Vitamin D receptor gene polymorphisms, muscle mass and muscular explosive strength in elite soccer players.

Myosotis Massidda

First

;Carla Maria Calò;Francesco Piras;Marcello Cominu;Marco Scorcu

2011-01-01

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Abstract

Objective: Vitamin D receptor (VDR) polymorphism is reported to be associated with muscle mass and strength [1], but the evidences for this is limited and conflicting. The present study examined the association between the polymorphisms of VDR gene BsmI, ApaI and FokI and muscular mass and strength in elite soccer players. Material/Methods: Thirty-nine top-level male soccer players (mean age 24.5±3.8) participated in the study. All examined athletes had reached National level. Ten out of thirty-nine athletes were official members of the National Teams and one of them had won the gold medal in the World FIFA (International Federation of Football Association) Championship in 2006. Athletes’ training consisted of 29.3±6.33 hours per week. Genomic DNA was extracted from buccal swabs, and VDR genotypes were determined by PCR. The explosive muscle strength of the lower limb was measure by mean of Squat Jump (SJ) and Counter Movement Jump (CMJ). Limb circumferences and skinfold thickness were measured on the right mid-thigh using a measuring tape and a skinfold calipers. Thigh muscle area (TMA) was calculated by an equation after measuring limb circumference and skinfold thickness. The differences in muscular strength and muscle area among VDR genotype groups were analyzed using one-way ANOVA. Results: The explosive leg muscle strength, and the thigh muscle area were not significantly different between VDR genotype groups. The analysis of variances indicate a similarity of TMA, SJ, CMJ values for BsmI (F=0.3884; df=6; p=0.87), ApaI (F=0.4708; df=6; p=0.82) and FokI genotypes (F=0.5701; df=6; p=0.74). However, the data also indicate a trend toward higher SJ value in soccer players with VDR FokI*ff genotype (ff, cm 44.4±8.9; Ff, cm 40.44±4.7; FF, cm 39.45±3.80) than those with FF homozygous. Conclusion: The data suggested that VDR BsmI and ApaI polymorphisms seem not to be associated with muscular strength and thigh muscle area in top-level soccer players. However, our results indicated that we cannot exclude the possibility that homozygosity for the FokI*f allele could represent an advantage to exert a better explosive muscular strength in soccer.