No correlation between circulating ACE activity and VO2max or mechanical efficiency in women

Area of Science:

• Exercise Physiology
• Human Genetics
• Cardiovascular Research

Background:

• The angiotensin-1 converting enzyme (ACE) I/D polymorphism is linked to varying ACE activity levels.
• Previous research suggests a potential association between ACE genotype and endurance phenotypes.
• Systemic ACE activity's role in regulating endurance performance remains unclear.

Purpose of the Study:

• To investigate the relationship between circulating ACE activity, ACE I/D genotype, mechanical efficiency, and maximal oxygen uptake.
• To analyze these associations in a cohort of sedentary women.
• To determine if ACE activity or genotype influences endurance phenotypes.

Main Methods:

• Sixty-two untrained women underwent submaximal cycle ergometry for mechanical efficiency assessment.
• Maximal oxygen uptake was measured during incremental treadmill running using indirect calorimetry.
• Circulating ACE activity was directly assayed from venous blood samples, and ACE I/D genotype was determined.

Main Results:

• ACE I/D genotype strongly correlated with circulating ACE activity (P < 0.0005).
• No statistically significant associations were found between circulating ACE activity or ACE genotype and measured endurance phenotypes (delta efficiency, gross efficiency, maximal aerobic power).
• Observed correlations were weak and non-significant (e.g., r = -0.122 for delta efficiency and ACE activity).

Conclusions:

• Systemic ACE activity does not appear to regulate endurance performance in sedentary individuals.
• These findings extend to a large cohort of sedentary women.
• The ACE I/D genotype's influence on endurance phenotypes in this population is not supported by this study.