Objective: To explore the association between α-actinin-3 (ACTN3) polymorphism and muscle strength in postmenopausal women. Methods: Five hundred and ninety-eight postmenopausal women with an average of (62.9±7.0) years old in Dongcheng District of Beijing were included. The ACTN3 polymorphism including rs540874, rs618838 and rs2229456 were genotyped by Sequenom Mass Array to explore their associations with muscle strength. One hundred and sixty-three of them were trained with regular Tai chi movement while 271 were administered with elemental calcium 600 mg/d combined with Vitamin D 800 U/d or calcitriol 0.25 μg/d for 2 years. Association between changes of muscle strength and ACTN3 polymorphism were analyzed. Results: The rs540874 genotypes were found to be significantly associated with chair stand test[GG (9.02±3.85) s vs GA (9.27±4.14) s vs AA (9.68±5.00) s, P=0.015]. Right grip strength in women with G allele were likely to be higher compared with A allele, but it was not statistically significant (P=0.056). Multiple linear regression showed that the chair stand test of AA genotype was statistically longer than that of GG and GA genotype (β=2.639, 95% CI: 1.632-4.646, P=0.010). The associations between rs618838, rs2229456 genotypes and muscle strength of both lower and upper limbs were not significant (all P>0.05). In addition, muscle strength of lower limbs of patients with rs540874 genotyped with G allele, rs618838 genotyped with C allele and rs2229456 genotyped with A allele increased significantly after enhanced exercise and vitamin D supplementation (all P<0.05). Conclusions: The rs540874 polymorphism of ACTN3 gene was associated with the muscle function of lower limb in postmenopausal women. The improvement of muscle strength after intervention were possibly correlated with rs540874, rs618838 and rs2229456 polymorphisms.
目的： 探究α－辅肌动蛋白3(ACTN3)基因多态性与绝经后女性肌肉强度的相关性。 方法： 纳入北京市东城区34个社区598例绝经后女性，年龄(62.9±7.0)岁。通过Sequenom Mass Array平台对ACTN3基因rs540874、rs618838、rs2229456位点进行基因分型，并分析其与绝经后女性肌肉强度的相关性。其中163例给予强化运动训练，271例给予钙剂600 mg/d＋普通维生素D 800 U/d或骨化三醇0.25 μg/d，随访2年，观察强化运动及维生素D补充后肌力变化与ACTN3基因型的相关性。 结果： rs540874位点不同基因型组间站立试验时间差异有统计学意义[GG(9.02±3.85)s比GA(9.27±4.14)s比AA(9.68±5.00)s，P＝0.015]。G等位基因携带者右手握力具有高于A等位基因携带者的趋势，但差异无统计学意义[GG(24.53±5.45)N比GA(24.26±4.79)N比AA(23.66±4.32)N，P＝0.056]。多重线性回归显示，AA基因型的受试者站立试验较GA、GG基因型显著延长(β＝2.639，95% CI：1.632～4.646，P＝0.010)。rs618838、rs2229456基因型与双手握力及站立试验时间均无明显相关性(均P>0.05)。此外，rs540874位点G等位基因携带者、rs618838位点C等位基因携带者、rs2229456位点A等位基因携带者强化运动及维生素D补充后下肢肌力均显著增加(均P<0.05)。 结论：ACTN3基因的rs540874位点与绝经后女性下肢肌力相关；rs540874、rs618838、rs2229456位点不同基因型可能与干预后下肢肌力获益有关。.
Keywords: Actinin; Muscle strength; Polymorphism, single nucleotide; Postmenopause.