Interleukin-6 − 174G/C gene polymorphism affects muscle damage response to acute eccentric resistance exercise in elderly obese women

The IL-6 gene polymorphism has been associated with disease prevalence and different physiological responses to exercise. Eccentric resistance exercise (ERE) is considered a nonpharmacological tool to prevent the chronic degenerative profile associated with aging and obesity. Consequently, the aim of the present study was to investigate the influence of IL-6 − 174G/C polymorphism on acute interleukin-6 (IL-6) and creatine kinase (CK) temporal response to ERE in elderly obese women. Ninety women completed seven sets of ten repetitions (eccentric only) of an acute ERE session at 110% of the ten repetitions maximum (10RM). IL-6 genotypes displayed no difference at baseline. ERE induced changes in CK concentration over time occurred only in the GG group, F(2.619, 136.173) = 5.199, p = 0.003, with CK activity increased from 106.8 ± 6.9 U/l pre-intervention to 122.7 ± 11.2 U/l at 24 h and 131.9 ± 14.4 U/l at 48 h post-exercise. IL-6 concentration in the GG group was lower than the CC/CG group only at 0 h post-exercise (3.78 ± 0.58 pg/ml versus 6.51 ± 1.91 pg/ml, p = 0.030). Only the GG genotype group had higher CK activity 24-48 h following ERE and greater CK integral values, while IL-6 activity over 48 h was higher in the CC/CG genotype group. In conclusion, IL-6 genotype affects CK and IL-6 in response to ERE. It is of interest that the ERE protocol induced an elevation in CK, indicating possible muscle damage without exacerbating IL-6 and CK for the GG genotype.