ACE ID genotype affects blood creatine kinase response to eccentric exercise

Area of Science:

• Exercise Physiology
• Genetics
• Molecular Biology

Background:

• Unaccustomed exercise can lead to muscle breakdown, evidenced by elevated serum creatine kinase (CK) levels.
• The skeletal muscle renin-angiotensin system (RAS) is implicated in exercise metabolism and muscle tissue injury.
• A common polymorphism in the angiotensin I-converting enzyme (ACE) gene (rs4646994), known as the I/D variant, influences ACE activity.

Purpose of the Study:

• To investigate the association between the ACE I/D genotype and the variability in creatine kinase (CK) response to unaccustomed eccentric exercise.
• To determine if the ACE genotype is an independent predictor of post-exercise muscle damage.

Main Methods:

• Young individuals performed maximal eccentric contractions of elbow flexor muscles.
• Serum CK activity was measured before and after exercise.
• ACE gene polymorphism (I/D) was determined and correlated with CK levels and changes.

Main Results:

• ACE genotype significantly correlated with post-exercise CK increase and peak CK activity.
• Individuals with the II genotype exhibited higher peak CK values compared to those with ID and DD genotypes.
• The ACE genotype was identified as a powerful independent determinant of peak CK activity, with the I allele associated with greater muscle damage.

Conclusions:

• The ACE I/D genotype is positively associated with the CK response to strenuous exercise.
• The II genotype may increase the risk of muscle damage from exercise, while the DD genotype might offer protective benefits.
• These findings highlight the role of the local RAS in regulating exercise-induced muscle injury.