Kir6.2基因E23K位点多态性与耐力训练后血糖、胰岛素和VO2max改变的关系

目的探讨Kir6.2基因E23K位点多态性与耐力训练所致的血糖、胰岛素和VO2max改变间的关系.方法采用PCR-RFLP技术对214例美国各种族50至75岁男女受试者的Kir6.2位点E23K多态性进行基因型分析.受试者在专人监控下进行24周的耐力训练后,观察其E23K与血糖、胰岛素和VO2max之间的关系.结果(1)三种基因型受试者的空腹血糖、胰岛素和VO2max的基础值无显著差异;(2)24周耐力训练后,三种基因型受试者的VO2max均显著升高(P＜0.05),体重和体脂则显著下降(P＜0.05),身高体重指数(BMI)和呼吸商(RER)则在男性各基因型中显著下降(P＜0.05);(3)24周耐力训练后,三种基因型受试者的空腹胰岛素水平和曲线下面积(AUC)均显著下降(P＜0.05),但训练并未引起空腹血糖及其AUC显著变化.(4)男性EK基因型RER显著低于EE和KK基因型,女性则表现为KK基因型显著高于EE基因型.结论(1)无论E23K位点的基因型为EE、EK或KK,24周的耐力训练均可提高受试者的VO2max并降低体重、体脂、空腹胰岛素水平和AUC;(2)耐力训练对男性BMI和RER降低的影响更显著;(3)E23K多态性与RER的关系较VO2max和血糖水平更密切.

Relation of E23K Variant of Kir6.2 to the Changes in Exercise- Induced Response of Glucose and Insulin and VO2max

Objective To observe the relationship between E23K variant of Kir6.2 and exercise-induced response of glucose and insulin and VO2max. Methods Two hundred and fourteen healthy sedentary men and women, aged 50 to 75 years, underwent VO2max, body composition, and glucose tolerance testing. The tests were repeated after 24 weeks of supervised exercise under low-fat diet.Results There were no significant differences in VO2max and fasting glucose or insulin levels among the three Kir6.2 genotype groups (EE, EK and KK). After 24 weeks of exercise, VO2max of the three groups increased significantly (P<0.05), while body weight and body fat decreased significantly (P<0.05), BMI and RER decreased significantly within the same group in men (P<0.05). Fasting insulin levels and AUC of the three groups decreased significantly (P<0.05), but the fasting glucose level and AUC remained unchanged after 24 weeks of exercise.Conclusion (1)24 weeks of exercise could improve VO2max and decrease body weight, body fat and fasting insulin level and AUC, no matter what E23K genotype group of Kir6.2 the subjects belong to; (2) Exercise affected BMI and RER in men more significantly; (3) The E23K genotype seemed to have closer relationship with RER than VO2max or glucose level.