VDR Gene Polymorphisms and Inter-Individual Variability in Response to Resistance Training.

A 12-week resistance training program induced significant improvements in multiple outcomes across all participants.

• 191 healthy Chinese Han adults participated (94 men, 97 women)
• Training consisted of twice-weekly sessions over 12 weeks
• Exercises included squat and bench press
• Outcomes measured included strength, power, body composition, and muscle morphology

The AG genotype of rs731236 (TaqI) was associated with greater gains in bone mineral content overall.

• rs731236 is also known as TaqI polymorphism
• This association was observed in overall (non-sex-stratified) analyses
• The CT genotype of rs1544410 (BsmI) was also associated with greater gains in bone mineral content
• Both findings were identified across the full cohort of 191 participants

In women, the rs731236-AA genotype was associated with better strength and power gains following resistance training.

• This finding was identified in sex-specific analyses of the 97 women in the cohort
• Strength and power gains were among the key indicators assessed pre- and post-intervention
• The association was distinct from the overall cohort finding for rs731236
• Sex-specific analyses revealed distinct patterns not apparent in overall analyses

In women, the rs731236-AG genotype was linked to greater body composition improvements following resistance training.

• This finding was identified in sex-specific analyses of the 97 women
• Body composition was one of the key indicators assessed before and after the intervention
• Different genotypes of the same polymorphism (rs731236) were associated with different phenotypic outcomes in women
• The AA genotype was associated with strength/power gains while the AG genotype was associated with body composition improvements, suggesting phenotype specificity

In men, the rs1544410-CC genotype (BsmI) was associated with superior lower-limb muscle growth.

• This finding was identified in sex-specific analyses of the 94 men in the cohort
• rs1544410 is also known as the BsmI polymorphism
• The association was specific to lower-limb muscle morphology outcomes
• This represents a male-specific finding not observed in the overall cohort analysis

The rs7975232 (ApaI) polymorphism showed no significant overall effect on resistance training adaptations.

• rs7975232 is also known as the ApaI polymorphism
• No significant associations were found in overall analyses for this SNP
• Sex-specific results for rs7975232 were not highlighted as significant
• This contrasts with the significant findings observed for rs731236 and rs1544410

The rs2228570 (FokI) polymorphism deviated from Hardy-Weinberg equilibrium in this sample.

• rs2228570 is also known as the FokI polymorphism
• Deviation from Hardy-Weinberg equilibrium was noted for this SNP
• This deviation may limit the interpretability of findings for this polymorphism
• The sample consisted of Chinese Han adults, and population-specific allele frequencies may contribute to this deviation

VDR gene polymorphisms rs731236 and rs1544410 demonstrate sex and phenotype specificity in their association with resistance training responses.

• Different genotypes of the same polymorphism were associated with different phenotypic outcomes
• Associations differed between men and women for the same polymorphisms
• The findings offer preliminary support for genotype-informed personalized training
• Results were observed in a Chinese Han adult population, potentially limiting generalizability to other ethnic groups