No description available.

No description available.

Patients with peripheral arterial disease (PAD) can only walk so far before they get leg pain (intermittent claudication) and have to stop. They are also at risk in the future of needing amputation of one of their limbs. Allopurinol is a new possible treatment for this condition as it has been shown in coronary arterial disease to prolong exercise before angina pain occurs. This is thought to be because allopurinol can both prevent oxygen wastage in tissues and prevent the formation of harmful oxidative stress. We hypothesised that allopurinol could prolong the time to leg pain in participants with PAD. In a double-blind, randomised controlled clinical trial 50 participants with PAD were randomised to receive either allopurinol 300mg twice daily or placebo for six months. The primary outcome was change in exercise capacity on treadmill testing at six months. Secondary outcomes were six-minute walking distance, Walking Impairment Questionnaire, SF-36 QoL questionnaire, flow-mediated dilatation and oxidised LDL. Outcome measures were repeated mid-study and at end of study. The mean age of participants was 68.4 years (SD 1.2) with 39/50 (78%) male. Only five participants withdrew in the course of the study, two in the active group and three in the placebo group. There was a significant reduction in uric acid levels in those on active treatment of 52.1% (p<0.001), but no significant change in either the pain-free or the maximum distance they were able to walk. Other measures of exercise capacity, blood vessel function and the participants’ own assessment of their health and walking ability also did not change during the course of the study. In summary, although allopurinol has been shown to be of benefit in a number of other diseases, in this study there was no evidence of any improvement following treatment in patients with peripheral arterial disease.

Abstract This study sought to develop an interval prone bridge fitness test to assess core stabilization in healthy adults (ages 18–39 years). Participants performed a prone bridge maneuver in alternating 15-sec work and 5-sec rest intervals with participants' RPE scores (0–10) recorded at the end of each work interval. The RPE score reported after 95 sec (RPE-95) was used to predict total interval prone bridge endurance time along with participants' self-reported level of physical activity (PA; sedentary = 0, low active = 1, active = 2, very active = 3). Multiple linear regression was employed to generate the following prediction equation (R = .86, SEE = 32.98 sec): Total time (sec) = 300.0 – (23.4 x RPE-95) + (17.7 x PA). Each predictor variable was statistically significant (RPE-95, p < .0001; PA, p = 0.006) and cross validation procedures using PRESS (predicted residual sum of squares) statistics revealed minimal shrinkage (Rp = .85 and SEEp = 32.89 sec). The mean and standard deviation (±SD) for the total duration of the interval prone bridge test and the RPE-95 data were 179.9 ± 65.2 sec and 6.3 ± 2.2, respectively. To assess test-retest reliability, a second test was completed about 48 hours after the first. The reliability study (n = 45) yielded an acceptable test-retest intraclass reliability coefficient (ICC = .95, SEM = 12.7 sec) when comparing total interval prone bridge endurance times across days. In summary, this interval prone bridge fitness test, and accompanying regression model, yields a relatively accurate estimate of total interval prone bridge test time in healthy men and women, using both RPE-95 and PA data.

The purpose of this study was to develop a multiple linear regression model to predict treadmill VO2max scores using both exercise and nonexercise data. One hundred five college-aged participants (53 male, 52 female, mean age 23.5 ± 2.8 yrs) successfully completed a submaximal cycle ergometer test and a maximal graded exercise test (GXT) on a motorized treadmill. The submaximal cycle protocol required participants to achieve a steady-state heart rate (HR) equal to at least 70% of age-predicted maximum HR (220-age), while the maximal treadmill GXT required participants to exercise to volitional fatigue. Relevant submaximal cycle ergometer test data included a mean (± SD) ending steady-state HR and ending workrate equal to 164.2 ± 13.0 and 115.3 ± 27.0, respectively. Relevant nonexercise data included a mean (± SD) body mass (kg), perceived functional ability [PFA] score, and physical activity rating [PA-R] score of 74.2 ± 15.1, 15.7 ± 4.3, and 4.7 ± 2.1, respectively. Multiple linear regression was used to generate the following prediction of cardiorespiratory fitness (R = 0.91, SEE = 3.36 ml∙kg-¹∙min-¹): VO2max = 54.513 + 9.752 (gender, 1 = male, 0 = female) − 0.297 (body mass, kg) + 0.739 (PFA, 2-26) + 0.077 (work rate, watts) − 0.072 (steady-state HR). Each predictor variable was statistically significant (p < .05) with beta weights for gender, body mass, PFA, exercise workrate, and steady-state HR equal to 0.594, -0.544, 0.388, 0.305, and -0.116, respectively. The predicted residual sums of squares (PRESS) statistics reflected minimal shrinkage (RPRESS = 0.90, SEEPRESS = 3.56 ml∙kg-¹∙min-¹) for the multiple linear regression model. In summary, the submaximal cycle ergometer protocol and accompanying prediction model yield relatively accurate VO2max estimates in healthy college-aged participants using both exercise and nonexercise data.

No description available.

No description available.

Obstructive sleep apnea syndrome (OSAS) is a serious disorder that affects an estimated 24% of middle-age males, and 9% of middle-aged females. In addition, a large portion of individuals with OSAS go undiagnosed. OSAS is associated with several adverse health problems, including the metabolic syndrome. Therefore, there is a clear need to identify new methods for assessing OSAS risk. The exercise test has been used effectively as a diagnostic and prognostic tool for those at high risk for cardiovascular disease and hypertension. Research into the cardiopulmonary responses to exercise testing in young adult men with OSAS has not been examined. Objectives: The objectives of this study were to: 1) evaluate whether OSAS is characterized by exaggerated ventilatory responses to ramp exercise testing, with a secondary aim to evaluate if variations in serum leptin concentration might exert a regulatory in ventilatory responses during exercise; 2) To evaluate whether autonomic control of the cardiovascular response during exercise is distorted by OSAS in young overweight men, as manifested by a blunting of heart rate and exaggeration of blood pressure responses.; 3) To explore whether various simple clinical measures and response patterns from graded exercise testing might serve to discriminate between young men with and without OSAS. Methods: For objectives one and two, 14 obese men with OSAS [age = 22.4 ± 2.8; body mass index (BMI) = 32.0 ± 3.7; apnea-hypopnea index (AHI) = 22.7 ± 18.5], 16 obese men without OSAS (age = 21.4 ± 2.6; BMI = 31.4 ± 3.7), and 14 normal weight subjects (objective 2) (age = 21.4 ± 2.1; BMI = 22.0 ± 1.3) were recruited. For objective three, 91 men (age = 21.6 ± 2.8; AHI range = 0.6 – 60.5; BMI range = 19.0 – 43.9) were recruited. Subjects completed a ramp cycle ergometer exercise test, and a fasting blood sample was obtained to measure plasma leptin and blood lipid levels. Repeated measures ANOVA and stepwise linear regression was used to examine objectives 1 and 2. For objective 3, stepwise linear regression and receiver operator curve (ROC) analysis was utilized. Results: Ventilation (VE), the ventilatory equivalents for oxygen (VE/VO₂) and carbon dioxide (VE/VCO₂) were greater in the OSAS subjects vs. the overweight subjects without OSAS (P = 0.05, P < 0.05 and P < 0.005, respectively) at all exercise intensities. Heart rate (HR) recovery was attenuated in the overweight OSAS subjects compared to the No-OSAS and Control groups throughout 5 minutes of active recovery (P = 0.009). Oxygen uptake, HR, and blood pressure did not differ throughout exercise. Leptin was not associated with ventilatory responses at any exercise intensity. Linear regression analysis revealed hip-to-height ratio (HHR), hip circumference (HC), triglyceride levels, and recovery systolic blood pressure ratio (SBPR) at 2 and 4 minutes were independent predictors of AHI (model fit: R² = 0.68, p <0.0001). ROC analysis determined that percent body fat, HHR, and recovery HR at 2 minutes and 4 minutes were the best single predictors of OSAS risk (AUC = 0.77 for each measure, p = 0.003). Conclusions: Unique ventilatory and hemodynamic characteristics to maximal exercise testing are exhibited in young men with OSAS. These characteristics may be related to alterations in the sympathetic nervous system and chemoreceptor activation, and may be early clinical signs in the progression of OSAS. These exercise characteristics, along with anthropometric and body composition measures may provide useful information in identifying young men at risk for OSAS. / Ph. D.

Obstructive sleep apnea (OSA) is a serious disorder that affects up to 24% of middle-aged males. The substantial cost and inconvenience associated with polysomnography limits the number of people who seek treatment. Therefore, information concerning exercise tolerance and hemodynamic function in obstructive sleep apnea (OSA) patients may add new and clinically meaningful information to the process of grading disease severity and/or assessing treatment outcomes. Objectives: The primary objective of this study was to explore relationships between polysomnography (PSG) markers of sleep function and resting and exercise measures of hemodynamic function in patients diagnosed with mild-to-severe OSA. A family of clinical markers including heart rate (HR), blood pressure (BP), cardiac index (CI), stroke volume index (SVI), total peripheral resistance (TPR), and oxygen uptake (VO2) were assessed in this study. A second objective was to explore differences in hemodynamic function at rest and during graded exercise in OSA patients versus control subjects matched for age and body mass index (BMI). A final objective was to evaluate the extent that treatment with nCPAP alone, or combined with a moderate aerobic exercise training program impacted markers of hemodynamic function (results not reported here). Methods: Eleven newly diagnosed OSA patients [5 male, 6 female; age: 46.5 + 12.0 yrs; respiratory disturbance index (RDI) = 30.2 + 15.0] and 10 apparently healthy control subjects (4 male, 6 female; age: 39.8 + 6.9 yrs) completed daytime resting measurements of heart rate variability (HRV) and blood pressure (BP); and underwent a maximal cycle ergometer exercise test at baseline and 6 wk post-treatment initiation. Pearson product moment correlations were calculated between PSG markers of sleep function and: (1) daytime measures of HRV; (2) BP; and (3) submaximal and peak exercise measures of hemodynamic function. Independent t tests were used to explore differences between OSA patients and controls. Results: Stage 1 sleep duration was significantly related to daytime SBP (r = 0.69; P < 0.05) and MAP (r = 0.72; P < 0.05). Daytime MAP (P = 0.01) and DBP (P = 0.02) were significantly different between groups. Exercise testing yielded the following results: RDI was significantly related to HR at 60 watts (r = -0.70; P = 0.02) and 100 watts (r = -0.69; P = 02); stage 2 sleep duration was inversely related to CI at 60 (r = -0.76; P = 0.03) and 100 watts. In addition, stage 1 sleep duration was significantly correlated with TPR at 60 watts (r = 0.70; P = 0.06) and 100 watts (r = 0.71; P = 0.05). At peak exercise, a significant relationship was noted between peak HR and stage 2 sleep duration (r = -0.73; P = 0.02); and RDI (r = -0.66; P = 0.03). Furthermore, relative VO2pk was positively correlated to REM sleep duration (r = 0.62; P = 0.04). Conclusions: Distinct patterns exist in measures of daytime HRV and BP may provide physicians unique and clinically useful information. In addition, peak exercise capacity is reduced in the OSA patient and may be related to a blunted HR response to graded exercise. / Ph. D.

Introdução. A necessidade de melhorar a acurácia do teste de esforço determinou o desenvolvimento de escores, cuja aplicabilidade já foi amplamente reconhecida. Objetivo. Avaliação prognóstica do coronariopata estável por meio de um novo escore simplificado ao ser comparado com o escore de Hubbard. Métodos. Um novo escore foi aplicado em 372 coronariopatas bi ou triarteriais, 71,8% homens com idade média de 59,5+9,07 anos, randomizados para angioplastia, revascularização cirúrgica e tratamento clínico, com seguimento de cinco anos. O óbito cardiovascular foi o desfecho primário. O infarto do miocárdio não-fatal, e o óbito e re-intervenção formaram o desfecho combinado secundário. O escore baseou-se em uma equação previamente validada, resultante da soma de um ponto para: gênero masculino, história de infarto, angina, diabetes, uso de insulina e ainda um ponto para cada década de vida a partir dos 40 anos. Para o teste positivo foi adicionado um ponto. Resultados. Ocorreram 36 óbitos (10 no grupo angioplastia, 15 no grupo revascularização e 11 no grupo clínico), p=0,61. Observou-se 93 eventos combinados: 37 no grupo angioplastia, 23 no grupo revascularização e 33 no grupo clínico (p=0,058). Duzentos e quarenta e sete pacientes apresentaram escore clínico 5 pontos e 216 pacientes 6 pontos. O valor de corte >5 ou >6 pontos identificou maior risco, com p=0,015 e p=0,012, respectivamente. A curva de sobrevida mostrou uma incidência de óbito após a randomização diferente daquela com escore 6 pontos (p=0,07), e uma incidência de eventos combinados diferente entre pacientes com escore <6 e 6 pontos (p=0,02). Conclusão. O novo escore demonstrou consistência na avaliação prognóstica do coronariopata estável multiarterial / Introduction. The need to improve the exercise testing accuracy, lead the development of scores, which applicability were already widely recognized. Objective. Prognostic evaluation of stable coronary disease throughout a new simplified score. Methods. A new score was applied in 372 bi or triarterial coronary patients, 71,8% men mean age 59,5+9,07 years, randomized for percutaneous coronary intervention (PCI), coronary artery bypass graft surgery (CABG) and clinical treatment, with 5 years follow-up. Cardiovascular death was considered the primary outcome. Non-fatal myocardial infarction, death and re-intervention were considered the combined secondary outcome. The score was based on a previously validated equation, resulting from a sum of one point score for: male gender, infarction history, angina, diabetes, use of insulin and one point score for each decade of life after the age of 40 years. Positive exercise testing summed one additional point score. Results. There were 36 deaths (10 in the PCI group, 15 in the CABG group and 11 in the clinical group), p=0.61. There were 93 combined events: 37 in the PCI group, 23 in CABG group and 33 in the clinical group (p=0.058). Two hundred and forty-seven patients presented a clinical score 5 points and 216 patients 6 points. The cut-off point 5 or 6 identified an increased risk, p=0.015 and p=0.012, respectively. The survival curve showed a different death incidence after the randomization when the score reached 6 points or more (p=0.07), and a distinct incidence of combined events between the patients with points score <6 and 6 (p=0.02). Conclusion. The new score showed to be consistent in the prognostic evaluation of stable multivessel coronary artery disease