難消化性デキストリン摂取が軽運動時における糖・脂質代謝に及ぼす影響

It has been reported that dextrin (DX) has an effect of inhibition from elevation of blood glucose concentration after taking a meal. A little increase of blood glucose concentration after the meal would not accelerate secretion of insulin from the pancreas, so that, the blood insulin concentration may not elevate so much after the meal. The purpose of this study is to investigate the effects of DX intake with light meal on carbohydrate and fat metabolism in light intensity exercise. Eight young male subjects participated in this study. They took the light meal one hour before exercise, and performed a 30-min exercise at light intensity of heart sound breaking point on a cycle ergometer under two conditions of taking the meal with and without DX. Heart rate, oxygen consumption, plasma lactate (LA), plasma glucose (BG) and plasma free fatty acid (FFA), and respiratory exchange ratio (RER) were determined at before meal, start of exercise after 60 minutes of taking the meal, midpoint of exercise (15-min point), end of exercise (30-min point) and recovery phase after 15 minutes from cessation of the exercise. Average heart rate were 126.3 (SD; 11.3) and 122.8 (10.1) bpm during exercises with and without DX, respectively (not significant). Oxygen consumptions were 1.18 (0.24) and 1.16 (0.22) 1/min during exercises with and without DX, respectively (not significant). LA showed same values (1.8 (0.6) mM) in both conditions (not significant). BG showed significantly low values in DX condition at start and end of exercise and recovery phase than that in non-DX condition. FFA showed also significantly low values in DX condition at start and end of exercise and recovery phase than that in non-DX condition. These results indicate that DX inhibit absorption of BG not only at rest but also during exercise, and intake of DX with a meal may affect to elevate FFA intake to active muscle during exercise.