有氧訓練與飲食對高齡小鼠心臟與代謝功能之影響

Abstract

過去研究指出有氧運動訓練可降低心血管疾病危險因子，但是否能抵銷高齡衰退與不健康飲食的雙重影響還不得而知，因此本研究目的是以動物模式的方式探討有氧訓練對於攝取高脂飲食高齡小鼠心臟與代謝功能的影響。研究方法：24月齡之C57BL/6J小鼠共28隻，以隨機的方式分成高脂飲食運動組 (HFD+EX) 、高脂飲食組 (HFD) 、標準飲食運動組 (SD+EX) 以及標準飲食組 (SD) ，運動組小鼠接受每週五天，每天五十分鐘的有氧訓練，並探討8週有氧訓練與高脂 (46.1% ) 飼料餵食後，各組小鼠心臟、運動與代謝功能之變化和差異。所有小鼠於介入前後進行各項生理數值檢測，所測得的實驗數據以SPSS 18.0統計軟體之二因子變異數分析與成對樣本T檢定進行統計分析。結果：在8週介入後，射血分數 (EF) 、左心室縮短率 (FS) 、每跳輸出量 (SV) 、左心室內徑 (IDs) 、最大攝氧量 (VO2max) 、基礎代謝率 (BMR) 與左心室收縮末期容積 (ESV) 部分SD+EX組無顯著差異，而SD與HFD組顯著下降；左心室舒張末期容積 (EDV) 與左心室質量 (LVM) 部份，HFD+ EX 組與HFD組顯著上升，SD+EX與SD組無顯著差異；三酸甘油酯 (TG) 部分，HFD組顯著上升，SD+EX組顯著下降，HFD+EX與SD組則無顯著差異。結論：有氧訓練可以延緩高齡小鼠心臟、運動與代謝功能衰退，而高脂飲食會造成心臟結構與血脂代謝進一步的惡化。

Previous studies indicate aerobic exercise can lower the risk of cardiovascular diseases; however, whether aerobic training can offset the dual effects of aging and unhealthy diet remains unknown. The purposes of this study were to investigate the effects of aerobic training on the cardiac and metabolic functions of the aging mice taking high-fat diet. Method: 28 C57BK/6J mice with 24 months of age were selected and randomly divided into four groups, Standard diet (SD), Standard diet+Exercise (SD+EX), High fat diet (HFD, 46.1% fat), and High fat diet+Exercise (HFD +EX). The mice of exercise groups were received aerobic training 5 days per week, 50 minutes each day for 8 weeks. The variables of cardiac, exercise and metabolic functions of all groups were measured before and after 8 weeks of intervention. The collected data were analyzed with a two-way ANOVA and a paired sample T test using SPSS 18.0. Results: After 8 weeks of intervention, there was no significant change in ejection fraction , fractional shortening, stroke volume, interior dimension systolic, VO2max, basal metabolic rate and end-systolic volume of group SD+EX, but significantly declines were found in the groups of SD and HFD. For end- diastolic volume and left ventricular mass, no significant change observed of SD+EX and SD groups, but a significant decrease in HFD+EX and HFD group. Additionally, there was a significant decline in triglyceride of SD+EX group, but no changes in the groups HFD+EX and SD. Conclusion: Aerobic training can slow down the deterioration in cardiac, metabolism and exercise performance, and the high-fat diet can cause further decay in heart structure and lipid metabolism of the elderly mice.