The Differential Effect of Schooling and Physical Activity on Dementia in Older Women and Men from Brazil: Implications for Policymaking.

BACKGROUND: Modifiable risk factors exert crucial impact on dementia. OBJECTIVE: We sought to answer the question: do two modifiable risk factors, schooling level and physical activity (PA), affect cognitive function similarly in each sex? METHODS: This cross-sectional study was conducted in 2019 and 2021, and the survey was applied to the residents of the metropolitan area of Santos, a seashore of Sao Paulo State. Four hundred and twenty-two participants (women = 254 and men = 168) were eligible. Baecke questionnaire for the elderly was applied for the classification as physically inactive (PI) or active (PA). Cognitive function was assessed by the Mini-Mental State Examination (MMSE) and the Clinical Dementia Rating (CDR). Participants were also stratified by schooling status for both sexes. RESULTS: Higher education had a sex-independent positive influence on MMSE and CDR (p < 0.001). PA influences positively MMSE in older women (PI: 25±5 and PA: 27±3, p < 0.03), but has no effect in older men (26±5 and 25±5, p > 0.05). Concordantly, older women who were PA (1.7 and 0 %) showed a lower prevalence of dementia compared with PI (6.2 and 2.1%), for mild and moderate respectively. Active older women had higher odds of improving the MMSE score (OR: 1.093; 95% CI: 1.008-1.186) than men (OR: 0.97 (95% CI: 0.896-1.051). CONCLUSION: Education affects cognitive function equally in Brazilian elderly whereas older women are more responsive to the beneficial effects of PA for dementia than men.

Age-friendly city: future perspectives for the Brazilian cities.

The world population is aging fast and not all cities are prepared to cope with the needs of the elderly people. Cities need to develop strategies for senior citizens including the aspects of health, nutrition, consumer protection, housing, transportation, environment, social welfare, income, employment, safety, and education. The World Health Organization (WHO) created a program dedicated to older adults called the age-friendly city. This program is about creating the environment and opportunities that enable older people to be and do what they value throughout their lives. Most of the elderly population lives in urban spaces, and aging represents a challenge as well as opportunities to the cities all over the world. Recently, only 16 Brazilian cities have received the seal of international certification by meeting the requirements stipulated by the WHO. In the State of Sao Paulo, only two cities have been qualified for this seal. Therefore, the aims of this article are (a) to provide a brief history of this important initiative taken by the WHO and (b) to urge the decision-makers of Brazilian municipalities to develop effective initiatives for their cities to be prepared for this demographic modification.

A população mundial está envelhecendo rapidamente, e nem todas as cidades estão preparadas para lidar com as necessidades dessa população. As cidades devem desenvolver estratégias para os idosos, incluindo aspectos de saúde, nutrição, defesa do consumidor, habitação, transporte, meio ambiente, assistência social, renda, emprego, segurança e educação. A Organização Mundial da Saúde (OMS) possui um programa denominado "cidade amiga dos idosos", cujos objetivos são preparar as cidades para o envelhecimento da população e minimizar os custos desse processo proporcionando a inserção ativa dos idosos na vida socioeconômica das cidades. A certificação (selo) de cidade amiga dos idosos pela OMS. A maioria da população idosa vive nos espaços urbanos, o que isso representa um desafio e um ambiente de oportunidades para as cidades. Um desafio, pois ao envelhecer ocorre uma maior demanda pelos cuidados em saúde e instituições de longa permanência. Por outro lado, a população idosa apresenta um potencial de ambiente de negócios específicos para essa faixa etária, como os setores de alimentação, educação, e setores de entretenimento. No Brasil, a população idosa responde por cerca de 20% do consumo nacional. Apenas 16 cidades brasileiras receberam esse selo de certificação internacional para atender aos requisitos estipulados pela OMS. No estado de São Paulo, apenas duas cidades foram qualificadas para a obtenção do selo. Portanto, os objetivos do presente artigo são a) fornecer um breve histórico desse importante programa da OMS; b) despertar nos gestores das cidades a vontade de desenvolver iniciativas efetivas para que as cidades estejam preparadas para um rápido envelhecimento populacional, que tenha potencial para contribuir com a sociedade em suas diferentes capacidades.

Age-friendly city: future perspectives for the Brazilian cities / Cidade amiga do idoso: perspectivas futuras para as cidades brasileiras

ABSTRACT The world population is aging fast and not all cities are prepared to cope with the needs of the elderly people. Cities need to develop strategies for senior citizens including the aspects of health, nutrition, consumer protection, housing, transportation, environment, social welfare, income, employment, safety, and education. The World Health Organization (WHO) created a program dedicated to older adults called the age-friendly city. This program is about creating the environment and opportunities that enable older people to be and do what they value throughout their lives. Most of the elderly population lives in urban spaces, and aging represents a challenge as well as opportunities to the cities all over the world. Recently, only 16 Brazilian cities have received the seal of international certification by meeting the requirements stipulated by the WHO. In the State of Sao Paulo, only two cities have been qualified for this seal. Therefore, the aims of this article are (a) to provide a brief history of this important initiative taken by the WHO and (b) to urge the decision-makers of Brazilian municipalities to develop effective initiatives for their cities to be prepared for this demographic modification.

RESUMO A população mundial está envelhecendo rapidamente, e nem todas as cidades estão preparadas para lidar com as necessidades dessa população. As cidades devem desenvolver estratégias para os idosos, incluindo aspectos de saúde, nutrição, defesa do consumidor, habitação, transporte, meio ambiente, assistência social, renda, emprego, segurança e educação. A Organização Mundial da Saúde (OMS) possui um programa denominado "cidade amiga dos idosos", cujos objetivos são preparar as cidades para o envelhecimento da população e minimizar os custos desse processo proporcionando a inserção ativa dos idosos na vida socioeconômica das cidades. A certificação (selo) de cidade amiga dos idosos pela OMS. A maioria da população idosa vive nos espaços urbanos, o que isso representa um desafio e um ambiente de oportunidades para as cidades. Um desafio, pois ao envelhecer ocorre uma maior demanda pelos cuidados em saúde e instituições de longa permanência. Por outro lado, a população idosa apresenta um potencial de ambiente de negócios específicos para essa faixa etária, como os setores de alimentação, educação, e setores de entretenimento. No Brasil, a população idosa responde por cerca de 20% do consumo nacional. Apenas 16 cidades brasileiras receberam esse selo de certificação internacional para atender aos requisitos estipulados pela OMS. No estado de São Paulo, apenas duas cidades foram qualificadas para a obtenção do selo. Portanto, os objetivos do presente artigo são a) fornecer um breve histórico desse importante programa da OMS; b) despertar nos gestores das cidades a vontade de desenvolver iniciativas efetivas para que as cidades estejam preparadas para um rápido envelhecimento populacional, que tenha potencial para contribuir com a sociedade em suas diferentes capacidades.

The effects of mirabegron on obesity-induced inflammation and insulin resistance are associated with brown adipose tissue activation but not beiging in the subcutaneous white adipose tissue.

Mirabegron is a selective ß3-adrenergic receptors agonist, which has been recently shown to improve metabolic health in rodents and humans. In this study, we investigated the effects of 2-week mirabegron treatment on the metabolic parameters of mice with a diet-induced obesity (DIO). C57BL/6JUnib mice were divided into control (CTR) and obese (OB) groups treated with vehicle, and an OB group treated with mirabegron (OB + MIRA). The obese groups were fed a high-fat diet for 12 weeks. Mirabegron (10 mg/kg/day) was administrated orally by gavage from weeks 10-12. After 2 weeks of mirabegron treatment, the energy expenditure was assessed with indirect calorimetry. Blood glucose, insulin, glycerol, free fatty acids (FFA), thiobarbituric acid reactive substance (TBAR), and tumour necrosis factor (TNF)-α levels were also assessed, and the HOMA index was determined. Liver tissue, brown adipose tissue (BAT), and inguinal white adipose tissue (iWAT) samples were collected for histological examination. The protein expressions of uncoupling protein 1 (UCP1) and mitochondrial transcription factor A (TFAM) were assessed using western blotting of the BAT and iWAT samples. In this study, mirabegron increased the energy expenditure and decreased adiposity in OB + MIRA. Increased UCP1 expression in BAT without changes in iWAT was also found. Mirabegron decreased circulating levels of FFA, glycerol, insulin, TNF-α, TBARS and HOMA index. DIO significantly increased the lipid deposits in the liver and BAT, but mirabegron partially reversed this change. Our findings indicate that treatment with mirabegron decreased inflammation and improved metabolism in obese mice. This effect was associated with increased BAT-mediated energy expenditure, but not iWAT beiging, which suggests that mirabegron might be useful for the treatment of obesity and diabetes.

Prevalence of physical inactivity and its effects on blood pressure and metabolic parameters in a Brazilian Urban Population / Prevalência de inatividade física e seus efeitos na pressão arterial e parâmetros metabólicos em uma população urbana brasileira

Background: Cardiovascular disease is the leading cause of mortality in the world and physical inactivity represents an important risk factor. Objective: This study aimed to evaluate the prevalence of physical inactivity in the adult population and its effects on blood pressure, blood glucose and lipid profile. Methods: A population-based cross-sectional study with stratified simple random sampling was conducted in 1,717 adults divided by age groups: 18-39, 40-49, 50-59, 60-69 and ≥ 70 years. The participants answered the physical activity questionnaire and were classified as physically active or inactive. The bootstrap statistical method was used to assess physical activity, associated with lipid profile and blood glucose levels. The level of significance was 5%. Results:The prevalence of physical inactivity in the general population was 65.8%. There was a significant difference in the group older than 70 years. There was a significant decrease in physical activity in the group with lower educational level, with a significant difference between social classes AB and C. The prevalence of hypertension was 27.5% among physically inactive and 21.4% among active individuals (p = 0.04). The prevalence of metabolic syndrome was 26.1% in inactive and 16.7% in the active individuals (p = 0.007). Total cholesterol, low-density lipoprotein and triglycerides levels were more elevated in the physically inactive group, which was not observed with high-density lipoprotein levels. Blood glucose was also higher in the inactive group. Conclusion: This study shows a high prevalence of physical inactivity and a positive correlation between risk factors for cardiovascular disease, mainly blood pressure, glucose and lipids profiles

Anti-contractile effects of perivascular adipose tissue in thoracic aorta from rats fed a high-fat diet: role of aerobic exercise training.

The aim of the present study was to evaluate the effects of aerobic exercise training on perivascular adipose tissue (PVAT) function in thoracic aorta from rats fed a high-fat diet. Aortic vascular reactivity was performed in sedentary (SD), trained (TR), sedentary high-fat diet (SD-HF), and trained high-fat diet (TR-HF) male Wistar rats in the absence (PVAT-) or in the presence (PVAT+) of thoracic PVAT. We also measured circulatory concentrations of leptin and tumour necrosis factor alpha (TNF-α), as well as the protein expressions of TNF-α receptor 1 (TNFR1) and inducible nitric oxide synthase (iNOS) on PVAT. In the SD-HF group, the body weight, epididymal fat pad, thoracic PVAT, circulatory triglycerides, insulin, leptin and TNF-α were increased when compared with the SD group, whereas exercise training reduced these values in TR-HF group. The relaxing response curves to acetylcholine and sodium nitroprusside were not modified by either intervention (high-fat diet or exercise training) or the presence of PVAT. The presence of PVAT had an anti-contractile effect in response to serotonin in all groups. In SD-HF group, the increased magnitude of anti-contractile effects was in parallel with an up-regulation of iNOS protein expression in PVAT without alteration in TNFR1. Exercise training was effective in normalizing the vascular reactivity in rings PVAT+ and in reducing the iNOS protein expression. Exercise training prevented the PVAT-induced alteration in thoracic aorta from rats fed a high-fat diet.

Metabolic parameters and responsiveness of isolated iliac artery in LDLr-/- mice: role of aerobic exercise training.

Physical inactivity and dyslipidemia are considered risk factors for cardiovascular diseases. There are few studies evaluating the effects of physical exercise in small-caliber artery in a model that mimics familial hypercholesterolemia. The aim of this study was to examine the effect of exercise training, at moderate intensity, on metabolic parameters and iliac artery responsiveness in LDL-/- mice. Sedentary (SD) and trained (TR) mice performed AET (5 days/week, 60 minutes/day at 60-70% of maximum speed) during 8 weeks. Body weight gain (BWG), epididymal fat, blood glucose, total cholesterol and triglycerides were evaluated. Concentration-response curves to acetylcholine (ACh), sodium nitroprusside, phenylephrine and U46619 were obtained in isolated iliac artery. The production of nitric oxide (NO) and reactive oxygen species as well as the expression and activity of MMP-2 were assessed. AET was effective in preventing BWG and epididymal fat gain, whereas no changes were observed in glucose, total cholesterol and triglycerides levels. Improvement in responsiveness to ACh was found in TR (Emax = 85±3%) compared with SD group (Emax = 62±5%) without changes in the maximal vascular response or potency to SNP, PHE and U46619. The NO level was increased (10.8-fold) while ROS formation was decreased (3.7-fold) in iliac artery from TR, without changes in MMP-2 activity or its expression. AET was effective to improve endothelium-dependent relaxation that was accompanied by increased NO production and decreased ROS formation in iliac artery. The intensity of AET should be greater to modify metabolic disorders in this experimental model of dyslipidemia.

Micturition dysfunction in four-month old ovariectomized rats: Effects of testosterone replacement.

AIMS: Androgen deficiency has been implicated in urological complications of postmenopausal women. This study examined the effects of testosterone replacements on the lower urinary tract dysfunction in 4-month old ovariectomized (OVX) rats. MAIN METHODS: Sprague-Dawley female rats were OVX bilaterally. Three months later, rats received single intramuscular injections of testosterone undecanoate. Cystometric study, and bladder and urethra smooth muscle reactivities were evaluated. KEY FINDINGS: Ovariectomy reduced by 65% (p<0.05) the serum testosterone levels. Testosterone replacement at 5mg/kg restored serum hormone levels to baseline, whereas 10mg/kg produced 14-fold higher testosterone levels. OVX rats exhibited significant increases of body weight, perigonadal fat and blood pressure, and reduced uterus weight, but none of these parameters were changed by testosterone replacements. OVX rats exhibited micturition dysfunction characterized by increases of basal pressure, threshold pressure, voiding frequency and post-voiding pressure. In addition, the bladder contractions induced by electrical-field stimulation (EFS) and carbachol were significantly reduced, whereas angiotensin II-induced urethral contractions were significantly increased in OVX rats. Testosterone replacement at 10mg/kg (but not at 5mg/kg) dose fully normalized the in vivo micturition dysfunction, as well as the in vitro bladder and urethral alterations. Testosterone (10mg/kg) also significantly potentiated the bladder relaxations induced by the ß3-adrenoceptor agonist mirabegron. The protective effects of testosterone were not modified by concomitant treatment with the aromatase inhibitor letrozole (2.5mg/kg, 4weeks). SIGNIFICANCE: The improvement of micturition dysfunction by testosterone replacement suggests that androgen therapy might be of therapeutic benefit for urological complications associated with post-menopause.

Circulating Concentrations of Adipocytokines and Their Receptors in the Isolated Corpus Cavernosum and Femoral Artery from Trained Rats on a High-Fat Diet.

BACKGROUND: The aim of the present study was to evaluate different signaling pathways by which exercise training would interfere in endothelial function in obesity. Therefore, we examined adipocytokine levels and their receptors in the corpus cavernosum and femoral artery from trained rats on a high-fat diet. METHODS: Functional experiments were performed in control sedentary and trained rats, and sedentary (h-SD) and trained male Wistar rats on a high-fat diet (h-TR). Nitric oxide (NO) and reactive oxygen species (ROS) were evaluated in vascular tissue. Circulating adipocytokines and their receptors were analyzed. RESULTS: In the h-SD group, the maximal responses to acetylcholine (ACh) were reduced in the femoral artery and corpus cavernosum as well as the electrical field stimulation, accompanied by an increase in circulating insulin, leptin, TNF-α, MCP-1, and PAI-1. Downregulation of ObR protein expression in the femoral artery was observed without alterations in AdipoR1 and TNFR1 in both preparations. A positive effect was observed in the h-TR group regarding the relaxation response to ACh and circulating adipocytokines, resulting in increased NO production and reduced ROS generation. Exercise restored the ObR protein expression only in the femoral artery. CONCLUSION: Aerobic exercise training ameliorated the inflammatory adipocytokines and restored the relaxation responses in the corpus cavernosum and femoral artery in rats on a high-fat diet.

Effect of aerobic exercise training on cGMP levels and blood pressure in treated hypertensive postmenopausal women

Abstract The second messenger cGMP has been largely studied as a therapeutic target in a variety of disorders such as erectile dysfunction, arterial hypertension and heart failure. Evidence has shown thatcGMP activators are less efficient in estrogen-deficiency animals, but no studies exist involving non-pharmacological approacheson NO/cGMP signaling pathway in hypertensive postmenopausal women. The aim of this study is to examine NO/cGMP pathway, redox state and blood pressure in trained treatedhypertensive (HT) postmenopausal women comparing with normotensive (NT) group. The rationale for that is most of HT patients is encouraged by physician to perform exercise associated with pharmacological treatments.Aerobic exercise training (AET) consisted of 24 sessions, 3 times/week.Parameters were evaluated at baseline and after AET for both groups (HT=28; NT=33).In treatedHT group, AET was significantly effective in increasing cGMP concentrations (28%) accompanied by an up-regulation of SOD (97%) and catalase activity (37%). In NT group, we found an increasein SOD activity (58%). TreatedHT postmenopausal women were still responsive to AET increasing cGMP levels and up-regulating antioxidant system. It should also be emphasized that these findings provide information on the circulating biomarkers that might delay the developing of cardiovascular events in this particular population.(AU)

The importance of animal studies in exercise science

Abstract The validity and relevance of research with animals for the development of knowledge in Exercise Science have for long been discussed. Given the complexity of the biological systems, the use of animal models offers a significant contribution to uncover new findings about acute and chronic effects of exercise, particularly when these studies in humans have limitations and ethical implications. There have been notable findings using experimental animals either in basic sciences or in clinical studies involving physiology, pharmacology, genetic, biochemistry, urology, endocrinology and cancer. This article presents a brief review of scientific research using animal models with a focus on exercise training as an effective tool for the prophylaxis and treatment of different pathological processes, which are the basis of many concepts taught and used in undergraduate courses and graduate programs, as well as in new researches showed in scientific conference meetings in numerous areas of science.(AU)

Resistance exercise improves metabolic parameters and changes adipocyte-derived leptin: a comparison between genders in untrained adults

This study examined gender differences after resistance exercise (RE) by measuring fasting plasma levels of creatine kinase, lipid profile, blood glucose, adiponectin, tumor necrosis factor alpha (TNF-α), and leptin. Thirteen women (23.6 ± 7.3 years) and 11 men (29.5 ± 9 years) were enrolled in the study. Two bouts of RE were performed on two different occasions separated by 48 h each. Blood samples were collected and analyzed at baseline and 15 h after the last RE session. Increased creatine kinase levels and improvements in lipid profile and blood glucose were found for both genders. No changes in adiponectin and TNF-α levels were observed for both genders, but leptin levels were reduced (p < 0.05) only for women after RE. Collectively, our findings clearly show that RE was effective in lowering blood glucose and that this effect was not accompanied by changes in adiponectin levels in healthy subjects, indicating that RE is still an important tool for the prevention of metabolic diseases. Furthermore, two sessions of RE promoted a reduction in leptin levels in women, even though no changes in body weight were found, showing that RE is an interesting approach to study obese patients and metabolic regulation

Heart rate variability as important approach for assessment autonomic modulation

Alterations in the heart rate recovery and heart rate variability have been associated with greater risk of mortality and early prognosis of cardiac diseases. Thus, strategies for assessing autonomic nervous system and its modulation to the heart are crucial for preventing cardiovascular events in healthy subjects as well as in cardiac patients. In this review, an update of studies examining heart rate variability (HRV) and its use as indicator of cardiac autonomic modulation will be discussed. It will be described the indexes and methods of analysis and its applicability and the effects of exercise training on HRV and heart rate recovery in different population

Combined effects of aerobic exercise and l-arginine ingestion on blood pressure in normotensive postmenopausal women: A crossover study.

After menopause the incidence of cardiovascular diseases increases in women. A decrease in nitric oxide (NO) bioavailability has been pointed out to play a major role in this phenomenon. Since it is believed that l-arginine administration could improve NO bioavailability, the aim of this study was to examine the effects of acute l-arginine administration associated with aerobic exercise on blood pressure (BP), redox state and inflammatory biomarkers in normotensive postmenopausal women (NPW). Sixteen volunteers (57±6yr) were subjected to four experimental sessions (crossover design): arginine+exercise (A-E); arginine (ARG); exercise+placebo (EXE); control (CON). Each session was initiated with either 9g of l-arginine ingestion (ARG or A-E days), placebo (EXE day), or nothing (CON day). The participants performed 30min of aerobic exercise (A-E and EXE days) or sitting rest (CON and ARG days). Blood samples were collected before each session and 45min after the intervention. Office BP and ambulatory blood pressure monitoring (ABPM) were evaluated. NO/cGMP pathway, redox state and inflammatory biomarkers were measured. Systolic BP decreased during the 24-hour in A-E and EXE sessions. However, diastolic BP reduced only in A-E session. No changes were found in the biomarkers concentrations. In conclusion, the association was effective in lowering diastolic BP in NPW. Additionally, physical exercise alone promoted a long lasting effect on systolic BP measured by ABPM in this population, although this beneficial effect was not associated with changes in the cardio-inflammatory biomarkers. Possibly, other factors such as neural influences could be mediating this effect.

Assessment of endothelial function by flow-mediated dilation in diabetic patients: effects of physical exercise

The endothelium is now recognized as an endocrine organ that acts to maintain vascular homeostasis regulating the vascular tone and structure. The endothelial cells synthetize a variety of mediators among them, the main agent is the nitric oxide (NO), a potent vasodilator. NO exerts its protective role preventing leukocyte adhesion and migration, expression of adhesion molecules, platelet aggregation, cell proliferation, and promoting the relaxation of smooth muscle cells. On the other hand, endothelial dysfunction present in many chronic diseases such as atherosclerosis, coronary artery disease, peripheral artery disease, hypertension and diabetes mellitus, is characterized by reduced NO bioavailability. Thus, a few decades ago, measurement of endothelial function has emerged as valuable tool that provides insights in the pathophysiological mechanisms, opportunity to identify early disease and cardiovascular risk, preventing future events or avoiding the progression of the disease. Diabetic patients, particularly, have been a target to apply this technique, mainly because this condition has been related with an impairment of endothelium-dependent dilation and it is believed that the endothelium dysfunction is the basis of diabetes complications such as coronary artery disease and accelerated atherosclerosis. In addition, cardiovascular complications represent the leading cause of morbidity and death in diabetes mellitus. Besides pharmacological therapy, lifestyle modifications have been recommended by specific organizations as a strategy to improve the endothelial function or even prevent the development of diabetes. The aim of this mini eview is to give an update about the importance of endothelium, most common non-invasive technique to evaluate its function, and to summarize some mechanisms involved in endothelial dysfunction and the beneficial effects of exercise in diabetes mellitus.

Resistance training prevents the cardiovascular changes caused by high-fat diet.

AIMS: Aerobic exercise is indicated for prevention and treatment of obesity-induced cardiovascular disorders. Although the resistance training (RT) may also produce effects similar to aerobic exercise, this is not completely clear yet. In the present study, we tested if RT in moderate intensity might prevent alterations in blood pressure (BP), sympathetic modulation of systolic blood pressure (SBP), baroreflex function and the changes in renin-angiotensin system (RAS) and cytokines mRNA expression within the nucleus of the tract solitary (NTS) in rats fed with high-fat diet (HFD). MAIN METHODS: Male Holtzman rats (300-320 g) were divided into 4 groups: sedentary with standard chow diet (SED-SD); sedentary with high-fat diet (SED-HFD); RT with standard chow diet (RT-SD); and RT with high-fat diet (RT-HFD). The trained groups performed a total of 10 weeks of moderate intensity RT in a vertical ladder. In the first 3 weeks all experimental groups were fed with SD. In the next 7 weeks, the SED-HFD and RT-HFD groups were fed with HFD. KEY FINDINGS: In SED-HFD, BP and sympathetic modulation of SBP increased, whereas baroreflex bradycardic responses were attenuated. RT prevented the cardiovascular and inflammatory responses (increases in tumoral necrosis factor-α and interleukin-1ß) produced by HFD in SED rats. The anti-inflammatory interleukin-10, angiotensin type 2 receptor, Mas receptor and angiotensin converting enzyme 2 mRNA expressions in the NTS increased in the RT-HFD compared to SED-HFD. SIGNIFICANCE: The data demonstrated that moderate intensity RT prevented obesity-induced cardiovascular disorders simultaneously with reduced inflammatory responses and modifications of RAS in the NTS.

Heart rate variability and plasma biomarkers in patients with type 1 diabetes mellitus: Effect of a bout of aerobic exercise.

OBJECTIVE: The aim of this study was to evaluate: (1) the cardiovascular parameters and plasma biomarkers in people with type 1 diabetes mellitus (T1DM) at baseline; and (2) the heart rate variability (HRV) and blood glucose in response to a session of aerobic exercise (AE) and during recovery period. RESEARCH DESIGN AND METHODS: Adults (18-35 years) were divided into two groups: control (CT, n=10) and T1DM (n=9). Anthropometric, cardiovascular, and biochemical parameters, and aerobic capacity (indirect peak oxygen uptake, VO2peak) were evaluated at baseline. Thirty minutes of AE (40-60% intensity) was performed on a treadmill. Blood glucose and HRV were determined at rest, during AE, and during the recovery period. RESULTS: Anthropometric measurements, cardiovascular parameters, aerobic capacity, and biochemical parameters were similar between the groups at baseline. In the T1DM group, blood glucose, glycated hemoglobin, and thiobarbituric acid reactive substances concentrations were increased while nitrite/nitrate (NOx(-)) levels were reduced. During AE, the magnitude of the reduction of blood glucose was greater than that during the recovery period in the T1DM group. The RR intervals and SDNN were reduced at rest as well as in the recovery period in T1DM subjects, whereas the RMSSD and pNN50 were only reduced during the recovery period. No changes were observed in low frequency (LF), high frequency (HF), and LF/HF ratio. CONCLUSION: Our study shows that T1DM patients on insulin therapy have poor blood glucose control with greater lipid peroxidation and lower NOx(-) levels, accompanied by an imbalance in autonomic function detected by the challenge of AE.

Improvement of the physical performance is associated with activation of NO/PGC-1α/mtTFA signaling pathway and increased protein expressions of electron transport chain in gastrocnemius muscle from rats supplemented with L-arginine.

AIM: To examine the influence of l-arginine supplementation in combination with physical training on mitochondrial biomarkers from gastrocnemius muscle and its relationship with physical performance. MAIN METHODS: Male Wistar rats were divided into four groups: control sedentary (SD), sedentary supplemented with l-arginine (SDLA), trained (TR) and trained supplemented with l-arginine (TRLA). Supplementation of l-arginine was administered by gavage (62.5mg/ml/day/rat). Physical training consisted of 60min/day, 5days/week, 0% grade, speed of 1.2km/h. The study lasted 8weeks. Skeletal muscle mitochondrial enriched fraction as well as cytoplasmic fractions were obtained for Western blotting and biochemical analyses. Protein expressions of transcriptor coactivator (PGC-1α), transcriptor factors (mtTFA), ATP synthase subunit c, cytochrome oxidase (COXIV), constitutive nitric oxide synthases (eNOS and nNOS), Cu/Zn-superoxide dismutase (SOD) and manganese-SOD (Mn-SOD) were evaluated. We also assessed in plasma: lipid profile, glycemia and malondialdehyde (MDA) levels. The nitrite/nitrate (NOx(-)) levels were measured in both plasma and cytosol fraction of the gastrocnemius muscle. KEY FINDINGS: 8-week l-arginine supplementation associated with physical training was effective in promoting greater tolerance to exercise that was accompanied by up-regulation of the protein expressions of mtTFA, PGC-1α, ATP synthase subunit c, COXIV, Cu/Zn-SOD and Mn-SOD. The upstream pathway was associated with improvement of NO bioavailability, but not in NO production since no changes in nNOS or eNOS protein expressions were observed. SIGNIFICANCE: This combination would be an alternative approach for preventing cardiometabolic diseases given that in overt diseases a profound impairment in the physical performance of the patients is observed.