ACE ID genotype affects blood creatine kinase response to eccentric exercise

tomed exercise may cause muscle breakdown with marked increase in serum creatine kinase (CK) activity. The skeletal muscle renin-angiotensin system (RAS) plays an important role in exercise metab-olism and tissue injury. A functional insertion (I)/deletion (D) poly-morphism in the angiotensin I-converting enzyme (ACE) gene (rs4646994) has been associated with ACE activity. We hypothesized that ACE ID genotype may contribute to the wide variability in individuals ’ CK response to a given exercise. Young individuals performed maximal eccentric contractions of the elbow flexor mus-cles. Pre- and postexercise CK activity was determined. ACE geno-type was significantly associated with postexercise CK increase and peak CK activity. Individuals harboring one or more of the I allele had a greater increase and higher peak CK values than individuals with the DD genotype. This response was dose-dependent (mean SE U/L: II, 8,882 2,362; ID, 4,454 1,105; DD, 2,937 753, ANOVA,