中国北方汉族男性雄激素受体基因(CAG)n多态与低氧训练后心功能变化的关联性

目的:探讨雄激素受体(AR)基因外显子1中(CAG)n多态与中国北方汉族男性心功能对低氧训练应答的关联性。方法:58名中国北方汉族健康青年男性进行为期30天的HiHiLo(常压低氧)训练,晚上居住房间的氧浓度为14.8～14.3%(模拟海拔约2800～3000米);每周进行3次、每次30分钟的低氧训练,训练强度为常氧75%VO2max强度,训练环境氧浓度15.4%～14.8%(模拟海拔约2500～2800米);每周进行5次、每次90分钟常氧环境下的专项训练。分别于低氧训练前和低氧训练后使用超声心动仪测试安静时,50W、100W、150W递增负荷运动,以及运动后恢复期的心功能。使用GeneScan和测序方法分析AR(CAG)n多态性。结果:(1)短链重复组(≤21和≤22)身高和低氧训练前体重基础值分别显著低于长链组(>21和>22);(2)≤22次重复组低氧训练前安静时、三种负荷和恢复时的每搏输出量基础值均显著低于>22组;(3)与低氧训练前相比,低氧训练后各基因型组安静、运动和恢复时的心率均显著下降,但是仅两个短链组每分输出量和心指数呈现显著性降低;(4)除≤21组50W和≤22组150W外,低氧训练后短链重复组安静和运动时ΔCI下降幅度均显著大于长链组。结论:AR基因(CAG)n多态与中国北方汉族男性心功能对模拟常压低氧环境下HiHiLo训练的应答可能存在关联性。

Association of Androgen Receptor Gene Repeat Polymorphism with the Response of Heart Function to Hypoxic Training in Men of Han Nationality

Objective To investigate the association of CAG repeat polymorphism in exon 1 of androgen receptor(AR)gene with the response of heart function to hypoxic training in men of Han nationality from northern China.Methods Fifty eight healthy young men of Han nationality completed a 30-day HiHiLo training(living high,exercising high and training low)in a simulated normobaric hypoxic environment.All subjects lived in an environment of 14.8~14.3% O2 concentration(simulating 2800–3000 m)during nighttime,and participated in hypoxic training three times a week,30 min each section,in an environment of 14.8-15.4% O2 concentration(simulating 2500～2800m)with the intensity of 75% individual VO2max at sea level.Heart function at rest,and during exercise with 50w,100w,and 150w and after exercise was measured by echocardiography before and after hypoxic training.GeneScan and gene sequencing method was used to analyse CAG 45 repeat polymorphism.Results(1)The baseline of height and weight before hypoxic training in shorter repeat groups(≤21 and ≤22)were significantly lower than that in longer groups(>21 and >22);(2)The baseline of stroke volume at rest,and during and after exercise in ≤22 repeat group was significantly lower than that in >22 group;(3)After hypoxic training,heart rate significantly decreased at rest,and during and after exercise in four genotype groups,however,the decreases in cardiac output and cardiac output index appeared significantly only in two shorter groups comparing with baselines of those before hypoxic training;(4)The degree of decrease in ΔCI at rest and during exercise in two shorter genotype groups was significant higher than that in longer ones after hypoxic training,except ≤21 group during exercise at 50w and ≤22 group at 150w.Conclusion This study reveals that AR CAG repeat polymorphism is probably associated with the response of cardiac function to simulated normobaric hypoxic HiHiLo training in men of Han nationality from northern China.