ACTN3 GENE R577X POLYMORPHISM ASSOCIATED WITH HIGH-DENSITY LIPOPROTEIN CHOLESTEROL AND ADIPONECTIN IN RUGBY PLAYERS

To determine the relationship between the R577X polymorphism of the α-actinin-3 (ACTN3), which may play a role in the individual differences observed in the effects of exercise on health benefits and antiatherogenic markers (i.e., high-density lipoprotein cholesterol [HDL-C] and adiponectin) in athletes.

Seventy-six male rugby players (mean age 19.8 years) were enrolled in this study. Genomic DNA was extracted from peripheral blood samples, and restriction fragment length polymorphism-polymerase chain reactions were conducted to assess ACTN3 genotypes. Body mass index (BMI), waist circumference, serum lipids including HDL-C, and adiponectin levels were measured. Current smoking and alcohol intake habits were evaluated with a questionnaire. All of the parameters were compared between 2 groups displaying frequently observed genotypes: one group consisting of patients having either the R/R or R/X genotype and a second group with the X/X genotype.

The frequency of the X allele was 0.55 and the distribution of the genotypes was 35.5% (n = 27) for X/X, 39.5% (n = 30) for R/X, and 25.0% (n = 19) for R/R. Serum HDL-C and adiponectin levels were significantly higher in X/X genotype compared to the R/R or R/X genotype (HDL-C 1.6 ± 0.3 [SD] vs. 1.4 ± 0.2 mmol/L; P<.01, adiponectin 8.8 ± 2.6 vs. 6.9 ± 2.3 μg/mL; P<.01), even after adjustments for confounders (P<.01).

There may be a relationship between the ACTN3 genotype and HDL-C and adiponectin levels in rugby players. This may be useful information when determining the individual responses of antiatherogenic markers to exercise.

ACTN3 = α-actinin-3 BMI = body mass index CVD = cardiovascular disease HDL-C = high-density lipoprotein cholesterol LDL-C = low-density lipoprotein cholesterol R = arginine (R) at amino acid position 577 of the ACTN3 protein TC = total cholesterol TG = triglyceride X = truncation at amino acid position 577 of the ACTN3 protein.