The ACTN3 R577X polymorphism is associated with metabolic alterations in a sex‐dependent manner in subjects from western Mexico.

Background: The ACTN3 gene is primarily expressed in fast skeletal muscle fibres. A common nonsense polymorphism in this gene is ACTN3 R577X (rs1815739), which causes an absolute deficiency of α‐actinin‐3 protein and alterations in muscle metabolism. Considering metabolic alterations are influenced by nutrition and genetic factors, as well as lifestyle factors, we hypothesise a possible association of the ACTN3 R577X polymorphism with metabolic alterations. Methods: In this cross‐sectional study, 397 adults met the inclusion criteria. Body composition was measured by electrical bioimpedance. Dietary data were analysed using Nutritionist Pro™ software. Biochemical variables were determined by dry chemistry. Genomic DNA was extracted from peripheral leukocytes and genotyping of the ACTN3 R577X polymorphism was determined by allelic discrimination using TaqMan probes. The statistical analyses were performed using SPSS statistical software. p < 0.05 was considered statistically significant. Results: The ACTN3 577XX genotype was associated with high glucose, triglyceride and very low density lipoprotein‐cholesterol levels and a higher frequency of hypertriglyceridaemia and insulin resistance in women. In males, the genetic variant showed a trend towards significance for insulin resistance. Conclusions: The ACTN3 R577X polymorphism was associated with metabolic alterations in women and a tendency was observed in men variant carriers. Thus, this common genetic variant could be implicated in the development of chronic metabolic diseases. Highlights: The ACTN3 R577X polymorphism is associated with metabolic alterations in women from western Mexico.Insulin resistance by the triglyceride‐glucose index was associated with the XX genotype in women, and there was a significant trend towards a higher proportion in XX genotype males compared to the RR/RX genotype.The XX ACTN3 genotype could be a predictor for metabolic alterations in a sex‐dependent manner.The present study does not exclude the potential role of ACTN3 R577X on gene–nutrient or gene–gene interactions related to metabolic alterations. [ABSTRACT FROM AUTHOR]