A physical activity programme and its effects on insulin resistance and oxidative defense in obese male patients with type 2 diabetes mellitus

High-Intensity Interval Versus Moderate-Intensity Continuous Exercise Training on Glycemic Control, Beta Cell Function, and Aerobic Fitness in Women with Type 2 Diabetes

Objective: This study aimed to compare the effects of High-Intensity Interval Training (HIIT) and Moderate-Intensity Continuous Training (MICT) on glycemic control, beta-cell function, and aerobic fitness in women with Type 2 Diabetes Mellitus (T2DM). Methods: Thirty-six women with T2DM were assigned equally to HIIT, MICT, and control (CON) groups. Participants in the exercise cohorts underwent a 12-week training regimen (three sessions per week), while the CON group maintained an inactive lifestyle. Glycaemia variables, beta-cell function, maximal oxygen uptake (VO2max), lipid profiles, and body composition were assessed at baseline and post-intervention. Results: Both HIIT and MICT interventions led to significant improvements in glucose, insulin, HbA1c, and insulin resistance index. Moreover, visceral adiposity index (VAI), lipid accumulation product (LAP), total cholesterol (TC), and low-density lipoprotein (LDL) levels significantly decreased in the HIIT and MICT groups after 12 weeks. Triglyceride (TG) levels decreased only after MICT, while high-density lipoprotein (HDL) levels increased after both interventions. Maximal oxygen uptake (VO2max), body mass, body mass index (BMI), and waist circumference (WC) significantly improved in all exercise groups. Notably, the HIIT group showed greater reductions in body mass compared to MICT. Nevertheless, beta-cell function remained unaltered after these two exercise regimens. Conclusion: Both HIIT and MICT interventions effectively managed T2DM in women, regardless of exercise intensity. The HIIT regimen can be considered for time-efficient lifestyle interventions in people with T2DM.

V, Shastry BA. Effectiveness of structured exercise program on insulin resistance and quality of life in type 2 diabetes mellitus-A randomized controlled trial

OBJECTIVE

Impaired glucose control & Insulin resistance are reported to be risk factors for the development of cardiovascular diseases. To find the effects of a structured exercise program on insulin resistance, glycaemic control, functional capacity, and quality of life in patients with Type 2 diabetes mellitus.

DESIGN

Randomized, controlled trial.

SETTING

Diabetic Foot Clinic, Department of Physiotherapy & Department of General Medicine, Kasturba Hospital in Manipal, Karnataka, India.

PARTICIPANTS

160 participants aged between 30-65 years with Type 2 diabetes mellitus.

INTERVENTION

A set of structured exercise programs (aerobic, resistance, and combined) along with the standard hospital care was performed 3-5 times weekly for 12 weeks.

MEASUREMENTS: PRIMARY OUTCOME MEASURES

Fasting Insulin Level, Homa-IR, Six-minute walk test (6MWT), and WHOQOL-BREF questionnaire at baseline and 12th week.

SECONDARY OUTCOME MEASURES

Body composition analysis, Fasting Blood Sugar, Postprandial Blood Sugar, Glycated Haemoglobin (HbA1c), and GPAQ questionnaire at baseline and 12th week.

RESULTS

Significant differences have been observed in Homeostasis model assessment for insulin resistance (Homa-IR) (F (1, 144) = 89.29, p < 0.001); Fasting insulin (FI) (F (1, 144) = 129.10, p < 0.001); Fasting blood sugar (FBS) (F (1, 144) = 12.193, p< 0.001); Post prandial blood sugar (PPBS) (F (1, 144) = 53.015, p< 0.001); glycated haemoglobin (HbA1c) (F (1, 144) = 80.050, p < 0.001); WHOQOL-Physical health (F (1, 144) = 20.008, p< 0.001), Psychological (F (1, 144) = 77.984, p< 0.001), Social relationship (F (1, 144) = 44.866, p< 0.001); Environmental (F (1, 144) = 69.974, p< 0.001); Six minute walk test (6MWT) (F (1, 144) = 84.135, p< 0.001) in the study group when compared with the control group from baseline to 12th week.

CONCLUSIONS

The study reveals that a 12-week structured exercise training program effectively reduces insulin resistance, improves quality of life, enhances functional capacity, and improves glycaemic control in type 2 diabetes mellitus.

The 10-week of aerobic-functional training improves fasting blood sugar, insulin resistance, and lipid profile in patients with diabetic peripheral neuropathy: A randomized controlled trial

Study aim: This study aimed to investigate the effect of a 10-week of combined training course on concentrations of blood sugar, Insulin Resistance (HOMA-IR), and lipid profile in patients with diabetic peripheral neuropathy.

Materials and methods: This clinical trial was performed in diabetic neuropathy women and men (30–60 years old). Participants were randomly assigned to two groups: exercise (EG; n = 10) and control (CG; n = 10). The EG performed 10-week programme with one session of aerobic exercises (40% to 70% of HRReserve) and one session of functional exercises (60–90 min/ day) at the same day for four days/week and the CG performed their daily activities. The Blood glucose, IR, and lipid profile were measured initially and after the intervention.

Results: Repeated-measures ANOVA showed significant decrease in fasting blood sugar (p < 0.01) and HOMA-IR (p < 0.01), and greater improvements in TG (p < 0.05) and LDL (p < 0.05) in EG than CG, but. HDL concentration did not show significant changes.

Conclusion: The 10-week of aerobic-functional training improves fasting blood sugar, IR, and lipid profile in patients with diabetic neuropathy.

Effectiveness of Physical Exercise on the Glycemic Control of Type 2 Diabetes Mellitus Patients: A Systematic Review

Introduction: Type 2 diabetes mellitus (T2DM) is one of the main causes of increasing global health morbidity and mortality for diabetes cases. Increasing the glycemic control in patients with T2DM is not enough if it is only treated with anti-hyperglycemic drugs. Physical exercise is an activity that is planned, structured and carried out to improve health or physical fitness and it is an effective way to improve glycemic control. The aim of this study was to search and review the research on effectiveness of physical exercise on glycemic control in T2DM.Methods: We searched the scientific literature on T2DM and physical exercise in the ScienceDirect, ProQuest, Scopus, Ebsco and Pubmed databases for original research studies and then we reviewed them systematically. Of the 1145 articles retrieved, 14 studies were obtained by the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodResults: Aerobic physical exercise improved the glycemic control of T2DM and it was widely used and significant for glycemic control. The schedule of 3 times a week for 60 minutes per session over 2 months was widely used and significant when it came to reducing blood glucose and hemoglobin A1c (HbA1c).Conclusion: This systematic review could be used as evidence when carrying out aerobic physical exercise interventions for the purpose of glycemic control.

Dietary program and physical activity impact on biochemical markers in patients with type 2 diabetes: A systematic review

Objectives

Evaluate the effectiveness of the implementation of independently or combined dietary and physical activity programs on the blood glucose values and lipid profile in patients with type 2 diabetes, including participants aged 60 years and over.

Design

Systematic review.

Data source

PubMed/Medline database, with language restrictions. Papers published between 2010 and 2016 were included.

Study selection

A total of 30 randomised controlled trials were included that focused on physical activity and dietary interventions in patients with type 2 diabetes mellitus and include participants aged 60 years and over.

Results

The selected articles have shown that the implementation of physical activity programs (aerobic, resistance, flexibility and combined exercises), and programs based on a higher intake of vegetables, grains, legumes, fruits, unsaturated fatty acids, as well as consumption of foods with low glycaemic index, calorie restriction, intake of probiotics, vitamin D supplementation and educational sessions about diabetes improves blood glucose levels, as well as the lipid profile, in patients with type 2 diabetes.

Conclusions

Physical activity and dietary programs are fundamental in the treatment and metabolic control of type 2 diabetes mellitus.

Improvement of obesity-linked skeletal muscle insulin resistance by strength and endurance training

Obesity-linked insulin resistance is mainly due to fatty acid overload in non-adipose tissues, particularly skeletal muscle and liver, where it results in high production of reactive oxygen species and mitochondrial dysfunction. Accumulating evidence indicates that resistance and endurance training alone and in combination can counteract the harmful effects of obesity increasing insulin sensitivity, thus preventing diabetes. This review focuses the mechanisms underlying the exercise role in opposing skeletal muscle insulin resistance-linked metabolic dysfunction. It is apparent that exercise acts through two mechanisms: (1) it stimulates glucose transport by activating an insulin-independent pathway and (2) it protects against mitochondrial dysfunction-induced insulin resistance by increasing muscle antioxidant defenses and mitochondrial biogenesis. However, antioxidant supplementation combined with endurance training increases glucose transport in insulin-resistant skeletal muscle in an additive fashion only when antioxidants that are able to increase the expression of antioxidant enzymes and/or the activity of components of the insulin signaling pathway are used.

The effects of three different exercise modalities on markers of male reproduction in healthy subjects: a randomized controlled trial

The aim of this study was to investigate the effects of moderate-intensity continuous training (MICT), high-intensity continuous training (HICT) and high-intensity interval training (HIIT) on markers of male reproduction including seminal markers of oxidative stress and inflammation as well as semen quality and sperm DNA integrity in healthy human subjects. A total of 397 healthy male volunteers were screened and 280 were randomly assigned to one of the MICT (n = 70), HICT (n = 70), HIIT (n = 70) and non-exercise (NON-EX, n = 70) groups. Subjects had inflammatory markers (IL-1β, IL-6, IL-8 and TNF-α), oxidants (ROS, MDA and 8-isoprostane), antioxidants (SOD, catalase and TAC), semen parameters and sperm DNA damage measured at baseline (T1), the end of week 12 (T2), the end of week 24 (T3), and 7 (T4) and 30 days (T5) after training. Chronic MICT, HICT and HIIT attenuated seminal markers of oxidative stress and inflammation with different kinetics for the three types of exercise (P < 0.05), and these changes were correlated with favorable improvements in semen quality parameters and sperm DNA integrity (P < 0.05). MICT was superior to HICT and HIIT in the improvements of markers of male reproductive function (P < 0.05). In conclusion, different exercise modalities favorably affect markers of male reproduction with different kinetics, suggesting intensity-, duration- and type-dependent adaptations to exercise training in healthy human subjects.

Energy Expenditure in People with Diabetes Mellitus: A Review

Physical activity (PA) is an important non-therapeutic tool in primary prevention and treatment of diabetes mellitus (DM). To improve activity-based health management, patients need to quantify activity-related energy expenditure and the other components of total daily energy expenditure. This review explores differences between the components of total energy expenditure in patients with DM and healthy people and presents various tools for assessing the energy expenditure in subjects with DM. From this review, it appears that patients with uncontrolled DM have a higher basal energy expenditure (BEE) than healthy people which must be considered in the establishment of new BEE estimate equations. Moreover, studies showed a lower activity energy expenditure in patients with DM than in healthy ones. This difference may be partially explained by patient with DMs poor compliance with exercise recommendations and their greater participation in lower intensity activities. These specificities of PA need to be taken into account in the development of adapted tools to assess activity energy expenditure and daily energy expenditure in people with DM. Few estimation tools are tested in subjects with DM and this results in a lack of accuracy especially for their particular patterns of activity. Thus, future studies should examine sensors coupling different technologies or method that is specifically designed to accurately assess energy expenditure in patients with diabetes in daily life.

High Intensity Interval Training Improves Glycaemic Control and Pancreatic β Cell Function of Type 2 Diabetes Patients

Physical activity improves the regulation of glucose homeostasis in both type 2 diabetes (T2D) patients and healthy individuals, but the effect on pancreatic β cell function is unknown. We investigated glycaemic control, pancreatic function and total fat mass before and after 8 weeks of low volume high intensity interval training (HIIT) on cycle ergometer in T2D patients and matched healthy control individuals. Study design/method: Elderly (56 yrs±2), non-active T2D patients (n = 10) and matched (52 yrs±2) healthy controls (CON) (n = 13) exercised 3 times (10×60 sec. HIIT) a week over an 8 week period on a cycle ergometer. Participants underwent a 2-hour oral glucose tolerance test (OGTT). On a separate day, resting blood pressure measurement was conducted followed by an incremental maximal oxygen uptake (V˙O_2max) cycle ergometer test. Finally, a whole body dual X-ray absorptiometry (DXA) was performed. After 8 weeks of training, the same measurements were performed. Results: in the T2D-group, glycaemic control as determined by average fasting venous glucose concentration (p = 0.01), end point 2-hour OGTT (p = 0.04) and glycosylated haemoglobin (p = 0.04) were significantly reduced. Pancreatic homeostasis as determined by homeostatic model assessment of insulin resistance (HOMA-IR) and HOMA β cell function (HOMA-%β) were both significantly ameliorated (p = 0.03 and p = 0.03, respectively). Whole body insulin sensitivity as determined by the disposition index (DI) was significantly increased (p = 0.03). During OGTT, the glucose continuum was significantly reduced at -15 (p = 0.03), 30 (p = 0.03) and 120 min (p = 0.03) and at -10 (p = 0.003) and 0 min (p = 0.003) with an additional improvement (p = 0.03) of its 1^st phase (30 min) area under curve (AUC). Significant abdominal fat mass losses were seen in both groups (T2D: p = 0.004 and CON: p = 0.02) corresponding to a percentage change of -17.84%±5.02 and -9.66%±3.07, respectively. Conclusion: these results demonstrate that HIIT improves overall glycaemic control and pancreatic β cell function in T2D patients. Additionally, both groups experienced abdominal fat mass losses. These findings demonstrate that HIIT is a health beneficial exercise strategy in T2D patients.

Financial strain is associated with increased oxidative stress levels: the Women's Health and Aging Studies

Elevated oxidative stress levels may be one mechanism contributing to poor health outcomes. Financial strain and oxidative stress are each predictors of morbidity and mortality, but little research has investigated their relationship. Community-dwelling older adults (n = 728) from the Women's Health and Aging Studies I and II were included in this cross-sectional analysis. Financial strain was ascertained as an ordinal response to: "At the end of the month, do you have more than enough money left over, just enough, or not enough?" Oxidative stress was measured using serum protein carbonyl concentrations. Linear regression was used to quantify the relationship between financial strain and oxidative stress. Participants who reported high financial strain exhibited 13.4% higher protein carbonyl concentrations compared to individuals who reported low financial strain (p = 0.002). High financial strain may be associated with increased oxidative stress, suggesting that oxidative stress could mediate associations between financial strain and poor health.

Physical exercise and redox balance in type 2 diabetics: effects of moderate training on biomarkers of oxidative stress and DNA damage evaluated through comet assay

Objective. Hyperglycemia leads to increased production of reactive oxygen species (ROS) in type 2 diabetes, which reduces cellular antioxidant defenses and induces DNA lesions. The aim of this study was to investigate the effects on redox homeostasis and DNA oxidative damage of exercise training in patients with type 2 diabetes compared with nondiabetic individuals. Methods and Results. 12 sedentary type 2 diabetic males (62.1 ± 4.3 yrs) and 12 sedentary healthy males (61.7 ± 3.9 yrs) were exposed to 4-month moderate training, 3 times per week, to evaluate the effect on plasma biomarkers of oxidative stress malondialdehyde and antioxidant status (GSSG, GSH/GSSG, and ascorbic acid) as well as basal and H₂O₂-induced DNA damage trough alkaline comet assay in peripheral blood lymphocytes. After training, glutathione and ascorbic acid levels increased in both groups, but only in diabetics the malondialdehyde as well as the DNA damage decreased. Conclusion. Our study demonstrates for the first time that moderate exercise training is not only effective in improving the redox homeostasis, through an increase of the endogenous antioxidant defences in healthy as well as in diabetic patients, but also, specifically in diabetic patients, effective in lowering the susceptibility to oxidative DNA damage and the lipid peroxidation levels.

Swimming training induces liver mitochondrial adaptations to oxidative stress in rats submitted to repeated exhaustive swimming bouts

BACKGROUND AND AIMS

Although acute exhaustive exercise is known to increase liver reactive oxygen species (ROS) production and aerobic training has shown to improve the antioxidant status in the liver, little is known about mitochondria adaptations to aerobic training. The main objective of this study was to investigate the effects of the aerobic training on oxidative stress markers and antioxidant defense in liver mitochondria both after training and in response to three repeated exhaustive swimming bouts.

METHODS

Wistar rats were divided into training (n = 14) and control (n = 14) groups. Training group performed a 6-week swimming training protocol. Subsets of training (n = 7) and control (n = 7) rats performed 3 repeated exhaustive swimming bouts with 72 h rest in between. Oxidative stress biomarkers, antioxidant activity, and mitochondria functionality were assessed.

RESULTS

Trained group showed increased reduced glutathione (GSH) content and reduced/oxidized (GSH/GSSG) ratio, higher superoxide dismutase (MnSOD) activity, and decreased lipid peroxidation in liver mitochondria. Aerobic training protected against exhaustive swimming ROS production herein characterized by decreased oxidative stress markers, higher antioxidant defenses, and increases in methyl-tetrazolium reduction and membrane potential. Trained group also presented higher time to exhaustion compared to control group.

CONCLUSIONS

Swimming training induced positive adaptations in liver mitochondria of rats. Increased antioxidant defense after training coped well with exercise-produced ROS and liver mitochondria were less affected by exhaustive exercise. Therefore, liver mitochondria also adapt to exercise-induced ROS and may play an important role in exercise performance.

Associations among physical activity, comorbidities, depressive symptoms and health-related quality of life in type 2 diabetes

OBJECTIVE: To investigate associations between physical activity, comorbidity severity, depressive symptoms, and health-related quality of life in type 2 diabetes mellitus. SUBJECTS AND METHODS: All individuals, 200 patients and 50 controls, aged from 40 to 60 years, were investigated by interview, and all variables were measured concurrently. Physical activity was evaluated by the International Physical Activity Questionnaire (IPAQ), Health-Related Quality of Life (HRQL) by the Short-Form Health Survey (SF-36), comorbidity severity by the Charlson Comorbidity Index (CCI), and depressive symptoms by the Beck Depression Inventory (BDI-II > 16). Single and multiple regression analysis evaluated the effects of independent variables on physical activity. RESULTS: The patients had more depressive symptoms and greater comorbidity severity (p < 0.005). Diabetic patients showed better activity levels (IPAQ) (p < 0.005). Functional Capacity, General State of Health, and Physical Limitation were the most affected subscales in the SF-36 evaluation of the HRQL. Sedentary diabetic patients had higher waist circumference, waist-to-hip ratios, more depressive symptoms, and worse HRQL. Functional capacity (p = 0.000), followed by General State of Health (p = 0.02), were the health status measure subscales independently associated with physical activity. Conclusions: The findings suggest that increasing patient independence and treating depressive symptoms can promote physical activity for type 2 diabetes mellitus patients. It is suggested that group activities and caregivers/family support might compensate for the patient dependence, and increase adherence to exercise programs in those that are less active.

Two Valid Measures of Self-rated Physical Activity and Capacity

Objectives:

Questionnaires on physical activity (PA) and physical capacity (PC) are valuable tools, as they are cost beneficial, and have high response rates. The validity of short versions of such questionnaires has not been examined satisfactorily. Therefore, we aimed at examining the validity of a set of questions coding for PA and PC.

Design:

The questions were administered to 217 men and women attending a cardiac rehabilitation program. Participants also gave blood samples, measuring HDL cholesterol, triglycerides (TG), insulin, glucose, and microCRP. The relations between PA and PC and biological markers were examined by linear regression analyses.

Results:

Measures for PC and for PA were identified by factor analysis, which proved internally consistent. TG, homeostatic model assessment (HOMA) score, and mCRP were all significantly associated with the measures of PC and PA.

Conclusions:

The measures of PA and PC are valid compared with biological markers, allowing cost-beneficial and time-efficient evaluation of important measures for cardiovascular health.

Regular physical exercise as a strategy to improve antioxidant and anti-inflammatory status: benefits in type 2 diabetes mellitus

Over the last 30 years the combination of both a sedentary lifestyle and excessive food availability has led to a significant increase in the prevalence of obesity and aggravation of rates of metabolic syndrome and type 2 diabetes mellitus (T2DM). Several lines of scientific evidence have been demonstrating that a low level of physical activity and decreased daily energy expenditure leads to the accumulation of visceral fat and, consequently, the activation of the oxidative stress/inflammation cascade, which underlies the development of insulin resistant T2DM and evolution of micro, and macrovascular complications. This paper focuses on the pathophysiological pathways associated with the involvement of oxidative stress and inflammation in the development of T2DM and the impact of regular physical exercise (training) as a natural antioxidant and anti-inflammatory strategy to prevent evolution of T2DM and its serious complications.

Patterns of yoga practice and physical activity following a yoga intervention for adults with or at risk for type 2 diabetes

BACKGROUND

The current study described patterns of yoga practice and examined differences in physical activity over time between individuals with or at risk for type 2 diabetes who completed an 8-week yoga intervention compared with controls.

METHODS

A longitudinal comparative design measured the effect of a yoga intervention on yoga practice and physical activity, using data at baseline and postintervention months 3, 6, and 15.

RESULTS

Disparate patterns of yoga practice occurred between intervention and control participants over time, but the subjective definition of yoga practice limits interpretation. Multilevel model estimates indicated that treatment group did not have a significant influence in the rate of change in physical activity over the study period. While age and education were not significant individual predictors, the inclusion of these variables in the model did improve fit.

CONCLUSIONS

Findings indicate that an 8-week yoga intervention had little effect on physical activity over time. Further research is necessary to explore the influence of yoga on behavioral health outcomes among individuals with or at risk for type 2 diabetes.

Voluntary exercise attenuates obesity-associated inflammation through ghrelin expressed in macrophages

Chronic low-level inflammation is associated with obesity and a sedentary lifestyle, causing metabolic disturbances such as insulin resistance. Exercise training has been shown to decrease chronic low-level systemic inflammation in high-fat diet (HFD)-induced obesity. However, the molecular mechanisms mediating its beneficial effects are not fully understood. Ghrelin is a peptide hormone predominantly produced in the stomach that stimulates appetite and induces growth hormone release. In addition to these well-known functions, recent studies suggest that ghrelin localizes to immune cells and exerts an anti-inflammatory effect. The purpose of the current study was to investigate the role of ghrelin expressed in macrophages in the anti-inflammatory effects of voluntary exercise training. Expression of tumor necrosis factor-α (TNF-α), monocyte chemotactic protein (MCP)-1 and F4/80 was increased in adipose tissue from mice fed a HFD (HFD mice) compared with mice fed a standard diet (SD mice), whereas the expression of these inflammatory cytokines was markedly decreased in mice performing voluntary wheel running during the feeding of a HFD (HFEx mice). The expression of TNF-α was also increased in peritoneal macrophages by a HFD and exercise training inhibited the increase of TNF-α expression. Interestingly, expression of ghrelin in peritoneal macrophages was decreased by a HFD and recovered by exercise training. Suppression of ghrelin expression by siRNA increased TNF-α expression and LPS-stimulated NF-κB activation in RAW264 cells, which is a macrophage cell line. TNF-α expression by stimulation with LPS was significantly suppressed in RAW264 cells cultured in the presence of ghrelin. These results suggest that ghrelin exerts potent anti-inflammatory effects in macrophages and functions as a mediator of the beneficial effects of exercise training.

Energy expenditure and plasma F2-isoprostanes across the menstrual cycle

INTRODUCTION

Habitual energy expenditure seems to favorably alter oxidant/antioxidant balance. Sparse evidence suggests that hormones that fluctuate during the menstrual cycle, particularly estrogens, may influence concentrations of oxidative biomarkers and their relation to energy expenditure.

METHODS

We investigated the relation between energy expenditure and plasma free F2-isoprostane concentrations in 259 healthy, regularly menstruating 18- to 44-yr-old participants of the BioCycle Study. Habitual energy expenditure was measured using a baseline International Physical Activity Questionnaire and categorized as low, moderate, or high. Women were followed for one or two subsequent menstrual cycles. Past-week and past-day physical activity were measured during follow-up using questionnaires and diaries, respectively. F2-isoprostane concentrations were measured in blood samples collected at both menses (approximate cycle day 2; low serum estradiol concentration) and the late follicular phase (approximate cycle day 12; peak estradiol concentration). Generalized estimating equations were used to model the energy expenditure/isoprostane association, adjusting for confounders.

RESULTS

Habitual energy expenditure was positively associated with F2-isoprostane concentration (adjusted difference in median F2-isoprostane, high versus low energy expenditure: 17.4%; 95% confidence interval (CI)=3.3%-31.4%). This association was not modified by cycle phase (interaction, P=0.61) or differences in peak estradiol concentration across women (interaction, P=0.20). Past-week and past-day physical activity measures were not associated with F2-isoprostane concentration (category trend, P=0.50 and P=0.18, respectively).

CONCLUSIONS

These results suggest that higher habitual energy expenditure may be associated with higher concentration of F2-isoprostanes in healthy, reproductive-aged women. Estradiol concentration changes during the menstrual cycle do not seem to influence this relationship.

Design and methods for a pilot randomized clinical trial involving exercise and behavioral activation to treat comorbid type 2 diabetes and major depressive disorder

BACKGROUND: The comorbidity of type 2 diabetes mellitus (T2DM) and depression is associated with poor glycemic control. Exercise has been shown to improve mood and glycemic control, but individuals with comorbid T2DM and depression are disproportionately sedentary compared to the general population and report more difficulty with exercise. Behavioral activation, an evidence-based depression psychotherapy, was designed to help people with depression make gradual behavior changes, and may be helpful to build exercise adherence in sedentary populations. This pilot randomized clinical trial will test the feasibility of a group exercise program enhanced with behavioral activation strategies among women with comorbid T2DM and depression. METHODS/DESIGN: Sedentary women with inadequately controlled T2DM and depression (N=60) will be randomly assigned to one of two conditions: exercise or usual care. Participants randomized to the exercise condition will attend 38 behavioral activation-enhanced group exercise classes over 24 weeks in addition to usual care. Participants randomized to the usual care condition will receive depression treatment referrals and print information on diabetes management via diet and physical activity. Assessments will occur at baseline and 3-, 6-, and 9-months following randomization. The goals of this pilot study are to demonstrate feasibility and intervention acceptability, estimate the resources and costs required to deliver the intervention and to estimate the standard deviation of continuous outcomes (e.g., depressive symptoms and glycosylated hemoglobin) in preparation for a fully-powered randomized clinical trial. DISCUSSION: A novel intervention that combines exercise and behavioral activation strategies could potentially improve glycemic control and mood in women with comorbid type 2 diabetes and depression. TRIAL REGISTRATION: NCT01024790.

Effect of antioxidant supplementation on insulin sensitivity in response to endurance exercise training

While production of reactive oxygen and nitrogen species (RONS) is associated with some of the beneficial adaptations to regular physical exercise, it is not established whether RONS play a role in the improved insulin-stimulated glucose uptake in skeletal muscle obtained by endurance training. To assess the effect of antioxidant supplementation during endurance training on insulin-stimulated glucose uptake, 21 young healthy (age 29 ± 1 y, BMI 25 ± 3 kg/m(2)) men were randomly assigned to either an antioxidant [AO; 500 mg vitamin C and 400 IU vitamin E (α-tocopherol) daily] or a placebo (PL) group that both underwent a supervised intense endurance-training program 5 times/wk for 12 wk. A 3-h euglycemic-hyperinsulinemic clamp, a maximal oxygen consumption (Vo(2max)) and maximal power output (P(max)) test, and body composition measurements (fat mass, fat-free mass) were performed before and after the training. Muscle biopsies were obtained for determination of the concentration and activity of proteins regulating glucose metabolism. Although plasma levels of vitamin C (P < 0.05) and α-tocopherol (P < 0.05) increased markedly in the AO group, insulin-stimulated glucose uptake increased similarly in both the AO (17.2%, P < 0.05) and the PL (18.9%, P < 0.05) group in response to training. Vo(2max) and P(max) also increased similarly in both groups (time effect, P < 0.0001 for both) as well as protein content of GLUT4, hexokinase II, and total Akt (time effect, P ≤ 0.05 for all). Our results indicate that administration of antioxidants during strenuous endurance training has no effect on the training-induced increase in insulin sensitivity in healthy individuals.

Oxidative stress and antioxidant defense mechanisms linked to exercise during cardiopulmonary and metabolic disorders

Oxidative stress has been implicated in the pathophysiology of multiple human diseases, in addition to the aging process. Although various stimuli exist, acute exercise is known to induce a transient increase in reactive oxygen and nitrogen species (RONS), evident by several reports of increased oxidative damage following acute bouts of aerobic and anaerobic exercise. Although the results are somewhat mixed and appear disease dependent, individuals with chronic disease experience an exacerbation in oxidative stress following acute exercise when compared to healthy individuals. However, this increased oxidant stress may serve as a necessary “signal” for the upregulation in antioxidant defenses, thereby providing protection against subsequent exposure to prooxidant environments within susceptible individuals. Here we present studies related to both acute exercise-induced oxidative stress in those with disease, in addition to studies focused on adaptations resulting from increased RONS exposure associated with chronic exercise training in persons with disease.

Does exercise affect the antioxidant system in patients with ankylosing spondylitis?

We aimed to investigate the effect of regular supervised exercise program on functional status, disease activity, and total antioxidant status (TAS) level in patients with ankylosing spondylitis (AS). Thirty-two patients (mean age: 44 years) with AS were included in the study and divided into two groups. Group 1, the exercise group (n = 16), attended a supervised exercise program that consisted of aerobic, strengthening, and stretching exercises for 1 h a day, five times a week for 3 weeks. Group 2, the control group, received a home exercise program (n:16). Bath AS Activity Index (BASDAI) and Bath AS Functional Index (BASFI) were calculated and serum TAS levels were measured for each patient at 0 and 3 weeks. There was no significant difference in patients' baseline characteristics (age, disease duration, BASFI, and BASDAI scores) between exercise and control groups. In the exercise group, there were significant improvements between pre-exercise and post-exercise assessments in BASFI (2.8 +/- 1,8; 1.7 +/- 1,40, p = 0.004) and BASDAI scores (2.1 +/- 1.7; 1.2 +/- 1.3, p = 0.01). Mean TAS levels were significantly decreased after supervised exercise program (1.48 +/- 0.16 mmol/L; 1.36 +/- 0.20 mmol/L, p = 0.03). In the control group, BASFI score (2.4 +/- 1.7; 2.9 +/- 2.1, p = 0.19), BASDAI score (2.6 +/- 2.2; 3.1 +/- 2.6, p = 0.33), and mean TAS levels (1.38 +/- 0.23 mmol/L; 1.39 +/- 0.20 mmol/L, p = 0.66) did not differ significantly between 0 and 3 weeks. Short-term, supervised exercise program improved functional status and decreased disease activity. However, the mechanism of this beneficial clinical effect does not seem to be through antioxidant activity.

The effects of polyphenol-containing antioxidants on oxidative stress and lipid peroxidation in Type 2 diabetes mellitus without complications

BACKGROUND

The hyperglycemia-induced oxidative stress in diabetes mellitus (DM) is the major factor in the pathogenesis of cardiovascular complications. The phenolic compounds are potent antioxidants that can reverse the factors leading to cardiovascular complications in DM. The aim of this study was to determine the antagonizing effects of a polyphenol-rich antioxidant supplement containing pomegranate extract, green tea extract, and ascorbic acid, on oxidative stress in Type 2 diabetic patients.

MATERIALS AND METHODS

A total of 114 male and female non-smokers (56 study, 58 placebo) with Type 2 DM and without any complications were recruited. The blood levels of fasting blood glucose, glycated hemoglobin, LDL, HDL, triglycerides, plasma malondialdehyde (MDA), total glutathione (GSH), hydrogen peroxide, and antioxidant capacity (AOC) were determined at the beginning and at the end of the 3-month trial. The differences of the data changes between the groups were statistically analyzed by Mann-Whitney U test.

RESULTS

The study group showed a decrease in LDL and an increase in HDL and the comparison with the difference in placebo group was statistically significant (p<0.001 for LDL and p<0.001 for HDL). Accordingly, as a by-product of lipid peroxidation, plasma MDA was decreased in the study group compared to the placebo group (p<0.001). As an indicator of increased antioxidant defense, total plasma GSH and AOC increased more in the study group compared to control group (p<0.001).

CONCLUSIONS

These observations indicated that the polyphenol-rich antioxidant supplement containing pomegranate extract, green tea extract, and ascorbic acid has important antagonizing effects on oxidative stress and lipid peroxidation in patients with Type 2 DM and might be beneficial in preventing cardiovascular complications.

Physical activity and reported barriers to activity among type 2 diabetic patients in the United arab emirates

OBJECTIVES

This study was designed to assess the physical activity practice among type 2 diabetic patients in the United Arab Emirates (UAE).

METHODS

This is a cross-sectional study of type 2 diabetic patients who participated in the outpatient clinics in Al-Ain District, during 2006. The patients completed an interviewer-administered questionnaire, and measurements of blood pressure, body mass index, body fat, abdominal circumference, glycemic control (HbA1c), and fasting lipid profile.

RESULTS

Of the 390 patients recruited, only 25% reported an increase in their physical activity levels following the diagnosis of diabetes, and only 3% reported physical activity levels that meet the recommended guidelines. More than half of the study subjects had uncontrolled hypertension (53%) and unacceptable lipid profiles; 71% had a high low-density lipoprotein (LDL), 73% had low high-density lipoprotein (HDL), and 59% had hypertriglyceridemia. Forty-four percent were obese and a further 34% were overweight. Abdominal obesity was also common (59%). Only 32% had an acceptable glycemic control.

CONCLUSIONS

The physical activity practice of type 2 diabetic patients in the UAE is largely inadequate to meet the recommended level necessary to prevent or ameliorate diabetic complications. Interventions aiming at overcoming the barriers to physical activity are urgently needed.

Effects of Aerobic Exercise on Microalbuminuria and Enzymuria in Type 2 Diabetic Patients

Increased urinary albumin excretion is a strong predictor for the development of overt diabetic nephropathy and overall cardiovascular morbidity and mortality in patients with type 2 diabetes. In a previous study, regular aerobic physical activity in overweight/obese patients with type 2 diabetes mellitus was found to have significant beneficial effects on glycemic control, insulin resistance, cardiovascular risk factors, and oxidative stress. The aim of the present study was to investigate the effects of aerobic exercise in the same cohort of type 2 diabetic patients on urinary albumin excretion, serum levels and urinary excretion of enzymes, tubular damage, and metabolic control markers in type 2 diabetic patients. Changes from baseline to 3 and 6 months of aerobic exercise were assessed for urinary albumin excretion, serum activities, and urinary excretion of N-acetyl-beta-D-glucosaminidase (NAGA), plasma cell glycoprotein 1 (PC-1) and aminopeptidase N (APN), as well as their association with insulin resistance, cardiovascular risk factors, and oxidative stress parameters in 30 male type 2 diabetic patients (aged 54.8 +/- 7.3 years, with a mean BMI of 30.8 +/- 3.0 kg/m2). Microalbuminuria was found in six (20%) diabetic patients at baseline, three of them (10%) after three months, and only one patient (3.33%) at the end of the study period. A significant correlation was found for urinary albumin excretion at baseline both with sulfhydryl-groups and catalase, but not for urinary albumin excretion with MDA and glutathione. The prevalence of microalbuminuria tended to decrease after six months of aerobic exercise in type 2 diabetic patients, independently of any improvement in insulin resistance and oxidative stress parameters. Neither between-group nor within-group changes were found for urinary PC-1, APN, and NAGA activity. Serum NAGA was significantly increased (p < 0.05) over the control level in diabetic patients at baseline, but it decreased to the normal level after six months of exercise. This study has shown that a six-month aerobic exercise, without any change in the medication, tended to decrease microalbuminuria without changing enzymuria. However, further studies are needed not only to confirm those findings, but to elucidate potential mechanisms that would clarify the beneficial effects of exercise.

Home-based resistance training improves arterial stiffness in healthy premenopausal women

The present study investigates the effect of home-based resistance training on arterial stiffness in healthy premenopausal women. Twelve healthy non-smoking and normotensive women who were not actively involved in regular physical exercise (aged 42-55 years) performed home-based resistance training twice weekly for 10 weeks using body weight and light dumbbells. Each training session required approximately 40 min to complete. Arterial stiffness was measured using brachial-ankle pulse wave velocity (baPWV). We also determined serum total cholesterol, HDL cholesterol, glucose, triglyceride, insulin, and adiponectin and calculated the homeostasis model assessment of insulin resistance (HOMA-IR), an index of insulin resistance. After home-based resistance training, baPWV, total cholesterol, LDL cholesterol, insulin, and the HOMA-IR decreased, whereas adiponectin increased (P < 0.05) and levels of HDL cholesterol, glucose, triglyceride, blood pressure, and heart rate remained unaffected. These results suggest that home-based resistance training benefits vascular function in healthy premenopausal women.

Raisins and additional walking have distinct effects on plasma lipids and inflammatory cytokines

Background

Raisins are a significant source of dietary fiber and polyphenols, which may reduce cardiovascular disease (CVD) risk by affecting lipoprotein metabolism and inflammation. Walking represents a low intensity exercise intervention that may also reduce CVD risk. The purpose of this study was to determine the effects of consuming raisins, increasing steps walked, or a combination of these interventions on blood pressure, plasma lipids, glucose, insulin and inflammatory cytokines.

Results

Thirty-four men and postmenopausal women were matched for weight and gender and randomly assigned to consume 1 cup raisins/d (RAISIN), increase the amount of steps walked/d (WALK) or a combination of both interventions (RAISINS + WALK). The subjects completed a 2 wk run-in period, followed by a 6 wk intervention. Systolic blood pressure was reduced for all subjects (P = 0.008). Plasma total cholesterol was decreased by 9.4% for all subjects (P < 0.005), which was explained by a 13.7% reduction in plasma LDL cholesterol (LDL-C) (P < 0.001). Plasma triglycerides (TG) concentrations were decreased by 19.5% for WALK (P < 0.05 for group effect). Plasma TNF-α was decreased from 3.5 ng/L to 2.1 ng/L for RAISIN (P < 0.025 for time and group × time effect). All subjects had a reduction in plasma sICAM-1 (P < 0.01).

Conclusion

This research shows that simple lifestyle modifications such as adding raisins to the diet or increasing steps walked have distinct beneficial effects on CVD risk.

Involvement of advanced glycation end products in the pathogenesis of diabetic complications: the protective role of regular physical activity

Advanced glycation end products (AGEs) may play an important role in the pathogenesis of chronic diabetic complications and in the natural process of biological aging. In fact, maintained hyperglycaemia favours the formation of AGEs at the tissue level in diabetic patients, which may influence the triggering of different chronic pathologies of diabetes such as retinopathy, nephropathy, neuropathy and macro- and micro-vascular diseases. Moreover, the literature has also demonstrated the involvement of AGEs in biological aging, which may explain the accelerated process of aging in diabetic patients. The practice of regular physical activity appears to positively influence glycaemic control, particularly in type 2 diabetes mellitus patients. This occurs through the diminution of fasting glycaemia, with a consequent reduction of glycation of plasmatic components suggested by the normalisation of HbA1c plasmatic levels. This exercise-induced positive effect is evident in the blood of diabetic patients and may also reach the endothelium and connective tissues of different organs, such as the kidneys and eyes, and systems, such as the cardiovascular and nervous systems, with a local reduction of AGEs production and further deceleration of organ dysfunction. The aim of this paper was to review the literature concerning this topic to coherently describe the harmful effects of AGEs in organ dysfunction induced by diabetes in advanced age as well as the mechanisms behind the apparent protection given by the practice of regular physical activity.

Oxidative stress and severe walking disability among older women

BACKGROUND

Oxidative stress has been implicated in sarcopenia and the loss of muscle strength with aging, but the relationship between oxidative stress and decrease in muscle strength and physical performance has not been well characterized. Serum protein carbonyls are markers of oxidative damage to proteins and are caused by oxidative stress.

METHODS

Serum protein carbonyls were measured at baseline and compared with a decrease in walking speed and development of severe walking disability (inability to walk or walking speed <0.4 m/sec) over 36 months of follow-up in 545 moderately to severely disabled women, aged > or =65 years, living in the community in Baltimore, Maryland (the Women's Health and Aging Study I).

RESULTS

After adjusting for age, body mass index, smoking, and chronic diseases, log(e) protein carbonyls (nmol/mg) were associated with a decrease in walking speed over 36 months (P=.002). During follow-up, 154 women (28.2%) developed severe walking disability. After adjusting for the same potential confounders, log(e) protein carbonyls were associated with incident severe walking disability (hazards ratio 1.42, 95% confidence interval, 1.02-1.98, P=.037).

CONCLUSION

High oxidative stress, as indicated by oxidative damage to proteins, is an independent predictor of decrease in walking speed and progression to severe walking disability among older women living in the community.

Combined aerobic and resistance training and vascular function: effect of aerobic exercise before and after resistance training

Aerobic exercise training combined with resistance training (RT) might prevent the deterioration of vascular function. However, how aerobic exercise performed before or after a bout of RT affects vascular function is unknown. The present study investigates the effect of aerobic exercise before and after RT on vascular function. Thirty-three young, healthy subjects were randomly assigned to groups that ran before RT (BRT: 4 male, 7 female), ran after RT (ART: 4 male, 7 female), or remained sedentary (SED: 3 male, 8 female). The BRT and ART groups performed RT at 80% of one repetition maximum and ran at 60% of the targeted heart rate twice each week for 8 wk. Both brachial-ankle pulse wave velocity (baPWV) and flow-mediated dilation (FMD) after combined training in the BRT group did not change from baseline. In contrast, baPWV after combined training in the ART group reduced from baseline (from 1,025 +/- 43 to 910 +/- 33 cm/s, P < 0.01). Moreover, brachial artery FMD after combined training in the ART group increased from baseline (from 7.3 +/- 0.8 to 9.6 +/- 0.8%, P < 0.01). Brachial artery diameter, mean blood velocity, and blood flow in the BRT and ART groups after combined training increased from baseline (P < 0.05, P < 0.01, and P < 0.001, respectively). These values returned to the baseline during the detraining period. These values did not change in the SED group. These results suggest that although vascular function is not improved by aerobic exercise before RT, performing aerobic exercise thereafter can prevent the deteriorating of vascular function.