, compromising immune homeostasis.
• This review examines age-related ANS alterations and their link to inflammation and endothelial dysfunction.

Purpose of the Study:

• To review mechanisms of age-related ANS dysfunction.
• To explore how ANS imbalance, assessed by MSNA and heart rate variability (HRV), promotes inflammation.
• To summarize the relationship between ANS dysfunction, inflammation, and endothelial dysfunction in aging.

Main Methods:

• Review of literature on aging, ANS function, inflammation, and endothelial function.
• Analysis of studies evaluating muscle sympathetic nerve activity (MSNA) and heart rate variability (HRV) in aging populations.
• Examination of the cholinergic anti-inflammatory reflex and its components.

Main Results:

• Aging is associated with increased muscle sympathetic nerve activity (MSNA) and potentially reduced vagal nerve activity.
• Dysfunctional cholinergic anti-inflammatory reflex in aging contributes to a pro-inflammatory state.
• ANS imbalance correlates with endothelial dysfunction, atherosclerosis, heart failure, and hypertension.

Conclusions:

• Age-related ANS dysfunction, particularly reduced vagal output, exacerbates inflammation and endothelial dysfunction.
• Heart rate variability (HRV) may predict inflammation and endothelial dysfunction in the elderly.
• Vagus nerve stimulation presents a potential therapeutic avenue for age-related cardiovascular and inflammatory conditions.