Nayara Yamada Tamburús

Aerobic exercise improves cardiac autonomic modulation in women with polycystic ovary syndrome

BACKGROUND This study aimed to evaluate the effects of aerobic exercise on cardiac autonomic modulation in women with polycystic ovary syndrome (PCOS). METHODS Thirty women with PCOS (25.8±4.8 years old; body mass index, BMI≥25 kg/m2) were divided into two groups; exercise group (n=15) and control group (n=15). R-R interval was recorded during 15-min at rest in the supine position. Heart rate variability (HRV) was analyzed by linear (rMSSD, SDNN, LF, HF, LFnu, HFnu, and LF/HF) and nonlinear methods (Shannon entropy, SE; symbolic analyses, 0 V%, 1 V%, 2LV%, and 2UV%) at baseline and after 16 weeks. The multivariate analysis of covariance was used to analyze the effects of exercise on HRV indexes, adjusted for changes in BMI, fasting insulin, and testosterone level. RESULTS The exercise group increased parasympathetic modulation (rMSSD, HF, HFnu, 2UV%; (p<0.05)) and decreased sympathetic modulation (LF, LFnu, 0 V%; (p<0.05)) independently of changes in BMI, fasting insulin, and testosterone level. Moreover, the exercise group decreased resting HR and systolic blood pressure (p<0.05). All parameters remained unchanged in the control group. CONCLUSIONS Aerobic exercise increased vagal modulation and decreased sympathetic modulation in women with PCOS. This finding reinforces the recommendations for exercise during the clinical management of these patients.

Interval training based on ventilatory anaerobic threshold increases cardiac vagal modulation and decreases high-sensitivity c-reative protein: randomized clinical trial in coronary artery disease

Background: Autonomic dysfunction and inflammatory activity are involved in the development and progression of coronary artery disease (CAD), and exercise training has been shown to confer a cardiovascular benefit. Objective: To evaluate the effects that interval training (IT) based on ventilatory anaerobic threshold (VAT) has on heart rate variability (HRV) and high-sensitivity C-reactive protein (hs-CRP) levels, as well as the relationship between both levels, in patients with CAD and/or cardiovascular risk factors (RF). Method: Forty-two men (aged 57.88±6.20 years) were divided into two training groups, CAD-T (n= 12) and RF-T (n= 10), and two control groups, CAD-C (n= 10) and RF-C (n=10). Heart rate and RR intervals in the supine position, cardiopulmonary exercise tests, and hs-CRP levels were measured before and after IT. HRV was analyzed by spectral and symbolic analysis. The CAD-T and RF-T underwent a 16-week IT program of three weekly sessions at training intensities based on the VAT. Results: In the RF-T, cardiac sympathetic modulation index and hs-CRP decreased (p<0.02), while cardiac parasympathetic modulation index increased (p<0.02). In the CAD-T, cardiac parasympathetic modulation index increased, while hs-CRP, systolic, and diastolic blood pressures decreased (p<0.02). Both control groups showed increase in hs-CRP parameters (p<0.02). There was a strong and significant association between parasympathetic and sympathetic modulations with hs-CRP. Conclusion: The IT program based on the VAT promoted a decrease in hs-CRP associated with improvement in cardiac autonomic modulation.

Association of estrogen receptor alpha gene polymorphisms with autonomic modulation of heart rate in users and nonusers of oral contraceptives

BACKGROUND This study examined the association between estrogen receptor α gene (ESR1) polymorphisms and blood pressure (BP), heart rate (HR) and autonomic modulation of HR in a sample population. STUDY DESIGN Two hundred thirty-two young healthy women were selected, and those using oral contraceptives (OC) were compared with nonusers (control group). Short-term HR variability (HRV) was evaluated in both the supine and sitting positions using temporal indices rMSSD [square root of the mean squared differences of successive R-R intervals (RRi) divided by the number of RRi minus one], SDNN (root mean square of differences from mean RRi, divided by the number of RRi) and frequency domain methods. Power spectral components were reported at low frequency (LF) and high frequency (HF) and as LF/HF ratio. ESR1 c.454-397T>C (rs2234693) and c.454-351A>G (rs9340799) polymorphisms were determined by polymerase chain reaction and fragment restriction analysis. RESULTS The ESR1 T>C and A>G polymorphisms had no effect on HR, rMSSD, SDNN, LF, HF or LF/HF ratio (supine or sitting), independently of OC use. The ESR1 T-A, T-G, C-A and C-G haplotypes were not associated with HR, BP or HRV. CONCLUSIONS ESR1 variants had no effect on the autonomic modulation of HR in young women users and nonusers of OC and may not be implicated in cardiovascular risk in young women.

Associations between heart rate recovery dynamics with estradiol levels in 20 to 60 year-old sedentary women

It is hypothesized that estradiol levels, as well as aging, influence cardiac autonomic function in women. The main aim of this study was to test the correlations between heart rate recovery (HRR) dynamics, as a proxy of cardiac autonomic function, with estradiol levels and age in women. This cross-sectional study involved 44 healthy women. Heart rate (HR) data were obtained beat-by-beat during the entire experiment. Maximal incremental exercise testing (IET) on a cycle ergometer was performed followed by 6 min of recovery. During the IET recovery period, the overall HRR dynamics were evaluated by exponential data modeling (time constant “τ”) where shorter τ indicates faster HRR adjustment. Considering the cardiac autonomic complexity, HRR dynamics were also evaluated by delta (Δ) analysis considering different HR data intervals. The relationship between HRR dynamics, estradiol levels and age was tested by Pearson product-moment correlation. The overall HRR dynamics (i.e., τ) were statistically correlated with age (r = 0.58, p < 0.001) and estradiol levels (r = -0.37, p = 0.01). The Δ analysis showed that the slower overall HRR associated with aging was a consequence of slower dynamics occurring within the 45–210 s interval, indicating slower sympathetic withdrawal. In conclusion, aging effects on HRR in women seems to be correlated with a slower sympathetic withdrawal. In addition, the cardioprotective effect previously associated with estradiol seems not to influence the autonomic modulation during exercise recovery periods in women.

Relationship between heart rate variability and VO 2peak in active women

OBJETIVO: Ava+liar a associacao entre os indices da variabilidade da frequencia cardiaca (VFC) e a aptidao cardiorrespiratoria.METODOS: Sessenta e duas mulheres (idade 22,1 ± 3,3 anos) foram divididas em quatro grupos: treinamento aerobio (AER, n = 15), treinamento de forca (FOR, n = 13), treinamento combinado (aerobio e forca) (AER+FOR, n = 15) e controle (C, n = 19). O teste cardiopulmonar foi realizado para avaliar a aptidao cardiorrespiratoria a partir do consumo de oxigenio pico (VO2pico). A FC foi coletada em repouso na postura supina. A VFC foi analisada a partir de metodos lineares e nao lineares.RESULTADOS: Os grupos AER e AER+FOR apresentaram maiores indices da VFC (lineares e nao lineares) indicadores da modulacao vagal e menores indices da VFC indicadores da modulacao simpatica, em relacao ao grupo C. Os grupos AER e AER+FOR apresentaram maior complexidade e menor regularidade dos intervalos RR e maior VO2pico em relacao aos grupos FOR e C. O VO2picoapresentou correlacao com os indices da VFC.CONCLUSAO: Este estudo mostrou que o treinamento fisico aerobio e combinado contribuiram significativamente para maior modulacao autonoma da FC e aptidao cardiorrespiratoria. A modulacao autonoma da FC, avaliada a partir de metodos lineares e nao lineares, esta associada ao maior consumo de oxigenio.OBJECTIVE: To evaluate the associations between heart rate variability (HRV) with cardiorespiratory fitness.METHODS: Sixty-two women (aged 22.1 ± 3.3) were divided into four groups: aerobic training (AER, n = 15), strength training (STR, n = 13), combined aerobic and strength training (AER+STR, n = 15) and controls (C, n = 19). Cardiopulmonary exercise testing was performed to measure cardiorespiratory fitness by assessing peak oxygen consumption (VO2peak). The HR was recorded at rest in the supine position. The HRV was analyzed by linear and nonlinear methods.RESULTS: The AER and AER+STR groups had higher vagal HRV (linear and nonlinear) indicators of vagal modulation and lower indices of HRV indicators of sympathetic modulation, compared to group C. The AER and AER+STR groups showed greater complexity and lower regularity of R-R intervals and higher peak compared to STR and C groups. The VO2peak was correlated with HRV indices.CONCLUSION: This study showed that aerobic and combined exercise significantly contributed to greater autonomic modulation of HR and cardiorespiratory fitness. The autonomic HR modulation, assessed by linear and nonlinear methods, was associated with a greater oxygen consumption.

Relación entre la variabilidad de la frecuencia cardíaca y VO 2pico en mujeres activas

OBJETIVO: Ava+liar a associacao entre os indices da variabilidade da frequencia cardiaca (VFC) e a aptidao cardiorrespiratoria.METODOS: Sessenta e duas mulheres (idade 22,1 ± 3,3 anos) foram divididas em quatro grupos: treinamento aerobio (AER, n = 15), treinamento de forca (FOR, n = 13), treinamento combinado (aerobio e forca) (AER+FOR, n = 15) e controle (C, n = 19). O teste cardiopulmonar foi realizado para avaliar a aptidao cardiorrespiratoria a partir do consumo de oxigenio pico (VO2pico). A FC foi coletada em repouso na postura supina. A VFC foi analisada a partir de metodos lineares e nao lineares.RESULTADOS: Os grupos AER e AER+FOR apresentaram maiores indices da VFC (lineares e nao lineares) indicadores da modulacao vagal e menores indices da VFC indicadores da modulacao simpatica, em relacao ao grupo C. Os grupos AER e AER+FOR apresentaram maior complexidade e menor regularidade dos intervalos RR e maior VO2pico em relacao aos grupos FOR e C. O VO2picoapresentou correlacao com os indices da VFC.CONCLUSAO: Este estudo mostrou que o treinamento fisico aerobio e combinado contribuiram significativamente para maior modulacao autonoma da FC e aptidao cardiorrespiratoria. A modulacao autonoma da FC, avaliada a partir de metodos lineares e nao lineares, esta associada ao maior consumo de oxigenio.OBJECTIVE: To evaluate the associations between heart rate variability (HRV) with cardiorespiratory fitness.METHODS: Sixty-two women (aged 22.1 ± 3.3) were divided into four groups: aerobic training (AER, n = 15), strength training (STR, n = 13), combined aerobic and strength training (AER+STR, n = 15) and controls (C, n = 19). Cardiopulmonary exercise testing was performed to measure cardiorespiratory fitness by assessing peak oxygen consumption (VO2peak). The HR was recorded at rest in the supine position. The HRV was analyzed by linear and nonlinear methods.RESULTS: The AER and AER+STR groups had higher vagal HRV (linear and nonlinear) indicators of vagal modulation and lower indices of HRV indicators of sympathetic modulation, compared to group C. The AER and AER+STR groups showed greater complexity and lower regularity of R-R intervals and higher peak compared to STR and C groups. The VO2peak was correlated with HRV indices.CONCLUSION: This study showed that aerobic and combined exercise significantly contributed to greater autonomic modulation of HR and cardiorespiratory fitness. The autonomic HR modulation, assessed by linear and nonlinear methods, was associated with a greater oxygen consumption.

Relação entre a variabilidade da frequência cardíaca e VO 2pico em mulheres ativas

OBJETIVO: Ava+liar a associacao entre os indices da variabilidade da frequencia cardiaca (VFC) e a aptidao cardiorrespiratoria.METODOS: Sessenta e duas mulheres (idade 22,1 ± 3,3 anos) foram divididas em quatro grupos: treinamento aerobio (AER, n = 15), treinamento de forca (FOR, n = 13), treinamento combinado (aerobio e forca) (AER+FOR, n = 15) e controle (C, n = 19). O teste cardiopulmonar foi realizado para avaliar a aptidao cardiorrespiratoria a partir do consumo de oxigenio pico (VO2pico). A FC foi coletada em repouso na postura supina. A VFC foi analisada a partir de metodos lineares e nao lineares.RESULTADOS: Os grupos AER e AER+FOR apresentaram maiores indices da VFC (lineares e nao lineares) indicadores da modulacao vagal e menores indices da VFC indicadores da modulacao simpatica, em relacao ao grupo C. Os grupos AER e AER+FOR apresentaram maior complexidade e menor regularidade dos intervalos RR e maior VO2pico em relacao aos grupos FOR e C. O VO2picoapresentou correlacao com os indices da VFC.CONCLUSAO: Este estudo mostrou que o treinamento fisico aerobio e combinado contribuiram significativamente para maior modulacao autonoma da FC e aptidao cardiorrespiratoria. A modulacao autonoma da FC, avaliada a partir de metodos lineares e nao lineares, esta associada ao maior consumo de oxigenio.OBJECTIVE: To evaluate the associations between heart rate variability (HRV) with cardiorespiratory fitness.METHODS: Sixty-two women (aged 22.1 ± 3.3) were divided into four groups: aerobic training (AER, n = 15), strength training (STR, n = 13), combined aerobic and strength training (AER+STR, n = 15) and controls (C, n = 19). Cardiopulmonary exercise testing was performed to measure cardiorespiratory fitness by assessing peak oxygen consumption (VO2peak). The HR was recorded at rest in the supine position. The HRV was analyzed by linear and nonlinear methods.RESULTS: The AER and AER+STR groups had higher vagal HRV (linear and nonlinear) indicators of vagal modulation and lower indices of HRV indicators of sympathetic modulation, compared to group C. The AER and AER+STR groups showed greater complexity and lower regularity of R-R intervals and higher peak compared to STR and C groups. The VO2peak was correlated with HRV indices.CONCLUSION: This study showed that aerobic and combined exercise significantly contributed to greater autonomic modulation of HR and cardiorespiratory fitness. The autonomic HR modulation, assessed by linear and nonlinear methods, was associated with a greater oxygen consumption.