Influence of acute exercise on hyperglycemia in insulin-treated type 2 diabetes

INTRODUCTION: The impact of exercise on blood glucose homeostasis has not been assessed in long-standing type 2 diabetes patients receiving exogenous insulin treatment. PURPOSE: To study the effects of an acute bout of exercise on the subsequent 24-h blood glucose excursions under free-living conditions in insulin-treated type 2 diabetes patients. METHODS: Eleven male type 2 diabetes patients (59 +/- 2 yr) performed an acute bout of exercise. One day before the exercise bout, a continuous glucose monitoring system (GlucoDay, A. Menarini Diagnostics) was inserted subcutaneously in the periumbilical region. The glucose sensor continuously measured glucose concentrations in the dialysate during a 48-h period. RESULTS: The prevalence of hyperglycemic glucose excursions was reduced by 39% during a 24-h period (equivalent to 3 h) after an acute bout of exercise (P < 0.05). Average glucose concentrations 24 h before and after the exercise bout did not differ (NS). Mean dialysate glucose concentrations and the prevalence of hyperglycemic periods correlated strongly with baseline blood HbA1c concentrations (Pearson's R = 0.69, P < 0.05). CONCLUSION: An acute bout of exercise effectively reduces the prevalence of hyperglycemia during a 24-h period under free-living conditions in long-standing type 2 diabetes patients on exogenous insulin therapy.     

Aerobic exercise training improves the role of high-density lipoprotein antioxidant and reduces plasma lipid peroxidation in type 2 diabetes mellitus

In this study, we analyzed the effect of aerobic exercise training (AET) and of a single bout of exercise on plasma oxidative stress and on antioxidant defenses in type 2 diabetes mellitus (DM) and in healthy control subjects (C). DM and C did not differ regarding triglycerides, high-density lipoprotein cholesterol (HDL-c), insulin, and HOMA index at baseline and after AET. To measure the lag time for low-density lipoprotein (LDL) oxidation (LAG) and the maximal rate of conjugated diene formation (MCD), participants' plasma HDL(2) and HDL(3) were incubated with LDL from pooled healthy donors' plasma. In the presence of HDL(3), both LAG and MCD were similar in C and DM, but only in DM did AET improve LAG and reduce MCD. In the presence of HDL(2), the lower baseline LAG in DM equaled C after AET. MCD was unchanged in DM after AET, but was lower than C only after AET. Furthermore, after AET plasma thiobarbituric acid-reactive substances were reduced only in DM subjects. Despite not modifying the total plasma antioxidant status and serum paraoxonase-1 activity in both groups, AET lowered the plasma lipid peroxides, corrected the HDL(2), and improved the HDL(3) antioxidant efficiency in DM independent of the changes in blood glucose, insulin, and plasma HDL concentration and composition.     

The effect of two exercise modalities on skeletal muscle capillary ultrastructure in individuals with type 2 diabetes

Type 2 diabetes is associated with microvascular dysfunction, but little is known about how capillary ultrastructure is affected by exercise training. To investigate the effect of two types of exercise training on skeletal muscle capillary ultrastructure and capillarization in individuals with type 2 diabetes, 21 individuals with type 2 diabetes were allocated (randomized controlled trial) to 11 weeks of aerobic exercise training consisting of either moderate‐intensity endurance training (END; n = 10) or low‐volume high‐intensity interval training (HIIT; n = 11). Skeletal muscle biopsies (m vastus lateralis) were obtained before and after the training intervention. At baseline, there was no difference in capillarization, capillary structure, and exercise hyperemia between the two groups. After the training intervention, capillary‐to‐fiber ratio increased by 8% ± 3% in the END group (P < 0.05) and was unchanged in the HIIT group with no difference between groups. Endothelium thickness increased (P < 0.05), basement membrane thickness decreased (P < 0.05), and the capillary lumen tended (P = 0.07) to increase in the END group, whereas these structural indicators were unchanged after HIIT. In contrast, skeletal muscle endothelial nitric oxide synthase (eNOS) increased after HIIT (P < 0.05), but not END, whereas there was no change in vascular endothelial growth factor (VEGF), superoxide dismutase (SOD)‐2, or NADPH oxidase after both training protocols. In contrast to END training, HIIT did not alter capillarization or capillary structure in individuals with type 2 diabetes. In conclusion, HIIT appears to be a less effective strategy to treat capillary rarefaction and reduce basement thickening in type 2 diabetes.     

短期运动干预方案对外科2型糖尿病住院患者术前血糖影响的初步研究

 目的 初步探讨短期运动干预方案对2型糖尿病(type 2 diabetes mellitus,T2DM)住院患者外科术前血糖的影响。方法 选择2017-08至2018-06解放军总医院第三医学中心收治的合并T2DM拟实施手术的住院患者45例,采用随机数字表法分为中强度间歇运动组、低强度持续运动组及对照组,每组15例。对运动组患者进行为期3~5 d不同强度和方式的运动干预;相同条件下对照组患者仅实施术前基础护理和常规宣教。随即通过生化检查和动态血糖监测系统(CGMS)评估干预前后3组患者空腹血糖(FPG)、餐后血糖(PPG)、空腹胰岛素(Fins)、稳态模型胰岛素抵抗指数(HOMA-IR),以及稳态模型胰岛素敏感指数自然对数(lnIS)以观察患者短期内血糖管控情况。结果 (1)运动组患者经过3 d运动干预后,中强度运动组血糖整体达标率高于对照组,且差异有统计学意义(P＜0.05);运动组的血糖指标中除FPG外,其余各项均低于对照组(P＜0.05);其中中强度间歇运动较低强度持续运动在患者PPG改善方面效果更为显著(P＜0.05)。(2)运动干预方案实施5 d后,低强度持续运动组患者血糖指标中PPG指标低于对照组,差异有统计学意义(P＜0.05);中强度间歇运动组患者除FPG外,其余各项血糖指标较对照组均发生显著变化,差异有统计学意义(P＜0.05)。结论 短期运动干预方案对2型糖尿病术前血糖调控有积极作用。     

二甲双胍与艾塞那肽治疗新诊断2型糖尿病的疗效及其对血糖波动的影响

 目的 比较艾塞那肽与二甲双胍治疗新诊断2型糖尿病的疗效及其对血糖波动的影响。方法 将68例新诊断2型糖尿病患者随机分为2组,分别为二甲双胍组35例,艾塞那肽组33例。治疗12周,比较2组治疗前后空腹血糖(FBG),餐后2 h血糖(2 h PG)、糖化血红蛋白(HbA1c)、血脂、体重指数,以及血糖波动指标日内平均血糖波动幅度(MAGE)、最大血糖波动幅度(LAGE)、平均餐后血糖波动幅度(MPPGE)的变化。结果 治疗12 周后,两组FBG、2 h PG、HbA1c、血糖波动指标较治疗前均明显下降,两组治疗后无统计学差异;两组治疗后三酰甘油(TG)较治疗前明显降低(P<0.05),二甲双胍组(1.88±0.57)mmol/L,艾塞那肽组(1.58±0.21)mmol/L,相比二甲双胍组,艾塞那肽组下降更为明显(P<0.05);体重指数艾塞那肽组治疗前体重(25.14±2.21)kg/m²,治疗后(23.16±1.46)kg/m²,治疗前后比较具有统计学差异(P<0.05)。结论 艾塞那肽与二甲双胍对新诊断2型糖尿病控制血糖效果具有同等的疗效,艾塞那肽在降低三酰甘油及体重方面更为显著。     

Reduced leg blood flow during submaximal exercise in type 2 diabetes

It is unclear whether impaired cardiac and/or vascular function contribute to exercise intolerance in patients with type 2 diabetes. PURPOSE: Magnetic resonance imaging (MRI) was used to determine whether reductions in cardiac output and/or femoral arterial blood flow contribute to reduced aerobic capacity in patients with type 2 diabetes. METHODS: Cardiac and femoral arterial blood flow MRI scans were performed at rest and during low-intensity leg exercise in eight patients with type 2 diabetes and 11 healthy individuals. Maximal aerobic capacity VO(2 max) and maximal oxygen pulse were also determined in all participants. RESULTS: V O(2 max) was 20% lower and maximal oxygen pulse was 16% lower in patients with type 2 diabetes (P < 0.05), whereas maximal heart rate was the same between groups. Low-intensity exercise induced a 20% increase in heart rate and cardiac output as well as a 60-70% increase in femoral blood flow in both groups (P < 0.05). Femoral arterial blood flow indexed to thigh lean mass was reduced during exercise in patients with type 2 diabetes compared with healthy individuals. Stroke volume indexed to fat-free mass was lower in patients with type 2 diabetes, but greater heart rate allowed cardiac output to be maintained during submaximal exercise. CONCLUSIONS: These findings suggest that impaired femoral arterial blood flow, an indirect marker of muscle perfusion, affects low-intensity exercise performance in patients with type 2 diabetes. However, because of lower exercising stroke volume, we propose that femoral arterial blood flow and, possibly, cardiac output, limit V O(2 max) in patients with type 2 diabetes.     

HDL atheroprotection by aerobic exercise training in type 2 diabetes mellitus

PURPOSE: In this study we analyzed the role played by aerobic exercise training in the plasma lipoprotein profile, prebeta 1-HDL concentration, and in the in vitro HDL3 ability to remove cholesterol from macrophages and inhibit LDL oxidation in type 2 diabetes mellitus (DM) patients and control subjects, in the fasting and postprandial states. METHODS: Healthy controls (HTC, N = 11; 1 M/10 F) and subjects with type 2 diabetes mellitus (DMT, N = 11; 3M/8F) were engaged in a 4-month aerobic training program, and compared with a group of sedentary subjects with type 2 diabetes mellitus (DMS, N = 10; 4 M/6 F). All groups were submitted to an oral fat load test to analyze all parameters, both at the beginning of the investigation protocol (basal) and at the end of the study period (final). RESULTS: Exercising did not modify body weight, BMI, plasma concentrations of total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides (TG), glucose, insulin, or HOMA-IR, but it reduced the waist circumference. The HDL3 composition did not change, and its ability to remove cell cholesterol was unaltered by aerobic training. In DMT but not in HTC, aerobic training improved 15% the HDL3 protective effect against LDL maximal oxidation rate in the fasting state, and reduced 24% the plasma prebeta 1-HDL concentration in the postprandial state, suggesting an enhanced prebeta 1-HDL conversion into larger, more mature HDL particles. In this regard, regular aerobic exercise enriched HDL2 with TG in the fasting and postprandial states in HTC and in the fasting phase in DMT. CONCLUSION: Our results show that aerobic exercise training in diabetes mellitus improves the HDL efficiency against LDL oxidation and favors HDL maturation. These findings were independent of changes in insulin resistance and of the rise of plasma HDL cholesterol concentration.     

2型糖尿病患者大脑静息葡萄糖代谢改变研究

目的探讨静息状态下2型糖尿病（T2DM）患者大脑葡萄糖代谢改变特点。方法回顾性分析96例已被临床确诊的T2DM患者的头部18F-FDG PET/CT显像资料。选取96名健康体检者作为对照组。采用统计参数地形图 8软件分析T2DM患者组与对照组PET脑代谢的改变。T2DM患者组与对照组图像采用体素对体素的两独立样本t检验。结果与对照组比较,T2DM患者18F-FDG PET/CT表现为多个脑区的葡萄糖代谢减低（t=5.51~6.42,均P < 0.001）,主要包括双侧额中下回、双侧颞上横回、双侧枕上中舌回、双侧楔前叶、双侧顶下缘角回、距状裂及周围皮层;未见明显代谢增高脑区。结论T2DM患者大脑静息葡萄糖代谢改变以区域性葡萄糖代谢减低为主,且基本呈双侧对称分布,主要涉及的脑区包括情感、认知功能区和视觉皮层区等。     

Acute effects of exercise on glucose tolerance in non-insulin-dependent diabetes

The evidence that exercise reduces resistant to the action of insulin has generated interest in the possibility that endurance exercise training may be a worthwhile primary therapeutic intervention in the treatment of mild non-insulin-dependent diabetes mellitus (NIDDM). Unfortunately, the results of several studies of exercise training in NIDDM have been discouraging since improvements in oral glucose tolerance (OGT) did not occur or were quite modest even though insulin resistance was reduced. Recently it was determined that 12 months of endurance exercise training at 75-90% of VO2max could normalize OGT in men with mild NIDDM when the post-training OGTT was performed within 18 h of the last bout of exercise. This, coupled with the fact that the enhanced action of insulin is lost in trained persons within a few days of cessation of training, suggests that improved glucose tolerance in NIDDM patients may be partly due to the persistent effects of the last bouts of exercise. Acute exercise in the form of 7 d of intense walking/cycling has been shown to improve glucose tolerance despite a significantly smaller increase in plasma insulin levels during the OGTT in NIDDM. Apparently, the improvement in OGT was due to a decrease in resistance to insulin over the short term since no changes in body weight, body fat, or VO2max took place. Thus, acute exercise of sufficient intensity and duration can increase peripheral insulin action and may contribute to the effects of long-term exercise training on improvement in OGT and the amelioration of insulin resistance in patients with NIDDM.     

Prior arm exercise speeds the VO2 kinetics during arm exercise above the heart level

PURPOSE: To test the hypothesis that the initial O2 uptake kinetics during exercise where the rise in blood flow (and, by implication, O2 delivery) to the working muscles during an abrupt increase in exercise intensity is reduced (i.e., arm exercise performed above the level of the heart) would be faster when preceded by a bout of high-intensity exercise. METHODS: Eleven physically active males completed two protocols, each consisting of two consecutive bouts of 6 min of high-intensity arm crank exercise separated by 6 min of recovery. In one protocol, the arm crank exercise was performed with the arms below the level of the heart (HL). RESULTS: In the HL protocol, the amplitudes of the VO2 fast and slow component were unaffected by prior exercise, whereas the VO2 fast component time constant was significantly reduced in the second bout (49.8+/-22.1 vs 40.7+/-13.2 s; P<0.05). CONCLUSION: The results of this study demonstrate that prior high-intensity exercise caused a significant speeding of the VO2 fast component response during subsequent high-intensity arm crank exercise performed above, and not below, the level of the heart.     

The effect of type 2 diabetes on diastolic function

PURPOSE: This study aimed to determine whether sedentary overweight subjects with type 2 diabetes have impaired diastolic function compared with equally sedentary and overweight nondiabetic subjects. METHODS: Mitral valve pulsed Doppler echocardiography and tissue Doppler imaging (TDI) were used to assess left ventricular structure and diastolic function in 40- to 60-yr-old sedentary overweight subjects with type 2 diabetes (N = 13) and age- and body mass-matched sedentary nondiabetic subjects (N = 15). Pseudonormal filling was identified using preload reduction and TDI. RESULTS: Traditional Doppler mitral inflow parameters were not different between groups; however, early diastolic relaxation, as measured by peak early mitral annular velocity (E') and the ratio of E' and peak late mitral annular velocity (E'/A'), was reduced in type 2 diabetic subjects (P < 0.05). The ratio of peak early mitral inflow (E) to E' (E/E'), an estimate of left ventricular filling pressure, was also higher in the type 2 diabetes group (P < 0.05). The proportions of diastolic impairment (69 vs 40%) and pseudonormal filling (39 vs 20%) were not different between groups (P = 0.18). CONCLUSION: These findings suggest that type 2 diabetes has an effect on diastolic function that is independent of age and body composition.     

The role of exercise in the treatment of cardiovascular disease associated with type 2 diabetes mellitus

The role of exercise training in the prevention and treatment of type 2 diabetes mellitus has been studied extensively over the past two decades. Although the primary treatment aim for patients with type 2 diabetes is metabolic control, the morbidity and mortality associated with the disease is more a function of cardiovascular disease. As exercise is associated with favourable reductions in the risk for cardiovascular disease in other high-risk populations, here we explore the role of exercise in the treatment of cardiovascular maladaptations associated with type 2 diabetes.The cardiovascular adaptation to type 2 diabetes is characterised by hypertrophy, stiffening and loss of functional reserve. Clinically, the cardiovascular adaptations to the diabetic state are associated with an increased risk for cardiovascular disease. Functionally, these adaptations have been shown to contribute to a reduced exercise capacity, which may explain the reduced cardiovascular fitness observed in this population.Exercise training is associated with improved exercise capacity in various populations, including type 2 diabetes. Several structural and functional adaptations within the cardiovascular system following exercise training could explain these findings, such as reductions in ventricular and vascular structural hypertrophy and compliance coupled with increased functional reserve. Although these cardiovascular adaptations to aerobic exercise training have been well documented in older populations with similar decrements in cardiovascular fitness and function, they have yet to be examined in patients with type 2 diabetes. For this reason, we contend that exercise training may be an excellent therapeutic adjunct in the treatment of diabetic cardiovascular disease.     

Contribution of autonomic dysfunction to abnormal exercise blood pressure in type 2 diabetes mellitus

ObjectivesThe purpose of this study was to compare the presence and severity of autonomic dysfunction in type 2 diabetes mellitus patients, with and without exaggerated blood pressure responses to exercise.DesignWe performed a cross-sectional analysis of 98 patients with type 2 diabetes mellitus (aged 59 ± 9).MethodsBoth time (standard deviation of RR intervals, root-mean-square of successive RR interval differences) and frequency (total spectral power, high frequency, low frequency, very low frequency) domains of heart rate variability were analysed in a 5 min recording at rest and 20 min after a maximal treadmill test. An exaggerated blood pressure response to exercise was identified by peak blood pressure ≥190/105 mm Hg (women) or ≥210/105 mm Hg (men).ResultsEach group of either exaggerated exercise blood pressure response or normal blood pressure response consisted of 49 patients. At rest there were no significant differences between groups for all time and frequency domain parameters of heart rate variability. Post-exercise, there was a significant (p < 0.05) reduction in the SDNN, RMSSD and TP in the exaggerated exercise blood pressure group. Independent correlates (p < 0.01) of exercise systolic blood pressure included post-exercise TP, resting systolic blood pressure, cardiac autonomic neuropathy and beta-blockers (beta = ?0.28, adj. R² = 0.32, p < 0.001).ConclusionsReduced post-exercise heart rate variability in patients with type 2 diabetes mellitus, with an exaggerated exercise blood pressure response suggests preclinical autonomic dysfunction characterized by impaired vagal modulation.     

麦冬提取物的降糖作用及其抗胰岛素抵抗的机制研究

目的 研究麦冬提取物降糖作用及胰岛素增敏相关机制.方法 首先诱导分化3T3-L1细胞为脂肪细胞,给予麦冬多糖(OPSR)和麦冬皂苷(OPG)干预后,检测葡萄糖消耗率,筛选出具有降糖作用的提取物;建立地塞米松诱导胰岛素抵抗(IR)脂肪细胞模型,给予OPSR干预,Western blotting检测瘦素、脂联素和抵抗素蛋白表达水平;建立2型糖尿病大鼠模型,经OPSR治疗4周后,测量体重(Bw)、甘油三酯(TG)、空腹血糖(FBG)、空腹胰岛素(FINs)的变化.结果 0.5～ 50mg/L OPSR呈剂量依赖性地促进脂肪细胞葡萄糖消耗,葡萄糖消耗比值分别为32.27％,75.14％和90.47％,而OPG作用很弱,在50mg/L时葡萄糖消耗比值仅为8.49％;OPSR明显促进瘦素、脂联素蛋白表达,抑制抵抗素蛋白表达(P＜0.05).OPSR治疗4周后,大鼠体重明显增加,TG、FBG、HOMA-IR显著降低(P＜0.05或P＜0.01).结论 OPSR能够促进脂肪细胞对葡萄糖的转运和利用,对T2DM大鼠具有降低FBG、TG和改善胰岛素抵抗作用,其机制与胰岛素抵抗脂肪细胞分泌的脂肪因子有关.     

2型糖尿病患者血糖波动与抑郁状态的相关性

 目的 探讨2型糖尿病(type 2 diabetes mellitus,T₂DM)患者血糖波动情况与抑郁状态的相关性。方法 选取2015-08至2016-09就诊医院内分泌科T₂DM患者42例为T₂DM组,选择年龄、性别相匹配的健康志愿者28名为对照组,对所有患者进行连续72 h动态血糖监测(continuous glucose monitoring system,CGMS);均行蒙哥马利抑郁评定量表(Montgomery and Asberg depression rating scale,MADRS)评分。比较两组MADRS评分、血糖波动参数,并分析T₂DM组血糖波动参数与MADRS的相关性。结果 T₂DM组MADRS评分为(15.67±7.43)分,对照组MADRS评分为(8.29±3.76)分,T₂DM组高于对照组,差异有统计学意义(t=4.818,P<0.01)。T₂DM组与对照组相比,平均血糖波动幅度(mean amplitude of plasma glucose excursions,MAGE)、全天血糖水平标准差(standard deviation of blood glucose,SDBG)、最大血糖波动幅度(largest amplitude of plasma glucose excursions, LAGE)、日间血糖平均绝对差(means of daily differences, MODD)、平均餐后血糖波动幅度(mean amplitude of plasma postprandial blood Glucose excursions, MPPGE)均明显升高,差异有统计学意义(P<0.01)。T₂DM患者MAGE与MADRS评分呈正相关(r=0.330,P<0.05)。结论 MAGE与抑郁的发生有关。