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1.
PLoS One ; 14(5): e0217058, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31112558

RESUMO

BACKGROUND: Obstructive sleep apnea (OSA) is a risk factor frequently present in patients with metabolic syndrome (MetS). Additionally, moderate and severe OSA are highly prevalent in patients with cardiac disease, as they increase the riskfor cardiovascular events by 80%. The gold standard diagnostic method for OSA is overnight polysomnography (PSG), which remains unaffordable for the overall population. The aim of the present study was to evaluate whether the Berlin Questionnaire (BQ) is anuseful tool for assessing the risk of OSA in patients with MetS. METHODS: 97 patients, previously untreated and recently diagnosed with MetS (National Cholesterol Education Program, Adult Treatment Panel III, ATP-III) underwent a PSG. OSA was characterized by the apnea-hypopnea index (AHI). BQ was administered before PSG and we evaluated sensitivity, specificity, positive and negative predictive values, and accuracy. RESULTS: Of the 97 patients with MetS, 81 patients had OSA, with 47 (48.5%) presenting moderate and severe OSA. For all MetS with OSA (AHI≥5 events/hour), the BQ showed good sensitivity (0.65, 95% CI 0.54 to 0.76) and fair specificity (0.38, 95% CI 0.15-0.65) with a positive predictive value of 0.84, a negative predictive value of 0.18 and an 84% accuracy. Similarly, for moderate-to-severe OSA (AHI≥15 events/hour) we found good sensitivity (0.73, 95% CI 0.58-0.85) and fair specificity (0.40, 95% CI 0.27-0.55). Interestingly, for severe OSA (AHI≥30 events/hour), there was a very good sensitivity (0.91, 95% CI 0.72-0.99) and moderate specificity (0.42, 95% CI 0.31-0.54). CONCLUSION: The BQ is a valid tool for screening the risk of OSA in MetS patients in general, and it is particularly useful in predicting severe OSA.

2.
Motriz (Online) ; 25(1): e101902, 2019. tab, graf
Artigo em Inglês | LILACS-Express | ID: biblio-1020084

RESUMO

Abstract Aim: This study tested the hypothesis that: 1- the exercise training would improve the heart rate recovery (HRR) decline after maximal exercise test in hypertensive patients and; 2- the exercise training would normalize HRR decline when compared to normotensive individuals. Methods: Sixteen hypertensive patients were consecutively allocated into two groups: Exercise-trained (n = 9, 47±2 years) and untrained (n = 7, 42±3 years). An exercise-trained normotensive group (n = 11, 41±2 years) was also studied. Heart rate was evaluated by electrocardiogram. The autonomic function was evaluated based on heart rate changes on the first and the second min of recovery after the maximal exercise test. Exercise training consisted of three 60-minute exercise sessions/week for 4 months. Results: In hypertensive patients, exercise training significantly increased the HRR decline in the first (-19±2 vs. -34±3 bpm, P = 0.001) and second (-33±3 vs. -49±2 bpm, P = 0.006) minutes after the maximal exercise test. In addition, after exercise training, the initial differences in the HRR decline after exercise between hypertensive patients and normotensive individuals were no longer observed (first minute: -34±3 vs. -29±3 bpm, P = 0.52, and second minute: -49±2 vs. -47±4 bpm, P = 0.99). Conclusion: Hypertension causes a delay in HRR after the maximal exercise test yet the exercise training normalizes HRR during the post-exercise period in hypertensive patients.

3.
Sleep Breath ; 2018 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-29948856

RESUMO

PURPOSE: We tested the hypothesis that (i) diet associated with exercise would improve arterial baroreflex (ABR) control in metabolic syndrome (MetS) patients with and without obstructive sleep apnea (OSA) and (ii) the effects of this intervention would be more pronounced in patients with OSA. METHODS: Forty-six MetS patients without (noOSA) and with OSA (apnea-hypopnea index, AHI > 15 events/h) were allocated to no treatment (control, C) or hypocaloric diet (- 500 kcal/day) associated with exercise (40 min, bicycle exercise, 3 times/week) for 4 months (treatment, T), resulting in four groups: noOSA-C (n = 10), OSA-C (n = 12), noOSA-T (n = 13), and OSA-T (n = 11). Muscle sympathetic nerve activity (MSNA), beat-to-beat BP, and spontaneous arterial baroreflex function of MSNA (ABRMSNA, gain and time delay) were assessed at study entry and end. RESULTS: No significant changes occurred in C groups. In contrast, treatment in both patients with and without OSA led to a significant decrease in weight (P < 0.05) and the number of MetS factors (P = 0.03). AHI declined only in the OSA-T group (31 ± 5 to 17 ± 4 events/h, P < 0.05). Systolic BP decreased in both treatment groups, and diastolic BP decreased significantly only in the noOSA-T group. Treatment decreased MSNA in both groups. Compared with baseline, ABRMSNA gain increased in both OSA-T (13 ± 1 vs. 24 ± 2 a.u./mmHg, P = 0.01) and noOSA-T (27 ± 3 vs. 37 ± 3 a.u./mmHg, P = 0.03) groups. The time delay of ABRMSNA was reduced only in the OSA-T group (4.1 ± 0.2 s vs. 2.8 ± 0.3 s, P = 0.04). CONCLUSIONS: Diet associated with exercise improves baroreflex control of sympathetic nerve activity and MetS components in patients with MetS regardless of OSA.

4.
Clinics (Sao Paulo) ; 73: e226, 2018 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-29791601

RESUMO

OBJECTIVES: Misuse of anabolic androgenic steroids in athletes is a strategy used to enhance strength and skeletal muscle hypertrophy. However, its abuse leads to an imbalance in muscle sympathetic nerve activity, increased vascular resistance, and increased blood pressure. However, the mechanisms underlying these alterations are still unknown. Therefore, we tested whether anabolic androgenic steroids could impair resting baroreflex sensitivity and cardiac sympathovagal control. In addition, we evaluate pulse wave velocity to ascertain the arterial stiffness of large vessels. METHODS: Fourteen male anabolic androgenic steroid users and 12 nonusers were studied. Heart rate, blood pressure, and respiratory rate were recorded. Baroreflex sensitivity was estimated by the sequence method, and cardiac autonomic control by analysis of the R-R interval. Pulse wave velocity was measured using a noninvasive automatic device. RESULTS: Mean spontaneous baroreflex sensitivity, baroreflex sensitivity to activation of the baroreceptors, and baroreflex sensitivity to deactivation of the baroreceptors were significantly lower in users than in nonusers. In the spectral analysis of heart rate variability, high frequency activity was lower, while low frequency activity was higher in users than in nonusers. Moreover, the sympathovagal balance was higher in users. Users showed higher pulse wave velocity than nonusers showing arterial stiffness of large vessels. Single linear regression analysis showed significant correlations between mean blood pressure and baroreflex sensitivity and pulse wave velocity. CONCLUSIONS: Our results provide evidence for lower baroreflex sensitivity and sympathovagal imbalance in anabolic androgenic steroid users. Moreover, anabolic androgenic steroid users showed arterial stiffness. Together, these alterations might be the mechanisms triggering the increased blood pressure in this population.


Assuntos
Anabolizantes/efeitos adversos , Androgênios/efeitos adversos , Sistema Nervoso Autônomo/efeitos dos fármacos , Barorreflexo/efeitos dos fármacos , Sistema Cardiovascular/efeitos dos fármacos , Nervo Vago/efeitos dos fármacos , Adulto , Sistema Nervoso Autônomo/fisiologia , Barorreflexo/fisiologia , Pressão Sanguínea/efeitos dos fármacos , Fenômenos Fisiológicos Cardiovasculares/efeitos dos fármacos , Estudos Transversais , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Força Muscular/efeitos dos fármacos , Exercícios de Alongamento Muscular , Análise de Onda de Pulso , Taxa Respiratória/efeitos dos fármacos , Fatores de Risco , Estatísticas não Paramétricas , Nervo Vago/fisiologia , Rigidez Vascular/efeitos dos fármacos
5.
Metab Syndr Relat Disord ; 16(1): 2-5, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29298404

RESUMO

BACKGROUND: Recent evidence suggests that obstructive sleep apnea (OSA) is common in patients with metabolic syndrome (MetS) and may contribute to metabolic deregulation, inflammation, and atherosclerosis in these patients. In clinical practice, however, OSA is frequently underdiagnosed. We sought to investigate the clinical predictors of OSA in patients with MetS. METHODS: We studied consecutive patients newly diagnosed with MetS (Adult Treatment Panel-III). All participants underwent clinical evaluation, standard polysomnography, and laboratory measurements. We performed a logistic regression model, including the following variables: gender, age >50 years, neck and waist circumferences, hypertension, diabetes, body mass index (BMI) >30 kg/m2, high risk for OSA by Berlin questionnaire, presence of excessive daytime somnolence (Epworth Sleepiness Scale), abnormal serum glucose, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol. RESULTS: We studied 197 patients (60% men; age: 49 ± 10 years; BMI: 32.9 ± 5.1 kg/m2). OSA (defined by an apnea-hypopnea index ≥15 events per hour) was diagnosed in 117 patients [59%; 95% confidence interval (CI): 52-66]. In multivariate analysis, male gender [odds ratio (OR): 3.28; 95% CI: 1.68-6.41; P < 0.01], abnormal glucose levels (OR: 3.01; 95% CI: 1.50-6.03; P < 0.01), excessive daytime sleepiness (OR: 2.38; 95% CI: 1.13-5.04; P = 0.02), and high risk for OSA by Berlin questionnaire (OR: 4.33; 95% CI: 2.06-9.11; P < 0.001) were independently associated with OSA. CONCLUSIONS: Simple clinical and metabolic characteristics may help to improve the underdiagnosis of OSA in patients with MetS.

6.
Clinics ; 73: e226, 2018. tab
Artigo em Inglês | LILACS-Express | ID: biblio-890749

RESUMO

OBJECTIVES: Misuse of anabolic androgenic steroids in athletes is a strategy used to enhance strength and skeletal muscle hypertrophy. However, its abuse leads to an imbalance in muscle sympathetic nerve activity, increased vascular resistance, and increased blood pressure. However, the mechanisms underlying these alterations are still unknown. Therefore, we tested whether anabolic androgenic steroids could impair resting baroreflex sensitivity and cardiac sympathovagal control. In addition, we evaluate pulse wave velocity to ascertain the arterial stiffness of large vessels. METHODS: Fourteen male anabolic androgenic steroid users and 12 nonusers were studied. Heart rate, blood pressure, and respiratory rate were recorded. Baroreflex sensitivity was estimated by the sequence method, and cardiac autonomic control by analysis of the R-R interval. Pulse wave velocity was measured using a noninvasive automatic device. RESULTS: Mean spontaneous baroreflex sensitivity, baroreflex sensitivity to activation of the baroreceptors, and baroreflex sensitivity to deactivation of the baroreceptors were significantly lower in users than in nonusers. In the spectral analysis of heart rate variability, high frequency activity was lower, while low frequency activity was higher in users than in nonusers. Moreover, the sympathovagal balance was higher in users. Users showed higher pulse wave velocity than nonusers showing arterial stiffness of large vessels. Single linear regression analysis showed significant correlations between mean blood pressure and baroreflex sensitivity and pulse wave velocity. CONCLUSIONS: Our results provide evidence for lower baroreflex sensitivity and sympathovagal imbalance in anabolic androgenic steroid users. Moreover, anabolic androgenic steroid users showed arterial stiffness. Together, these alterations might be the mechanisms triggering the increased blood pressure in this population.

7.
Diabetol Metab Syndr ; 9: 87, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29090024

RESUMO

BACKGROUND: Metabolic syndrome (MetS) is associated with structural and functional vascular abnormalities, which may lead to increased arterial stiffness, more frequent cardiovascular events and higher mortality. However, the role played by clustering of risk factors and the combining pattern of MetS risk factors and their association with the arterial stiffness have yet to be fully understood. Age, hypertension and diabetes mellitus seem to be strongly associated with increased pulse wave velocity (PWV). This study aimed at determining the clustering and combining pattern of MetS risk factors and their association with the arterial stiffness in non-diabetic and non-hypertensive patients. METHODS: Recently diagnosed and untreated patients with MetS (n = 64, 49 ± 8 year, 32 ± 4 kg/m2) were selected, according to ATP III criteria and compared to a control group (Control, n = 17, 49 ± 6 year, 27 ± 2 kg/m2). Arterial stiffness was evaluated by PWV in the carotid-femoral segment. Patients were categorized and analyzed according MetS risk factors clustering (3, 4 and 5 factors) and its combinations. RESULTS: Patients with MetS had increased PWV when compared to Control (7.8 ± 1.1 vs. 7.0 ± 0.5 m/s, p < 0.001). In multivariate analysis, the variables that remained as predictors of PWV were age (ß = 0.450, p < 0.001), systolic blood pressure (ß = 0.211, p = 0.023) and triglycerides (ß = 0.212, p = 0.037). The increased number of risk factors reflected in a progressive increase in PWV. When adjusted to systolic blood pressure, PWV was greater in the group with 5 risk factors when compared to the group with 3 risk factors and Control (8.5 ± 0.4 vs. 7.5 ± 0.2, p = 0.011 and 7.2 ± 0.3 m/s, p = 0.012). Similarly, the 4 risk factors group had higher PWV than the Control (7.9 ± 0.2 vs. 7.2 ± 0.3, p = 0.047). CONCLUSIONS: The number of risk factors seems to increase arterial stiffness. Notably, besides age and increased systolic blood pressure, alterations in the triglycerides worsened the stiffness of large vessels, emphasizing the importance in addressing this risk factor in MetS patients.

8.
J Clin Hypertens (Greenwich) ; 19(9): 840-847, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28868764

RESUMO

Metabolic syndrome (MetS) causes autonomic alteration and vascular dysfunction. The authors investigated whether impaired fasting glucose (IFG) is the main cause of vascular dysfunction via elevated sympathetic tone in nondiabetic patients with MetS. Pulse wave velocity, muscle sympathetic nerve activity (MSNA), and forearm vascular resistance was measured in patients with MetS divided according to fasting glucose levels: (1) MetS+IFG (blood glucose ≥100 mg/dL) and (2) MetS-IFG (<100 mg/dL) compared with healthy controls. Patients with MetS+IFG had higher pulse wave velocity than patients with MetS-IFG and controls (median 8.0 [interquartile range, 7.2-8.6], 7.3 [interquartile range, 6.9-7.9], and 6.9 [interquartile range, 6.6-7.2] m/s, P=.001). Patients with MetS+IFG had higher MSNA than patients with MetS-IFG and controls, and patients with MetS-IFG had higher MSNA than controls (31±1, 26±1, and 19±1 bursts per minute; P<.001). Patients with MetS+IFG were similar to patients with MetS-IFG but had higher forearm vascular resistance than controls (P=.008). IFG was the only predictor variable of MSNA. MSNA was associated with pulse wave velocity (R=.39, P=.002) and forearm vascular resistance (R=.30, P=.034). In patients with MetS, increased plasma glucose levels leads to an adrenergic burden that can explain vascular dysfunction.


Assuntos
Glicemia/análise , Intolerância à Glucose/complicações , Síndrome Metabólica/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Glicemia/metabolismo , Feminino , Intolerância à Glucose/epidemiologia , Intolerância à Glucose/fisiopatologia , Humanos , Resistência à Insulina , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/epidemiologia , Pessoa de Meia-Idade , Estado Pré-Diabético/complicações , Estudos Prospectivos , Análise de Onda de Pulso/métodos , Fatores de Risco , Resistência Vascular/fisiologia , Rigidez Vascular/fisiologia , Circunferência da Cintura
9.
Am J Physiol Heart Circ Physiol ; 311(5): H1180-H1188, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27591218

RESUMO

Heart failure (HF) is characterized by decreased exercise capacity, attributable to neurocirculatory and skeletal muscle factors. Cardiac resynchronization therapy (CRT) and exercise training have each been shown to decrease muscle sympathetic nerve activity (MSNA) and increase exercise capacity in patients with HF. We hypothesized that exercise training in the setting of CRT would further reduce MSNA and vasoconstriction and would increase Ca2+-handling gene expression in skeletal muscle in patients with chronic systolic HF. Thirty patients with HF, ejection fraction <35% and CRT for 1 mo, were randomized into two groups: exercise-trained (ET, n = 14) and untrained (NoET, n = 16) groups. The following parameters were compared at baseline and after 4 mo in each group: V̇o2 peak, MSNA (microneurography), forearm blood flow, and Ca2+-handling gene expression in vastus lateralis muscle. After 4 mo, exercise duration and V̇o2 peak were significantly increased in the ET group (P = 0.04 and P = 0.01, respectively), but not in the NoET group. MSNA was significantly reduced in the ET (P = 0.001), but not in NoET, group. Similarly, forearm vascular conductance significantly increased in the ET (P = 0.0004), but not in the NoET, group. The expression of the Na+/Ca2+ exchanger (P = 0.01) was increased, and ryanodine receptor expression was preserved in ET compared with NoET. In conclusion, the exercise training in the setting of CRT improves exercise tolerance and neurovascular control and alters Ca2+-handling gene expression in the skeletal muscle of patients with systolic HF. These findings highlight the importance of including exercise training in the treatment of patients with HF even following CRT.


Assuntos
Cálcio/metabolismo , Terapia de Ressincronização Cardíaca , Terapia por Exercício , Exercício , Insuficiência Cardíaca/terapia , Acoplamento Neurovascular , Músculo Quadríceps/metabolismo , Sistema Nervoso Simpático/metabolismo , Ecocardiografia , Teste de Esforço , Tolerância ao Exercício , Feminino , Antebraço/irrigação sanguínea , Expressão Gênica , Insuficiência Cardíaca/genética , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/inervação , Músculo Esquelético/metabolismo , Consumo de Oxigênio , Músculo Quadríceps/inervação , RNA Mensageiro/metabolismo , Fluxo Sanguíneo Regional , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Trocador de Sódio e Cálcio/genética
10.
Obesity (Silver Spring) ; 23(8): 1582-90, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26148219

RESUMO

OBJECTIVE: Chemoreflex hypersensitity was caused by obstructive sleep apnea (OSA) in patients with metabolic syndrome (MetS). This study tested the hypothesis that hypocaloric diet and exercise training (D+ET) would improve peripheral and central chemoreflex sensitivity in patients with MetS and OSA. METHODS: Patients were assigned to: (1) D+ET (n = 16) and (2) no intervention control (C, n = 8). Minute ventilation (VE, pre-calibrated pneumotachograph) and muscle sympathetic nerve activity (MSNA, microneurography) were evaluated during peripheral chemoreflex sensitivity by inhalation of 10% O2 and 90% N2 with CO2 titrated and central chemoreflex by 7% CO2 and 93% O2 for 3 min at study entry and after 4 months. RESULTS: Peak VO2 was increased by D+ET; body weight, waist circumference, glucose levels, systolic/diastolic blood pressure, and apnea-hypopnea index (AHI) (34 ± 5.1 vs. 18 ± 3.2 events/h, P = 0.04) were reduced by D+ET. MSNA was reduced by D+ET at rest and in response to hypoxia (8.6 ± 1.2 vs. 5.4 ± 0.6 bursts/min, P = 0.02), and VE in response to hypercapnia (14.8 ± 3.9 vs. 9.1 ± 1.2 l/min, P = 0.02). No changes were found in the C group. A positive correlation was found between AHI and MSNA absolute changes (R = 0.51, P = 0.01) and body weight and AHI absolute changes (R = 0.69, P < 0.001). CONCLUSIONS: Sympathetic peripheral and ventilatory central chemoreflex sensitivity was improved by D+ET in MetS+OSA patients, which may be associated with improvement in sleep pattern.


Assuntos
Dieta Redutora , Exercício , Síndrome Metabólica/complicações , Obesidade/terapia , Apneia Obstrutiva do Sono/complicações , Sistema Nervoso Simpático/fisiopatologia , Adulto , Dióxido de Carbono/metabolismo , Células Quimiorreceptoras/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Sistema Nervoso Simpático/metabolismo , Resultado do Tratamento
11.
Sleep ; 38(7): 1059-66, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25669187

RESUMO

STUDY OBJECTIVES: The attenuation of heart rate recovery after maximal exercise (ΔHRR) is independently impaired by obstructive sleep apnea (OSA) and metabolic syndrome (MetS). Therefore, we tested the hypotheses: (1) MetS + OSA restrains ΔHRR; and (2) Sympathetic hyperactivation is involved in this impairment. DESIGN: Cross-sectional study. PARTICIPANTS: We studied 60 outpatients in whom MetS had been newly diagnosed (ATP III), divided according to apnea-hypopnea index (AHI) ≥ 15 events/h in MetS + OSA (n = 30, 49 ± 1.7 y) and AHI < 15 events/h in MetS - OSA (n = 30, 46 ± 1.4 y). Normal age-matched healthy control subjects (C) without MetS and OSA were also enrolled (n = 16, 46 ± 1.7 y). INTERVENTIONS: Polysomnography, microneurography, cardiopulmonary exercise test. MEASUREMENTS AND RESULTS: We evaluated OSA (AHI - polysomnography), muscle sympathetic nerve activity (MSNA - microneurography) and cardiac autonomic activity (LF = low frequency, HF = high frequency, LF/HF = sympathovagal balance) based on spectral analysis of heart rate (HR) variability. ΔHRR was calculated (peak HR minus HR at first, second, and fourth minute of recovery) after cardiopulmonary exercise test. MetS + OSA had higher MSNA and LF, and lower HF than MetS - OSA and C. Similar impairment occurred in MetS - OSA versus C (interaction, P < 0.01). MetS + OSA had attenuated ΔHRR at first, second, and at fourth minute than did C, and attenuated ΔHRR at fourth minute than did MetS - OSA (interaction, P < 0.001). Compared with C, MetS - OSA had attenuated ΔHRR at second and fourth min (interaction, P < 0.001). Further analysis showed association of the ΔHRR (first, second, and fourth minute) and AHI, MSNA, LF and HF components (P < 0.05 for all associations). CONCLUSIONS: The attenuation of heart rate recovery after maximal exercise is impaired to a greater degree where metabolic syndrome (MetS) is associated with moderate to severe obstructive sleep apnea (OSA) than by MetS with no or mild or no OSA. This is at least partly explained by sympathetic hyperactivity.


Assuntos
Exercício/fisiologia , Síndrome Metabólica/complicações , Síndrome Metabólica/fisiopatologia , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Nervo Vago/fisiologia , Adulto , Estudos Transversais , Teste de Esforço , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia
12.
Am J Physiol Heart Circ Physiol ; 307(11): H1655-66, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25305179

RESUMO

Previous studies have demonstrated that muscle mechanoreflex and metaboreflex controls are altered in heart failure (HF), which seems to be due to changes in cyclooxygenase (COX) pathway and changes in receptors on afferent neurons, including transient receptor potential vanilloid type-1 (TRPV1) and cannabinoid receptor type-1 (CB1). The purpose of the present study was to test the hypotheses: 1) exercise training (ET) alters the muscle metaboreflex and mechanoreflex control of muscle sympathetic nerve activity (MSNA) in HF patients. 2) The alteration in metaboreflex control is accompanied by increased expression of TRPV1 and CB1 receptors in skeletal muscle. 3) The alteration in mechanoreflex control is accompanied by COX-2 pathway in skeletal muscle. Thirty-four consecutive HF patients with ejection fractions <40% were randomized to untrained (n = 17; 54 ± 2 yr) or exercise-trained (n = 17; 56 ± 2 yr) groups. MSNA was recorded by microneurography. Mechanoreceptors were activated by passive exercise and metaboreceptors by postexercise circulatory arrest (PECA). COX-2 pathway, TRPV1, and CB1 receptors were measured in muscle biopsies. Following ET, resting MSNA was decreased compared with untrained group. During PECA (metaboreflex), MSNA responses were increased, which was accompanied by the expression of TRPV1 and CB1 receptors. During passive exercise (mechanoreflex), MSNA responses were decreased, which was accompanied by decreased expression of COX-2, prostaglandin-E2 receptor-4, and thromboxane-A2 receptor and by decreased in muscle inflammation, as indicated by increased miRNA-146 levels and the stable NF-κB/IκB-α ratio. In conclusion, ET alters muscle metaboreflex and mechanoreflex control of MSNA in HF patients. This alteration with ET is accompanied by alteration in TRPV1 and CB1 expression and COX-2 pathway and inflammation in skeletal muscle.


Assuntos
Terapia por Exercício , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/terapia , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatologia , Reflexo/fisiologia , Adulto , Idoso , Doença Crônica , Ciclo-Oxigenase 2/fisiologia , Teste de Esforço , Feminino , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Receptor CB1 de Canabinoide/biossíntese , Transdução de Sinais/fisiologia , Volume Sistólico/fisiologia , Sistema Nervoso Simpático/fisiopatologia , Canais de Cátion TRPV/biossíntese
13.
Am J Physiol Heart Circ Physiol ; 304(7): H1038-44, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23355343

RESUMO

The incidence and strength of muscle sympathetic nerve activity (MSNA) depend on the magnitude (gain) and latency (time delay) of the arterial baroreflex control (ABR). However, the impact of metabolic syndrome (MetS) and obstructive sleep apnea (OSA) on oscillatory pattern of MSNA and time delay of the ABR of sympathetic activity is unknown. We tested the hypothesis that MetS and OSA would impair the oscillatory pattern of MSNA and the time delay of the ABR of sympathetic activity. Forty-three patients with MetS were allocated into two groups according to the presence of OSA (MetS + OSA, n = 21; and MetS - OSA, n = 22). Twelve aged-paired healthy controls (C) were also studied. OSA (apnea-hypopnea index > 15 events/h) was diagnosed by polysomnography. We recorded MSNA (microneurography), blood pressure (beat-to-beat basis), and heart rate (EKG). Oscillatory pattern of MSNA was evaluated by autoregressive spectral analysis and the ABR of MSNA (ABRMSNA, sensitivity and time delay) by bivariate autoregressive analysis. Patients with MetS + OSA had decreased oscillatory pattern of MSNA compared with MetS - OSA (P < 0.01) and C (P < 0.001). The sensitivity of the ABRMSNA was lower and the time delay was greater in MetS + OSA compared with MetS - OSA (P < 0.001 and P < 0.01, respectively) and C (P < 0.001 and P < 0.001, respectively). Patients with MetS - OSA showed decreased oscillatory pattern of MSNA compared with C (P < 0.01). The sensitivity of the ABRMSNA was lower in MetS - OSA than in C group (P < 0.001). In conclusion, MetS decreases the oscillatory pattern of MSNA and the magnitude of the ABRMSNA. OSA exacerbates these autonomic dysfunctions and further increases the time delay of the baroreflex response of MSNA.


Assuntos
Barorreflexo/fisiologia , Síndrome Metabólica/fisiopatologia , Tempo de Reação , Apneia Obstrutiva do Sono/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Adulto , Pressão Sanguínea , Estudos de Casos e Controles , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Apneia Obstrutiva do Sono/diagnóstico
14.
Sleep ; 36(1): 41-9, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23288970

RESUMO

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is often observed in patients with metabolic syndrome (MetS). In addition, the association of MetS and OSA substantially increases sympathetic nerve activity. However, the mechanisms involved in sympathetic hyperactivation in patients with MetS + OSA remain to be clarified. We tested the hypothesis that chemoreflex sensitivity is heightened in patients with MetS and OSA. DESIGN: Prospective clinical study. PARTICIPANTS: Forty-six patients in whom MetS was newly diagnosed (ATP-III) were allocated into: (1) MetS + OSA (n = 24, 48 ± 1.8 yr); and (2) MetS - OSA (n = 22, 44 ± 1.7 yr). Eleven normal control subjects were also studied (C, 47 ± 2.3 yr). MEASUREMENTS: OSA was defined as an apnea-hypopnea index ≥ 15 events/hr (polysomnography). Muscle sympathetic nerve activity (MSNA) was measured by microneurography technique. Peripheral chemoreflex sensitivity was assessed by inhalation of 10% oxygen and 90% nitrogen (carbon dioxide titrated), and central chemoreflex sensitivity by 7% carbon dioxide and 93% oxygen. RESULTS: Physical characteristics and MetS measures were similar between MetS + OSA and MetS - OSA. MSNA was higher in MetS + OSA patients compared with MetS - OSA and C (33 ± 1.3 versus 28 ± 1.2 and 18 ± 2.2 bursts/min, P < 0.05). Isocapnic hypoxia caused a greater increase in MSNA in MetS + OSA than MetS - OSA and C (P = 0.03). MSNA in response to hyperoxic hypercapnia was greater in MetS + OSA compared with C (P = 0.005). Further analysis showed a significant association between baseline MSNA and peripheral (P < 0.01) and central (P < 0.01) chemoreflex sensitivity. Min ventilation in response to hyperoxic hypercapnia was greater in MetS + OSA compared with C (P = 0.001). CONCLUSION: OSA increases sympathetic peripheral and central chemoreflex response in patients with MetS, which seems to explain, at least in part, the increase in sympathetic nerve activity in these patients. In addition, OSA increases ventilatory central chemoreflex response in patients with MetS.


Assuntos
Células Quimiorreceptoras/metabolismo , Síndrome Metabólica/complicações , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Adulto , Análise de Variância , Dióxido de Carbono/metabolismo , Feminino , Humanos , Hipercapnia/complicações , Hipercapnia/metabolismo , Hipercapnia/fisiopatologia , Hipóxia/complicações , Hipóxia/metabolismo , Hipóxia/fisiopatologia , Masculino , Síndrome Metabólica/metabolismo , Pessoa de Meia-Idade , Nitrogênio/metabolismo , Oxigênio/metabolismo , Polissonografia/métodos , Estudos Prospectivos , Ventilação Pulmonar , Reflexo , Apneia Obstrutiva do Sono/metabolismo , Sistema Nervoso Simpático/metabolismo
15.
Eur J Appl Physiol ; 113(3): 671-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22918560

RESUMO

Previous investigations show that metabolic syndrome (MetSyn) causes sympathetic hyperactivation. Symptoms of anxiety and mood disturbance (AMd) provoke sympatho-vagal imbalance. We hypothesized that AMd would alter even further the autonomic function in patients with MetSyn. Twenty-six never-treated patients with MetSyn (ATP-III) were allocated to two groups, according to the levels of anxiety and mood disturbance: (1) with AMd (MetSyn + AMd, n = 15), and (2) without AMd (MetSyn, n = 11). Ten healthy control subjects were also studied (C, n = 10). AMd was determined using quantitative questionnaires. Muscle sympathetic nerve activity (MSNA, microneurography), blood pressure (oscillometric beat-to-beat basis), and heart rate (ECG) were measured during a baseline 10-min period. Spectral analysis of RR interval and systolic arterial pressure were analyzed, and the power of low (LF) and high (HF) frequency bands were determined. Sympatho-vagal balance was obtained by LF/HF ratio. Spontaneous baroreflex sensitivity (BRS) was evaluated by calculation of α-index. MSNA was greater in patients with MetSyn + AMd compared with MetSyn and C. Patients with MetSyn + AMd showed higher LF and lower HF power compared with MetSyn and C. In addition, LF/HF balance was higher in MetSyn + AMd than in MetSyn and C groups. BRS was decreased in MetSyn + AMd compared with MetSyn and C groups. Anxiety and mood disturbance alter autonomic function in patients with MetSyn. This autonomic dysfunction may contribute to the increased cardiovascular risk observed in patients with mood alterations.


Assuntos
Ansiedade/complicações , Sistema Nervoso Autônomo/fisiopatologia , Sistema Cardiovascular/fisiopatologia , Síndrome Metabólica/complicações , Síndrome Metabólica/fisiopatologia , Transtornos do Humor/complicações , Adulto , Ansiedade/epidemiologia , Ansiedade/fisiopatologia , Doenças do Sistema Nervoso Autônomo/epidemiologia , Doenças do Sistema Nervoso Autônomo/etiologia , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Barorreflexo/fisiologia , Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/fisiopatologia , Sistema Cardiovascular/inervação , Estudos de Casos e Controles , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos do Humor/epidemiologia , Transtornos do Humor/fisiopatologia , Fatores de Risco , Sistema Nervoso Simpático/fisiopatologia
16.
Steroids ; 77(13): 1321-6, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22939845

RESUMO

OBJECTIVE: To evaluate the effects of anabolic androgenic steroids (AAS) on chylomicron metabolism. METHODS: An artificial lipid emulsion labeled with radioactive cholesteryl ester (CE) and triglycerides (TG) mimicking chylomicrons was intravenously injected into individuals who regularly weight trained and made regular use of AAS (WT+AAS group), normolipidemic sedentary individuals (SDT group) and individuals who also regularly weight trained but did not use AAS (WT group). Fractional clearance rates (FCR) were determined by compartmental analysis for emulsion plasma decay curves. RESULTS: FCR-CE for the WT+AAS group was reduced (0.0073 ± 0.0079 min(-1), 0.0155 ± 0.0100 min(-1), 0.0149 ± 0.0160 min(-1), respectively; p<0.05), FCR-TG was similar for both the WT and SDT groups. HDL-C plasma concentrations were lower in the WT+AAS group when compared to the WT and SDT groups (22 ± 13; 41 ± 7; 38 ± 13 mg/dL, respectively; p<0.001). Hepatic triglyceride lipase activity was greater in the WT+AAS group when compared to the WT and SDT groups (7243 ± 1822; 3898 ± 1232; 2058 ± 749, respectively; p<0.001). However, no difference was observed for lipoprotein lipase activity. CONCLUSIONS: Data strongly suggest that AAS may reduce the removal from the plasma of chylomicron remnants, which are known atherogenic factors.


Assuntos
Androgênios/farmacologia , Quilomícrons/metabolismo , Esteroides/farmacologia , Adulto , Quilomícrons/química , Humanos , Masculino , Treinamento de Resistência , Comportamento Sedentário , Triglicerídeos/química
17.
Hypertension ; 58(6): 1049-56, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22025377

RESUMO

Autonomic dysfunction, including baroreceptor attenuation and sympathetic activation, has been reported in patients with myocardial infarction (MI) and has been associated with increased mortality. We tested the hypotheses that exercise training (ET) in post-MI patients would normalize arterial baroreflex sensitivity (BRS) and muscle sympathetic nerve activity (MSNA), and long-term ET would maintain the benefits in BRS and MSNA. Twenty-eight patients after 1 month of uncomplicated MI were randomly assigned to 2 groups, ET (MI-ET) and untrained. A normal control group was also studied. ET consisted of three 60-minute exercise sessions per week for 6 months. We evaluated MSNA (microneurography), blood pressure (automatic oscillometric method), heart rate (ECG), and spectral analysis of RR interval, systolic arterial pressure (SAP), and MSNA. Baroreflex gain of SAP-RR interval and SAP-MSNA were calculated using the α-index. At 3 to 5 days and 1 month after MI, MSNA and low-frequency SAP were significantly higher and BRS significantly lower in MI patients when compared with the normal control group. ET significantly decreased MSNA (bursts per 100 heartbeats) and the low-frequency component of SAP and significantly increased the low-frequency component of MSNA and BRS of the RR interval and MSNA. These changes were so marked that the differences between patients with MI and the normal control group were no longer observed after ET. MSNA and BRS in the MI-untrained group did not change from baseline over the same time period. ET normalizes BRS, low-frequency SAP, and MSNA in patients with MI. These improvements in autonomic control are maintained by long-term ET. These findings highlight the clinical importance of this nonpharmacological therapy based on ET in the long-term treatment of patients with MI.


Assuntos
Doenças do Sistema Nervoso Autônomo/prevenção & controle , Barorreflexo/fisiologia , Terapia por Exercício , Infarto do Miocárdio/reabilitação , Antagonistas Adrenérgicos beta/farmacologia , Doenças do Sistema Nervoso Autônomo/complicações , Fatores de Confusão (Epidemiologia) , Feminino , Frequência Cardíaca/efeitos dos fármacos , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/inervação , Infarto do Miocárdio/fisiopatologia , Reflexo Anormal , Resultado do Tratamento
18.
Atherosclerosis ; 219(2): 532-7, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21906740

RESUMO

OBJECTIVE: To evaluate the effects of resistance training (RT) on the metabolism of an LDL-like nanoemulsion and on lipid transfer to HDL, an important step of HDL metabolism. METHODS: LDL-like nanoemulsion plasma kinetics was studied in 15 healthy men under regular RT for 1-4 years (age = 25 ± 5 years, VO(2)peak = 50 ± 6 mL/kg/min) and in 15 healthy sedentary men (28 ± 7 years, VO(2)peak = 35 ± 9 mL/kg/min). LDL-like nanoemulsion labeled with (14)C-cholesteryl-ester and (3)H-free-cholesterol was injected intravenously, plasma samples were collected over 24-h to determine decay curves and fractional clearance rates (FCR). Lipid transfer to HDL was determined in vitro by incubating of plasma samples with nanoemulsions (lipid donors) labeled with radioactive free-cholesterol, cholesteryl-ester, triacylglycerols and phospholipids. HDL size, paraoxonase-1 activity and oxidized LDL levels were also determined. RESULTS: The two groups showed similar LDL and HDL-cholesterol and triacylglycerols, but oxidized LDL was lower in RT (30 ± 9 vs. 61 ± 19 U/L, p = 0.0005). In RT, the nanoemulsion (14)C-cholesteryl-ester was removed twice as fast than in sedentary individuals (FCR: 0.068 ± 0.023 vs. 0.037 ± 0.028, p = 0.002), as well as (3)H-free-cholesterol (0.041 ± 0.025 vs. 0.022 ± 0.023, p = 0.04). While both nanoemulsion labels were removed at the same rate in sedentary individuals, RT (3)H-free-cholesterol was removed slower than (14)C-cholesteryl-ester (p = 0.005). HDL size, paraoxonase 1 and the transfer rates to HDL of the four lipids were the same in both groups. CONCLUSIONS: RT accelerated the clearance of LDL-like nanoemulsion, which probably accounts for the oxidized LDL levels reduction in RT. RT also changed the balance of free and esterified cholesterol FCR's. However, RT had no effect on HDL metabolism related parameters.


Assuntos
Ésteres do Colesterol/farmacocinética , LDL-Colesterol/farmacocinética , Treinamento de Resistência , Comportamento Sedentário , Adolescente , Adulto , Arildialquilfosfatase/sangue , Brasil , Ésteres do Colesterol/administração & dosagem , Ésteres do Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/administração & dosagem , LDL-Colesterol/sangue , Emulsões , Humanos , Injeções Intravenosas , Lipoproteínas LDL/sangue , Masculino , Nanopartículas , Consumo de Oxigênio , Tamanho da Partícula , Fosfolipídeos/sangue , Triglicerídeos/sangue , Adulto Jovem
19.
Sleep ; 33(9): 1193-9, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20857866

RESUMO

STUDY OBJECTIVES: Metabolic syndrome (MetSyn) increases overall cardiovascular risk. MetSyn is also strongly associated with obstructive sleep apnea (OSA), and these 2 conditions share similar comorbidities. Whether OSA increases cardiovascular risk in patients with the MetSyn has not been investigated. We examined how the presence of OSA in patients with MetSyn affected hemodynamic and autonomic variables associated with poor cardiovascular outcome. DESIGN: Prospective clinical study. PARTICIPANTS: We studied 36 patients with MetSyn (ATP-III) divided into 2 groups matched for age and sex: (1) MetSyn+OSA (n = 18) and (2) MetSyn-OSA (n = 18). MEASUREMENTS: OSA was defined by an apnea-hypopnea index (AHI) > 15 events/hour by polysomnography. We recorded muscle sympathetic nerve activity (MSNA - microneurography), heart rate (HR), and blood pressure (BP - Finapres). Baroreflex sensitivity (BRS) was analyzed by spontaneous BP and HR fluctuations. RESULTS: MSNA (34 +/- 2 vs 28 +/- 1 bursts/min, P = 0.02) and mean BP (111 +/- 3 vs. 99 +/- 2 mm Hg, P = 0.003) were higher in patients with MetSyn+OSA versus patients with MetSyn-OSA. Patients with MetSyn+OSA had lower spontaneous BRS for increases (7.6 +/- 0.6 vs 12.2 +/- 1.2 msec/mm Hg, P = 0.003) and decreases (7.2 +/- 0.6 vs 11.9 +/- 1.6 msec/mm Hg, P = 0.01) in BP. MSNAwas correlated with AHI (r = 0.48; P = 0.009) and minimum nocturnal oxygen saturation (r = -0.38, P = 0.04). CONCLUSION: Patients with MetSyn and comorbid OSA have higher BP, higher sympathetic drive, and diminished BRS, compared with patients with MetSyn without OSA. These adverse cardiovascular and autonomic consequences of OSA may be associated with poorer outcomes in these patients. Moreover, increased BP and sympathetic drive in patients with MetSyn+OSA may be linked, in part, to impairment of baroreflex gain.


Assuntos
Doenças Cardiovasculares/etiologia , Síndrome Metabólica/complicações , Síndrome Metabólica/fisiopatologia , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/fisiopatologia , Adulto , Barorreflexo , Pressão Sanguínea , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Frequência Cardíaca , Humanos , Masculino , Síndrome Metabólica/metabolismo , Pessoa de Meia-Idade , Consumo de Oxigênio , Fatores de Risco , Apneia Obstrutiva do Sono/metabolismo , Vasodilatação
20.
PLoS One ; 5(8): e12065, 2010 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-20711453

RESUMO

BACKGROUND: Obstructive Sleep Apnea (OSA) is tightly linked to some components of Metabolic Syndrome (MetS). However, most of the evidence evaluated individual components of the MetS or patients with a diagnosis of OSA that were referred for sleep studies due to sleep complaints. Therefore, it is not clear whether OSA exacerbates the metabolic abnormalities in a representative sample of patients with MetS. METHODOLOGY/PRINCIPAL FINDINGS: We studied 152 consecutive patients (age 48+/-9 years, body mass index 32.3+/-3.4 Kg/m2) newly diagnosed with MetS (Adult Treatment Panel III). All participants underwent standard polysomnography irrespective of sleep complaints, and laboratory measurements (glucose, lipid profile, uric acid and C-reactive protein). The prevalence of OSA (apnea-hypopnea index>or=15 events per hour of sleep) was 60.5%. Patients with OSA exhibited significantly higher levels of blood pressure, glucose, triglycerides, cholesterol, LDL, cholesterol/HDL ratio, triglycerides/HDL ratio, uric acid and C-reactive protein than patients without OSA. OSA was independently associated with 2 MetS criteria: triglycerides: OR: 3.26 (1.47-7.21) and glucose: OR: 2.31 (1.12-4.80). OSA was also independently associated with increased cholesterol/HDL ratio: OR: 2.38 (1.08-5.24), uric acid: OR: 4.19 (1.70-10.35) and C-reactive protein: OR: 6.10 (2.64-14.11). Indices of sleep apnea severity, apnea-hypopnea index and minimum oxygen saturation, were independently associated with increased levels of triglycerides, glucose as well as cholesterol/HDL ratio, uric acid and C-reactive protein. Excessive daytime sleepiness had no effect on the metabolic and inflammatory parameters. CONCLUSIONS/SIGNIFICANCE: Unrecognized OSA is common in consecutive patients with MetS. OSA may contribute to metabolic dysregulation and systemic inflammation in patients with MetS, regardless of symptoms of daytime sleepiness.


Assuntos
Síndrome Metabólica/complicações , Síndrome Metabólica/metabolismo , Apneia Obstrutiva do Sono/complicações , Biomarcadores/metabolismo , Humanos , Inflamação/metabolismo , Modelos Lineares , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Risco
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