Physical activity is important for the management and treatment of type 2 diabetes (T2D). Interval exercise training has been shown to improve glycemic control in people with T2D; however, studies have generally utilized high volume protocols and/or specialized equipment that limit translation to a “real world” setting. The present proof-of-concept study examined the efficacy of brief, intermittent stair climbing exercise to improve indices of glycemic control in adults with T2D, using continuous glucose monitoring (CGM) under controlled dietary conditions. Each session involved 3 x 60-s bouts of vigorously ascending and slowly descending a single flight of stairs. This was set within a 10-min period, which otherwise involved walking for a warm-up, cool-down and recovery in between bouts. Data are reported for n=5 participants (52 ± 18 y, BMI: 31 ± 5 kg/m2, HbA1c: 6.6 ± 0.7 %; mean ± SD) who performed 18 training sessions over 6 weeks. Mean 24-h glucose and time spent in hyperglycemia (> 10 mmol/L) were unchanged after an acute session of stair climbing (p=0.38 and p=0.42, respectively) or after 6 weeks of training (p=0.15 and p=0.47, respectively). Measures of glycemic variability were improved in the 24-h period following a single session of stair climbing, based on reductions in the mean amplitude of glycemic excursions (MAGE) (4.4 ± 1.5 vs. 3.5 ± 1.0 mmol/L, p =0.02) and the standard deviation (SD) around the mean (1.7 ± 0.5 vs. 1.4 ± 0.5 mmol/L, p=0.02). There was a meal-specific improvement in postprandial hyperglycemia after training, with the incremental area under the curve (iAUC) of the lunchtime meal reduced by 36 ± 42 % (p=0.01). These preliminary results demonstrate the feasibility of stair climbing as a physical activity option for people with T2D, although the acute and chronic effects of this training on indices of glycemic control remain equivocal. / Thesis / Master of Science in Kinesiology / Physical activity is important for the management of type 2 diabetes (T2D). Interval training, which involves alternating periods of relatively intense exercise and recovery, can improve blood sugar control in adults with T2D. This has largely been shown in laboratory settings using specialized equipment and protocols that may not be practical or time-efficient. This small, proof-of-concept study examined whether brief, intermittent stair climbing exercise could improve blood sugar control in people with T2D. Average blood sugar measured over 24 hours was unchanged after a single bout of stair climbing and after 18 sessions of training performed over 6 weeks. However, stair-climbing exercise reduced blood sugar fluctuations in response to specific meals. These preliminary findings suggest that interval stair climbing is a feasible exercise option for adults with T2D, but the precise effects on blood sugar control remain to be clarified.

T2DM is a chronic disease characterized by postprandial hyperglycemia. One of the therapeutic approaches to attenuate hyperglycemia is to inhibit intestinal ɑ-glucosidase enzyme and/or suppress glucose transporters that regulate intestinal glucose transporters such as SGLT1 & GLUT2. Berries rich in polyphenol antioxidants have various health benefits. Although the antidiabetic effects of various berry extracts or berry mixture in pre-clinical and clinical studies, the underlying pathways at the molecular level is still unclear. In this study, we investigated antioxidant and antidiabetic effects of selected berry extracts by determining free radical scavenging activates, Caco-2 intestinal ɑ-glucosidase activity, glucose uptake and the gene expression of ɑ-glucosidase and glucose transporters in Caco-2 cells. Total phenolic contents of berry extracts varied from 28.55 ± 0.06 to 56.15 ± 1.08 gallic acid equivalent (GAE μg/mL) and correlated with antioxidant capacities. Both cranberry extract (CBE) and blackberry extract (BBE) at 200 μg/mL concentration significantly decreased glucose uptake in Caco-2 cells. While mRNA expression and activity of ɑ-glucosidase were inhibited by CBE and BBE, mRNA expression of SGLT1 and GLUT2 was only inhibited by CBE. Moreover, CBE and BBE significantly decreased glucose uptake in the presence of sucrose and AS. Our data suggest that CBE and BBE have different molecular mechanisms in suppressing hyperglycemia and their effects are mediated by inhibiting carbohydrate digestion and absorption.

京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第20464号 / 人博第814号 / 新制||人||195(附属図書館) / 28||人博||814(吉田南総合図書館) / 京都大学大学院人間・環境学研究科共生人間学専攻 / (主査)教授 林 達也, 教授 石原 昭彦, 准教授 久代 恵介 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DGAM