Cardiovascular Responses To Postural Change And Aerobic Capacity In Middle-aged Men And Women Before And After Aerobic Physical Training

Objective: To compare the cardiovascular responses to passive postural maneuvers (tilt test) and the cardiorespiratory capacity in middle-aged men and women, before and after aerobic physical training. Methods: Seven men (44.6±2.1 years old) and seven women (51.7±4.8 years old) participated in aerobic physical training for 12 weeks. The tilt test protocol (five minutes supine, ten minutes tilted at 70° and five minutes supine) was followed, with arterial blood pressure and heart rate monitoring. A cycle ergometer protocol was used to measure cardiorespiratory capacity. Results: In the sedentary condition, men showed greater parasympathetic influence in heart rate control, as demonstrated by their higher RR interval (iRR) during the tilt test. After training, the iRR values became more similar in the two groups, although the women had higher iRR in the supine position and the men continued to present higher iRR under tilted conditions. The women's blood pressures continued to be higher after training, but heart rate tended to become similar in the two groups. The cardiorespiratory capacity patterns in the two groups were similar after training. Except for absolute heart rate values, for which there were no differences between the groups, the men's values were higher than those of the women for all other variables. It was also observed that, after the training, the women's blood pressures were significantly lower, even though their pressures remained higher than the men's. Conclusions: The training seemed to reduce the women's arterial blood pressure levels and improve both groups' cardiorespiratory capacity, but the men continued to present better performance than the women.125392400Pollock, M.L., Dawson, G.A., Physiologic responses of men 49 to 65 years of age to endurance training (1976) J Am Geriatr Soc, 24 (3), pp. 97-104Haddock, B.L., Marshak, H.P.H., Mason, J.J., Blix, G., The effect of hormone replacement therapy and exercise on cardiovascular disease risk factors in postmenopausal women (2000) Sports Med, 29 (1), pp. 39-49Liu, C.C., Kuo, T.B., Yang, C.C., Effects of estrogen on gender-related autonomic differences in humans (2003) Am J Physiol Heart Circ Physiol, 285 (5), pp. H2188-H2193Rosano, G.M., Vitale, C., Fini, M., Hormone replacement therapy and cardioprotection: What is good and what is bad for the cardiovascular system? (2006) Ann. N.Y. Acad Sci, 1092, pp. 341-348Ghorayeb N, Baptista CA, Dioguardi GS, Reginatto LE. Atividade física na mulher. Rev Soc Cardiol Est São Paulo, SOCESP.1996;6:540-2Kannel, W.B., Hjortland, M.C., McNamara, P.M., Gordon, T., Menopause and risk of cardiovascular disease: The Framingham study (1976) Ann Intern Med, 85 (4), pp. 447-452Tank, J., Does aging cause women to be more sympathetic than men? (2005) Hypertension, 45 (4), pp. 489-490Kuttenn, F., Gerson, M., Hormone replacement therapy of menopause, heart and blood vessels (2001) Arch Mal Coeur Vaiss, 94 (7), pp. 685-689Vanoli, E., De Ferrari, G.M., Stramba-Badiale, M., Hull Jr, S.S., Foreman, R.D., Schwartz, P.J., Vagal stimulation and prevention of sudden death in conscious dogs with a healed myocardial infarction (1991) Circ Res, 68 (5), pp. 1471-1481Smith, J.J., Kampine, J.P., (1990) Regulation of arterial blood pressure, , editores. Circulatory physiology, the essentials. 3aed. Baltimore: Williams &ampWilkins;Kuo, T.B., Lin, T., Yang, C.C., Li, C.L., Chen, C.F., Chou, P., Effect of aging on gender differences in neural control of heart rate (1999) Am J Physiol, 277 (6 PART 2), pp. H2233-H2239Evans, J.M., Ziegler, M.G., Patwardhan, A.R., Ott, J.B., Kim, C.S., Leonelli, F.M., Gender differences in autonomic cardiovascular regulation: Spectral, hormonal, and hemodynamic indexes (2001) J Appl Physiol, 91 (6), pp. 2611-2618Pikkujämsä, S.M., Mäkikallio, T.H., Airaksinen, K.E., Huikuri, H.V., Determinants and interindividual variation of R-R interval dynamics in healthy middle-aged subjects (2001) Am J Physiol Heart Circ Physiol, 280 (3), pp. H1400-H1406Neves, V.F., Silva de, S.M., Gallo Jr, L., Catai, A.M., Martins, L.E., Crescêncio, J.C., Autonomic modulation of heart rate of young and postmenopausal women undergoing estrogen therapy (2007) Braz J Med Biol Res, 40 (4), pp. 491-499(2005) ACSM's guidelines for exercise testing and prescription/ACSM, , American College of Sports Medicine, Philadelphia: Lippincott Williams & Wilkins;Maciel, B.C., Gallo Júnior, L., Marin Neto, J.A., Lima Filho, E.C., Terra Filho, J., Manço, J.C., Parasympathetic contribution to bradycardia induced by endurance training in man (1985) Cardiovasc Res, 19 (10), pp. 642-648Martinelli, F.S., (1996) Respostas da freqüência cardíaca e da pressão arterial sistêmica às manobras postural passiva e de valsalva, em indivíduos sedentários e atletas corredores de longa distância, , dissertação, Campinas: Unicamp;Goldsmith, R.L., Bigger Jr, J.T., Steinman, R.C., Fleiss, J.L., Comparison of 24-hour parasympathetic activity in endurance-trained and untrained young men (1992) J Am Coll. Cardiol, 20 (3), pp. 552-558Shin, K., Minamitani, H., Onishi, S., Yamazaki, H., Lee, M., Autonomic differences between athletes and nonathletes: Spectral analysis approach (1997) Med Sci Sports Exerc, 29 (11), pp. 1482-1490Seals, D.R., Taylor, J.A., Ng, A.V., Esler, M.D., Exercise and aging: Autonomic control of the circulation (1994) Med Sci Sports Exerc, 26 (5), pp. 568-576Chacon-Mikahil, M.P.T., (1998) Estudo da variabilidade da freqüência cardíaca nos domínios do tempo e da freqüência antes e após o treinamento aeróbio em homens de meia idade [tese], , Campinas: Unicamp;Laitinen, T., Niskanen, L., Geelen, G., Länsimies, E., Hartikainen, J., Age dependency of cardiovascular autonomic responses to head-up tilt test in healthy subjects (2004) J Appl Physiol, 96 (6), pp. 2333-2340Gordon, C.C., Chumlea, W.C., Roche, A.F., Stature, Recumbent Length, Weight (1988) Anthropometric standardizing reference manual, pp. 3-8. , Lohman TG et al, editores, Champaign, Illinois: Human Kinetics Books;Wasserman, K., Whipp, B.J., Koyl, S.N., Beaver, W.L., Anaerobic threshold and respiratory gas exchange during exercise (1973) J Appl Physiol, 35 (2), pp. 236-243Montano, N., Ruscone, T.G., Porta, A., Lombardi, F., Pagani, M., Malliani, A., Power spectrum analysis of heart rate variability to assess the changes in sympathovagal balance during graded orthostatic tilt (1994) Circulation, 90 (4), pp. 1826-1831Shoemaker, J.K., Hogeman, C.S., Khan, M., Kimmerly, D.S., Sinoway, L.I., Gender affects sympathetic and hemodynamic response to postural stress (2001) Am J Physiol Heart Circ Physiol, 281 (5), pp. H2028-H2035Bigger Jr, J.T., Fleiss, J.L., Steinman, R.C., Rolnitzky, L.M., Kleiger, R.E., Rottman, J.N., Correlations among time and frequency domain measures of heart period variability two weeks after acute myocardial infarction (1992) Am J Cardiol, 69 (9), pp. 891-898Almeida, M.B.E., Araújo, C.G.S., Effects of aerobic training on heart rate (2003) Rev Bras Med Esporte, 9 (2), pp. 113-120Yataco, A.R., Fleisher, L.A., Katzel, L.I., Heart rate variability and cardiovascular fitness in senior athletes (1997) Am J Cardiol, 80 (10), pp. 1389-1391Rennie, K.L., Hemingway, H., Kumari, M., Brunner, E., Malik, M., Marmot, M., Effects of moderate and vigorous physical activity on heart rate variability in a British study of civil servants (2003) Am J Epidemiol, 158 (2), pp. 135-14

Autonomic modulation of heart rate of young and postmenopausal women undergoing estrogen therapy

The aim of the present study was to determine whether estrogen therapy (ET) reduces alterations of the autonomic control of heart rate (HR) due to hypoestrogenism and aging. Thirteen young (24 ± 2.6 years), 10 postmenopausal (53 ± 4.6 years) undergoing ET (PM-ET), and 14 postmenopausal (56 ± 2.6 years) women not undergoing ET (PM) were studied. ET consisted of 0.625 mg/day conjugated equine estrogen. HR was recorded continuously for 8 min at rest in the supine and sitting positions. HR variability (HRV) was analyzed by time (SDNN and rMSSD indices) and frequency domain methods. Power spectral components are reported as normalized units (nu) at low (LF) and high (HF) frequencies, and as LF/HF ratio. Intergroup comparisons: SDNN index was higher in young (median: supine, 47 ms; sitting, 42 ms) than in PM-ET (33; 29 ms) and PM (31; 29 ms) women (P < 0.05). PM showed lower HFnu, higher LFnu and higher LF/HF ratio (supine: 44, 56, 1.29; sitting: 38, 62, 1.60) than the young group in the supine position (61, 39, 0.63) and the PM-ET group in the sitting position (57, 43, 0.75; P < 0.05). Intragroup comparisons: HR was lower in the supine than in the sitting position for all groups (P < 0.05). The HRV decrease from the supine to the sitting position was significant only in the young group. These results suggest that HRV decreases during aging. ET seems to attenuate this process, promoting a reduction in sympathetic activity on the heart and contributing to the cardioprotective effect of estrogen hormones.49149

Evaluation of Cardiac Autonomic Modulation Using Symbolic Dynamics after Cardiac Transplantation

Objective: To characterize the behavior of cardiac autonomic modulation in individuals with different times after orthotopic heart transplantation (HTx) using symbolic dynamics analysis. Methods: Sixty patients were evaluated after HTx. We recorded their instantaneous R-R intervals (RRi) by cardiac monitor Polar (R) RS800CX (TM) (Polar Electro Oy, Kempele, Finland) for 10 minutes. The same sequence of RRi with 256 consecutive beats was used to perform spectral analysis and symbolic dynamics analysis. We used hierarchical clustering to form groups. One-way analysis of variance (ANOVA) (with Holm-Sidak method) or one-way Kruskal-Wallis test (with Dunn's post-hoc test) was used to analyze the difference between groups. Linear correlation analysis between variables was performed using Pearson's or Spearman's tests. P-value &lt; 0.05 was considered statistically significant. Results: The 0V% index increased, the 2UV% index and the normalized complexity index decreased with an increase of HTx postoperative time. There were a negative correlation between complexity indexes and 0V% and a positive correlation between complexity indexes and 2UV%. Conclusion: Symbolic dynamics indexes were able to show a specific cardiac autonomic modulation pattern for HTx recipients with different postoperative times

Effect of the postural challenge on the dependence of the cardiovascular control complexity on age

Short-term complexity of heart period (HP) and systolic arterial pressure (SAP) was computed to detect age and gender influences over cardiovascular control in resting supine condition (REST) and during standing (STAND). Healthy subjects (n = 110, men = 55) were equally divided into five groups (21-30; 31-40; 41-50; 51-60; and 61-70 years of age). HP and SAP series were recorded for 15 min at REST and during STAND. A normalized complexity index (NCI) based on conditional entropy was assessed. At REST we found that both NCIHP and NCISAP decreased with age in the overall population, but only women were responsible for this trend. During STAND we observed that both NCIHP and NCISAP were unrelated to age in the overall population, even when divided by gender. When the variation of NCI in response to STAND (\u394NCI = NCI at REST-NCI during STAND) was computed individually, we found that \u394NCIHP progressively decreased with age in the overall population, and women were again responsible for this trend. Conversely, \u394NCISAP was unrelated to age and gender. This study stresses that the complexity of cardiovascular control and its ability to respond to stressors are more importantly lost with age in women than in men

Evaluation of acute effect of light-emitting diode (LED) phototherapy on muscle deoxygenation and pulmonary oxygen uptake kinetics in patients with diabetes mellitus : study protocol for a randomized controlled trial

BACKGROUND: Type 2 diabetes mellitus (DM) is responsible for a significant reduction in the quality of life due to its negative impact on functional capacity. Cardiopulmonary fitness impairment in DM patients has been associated with limited tissue oxygenation. Phototherapy is widely utilized to treat several disorders due to expected light-tissue interaction. This type of therapy may help to improve muscular oxygenation, thereby increasing aerobic fitness and functional capacity. METHODS/DESIGN: This study is a randomized, double-blind, placebo-controlled crossover trial approved by the Ethics Committee of the Federal University of S\ue3o Carlos and registered at ClinicalTrials.gov. Four separate tests will be performed to evaluate the acute effect of phototherapy. All participants will receive both interventions in random order: light-emitting diode therapy (LEDT) and placebo, with a minimum 14-day interval between sessions (washout period). Immediately after the intervention, participants will perform moderate constant workload cycling exercise corresponding to 80 % of the pulmonary oxygen uptake [Formula: see text] during the gas exchange threshold (GET). LEDT will be administered with a multidiode cluster probe (50 GaAIA LEDs, 850 \u3b7m, 75 mW each diode, and 3 J per point) before each exercise session. Pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure will be measured using a computerized metabolic cart, a near-infrared spectrometer, an electrocardiogram, and a photoplethysmography system, respectively. DISCUSSION: The main objective of this study is to evaluate the acute effects of muscular pre-conditioning using LED phototherapy on pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure dynamics during dynamic moderate exercise. We hypothesize that phototherapy may be beneficial to optimize aerobic fitness in the DM population. Data will be published after the study is completed. TRIAL REGISTRATION: Registered at ClinicalTrials.gov under trial number NCT01889784 (date of registration 5 June 2013)

Short-term complexity indexes of heart period and systolic arterial pressure variabilities provide complementary information

It is unclear whether the complexity of the variability of the systolic arterial pressure (SAP) provides complementary information to that of the heart period (HP). The complexity of HP and SAP variabilities was assessed from short beat-to-beat recordings (i.e., 256 cardiac beats). The evaluation was made during a pharmacological protocol that induced vagal blockade with atropine or a sympathetic blockade (beta-Adrenergic blockade with propranolol or central sympathetic blockade with clonidine) alone or in combination, during a graded head-up tilt, and in patients with Parkinson's disease (PD) without orthostatic hypotension undergoing orthostatic challenge. Complexity was quantified according to the mean square prediction error (MSPE) derived from univariate autoregressive (AR) and multivariate AR (MAR) models. We found that: 1) MSPEMAR did not provide additional information to that of MSPE AR; 2) SAP variability was less complex than that of HP; 3) because HP complexity was reduced by either vagal blockade or vagal withdrawal induced by head-up tilt and was unaffected by beta-Adrenergic blockade, HP was under vagal control; 4) because SAP complexity was increased by central sympathetic blockade and was unmodified by either vagal blockade or vagal withdrawal induced by head-up tilt, SAP was under sympathetic control; 5) SAP complexity was increased in patients with PD; and 6) during orthostatic challenge, the complexity of both HP and SAP variabilities in patients with PD remained high, thus indicating both vagal and sympathetic impairments. Complexity indexes derived from short HP and SAP beat-to-beat series provide complementary information and are helpful in detecting early autonomic dysfunction in patients with PD well before circulatory symptoms become noticeable

Cardiovascular variability analysis and baroreflex estimation in patients with type 2 diabetes in absence of any manifest neuropathy : correction

[This corrects the article DOI: 10.1371/journal.pone.0148903.]