Vascular function in health, hypertension, and diabetes: effect of physical activity on skeletal muscle microcirculation

Diazoxide and moderate-intensity exercise improve skeletal muscle function by decreasing oxidants and enhancing antioxidant defenses in hypertensive male rats

High sodium intake is decisive in the incidence increase and prevalence of hypertension, which has an impact on skeletal muscle functionality. Diazoxide is an antihypertensive agent that inhibits insulin secretion and is an opener of KATP channels (adosine triphosphate sensitive potasium channels). For this reason, it is hypothesized that moderate-intensity exercise and diazoxide improve skeletal muscle function by reducing the oxidants in hypertensive rats. Male Wistar rats were assigned into eight groups: control (CTRL), diazoxide (DZX), exercise (EX), exercise + diazoxide (EX + DZX), hypertension (HTN), hypertension + diazoxide (HTN + DZX), hypertension + exercise (HTN + EX), and hypertension + exercise + diazoxide (HTN + EX + DZX). To induce hypertension, the rats received 8% NaCl dissolved in water orally for 30 days; in the following 8 weeks, 4% NaCl was supplied to maintain the pathology. The treatment with physical exercise of moderate intensity lasted 8 weeks. The administration dose of diazoxide was 35 mg/kg intraperitoneally for 14 days. Tension recording was performed on the extensor digitorum longus and the soleus muscle. Muscle homogenates were used to measure oxidants using fluorescent probe and the activity of antioxidant systems. Diazoxide and moderate-intensity exercise reduced oxidants and increased antioxidant defenses.

Association between joint physical activity and healthy dietary patterns and hypertension in US adults: cross-sectional NHANES study

BACKGROUND

Lack of physical activity (PA), poor dietary habits, or other unhealthy lifestyle behaviors are potential modifiable risk factors for hypertension. It has been sufficiently demonstrated in previous studies that physical activity or healthy dietary patterns can reduce the risk of hypertension. However, no research focused on the joint effects of PA and healthy dietary patterns on hypertension in a representative sample of adults.

METHODS

We used data collected from the 2007-2018 National Health and Nutrition Examination Survey. Healthy dietary patterns were assessed with the Healthy Eating Index 2015 (HEI-2015), and PA was measured using the metabolic equivalent minutes per week reported in questionnaires. We created four lifestyle categories based on the HEI-2015 and PA: (1) unhealthy diet and physically inactive (less than recommended PA), (2) healthy diet but physically inactive, (3) unhealthy diet but physically active (recommended PA), (4) healthy diet and physically active. Logistic regression was used to evaluate the association between joint PA and HEI-2015 and hypertension.

RESULTS

A total of 24,453 participants were enrolled in the study. Compared with unhealthy diet and physically inactive individuals, only healthy diet and physically active participants (adjusted odds ratio [AOR]: 0.77, 95% CI 0.65-0.9) were negatively associated with hypertension, while healthy diet but physically inactive participants (AOR: 0.89, 95% CI 0.76-1.03) and unhealthy diet but physically active participants (AOR: 0.9, 95% CI 0.76-1.06) were not associated with hypertension.

CONCLUSION

In a representative sample of US adults, our findings suggest that individuals with recommended PA and healthy dietary patterns have a lower risk of hypertension than those with an unhealthy diet or less than recommended PA. Healthy eating habits and regular PA are potential preventive precautions against hypertension.

Trends in deaths and disability-adjusted life-years of stroke attributable to low physical activity worldwide, 1990-2019

BACKGROUND

Low physical activity (LPA) is linked to the risk of stroke, but the disease burden of stroke attributable to LPA needs to be understood to develop effective preventive strategies. We aim to assess spatiotemporal trends in the global burden of stroke attributable to LPA from 1990 to 2019.

METHODS

Based on the Global Burden of Disease, Injuries, and Risk Factors Study, our research examined deaths, the Disability-Adjusted Life Years (DALYs), the Age-Standardized Mortality Rate (ASMR), the Age-Standardized DALY Rate (ASDR), and the Estimated Annual Percentage Change (EAPC) for stroke attributable to LPA.

RESULTS

Deaths and DALYs were on the rise worldwide from 1990 to 2019, with increases of 72.72% for the former and 67.41% for the latter; ASMR and ASDR decreased, with the ASMR-related EAPC of -1.61 (95% CI:-1.71--1.5) and ASDR-related EAPC of -1.35 (95% CI:-1.43--1.27); females had more numbers of deaths and DALYs, and the majorities of deaths and DALYs were shared by those aged ≥ 70. The highest burden rates were shared by North Africa, the Middle East, and Tropical Latin America; the ASMR-related EAPC was associated with the ASMR in 1990 (R = -0.26, P < 0.001) and the Socio-Demographic Index (SDI) across different countries in 2019 (R = -0.61, P < 0.001), respectively, and such patterns were similar to what ASDR and the ASDR-related EAPC had; the Human Development Index (HDI) in 2019 was associated with the ASMR-related EAPC (R = 0.63, P < 0.001) and the ASDR-related EAPC across different countries (R = -0.62, P < 0.001), respectively.

CONCLUSIONS

Globally, deaths and DALYs of stroke attributable to LPA were on the rise, although their age-standardized rates presented downward over the past three decades; the burden of stroke attributable to LPA showed upward trends especially in those aged ≥ 70 and females in the regions of East Asia, North Africa, and the Middle East, which need more attention to the effects of physical activity on health interventions.

The mediation role of physical fitness in association between muscle-strengthening physical activities and its component with blood pressure among young adults: considering gender and abnormal blood pressure as moderators, moderate-vigorous physical activity, sleep behavior, sedentary behavior, mental wellbeing and BMI as covariates

Background

Global burden of hypertension among young people continues to increase. There have been many studies examining the effect of aerobic and muscle-strengthening physical activity on blood pressure, many of them didn't consider interdependence between them. Conflicting results of health-related fitness, particularly handgrip strength, as intermediate outcomes of muscle-strengthening physical activity on blood pressure also emerged. This research will carry out a mediation-moderation analysis to find out the relationship between muscle strengthening physical activity and blood pressure among young adults by considering health-related fitness and 24-hour movement behavior.

Methods

A cross-sectional study among 221 Indonesian young adults attending a physical activity intervention collected participant's muscle-strengthening physical activity, and 24 h movement behavior, including aerobic physical activity, sedentary and sleep behavior, and mental well-being using validated questionnaires. Mediation and moderation analyses were conducted using Process Macro model 10 on SPSS 25 to investigate the association of muscle-strengthening physical activity on blood pressure, with gender and blood pressure as moderator, mediators consist of handgrip strength, muscle mass percentage and cardiorespiratory fitness. A subgroup analysis was conducted based on participant's cardiorespiratory fitness level.

Results

Volume of muscle-strengthening physical activities in a week have a direct association with systolic blood pressure among prehypertensive male with an effect of 0,00989359 (95% CI 0,0046488 to 0,00336478). Considering its volume as mediator, the frequency of muscle-strengthening physical activity contributed to a significant direct effect on diastolic blood pressure in both genders, but the duration of MSPA has a significant direct effect on systolic blood pressure in male subjects. There is no component of physical fitness that provides a significant mediating effect. After a subgroup analysis, the relationship between MSPA Volume and blood pressure is not significant for individuals with a high level of cardiorespiratory fitness.

Conclusions

This study shows that increased participation in muscle strengthening physical activity, especially in subject with low cardiorespiratory fitness, could increase blood pressure in prehypertensive young adult male population without mediation by physical fitness. Further research is needed to investigate other mechanisms that influence this relationship.

Effects of exergaming on the microcirculation of adolescents with overweight or obesity-a clinical trial efficacy

To assess the effect of exergaming on the microcirculation function of adolescents with overweight or obesity, this non-randomized clinical trial efficacy was conducted with 61 adolescents aged between 10 and 16 years. The intervention group (n = 31) performed exergaming three times per week for 8 weeks. Both groups received guidelines for a healthy diet and staying physically active. Microcirculation was assessed using a laser Doppler flowmetry (LDF) at baseline and after intervention. Primary outcomes derived from LDF assessment included resting flow, maximum flow, maximum/resting flow ratio, area under hyperemia, and post-occlusive reactive hyperemia (PORH). Secondary outcomes were body mass index and systemic blood pressure. Unpaired Student's t test compared intergroup analyses, and paired Student's t test compared intragroup analyses. The significance was set at 5%. Statistical analysis intergroup and intragroup was done by fitting a two-way mixed effects model. Microcirculation was similar between groups. Maximum flow (109.0 ± 38.3 versus 124.6 ± 43.0, P = 0.022), area under hyperemia (1614 ± 472 versus. 1755 ± 461, P = 0.023), and PORH (2.18 ± 0.49 versus 2.01 ± 0.52, P = 0.031) were statistically different after intervention. Body mass index decreased in intervention (24.5 ± 3.8-24.1 ± 4.0 kg/m², P = 0.002) and control (25.2 ± 3.2-25.1 ± 3.3 kg/m², P = 0.031) groups. Systolic blood pressure decreased significantly in the intervention group (110 ± 10-106 ± 9 mm Hg; P = 0.041) but not diastolic blood pressure (66.0 ± 7-68.8 ± 8 mm Hg; P = 0.089). Exergaming for 8 weeks led to improvements in the microcirculation function in adolescents with overweighed or obesity. Clinical trials: NTC03532659.

Aerobic exercise improves central blood pressure and blood pressure variability among patients with resistant hypertension: results of the EnRicH trial

Central blood pressure (BP) and BP variability are associated with cardiovascular disease risk. However, the influence of exercise on these hemodynamic parameters is unknown among patients with resistant hypertension. The EnRicH (The Exercise Training in the Treatment of Resistant Hypertension) was a prospective, single-blinded randomized clinical trial (NCT03090529). Sixty patients were randomized to a 12-week aerobic exercise program or usual care. The outcome measures include central BP, BP variability, heart rate variability, carotid-femoral pulse wave velocity, and circulating cardiovascular disease risk biomarkers including high-sensitivity C-reactive protein, angiotensin II, superoxide dismutase, interferon gamma, nitric oxide, and endothelial progenitor cells. Central systolic BP decreased by 12.22 mm Hg (95% CI, -1.88 to -22.57, P = 0.022) as did BP variability by 2.85 mm Hg (95% CI, -4.91 to -0.78, P = 0.008), in the exercise (n = 26) compared to the control group (n = 27). Interferon gamma -4.3 pg/mL (95%CI, -7.1 to -1.5, P = 0.003), angiotensin II -157.0 pg/mL (95%CI, -288.1 to -25.9, P = 0.020), and superoxide dismutase 0.4 pg/mL (95%CI, 0.1-0.6, P = 0.009) improved in the exercise compared to the control group. Carotid-femoral pulse wave velocity, heart rate variability, high-sensitivity C-reactive protein, nitric oxide, and endothelial progenitor cells were not different between groups (P > 0.05). In conclusion, a 12-week exercise training program improved central BP and BP variability, and cardiovascular disease risk biomarkers in patients with resistant hypertension. These markers are clinically relevant as they are associated with target organ damage and increased cardiovascular disease risk and mortality.

Hypoxic Training Ameliorates Skeletal Muscle Microcirculation Vascular Function in a Sirt3-Dependent Manner

Hypoxic training improves the microcirculation function of human skeletal muscle, but its mechanism is still unclear. Silent information regulator 2 homolog 3 (Sirt3) can improve mitochondrial function and oxidative status. We aimed to examine the role of Sirt3 in the process of hypoxic training, which affects skeletal muscle microcirculation. C57BL/6 mice were assigned to control (C), hypoxic training (HT), Sirt3 inhibitor 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP), and 3-TYP + hypoxic training (3-TYP + HT) groups (n = 6/group). Sirt3 inhibition was induced by intraperitoneal injection of Sirt3 inhibitor 3-TYP. After 6 weeks of intervention, microcirculatory capillary formation and vasomotor capacity were evaluated using immunofluorescence, Western blot, biochemical tests, and transmission electron microscopy (TEM). Laser Doppler flowmetry was used to evaluate skeletal muscle microcirculation blood flow characteristics. Six weeks of hypoxic training enhanced skeletal muscle microcirculation function and increased microcirculatory vasodilation capacity and capillary formation. After the pharmacological inhibition of Sirt3, the reserve capacity of skeletal muscle microcirculation was reduced to varying degrees. After the inhibition of Sirt3, mice completed the same hypoxic training, and we failed to observe the microcirculation function adaptation like that observed in hypoxic training alone. The microcirculation vasodilation and the capillaries number did not improve. Hypoxic training improved skeletal muscle microcirculation vasodilation capacity and increased skeletal muscle microcirculation capillary density. Sirt3 is involved in the adaptation of skeletal muscle microcirculation induced by hypoxic training.

Plin5, a New Target in Diabetic Cardiomyopathy

Abnormal lipid accumulation is commonly observed in diabetic cardiomyopathy (DC), which can create a lipotoxic microenvironment and damage cardiomyocytes. Lipid toxicity is an important pathogenic factor due to abnormal lipid accumulation in DC. As a lipid droplet (LD) decomposition barrier, Plin5 can protect LDs from lipase decomposition and regulate lipid metabolism, which is involved in the occurrence and development of cardiovascular diseases. In recent years, studies have shown that Plin5 expression is involved in the pathogenesis of DC lipid toxicity, such as oxidative stress, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, and insulin resistance (IR) and has become a key target of DC research. Therefore, understanding the relationship between Plin5 and DC progression as well as the mechanism of this process is crucial for developing new therapeutic approaches and exploring new therapeutic targets. This review is aimed at exploring the latest findings and roles of Plin5 in lipid metabolism and DC-related pathogenesis, to explore possible clinical intervention approaches.

Does Systemic Arterial Hypertension Change the Function of the Stomatognathic System?

The aim of this study was to evaluate the stomatognathic system of individuals with controlled systemic hypertension through comparison with a disease-free control group. Seventy individuals (44 female and 26 male) were divided into two groups: a controlled systemic hypertension (n=35) and a disease-free control (n=35). The individuals were evaluated on the basis of masticatory cycle efficiency of the value of the ensemble-averaged integrated linear envelope to the electromyographic signal of the masseter and temporalis muscles in the habitual (peanuts and raisins) and non-habitual chewing (Parafilm M); molar bite force (right and left) and ultrasound images from the bilateral masseter and temporal muscles at rest and maximum voluntary contraction. The data obtained were tabulated and submitted to statistical analysis (p&lt;0.05). There was a significant difference between groups in the habitual (peanuts and raisins) and non-habitual (Parafilm M) chewing with reduced muscle activity to controlled systemic hypertension group. Muscle thickness occurred significant difference between groups at rest and maximum voluntary contraction of the temporalis muscles. There was no significant difference between groups in maximum molar bite force. The present study findings indicate that the controlled systemic hypertension promotes functional changes of the masticatory system, especially with respect to its masticatory efficiency and muscle thickness.

Association between self-reported physical activity and indicators of cardiovascular risk in community-dwelling older adults with hypertension in Korea: A cohort study

The prevalence of hypertension has increased with the rise in the elderly population, and high blood pressure is a major cause of cardiovascular disease. Physical activity is an important strategy for preventing cardiovascular disease. The study aimed to explore the association between physical activity and cardiovascular risk indicators in community-dwelling older adults with hypertension.This study is a secondary data analysis of a prospective longitudinal study using data from the Elderly Cohort Database of the National Health Insurance Service in South Korea between 2002 and 2013. Participants included 10,588 older adults (≥60 years) with hypertension. Data assessing self-reported physical activity and directly measured blood pressure, fasting blood glucose, body mass index, and total cholesterol levels throughout the 12-year study were extracted from the original database and analyzed. Participants were categorized into 4 groups based on the reported changes in physical activity over time: Group I (Maintaining No Physical Activity Group), II (Changing from No Physical Activity to Physical Activity Group), III (Changing from Physical Activity to No Physical Activity Group), and IV (Maintaining Physical Activity Group). Cox proportional hazard model was used to confirm the risk of cardiovascular indicators over time in each group.Participants' mean age was 64.2 years in the initial year of 2002. The number of participants in Groups I, II, III, and IV was 4032, 2697, 1919, and 1940, respectively. Group IV showed a significant decline in risk for uncontrolled hypertension compared to Group I (hazard ratio = 0.87, 95% confidence interval [0.800-0.948]). Group II showed a significant decrease in risk for uncontrolled diabetes compared to Group I (hazard ratio = 0.94, 95% confidence interval [0.888-0.999]).The findings indicated that physical activity is a significant factor associated with indicators of cardiovascular risk in older people with high blood pressure. Healthcare providers should be aware of the importance of older adults' physical activity and encourage them to perform and maintain it steadily for better long-term cardio-metabolic outcomes.

A Review of the Properties of Anthocyanins and Their Influence on Factors Affecting Cardiometabolic and Cognitive Health

The incidence of cardiovascular and metabolic diseases has increased over the last decades and is an important cause of death worldwide. An upcoming ingredient on the nutraceutical market are anthocyanins, a flavonoid subgroup, abundant mostly in berries and fruits. Epidemiological studies have suggested an association between anthocyanin intake and improved cardiovascular risk, type 2 diabetes and myocardial infarct. Clinical studies using anthocyanins have shown a significant decrease in inflammation markers and oxidative stress, a beneficial effect on vascular function and hyperlipidemia by decreasing low-density lipoprotein and increasing high-density lipoprotein. They have also shown a potential effect on glucose homeostasis and cognitive decline. This review summarizes the effects of anthocyanins in in-vitro, animal and human studies to give an overview of their application in medical prevention or as a dietary supplement.

Effects of exercise training in heart failure with preserved ejection fraction: an updated systematic literature review

Physical activity is associated with a lower risk of adverse cardiovascular outcomes, including heart failure (HF). Exercise training is a class IA level recommendation in patients with stable HF, but its impact is less clear in heart failure with preserved ejection fraction (HFpEF). The aim of this study was to analyze the effects of the exercise training on cardiovascular outcomes in patients with HFpEF. A systematic literature search was conducted on the main electronic databases, proceedings of major meetings, and reference lists of the identified studies, using specific terms for only English language studies published between 2000 and 2018. We followed the PRISMA to perform our review. Quality of studies was also assessed. The systematic review identified 9 studies on 348 patients, of moderate (n = 2) to good (n = 7) quality. The training consisted of a combination of supervised in-hospital and home-based outpatient programs, including aerobic exercise, endurance and resistance training, walking, and treadmill and bicycle ergometer. Most of the protocols ranged 12-16 weeks, with a frequency of 2-3 sessions weekly, lasting 20-60 min per session. There were significant improvements in peak oxygen uptake, 6-min walking test distance, and ventilatory threshold, whereas quality of life and echocardiographic parameters improved only in some studies. Endothelial function/arterial stiffness remained unchanged. No adverse events were reported. Appropriate exercise programs are able to get a favorable cardiovascular outcome in patients with HFpEF. This could also benefit in terms of quality of life, even if more controversial. Further researches are necessary.

Neurovascular Dysregulation During Exercise in Type 2 Diabetes

Emerging evidence suggests that type 2 diabetes (T2D) may impair the ability to properly adjust the circulation during exercise with augmented blood pressure (BP) and an attenuated contracting skeletal muscle blood flow (BF) response being reported. This review provides a brief overview of the current understanding of these altered exercise responses in T2D and the potential underlying mechanisms, with an emphasis on the sympathetic nervous system and its regulation during exercise. The research presented support augmented sympathetic activation, heightened BP, reduced skeletal muscle BF, and impairment in the ability to attenuate sympathetically mediated vasoconstriction (i.e., functional sympatholysis) as potential drivers of neurovascular dysregulation during exercise in T2D. Furthermore, emerging evidence supporting a contribution of the exercise pressor reflex and central command is discussed along with proposed future directions for studies in this important area of research.

Hypertension is associated with an increased risk for severe imported falciparum malaria: a tertiary care hospital based observational study from Berlin, Germany

Background

Increasing numbers of aging individuals with chronic co-morbidities travel to regions where falciparum malaria is endemic. Non-communicable diseases are now leading risk factors for death in such countries. Thus, the influence of chronic diseases on the outcome of falciparum malaria is an issue of major importance. Aim of the present study was to assess whether non-communicable diseases increase the risk for severe imported falciparum malaria.

Methods

A retrospective observational study of all adult cases with imported falciparum malaria hospitalized between 2001 and 2015 in the tertiary care Charité University Hospital, Berlin, was performed.

Results

A total of 536 adult patients (median age 37 years; 31.3% female) were enrolled. Of these, 329 (61.4%) originated from endemic countries, 207 patients (38.6%) from non-endemic regions. Criteria for severe malaria were fulfilled in 68 (12.7%) cases. With older age, lack of previous malaria episodes, being a tourist, and delayed presentation, well-characterized risk factors were associated with severe malaria in univariate analysis. After adjustment for these potential confounders hypertension (adjusted odds ratio aOR, 3.06 95% confidence interval, CI 1.34–7.02), cardiovascular diseases (aOR, 8.20 95% CI 2.30–29.22), and dyslipidaemia (aOR, 6.08 95% CI 1.13–32.88) were individual diseases associated with severe disease in multivariable logistic regression. Hypertension proved an independent risk factor among individuals of endemic (aOR, 4.83, 95% CI 1.44–16.22) as well as of non-endemic origin (aOR, 3.60 95% CI 1.05–12.35).

Conclusions

In imported falciparum malaria hypertension and its related diseases are risk factors for severe disease.

Effects of Local Vibration With Different Intermittent Durations on Skin Blood Flow Responses in Diabetic People

Objective: Poor blood flow supply is an important pathological factor that leads to the development and deterioration of diabetic foot ulcers. This study aims to investigate the acute effects of local vibration with varying intermittent durations on the plantar skin blood flow (SBF) response in diabetic and healthy subjects.

Methods: Eleven diabetic patients (7 males, 4 females) and 15 healthy adults (6 males, 9 females) participated in this experiment and accepted three tests. Local continuous vibration (LCV) and two levels of local intermittent vibration (LIV1 and LIV2) were randomly applied to the middle metatarsal head of each subject's right foot in each test. The SBF was measured prior to intervention (Baseline), during Vibration and during the Recovery Stage for each test. The mean SBF in each stage, the change percentages and change rates of SBF in Vibration and Recovery stage among three tests were compared and analyzed for both diabetic and healthy subjects.

Results: For diabetic subjects, the SBF was significantly increased in both Vibration and Recovery Stage with local intermittent vibrations (LIV1 and LIV2), but not with LCV. However, there was no significant difference in change percentage and change rate of SBF in diabetic subjects across the three tests. For healthy subjects, all vibration interventions significantly increased the SBF in the Vibration Stage and in the first 1.5 min of the Recovery Stage. Also, the change rate of SBF during the Vibration stage in LIV1 test was significantly greater than that in LIV2 test for healthy subjects. Moreover, change percentage of SBF in Vibration stage of LIV1 test and in some periods of Recovery stages of LIV1 and LIV2 tests for diabetic subjects were lower than for healthy subjects; the absolute change rate of SBF in LIV1 test for diabetic subjects was also lower than for healthy subjects.

Conclusion: These findings suggest that both LIV1 and LIV2 may effectively improve SBF in the feet of diabetic people, but LCV may not achieve the same level of vasodilatation. The diabetic subjects were also found to have a lower SBF response to applied vibration than the healthy subjects.

Plin5/p-Plin5 Guards Diabetic CMECs by Regulating FFAs Metabolism Bidirectionally

Background

Hyper-free fatty acidemia (HFFA) impairs cardiac capillaries, as well as type 2 diabetes mellitus (T2DM). Perilipin 5 (Plin5) maintains metabolic balance of free fatty acids (FFAs) in high oxidative tissues via the states of nonphosphorylation and phosphorylation. However, when facing to T2DM-HFFA, Plin5's role in cardiac microvascular endothelial cells (CMECs) is not defined.

Methods

In mice of WT or Plin5^−/−, T2DM models were rendered by high-fat diet combined with intraperitoneal injection of streptozocin. CMECs isolated from left ventricles were incubated with high glucose (HG) and high FFAs (HFFAs). Plin5 phosphorylation was stimulated by isoproterenol. Plin5 expression was knocked down by small interfering RNA (siRNA). We determined cardiac function by small animal ultrasound, apoptotic rate by flow cytometry, microvessel quantity by immunohistochemistry, microvascular integrity by scanning electron microscopy, intracellular FFAs by spectrophotometry, lipid droplets (LDs) by Nile red staining, mRNAs by quantitative real-time polymerase chain reaction, proteins by western blots, nitric oxide (NO) and reactive oxygen species (ROS) by fluorescent dye staining and enzyme-linked immunosorbent assay kits.

Results

In CMECs, HFFAs aggravated cell injury induced by HG and activated Plin5 expression. In mice with T2DM-HFFA, Plin5 deficiency reduced number of cardiac capillaries, worsened structural incompleteness, and enhanced diastolic dysfunction. Moreover, in CMECs treated with HG-HFFAs, both ablation and phosphorylation of Plin5 reduced LDs content, increased intracellular FFAs, stimulated mitochondrial β-oxidation, added ROS generation, and reduced the expression and activity of endothelial nitric oxide synthase (eNOS), eventually leading to increased apoptotic rate and decreased NO content, all of which were reversed by N-acetyl-L-cysteine.

Conclusion

Plin5 preserves lipid balance and cell survival in diabetic CMECs by regulating FFAs metabolism bidirectionally via the states of nonphosphorylation and phosphorylation.

Endothelial function following interval exercise plus low-calorie diet treatment in obese females

We determined if interval exercise plus a low-calorie diet (LCD + INT) increases endothelial function more than an energy-matched LCD. Obese women (47.2 ± 2.6y, 37.5 ± 1.3kg/m2 ) were randomized to 13 days of a LCD (n = 12; mixed meals of ~ 1200kcal/d) or LCD + INT (n = 13; 12 supervised 60-min INT bouts of 3 min at 90% and 50% HRpeak ). LCD + INT subjects received 350kcal postexercise to equate energy availability with LCD. Fitness (VO2 peak) and body composition (BodPod) were determined and a 120 min, 75 g oral glucose tolerance test was performed to examine fasting and postprandial flow-mediated dilation (FMD, endothelial function), respiratory exchange ratio (RER) via indirect calorimetry as well as glucose and insulin incremental area under the curve (iAUC120min ). LCD + INT increased VO2 peak (P = 0.02) compared with LCD, and both treatments decreased fat mass (P < 0.001) and insulin iAUC120min (P = 0.03). There was no overall treatment effect on fasting or iAUC120min FMD. However, in participants who increased fasting endothelial function after each treatment (Δ > 50%; LCD n = 5, LCD + INT n = 7), LCD + INT increased fasted (P = 0.005) and decreased iAUC120min (P = 0.003) FMD compared with LCD. Enhanced fitness correlated with increased fasting FMD (r = 0.43, P = 0.03) and diminished FMD iAUC120min (r = -0.44, P = 0.03). Decreased FMD iAUC120min correlated with reduced glucose iAUC120min (r = 0.64, P = 0.001) as well as increased 60-min RER (r = -0.42, P = 0.04). Low baseline fasting and iAUC120min FMD was also linked to enhanced fasting and iAUC120min FMD post-treatment (r = -0.71, P < 0.001; r = -0.89, P < 0.001, respectively). In conclusion, increasing fitness via INT may increase the effect of LCD on lowering cardiovascular disease risk in obese women.

Effects of Resistance and Combined training on Vascular Function in Type 2 Diabetes: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Cardiovascular disease (CVD) is the main cause of mortality in type 2 diabetes (T2D). Exercise can reduce the risk factors associated with CVD in T2D patients. However, research evaluating its beneficial effects in these patients has used different measurement protocols and types of exercise, complicating comparison.

AIM

To assess the effects of resistance training (RT) and combined training (CT) on the vascular function of T2D patients.

METHODS

A database search (MEDLINE, Scopus, and Web of Science) was performed to identify relevant articles that were published up to August 2017. Only original studies evaluating the effects of RT or CT interventions on vascular function in T2D patients were included. The articles were reviewed independently by at least three reviewers. The Cochrane guidelines were used to assess the methodological quality of the studies. Fourteen studies were finally included. Two studies only used RT and twelve studies used CT as intervention strategy.

RESULTS AND CONCLUSIONS

The results show that resistance training is a useful means for primary treatment of vascular diseases and maintenance of vascular function in T2D patients. However, more studies are necessary to gain full knowledge of the beneficial effects and to identify tailored exercise plans to optimize these benefits. The information provided in this review may help to improve current treatment of vascular diseases in T2D patients and to design future studies.

Associations between physical activity and cataract treated surgically in patients with diabetes: findings from the 45 and Up Study

AIM

To investigate the association between physical activity (PA) and incidence of cataract surgery among patients with diabetes.

METHODS

We obtained data from all diabetic subjects aged 45-65 years from the baseline of the prospective 45 and Up Study from 2006 to 2009 and linked to the Medicare Benefits Schedule (MBS) and Pharmaceutical Benefits Scheme (PBS) until 2016. Diabetes was defined as self-reported on questionnaire or diabetes medication history based on PBS. Cataract surgery was determined based on the MBS, and metabolic equivalent intensity level number of PA sessions per week was used to assess PA. Cox regression was used to assess the association between baseline PA and cataract surgery during the follow-up.

RESULTS

A total of 9113 diabetic participants in the 45 and Up Study were included in the current analysis with a mean age of 57.3±5.2 years (43.6% female). During a mean follow-up of 8.8 years, 950 participants (10.4% of baseline) received cataract surgery with a corresponding incidence of 12.4/1000 person-years. Cox regression analysis showed that people with less PA (p=0.01), older age (p<0.001), female gender (p<0.001), higher educational level (p<0.001) and longer diabetic duration (p<0.001) had significantly higher cataract surgery risk. Participants with a PA level of ≥14 sessions per week had 19% decreased risk of cataract surgery compared to those with <5 sessions per week. Stratification analysis showed that participants with more obesity (p value for interaction=0.03), not taking insulin (p value for interaction=0.01) and without cardiovascular disease (p value for interaction=0.008) could benefit significantly more from PA in reducing their cataract surgery risk.

CONCLUSIONS

More vigorous PA was independently associated with a reduced risk of cataract surgery in working-aged patients with diabetes.

Activity-Induced Increase in Achilles Tendon Blood Flow Is Age and Sex Dependent

BACKGROUND

Previous research of a young adult population identified a lower increase in Achilles tendon blood flow immediately after a running activity as a significant predictor for the development of Achilles tendinopathy (AT). Furthermore, advancing age is often mentioned as a risk factor for the development of AT, and the highest incidence for AT is reported to occur in middle-aged recreational male athletes.

PURPOSE

To investigate the effect of age, sex, and type of physical activity on the increase in Achilles tendon blood flow.

STUDY DESIGN

Controlled laboratory study.

METHODS

Blood flow measurements of 33 subjects aged 18 to 25 years and 30 subjects aged 40 to 55 years were obtained before and after 4 physical activities performed in randomized order: running, cycling, dynamic stretching, and rope skipping. Blood flow measurements of the Achilles tendon were performed before, immediately after, 5 minutes after, and 10 minutes after the physical activities. The effect of age, sex, and physical activities on the increase in blood flow was investigated with linear mixed models.

RESULTS

The results of this study identified that running, rope skipping, and cycling resulted in a significant increase in tendon blood flow ( P ≤ .001), whereas stretching did not. Prominent was the finding that the increase in blood flow after activity was significantly lower in the older population as compared with the younger population ( P < .001). Furthermore, male participants in the older group showed a significantly lower increase in tendon blood flow than did their female counterparts ( P = .019).

CONCLUSION

This study identified that sex and age significantly influence the increase in blood flow after activity, possibly explaining the increased risk for AT among middle-aged recreational athletes.

CLINICAL RELEVANCE

This study possibly identified one of the mechanisms explaining why an older male population is at increased risk for developing AT. Given that the lower increase in blood flow is an identified risk factor according to previous research, preventative measures should focus on improving this blood flow during physical activity in the physically active older male population. Registration: NCT03218605 ( ClinicalTrials.gov identifier).

The influence of resting blood pressure on muscle strength in healthy adults

Adverse alterations in the skeletal muscle response to exercise have been noted among adults with hypertension. The influence of resting blood pressure (BP) on muscle strength is unknown. We hypothesized that adults with high BP would exhibit lower muscular strength than adults with normal BP. An isokinetic dynamometer tested 21 measures of isometric and isokinetic muscle strength. BP was measured by auscultation. Patients were categorized into having normal (<120 and <80 mmHg) or high (≥120 and/or ≥80 mmHg) BP. Height (cm) and weight (kg) were measured to calculate BMI (kg/m). Analysis of covariance tested differences in muscle strength between BP groups with sex, age, and height as covariates. Patients [420 (49%) men] were middle-aged (44.1±16.1 years) and overweight (26.4±4.8 kg/m) with 187 having normal (107.7±7.3/68.3±6.3 mmHg) and 233 having high (127.8±9.8/80.8±8.1 mmHg) BP. For upper body, three of five extension measures and five of five flexion measures, as well as handgrip, were greater in the high than the normal BP group (P≤0.05). For lower body, five of five extension measures were greater in the high than the normal BP group, whereas there were no differences between BP groups for the five flexion measures (P>0.05). Contrary to our hypothesis, adults with high BP displayed greater muscle strength than adults with normal BP. Reasons for our findings are unclear, but may be because of shifts in muscle fiber type from type I to type IIb/x and oxidative to glycolytic metabolism; alterations may result in a more strength-adapted phenotype among adults with high BP such as we observed.

Observations on the perfusion recovery of regenerative angiogenesis in an ischemic limb model under hyperoxia

This study combines two well‐known vascular research models, hyperoxia and hind limb ischemia, aiming to better characterize capacities of the hyperoxia challenge. We studied two groups of C57/BL6 male mice, a control (C) and a hind limb ischemia (HLI) group. Perfusion from both limbs was recorded in all animals by laser Doppler techniques under an oxygen (O₂) saturated atmosphere, once for control and, during 35 days for the HLI group. We used a third set of normoxic animals for HLI morphometric control. The expected variability of responses was higher for the younger animals. In the HLI group, capillary density normalized at Day 21 as expected, but not microcirculatory physiology. In the operated limb, perfusion decreased dramatically following surgery (Day 4), as a slight reduction in the non‐operated limb was also noted. Consistently, the response to hyperoxia was an increased perfusion in the ischemic limb and decreased perfusion in the contralateral limb. Only at Day 35, both limbs exhibited similar flows, although noticeably lower than Day 0. These observations help to understand some of the functional variability attributed to the hyperoxia model, by showing (i) differences in the circulation of the limb pairs to readjust a new perfusion set‐point even after ischemia, an original finding implying that (ii) data from both limbs should be recorded when performing distal measurements in vivo. Our data demonstrate that the new vessels following HLI are not functionally normal, and this also affects the non‐operated limb. These findings confirm the discriminative capacities of the hyperoxia challenge and suggest its potential utility to study other pathologies with vascular impact.

Assessing the evidence: Exploring the effects of exercise on diabetic microcirculation

Diabetes mellitus (DM) is associated with cardiovascular complications. Impairment of glycemic control induces noxious glycations, an increase in oxydative stress and dearangement of various metabolic pathways. DM leads to dysfunction of micro- and macrovessels, connected to metabolic, endothelial and autonomic nervous system. Thus, assessing vascular reactivity might be one of the clinical tools to evaluate the impact of harmful effects of DM and potential benefit of treatment; skin and skeletal muscle microcirculation have usually been tested. Physical exercise improves vascular dysfunction through various mechanisms, and is regarded as an additional effective treatment strategy of DM as it positively impacts glycemic control, improves insulin sensitivity and glucose uptake in the target tissues, thus affecting glucose and lipid metabolism, and increases the endothelium dependent vasodilation. Yet, not all patients respond in the same way so titrating the exercise type individualy would be desirable. Resistance training has, apart from aerobic one, been shown to positively correlate to glycemic control, and improve vascular reactivity. It has been prescribed in various forms or in combination with aerobic training. This review would assess the impact of different modes of exercise, the mechanisms involved, and its potential positive and negative effects on treating patients with Type I and Type II DM, focusing on the recent literature.

Relationship Between Physical Activity, Body Mass Index, and Risk of Heart Failure

BACKGROUND

Lower leisure-time physical activity (LTPA) and higher body mass index (BMI) are independently associated with risk of heart failure (HF). However, it is unclear if this relationship is consistent for both heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF).

OBJECTIVES

This study sought to quantify dose-response associations between LTPA, BMI, and the risk of different HF subtypes.

METHODS

Individual-level data from 3 cohort studies (WHI [Women's Health Initiative], MESA [Multi-Ethnic Study of Atherosclerosis], and CHS [Cardiovascular Health Study]) were pooled and participants were stratified into guideline-recommended categories of LTPA and BMI. Associations between LTPA, BMI, and risk of overall HF, HFpEF (ejection fraction ≥45%), and HFrEF (ejection fraction <45%) were assessed by using multivariable adjusted Cox models and restricted cubic splines.

RESULTS

The study included 51,451 participants with 3,180 HF events (1,252 HFpEF, 914 HFrEF, and 1,014 unclassified HF). In the adjusted analysis, there was a dose-dependent association between higher LTPA levels, lower BMI, and overall HF risk. Among HF subtypes, LTPA in any dose range was not associated with HFrEF risk. In contrast, lower levels of LTPA (<500 MET-min/week) were not associated with HFpEF risk, and dose-dependent associations with lower HFpEF risk were observed at higher levels. Compared with no LTPA, higher than twice the guideline-recommended minimum LTPA levels (>1,000 MET-min/week) were associated with an 19% lower risk of HFpEF (hazard ratio: 0.81; 95% confidence interval: 0.68 to 0.97). The dose-response relationship for BMI with HFpEF risk was also more consistent than with HFrEF risk, such that increasing BMI above the normal range (≥25 kg/m2) was associated with a greater increase in risk of HFpEF than HFrEF.

CONCLUSIONS

Our study findings show strong, dose-dependent associations between LTPA levels, BMI, and risk of overall HF. Among HF subtypes, higher LTPA levels and lower BMI were more consistently associated with lower risk of HFpEF compared with HFrEF.

The Role of Metformin in Controlling Oxidative Stress in Muscle of Diabetic Rats

Metformin can act in muscle, inhibiting the complex I of the electron transport chain and decreasing mitochondrial reactive oxygen species. Our hypothesis is that the inhibition of complex I can minimize damage oxidative in muscles of hypoinsulinemic rats. The present study investigated the effects of insulin and/or metformin treatment on oxidative stress levels in the gastrocnemius muscle of diabetic rats. Rats were rendered diabetic (D) with an injection of streptozotocin and were submitted to treatment with insulin (D+I), metformin (D+M), or insulin plus metformin (D+I+M) for 7 days. The body weight, glycemic control, and insulin resistance were evaluated. Then, oxidative stress levels, glutathione antioxidant defense system, and antioxidant status were analyzed in the gastrocnemius muscle of hypoinsulinemic rats. The body weight decreased in D+M compared to ND rats. D+I and D+I+M rats decreased the glycemia and D+I+M rats increased the insulin sensitivity compared to D rats. D+I+M reduced the oxidative stress levels and the activity of catalase and superoxide dismutase in skeletal muscle when compared to D+I rats. In conclusion, our results reveal that dual therapy with metformin and insulin promotes more benefits to oxidative stress control in muscle of hypoinsulinemic rats than insulinotherapy alone.

Regulation of arterial reactivity by concurrent signaling through the E-prostanoid receptor 3 and angiotensin receptor 1

Prostaglandin E2 (PGE2), a cyclooxygenase metabolite that generally acts as a systemic vasodepressor, has been shown to have vasopressor effects under certain physiologic conditions. Previous studies have demonstrated that PGE2 receptor signaling modulates angiotensin II (Ang II)-induced hypertension, but the interaction of these two systems in the regulation of vascular reactivity is incompletely characterized. We hypothesized that Ang II, a principal effector of the renin-angiotensin-aldosterone system, potentiates PGE2-mediated vasoconstriction. Here we demonstrate that pre-treatment of arterial rings with 1nM Ang II potentiated PGE2-evoked constriction in a concentration dependent manner (AUC-Ang II 2.778±2.091, AUC+Ang II 22.830±8.560, ***P<0.001). Using genetic deletion models and pharmacological antagonists, we demonstrate that this potentiation effect is mediated via concurrent signaling between the angiotensin II receptor 1 (AT1) and the PGE2 E-prostanoid receptor 3 (EP3) in the mouse femoral artery. EP3 receptor-mediated vasoconstriction is shown to be dependent on extracellular calcium in combination with proline-rich tyrosine kinase 2 (Pyk2) and Rho-kinase. Thus, our findings reveal a novel mechanism through which Ang II and PGE2 regulate peripheral vascular reactivity.

Mechanisms of vascular dysfunction in acute phase of Trypanosoma cruzi infection in mice

Vascular disorders have a direct link to mortality in the acute phase of Trypanosoma cruzi infection. However, the underlying mechanisms of vascular dysfunction in this phase are largely unknown. We hypothesize that T. cruzi invades endothelial cells causing dysfunction in contractility and relaxation of the mouse aorta. Immunodetection of T. cruzi antigen TcRBP28 was observed in endothelial cells. There was a decreased endothelial nitric oxide synthase (eNOS)-derived NO-dependent vascular relaxation, and increased vascular contractility accompanied by augmented superoxide anions production. Endothelial removal, inhibition of cyclooxygenase 2 (COX-2), blockade of thromboxane A2 (TXA2) TP receptors, and scavenger of superoxide normalized the contractile response. COX-2, thromboxane synthase, inducible nitric oxide synthase (iNOS), p65 NFκB subunit and p22(phox) of NAD(P)H oxidase (NOX) subunit expressions were increased in vessels of chagasic animals. Serum TNF-α was augmented. Basal NO production, and nitrotyrosine residue expression were increased. It is concluded that T. cruzi invades mice aorta endothelial cells and increases TXA2/TP receptor/NOX-derived superoxide formation. Alongside, T. cruzi promotes systemic TNF-α increase, which stimulates iNOS expression in vessels and nitrosative stress. In light of the heart failure that develops in the chronic phase of the disease, to understand the mechanism involved in the increased contractility of the aorta is crucial.