ANA MARIA FONSECA WANDERLEY BRAGA
Índice h a partir de 2011
6
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina - Médico
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
- Obstructive Sleep Apnea Impairs Postexercise Sympathovagal Balance in Patients with Metabolic Syndrome(2015) CEPEDA, Felipe X.; TOSCHI-DIAS, Edgar; MAKI-NUNES, Cristiane; RONDON, Maria Urbana P. B.; ALVES, Maria Janieire N. N.; BRAGA, Ana Maria F. W.; MARTINEZ, Daniel G.; DRAGER, Luciano F.; LORENZI-FILHO, Geraldo; NEGRAO, Carlos E.; TROMBETTA, Ivani C.Study Objectives: The attenuation of heart rate recovery after maximal exercise (Delta HRR) is independently impaired by obstructive sleep apnea (OSA) and metabolic syndrome (MetS). Therefore, we tested the hypotheses: (1) MetS + OSA restrains Delta HRR; 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. Delta HRR 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 Delta HRR at first, second, and at fourth minute than did C, and attenuated Delta HRR at fourth minute than did MetS - OSA (interaction, P < 0.001). Compared with C, MetS - OSA had attenuated Delta HRR at second and fourth min (interaction, P < 0.001). Further analysis showed association of the Delta HRR (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.
- Obstructive Sleep Apnea is Associated with Increased Chemoreflex Sensitivity in Patients with Metabolic Syndrome(2013) TROMBETTA, Ivani C.; MAKI-NUNES, Cristiane; TOSCHI-DIAS, Edgar; ALVES, Maria-Janieire N. N.; RONDON, Maria Urbana P. B.; CEPEDA, Felipe X.; DRAGER, Luciano F.; BRAGA, Ana Maria F. W.; LORENZI-FILHO, Geraldo; NEGRAO, Carlos E.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.
- Diet and exercise improve chemoreflex sensitivity in patients with metabolic syndrome and obstructive sleep apnea(2015) MAKI-NUNES, Cristiane; TOSCHI-DIAS, Edgar; CEPEDA, Felipe X.; RONDON, Maria Urbana P. B.; ALVES, Maria-Janieire N. N.; FRAGA, Raffael F.; BRAGA, Ana Maria F. W.; AGUILAR, Adriana M.; AMARO, Aline C.; DRAGER, Luciano F.; LORENZI-FILHO, Geraldo; NEGRAO, Carlos E.; TROMBETTA, Ivani C.ObjectiveChemoreflex 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. MethodsPatients 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% O-2 and 90% N-2 with CO2 titrated and central chemoreflex by 7% CO2 and 93% O-2 for 3 min at study entry and after 4 months. ResultsPeak VO2 was increased by D+ET; body weight, waist circumference, glucose levels, systolic/diastolic blood pressure, and apnea-hypopnea index (AHI) (345.1 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). ConclusionsSympathetic peripheral and ventilatory central chemoreflex sensitivity was improved by D+ET in MetS+OSA patients, which may be associated with improvement in sleep pattern.
conferenceObject Attenuated Heart Rate Recovery is Associated with Sympathetic Hyperactivity in Patients with Metabolic Syndrome and Obstructive Sleep Apnea(2013) CEPEDA, Felipe Xerez; TOSCHI-DIAS, Edgar; GODOY, Daniel Martinez; MAKI-NUNES, Cristiane; RONDON, Maria Urbana P. B.; ALVES, Maria Janieire N. N.; BRAGA, Ana Maria F. W.; DRAGER, Luciano F.; LORENZI-FILHO, Geraldo; NEGRAO, Carlos E.; TROMBETTA, Ivani C.Obstructive sleep apnea (OSA) and metabolic syndrome (MetS) are independently associated with impaired heart rate recovery (HRR) after maximal exercise. We tested the hypotheses that: 1) MetS+OSA would have an additive effect on attenuation of HRR; 2) The sympathetic hyperactivation would be involved on slower HRR. Newly diagnosed MetS (ATP III) patients, sedentary were divided into: MetS+OSA (n=18, 49±2y) and MetS-OSA (n=21, 44±2y). Normal individuals were also studied (C, n=13, 47±2y). OSA was characterized by apnea-hypopnea index (AHI) >15events/h (polysomnography). Muscle sympathetic nerve activity (MSNA, microneurography), heart rate (EKG), low (LF) and high (HF) frequency power bands and sympatho-vagal balance (LF/HF-Spectral analysis) were measured. The HRR was calculated (HRpeak minus HHR at 1st, 2nd, 4th min). MetS+OSA had higher MSNA, LF and LF/HF compared with MetS-OSA and C. MSNA was higher in MetS-OSA than in C. HF power was lower in MetS+OSA compared with MetS-OSA and C. HRR at 1st, 2nd min was lower in MetS+OSA compared with C (P<0.01) and lower at 4th min compared with Met-OSA and C (P<0.01). Further analyses showed an association between MSNA levels and HRR (P<0.01). In conclusion, OSA exacerbates the attenuation of HRR after maximal exercise in patients with MetS. In addition, the attenuation of HRR is associated with sympathetic hyperactivation.