阻力訓練強度對於糖尿病前期高齡者血糖調控之影響

Abstract

前言：代謝能力下降，肌肉質量流失、脂肪組織增加及慢性發炎加劇會伴隨老化而產生，進而造成空腹血糖異常或葡萄糖耐受度不佳等問題，增加罹患二型糖尿病之風險。有氧運動的建議處方較多證據支持，然而阻力訓練對於血糖調控仍有不一致的結果。且有文獻指出高強度阻力訓練對高齡族群血糖調控產生不良的影響。此外，較少研究以相同訓練量下，不同強度的阻力訓練進行探討。目的：探討在相同訓練量下，不同阻力訓練強度對於糖尿病前期高齡者的血糖調控、發炎狀態及身體組成之影響。方法：31名糖尿病前期高齡者作為受試者，依身體組成、空腹血糖、口服葡萄糖耐受度測試後2小時血糖配對分派至高強度組 (80%1RM) 16名及低強度組 (40%1RM) 15名受試者。受試者完成10週的阻力訓練，每週訓練三次，每次訓練間隔48小時，使用8項器械式器材進行全身的阻力訓練。訓練前及訓練結束後進行血糖調控、發炎激素及身體組成的測量。以二因子混合設計變異數分析進行統計分析，考驗受試者訓練前後各依變項在組別、時間差異。結果：24位受試者完成10週阻力訓練以及所有檢測 (高強度：13名；低強度：11名)。平均週訓練量兩組無顯著差異 (p > .05)；最大肌力進步幅度高強度顯著高於低強度組 (高強度：22% vs. 低強度：12%，p< .05)。血糖調控指標：阻力運動訓練能降低高齡糖尿病前期空腹血糖 (訓練前：104 ± 6 mg/dl；訓練後vs. 100 ± 6 mg/dl，p < .05)，其餘指標 (空腹胰島素、HOMA-IR、OGTT 2小時後血糖、OGTT AUC) 訓練前後無顯著差異 (p > .05)。發炎激素：訓練後高強度組TNF-α濃度顯著低於低強度組 (高強度：1.34 ± 0.27 pg/ml vs.低強度：1.51 ± 0.29 pg/ml，p < .05)，且同時低於訓練前 (訓練前：1.79 ± 0.47 pg/ml vs.訓練後：1.34 ± 0.27 pg/ml，p < .05)，其餘發炎激素 (IL-6、CRP) 則皆無顯著差異 (p > .05)。結論：阻力運動能改善糖尿病前期老年族群的空腹血糖，且高強度組還能降低TNF-α濃度。這些結果顯示阻力運動可能有助於預防或延緩高齡者罹患二型糖尿病。Introduction: Aging-related disorders, such as loss of muscle mass, obesity and chronic inflammation, may induce insulin resistance and increase risk for prediabetes or type 2 diabetes. Aerobic exercise can effectively improve glycemic control; however, the effect of resistance exercise on glycemic control remains controversial. Few studies have shown that high intensity resistance exercise impaired the glycemic control in elders. In addition, few studies have investigated resistance training with different intensities in the same training volume. Purpose: The present study was to investigate effects of low-intensity versus high-intensity resistance training on glycemic control, markers of inflammation, and body composition in older adults with prediabetes. Methods: 31 older adults with prediabetes were recruited in this study. Participants were matched and assigned in high intensity group (High, n = 16, 80%1RM) or low intensity group (Low, n = 15, 40%1RM). Both groups completed 10 weeks (3-day/week) resistance training. Glycemic control, markers of inflammation, and body composition were performed pre- (PRE) and post-training (POST). Two-way mixed ANOVA was used to analyze the data. Results: 24 participants completed the 10 weeks resistance training and the measurements. No significant difference was observed in a weekly training volume between both groups (p > .05). The improvement of muscle strength in High was significant higher than Low (High: 22% vs. Low: 12%, p< .05). Resistance training reduced fasting glucose levels (PRE: 104 ± 6 mg/dl；vs. POST: 100 ± 6 mg/dl, p < .05). After the training, High significantly lowered TNF-α levels compared with Low (High: 1.34 ± 0.27 pg/ml vs. Low: 1.51 ± 0.29 pg/ml, p < .05) and PRE (PRE: 1.79 ± 0.47 pg/ml vs. POST: 1.34 ± 0.27 pg/ml, p < .05). There were no significant differences in the remaining dependent variables. Conclusions: Resistance training improved fasting glucose in in older adults with prediabetes. Furthermore, only high-intensity resistance training lowered TNF-α levels. These findings underscore the ability of resistance exercise may help prevent or delay type 2 diabetes in older adults.