运动性哮喘患者中嗜酸细胞、T淋巴细胞、白三烯作用的研究

目的探讨嗜酸细胞、T淋巴细胞、白三烯和运动性哮喘(EIA)的关系.方法分别测定13例运动性哮喘患者和19例非运动性哮喘患者运动前、后血清中的嗜酸细胞阳离子蛋白(ECP)浓度和白细胞介素4(IL-4)mRNA和白细胞介素5(IL-5)mRNA值以及外周血CD+25T淋巴细胞占总淋巴细胞的百分比(CD+25%);另外测定22例运动性哮喘患者运动前和运动后2h尿液中白三烯E4(LTE4)浓度,给予白三烯受体拮抗剂扎鲁斯特治疗;并与正常对照组进行对照.结果哮喘患者运动前ECP和CD+25%与一秒钟用力呼气容积(FEV1)呈负相关(r分别为-0.79、-0.61,P均<0.01).运动性哮喘组与非运动性哮喘组之间IL-4mRNA、IL-5mRNA、CD+25%、ECP在运动前、运动后10和60min比较差异无显著性(P>0.05).运动性哮喘组、非运动性哮喘组、对照组之间最大分钟通气量(Emax)分别为(73.6±34.2)L/min、(69.1±22.1)L/min、(59.6±23.5)L/min,组间比较差异无显著性(P均>0.05).运动性哮喘组运动2h后尿液中LTE4浓度为(225.7±97.4)ng/L与运动前(152.9±89.4)ng/L比较,差异有显著性(P<0.01);服用扎鲁斯特后,运动性哮喘运动后反应与用药前比较明显减轻,其中运动后1h内FEV1下降与时间形成的曲线下面积[AUC0～60min(用药前为1.0用药后为0.3)]、运动后FEV1恢复至运动前所需时间(用药前为75min∶用药后为45min)、运动前、后FEV1下降的百分比(用药前为-22.9%∶用药后为-6.9%,P均<0.01).结论过度通气并非EIA形成的主要因素;T淋巴细胞的激活以及主要由Th2细胞分泌的细胞因子IL-4、IL-5,嗜酸细胞分泌的ECP在EIA的发生中未起主导作用;白三烯在运动性哮喘的发生中起到重要作用.     

Exercise, echocardiography

Exercise testing is an indispensable component of clinical cardiology. Latent disease or the full extent of a problem may not be apparent on a resting examination. Some form of stress is frequently necessary, especially in patients with coronary disease, to appreciate whether a patient has stress-induced ischaemia as manifested by exercise-induced chest discomfort, a drop in blood pressure or electrocardiographic changes of ischaemia. Unfortunately as with every test ECG and clinical monitoring have limitations. Patients may have ischaemia without pain, ECG changes may be non-specific, a resting abnormal ECG has limited value, and the location and amount of ischaemic muscle is not directly assessed. Monitoring the echocardiogram adds significant additional information to routine stress testing. By visualising the myocardium in the exercising individual, it is possible to assess a fundamental manifestation of ischaemia, regional wall motion abnormalities. This information kelps identify the vessels and the amount of muscle involved. In addition resting wall motion abnormalities may detect clinically silent infarction or hibernating myocardium. Direct visualisation of the exercising heart provides an improved understanding of a patient's cardiac status. The technique is particularly useful in evaluating revascularisation procedures. Advances in instrumentation have reduced or eliminated many of the technical difficulties with obtaining and interpreting exercise echocardiograms. This examination has become an extremely useful adjunct to routine stress testing.     

The joint associations of occupational, commuting, and leisure-time physical activity, and the Framingham risk score on the 10-year risk of coronary heart disease.

AIMS: To determine joint associations of different kinds of physical activity and the Framingham risk score (FRS) with the 10-year risk of coronary heart disease (CHD) events. METHODS AND RESULTS: Study cohorts included 41 053 Finnish participants aged 25-64 years without history of CHD and stroke. The multivariable-adjusted 10-year hazard ratios (HRs) of coronary events associated with low, moderate, and high occupational physical activity were 1.00, 0.66, and 0.74 (Ptrend<0.001) for men, and 1.00, 0.53, and 0.58 (Ptrend<0.001) for women, respectively. The multivariable-adjusted 10-year HRs of coronary events associated with low, moderate, and high leisure-time physical activity were 1.00, 0.97, and 0.66 (Ptrend=0.002) for men, and 1.00, 0.74, and 0.54 (Ptrend=0.003) for women, respectively. Active commuting had a significant inverse association with 10-year risk of coronary events in women only. The FRS predicted 10-year risk of coronary events among both men and women. The protective effects of occupational, commuting, or leisure-time physical activity were consistent in subjects with a very low (<6%), low (6-9%), intermediate (10-19%), or high (>or=20%) risk of the FRS. CONCLUSION: Moderate or high levels of occupational or leisure-time physical activity among both men and women, and daily walking or cycling to and from work among women are associated with a reduced 10-year risk of CHD events. These favourable effects of physical activity on CHD risk are observed at all levels of CHD risk based on FRS assessment.     

The Obesity Paradox, Weight Loss, and Coronary Disease

Purpose

Because obesity is a cardiovascular risk factor but is associated with a more favorable prognosis among cohorts of cardiac patients, we assessed this “obesity paradox” in overweight and obese patients with coronary heart disease enrolled in a cardiac rehabilitation and exercise training (CRET) program, making this assessment in patients classified as overweight/obese using both traditional body mass index (BMI) and percent body fat assessments. Additionally, we assessed the efficacy and safety of purposeful weight loss in overweight and obese coronary patients.

Patients and Methods

We retrospectively studied 529 consecutive CRET patients following major coronary events before and after CRET, and compared baseline and post program data in 393 overweight and obese patients (body mass index [BMI] ≥25 kg/m²) divided by median weight change (median = −1.5%; mean +2% vs −5%, respectively). In addition, we assessed 3-year total mortality in various baseline BMI categories as well as compared mortality in those with high baseline percent fat (>25% in men and >35% in women) versus those with low baseline fat.

Results

Following CRET, the overweight and obese with greater weight loss had improvements in BMI (−5%; P <.0001), percent fat (−8%; P <.0001), peak oxygen consumption (+16%; P <.0001), low-density lipoprotein cholesterol (−5%; P <.02), high-density lipoprotein cholesterol (+10%; P <.0001), triglycerides (−17%; P <.0001), C-reactive protein (−40%; P <.0001), and fasting glucose (−4%; P = .02), as well as marked improvements in behavioral factors and quality-of-life scores. Those with lower weight loss had no significant improvements in percent fat, low-density lipoprotein cholesterol, triglycerides, C-reactive protein, and fasting glucose. During 3-year follow-up, overall mortality trended only slightly lower in those with baseline overweightness/obesity who had more weight loss (3.1% vs 5.1%; P = .30). However, total mortality was considerably lower in the baseline overweight/obese (BMI ≥25 kg/m²) than in 136 CRET patients with baseline BMI <25 kg/m² (4.1% vs 13.2%; P <.001), as well as in those with high baseline fat compared with those with low fat (3.8% vs 10.6%; P <.01).

Conclusions

Purposeful weight loss with CRET in overweight/obese coronary patients is associated with only a nonsignificant trend for lower mortality but is characterized by marked improvements in obesity indices, exercise capacity, plasma lipids, and inflammation, as well as behavioral factors and quality of life. Although an “obesity paradox” exists using either baseline BMI or baseline percent fat criteria, these results support the safety and potential long-term benefits of purposeful weight loss in overweight and obese patients with coronary heart disease.     

Exercise blood pressure response, albuminuria, and arterial stiffness in hypertension

Background

A hypertensive response to exercise is associated with high cardiovascular risk, whereas the data about its relation to surrogates of subclinical atherosclerosis are scarce. We investigated the relationships of a hypertensive response to exercise with urinary albumin excretion and arterial stiffness in hypertensives.

Methods

There were 171 untreated males (mean age 52 years, all Caucasian) with stage I-II essential hypertension and a negative treadmill exercise test divided into those with a hypertensive response to exercise (n = 48) (peak exercise systolic blood pressure ≥210 mm Hg) and to those with normal blood pressure response (n = 123). Albumin-to-creatinine ratio values were determined as the mean of 3 nonconsecutive morning spot urine samples, and arterial stiffness was evaluated on the basis of carotid-to-femoral pulse wave velocity.

Results

Patients with a hypertensive response to exercise compared with those with normal blood pressure response exhibited greater log albumin-to-creatinine ratio (1.52 ± 0.59 vs 0.97 ± 0.33 mg/g) and higher pulse wave velocity (8.7 ± 1.6 vs 7.7 ± 1.2 m/s), independent of potentially confounding demographic and clinical factors. Resting systolic blood pressure (odds ratio [OR] 1.11, 95% confidence interval [CI], 1.06-1.16), body mass index (OR 1.12, 95% CI, 1.02-1.23), resting heart rate (OR 0.96, 95% CI, 0.93-0.99), and albumin-to-creatinine ratio (OR 7.45, 95% CI, 2.54-21.83) were independently associated with a hypertensive response to exercise.

Conclusion

A hypertensive response to exercise is related to augmented albumin-to-creatinine ratio and arterial stiffness, reflecting accelerated subclinical atherosclerosis. The association of albumin excretion with exercise blood pressure response suggests that albuminuria constitutes an important factor in the interpretation of the hypertensive response to exercise-associated risk.     

Multivariable analysis of heart rate recovery after cycle ergometry in heart failure: exercise in heart failure

Purpose

The purpose of this study was to investigate the association between impairment in heart rate recovery (HR_rec) after cycle ergometry and prognostic markers in patients with heart failure (HF) compared with healthy controls.

Methods

Fifty patients with chronic HF (systolic HF, N = 30; diastolic HF, N = 20; mean age = 62 ± 12 years) and 50 healthy controls (N = 50; mean age = 66 ± 13 years) underwent 2-dimensional and M-mode echocardiography followed by cardiopulmonary exercise testing. Independent predictors of HR_rec at 1 and 2 minutes after exercise were analyzed by univariable and multivariable regression analyses, and receiver operating characteristics were performed to obtain area under the curve.

Results

In HF, left ventricular end-diastolic diameter (millimeters), left ventricular ejection fraction (%), N-terminal pro-brain natriuretic peptide (picograms/milliliter), peak oxygen uptake (VO₂peak [milliliters/kilogram/min]), and peak heart rate (HR_peak) showed a significant association with HR_rec (beats/min) in univariate regression analyses (P < .001), but only VO₂peak remained independently predictive of both HR_rec1 (P = .034) and HR_rec2 (P = .008) in the multivariable regression analyses. In controls, VO₂peak (P = .035) and HR_peak (P = .032) were significantly associated with HR_rec2 in univariate analyses only. Optimal cutoff values for discriminating HF versus non-HF based on HR_rec were 17.5 beats/min (sensitivity 92%; specificity 74%) for HR_rec1 and 31.5 beats/min (sensitivity 94%; specificity 86%) for HR_rec2. Optimal cutoff values for discriminating systolic HF versus diastolic HF were 12.5 beats/min (sensitivity 78%; specificity 80%) for HR_rec1 and 24.5 beats/min (sensitivity 82%; specificity 90%) for HR_rec2.

Conclusion

Impairment in after exercise HR_rec is significantly and independently associated with VO2peak in HF and thus might constitute a useful tool for assessing the degree of functional status during exercise rehabilitation.     

Does action follow intention with participation in home and group-based falls prevention exercise programs? An exploratory,prospective, observational study

BackgroundExercise for falls prevention is effective but of limited uptake in real life. The link between intention and behavior is central to many health-behavior models, but has not been examined in the falls prevention exercise context.ObjectiveThis study examines this relationship and prospectively identifies factors associated with participation in group and home-based falls prevention exercise.DesignThis was an observational study of community-dwelling adults in Australia >70 years of age with a 12 month follow-up (n = 394 commenced baseline assessment, n = 247 commenced follow-up).MethodsIntention, and other potential predictive factors examined, were measured at baseline while participation was measured using self-report at 12 month follow-up.ResultsBetween 65% and 72% of our sample at baseline agreed or strongly agreed they would participate in the falls prevention exercise programs. n = 27 respondents participated in home-based exercise during follow-up and had intention to do so while n = 29 who participated did not have intention. In contrast, n = 43 respondents participated in group exercise and had intention to do so compared to 11 who participated but did not intend to at baseline. Perception of personal effectiveness and previous exposure to the exercise intervention were most strongly predictive of future participation.ConclusionMore people who do not want to participate in home exercise actually participate in home exercise than people who do not want to participate in group exercise that actually do. It may be easier to convince people who do not want to participate in falls prevention exercise to participate in a home program.     

Left ventricular end‐diastolic volume predicts exercise capacity in patients with a normal ejection fraction

Background

Exercise capacity is a powerful predictor of all‐cause mortality. The duration of exercise with treadmill stress testing is an important prognostic marker in both healthy subjects and patients with cardiovascular disease. Left ventricular (LV) structure is known to adapt to sustained changes in level of physical activity.

Hypothesis

Poor exercise capacity in patients with a preserved LV ejection fraction (LVEF) should be reflected in smaller LV dimensions, and a normal exercise capacity should be associated with larger LV dimensions, irrespective of comorbidities.

Methods

This hypothesis was first tested in a cross‐sectional analysis of 201 patients with normal chamber dimensions and preserved LVEF who underwent a clinically indicated treadmill stress echocardiogram using the Bruce protocol (derivation cohort). The best LV dimensional predictor of exercise capacity was then tested in 1285 patients who had a Bruce‐protocol treadmill exercise stress test and a separate transthoracic echocardiogram (validation cohort).

Results

In the derivation cohort, there was a strong positive relationship between exercise duration and LV end‐diastolic volume deciles (r ² = 0.85; P < 0.001). Regression analyses of several LV dimensional parameters revealed that the body surface area–based LV end‐diastolic volume index was best suited to predict exercise capacity (P < 0.0001). In a large validation cohort, LV end‐diastolic volume was confirmed to predict exercise capacity (P < 0.0001).

Conclusions

Among patients referred for outpatient stress echocardiography who have a preserved LVEF and no evidence of myocardial ischemia, we found a strong positive association between LV volume and exercise capacity.     

The Combined Effect of Alcohol and Physical Exercise on Serum Testosterone, Luteinizing Hormone, and Cortisol in Males

The combined effect of alcohol and physical exercise on the serum levels of testosterone, luteinizing hormone, and cortisol was studied in healthy male volunteers by performing an exhaustive ergometer exercise (1) followed by alcohol intoxication (induced by 1.5 g of alcohol/kg body weight), (2) during alcohol intoxication (induced by 0.8 g of alcohol/kg body weight), and (3) during hangover (13 hr after a dose of 1.5 g of alcohol/kg body weight). Physical stress immediately before alcohol administration prolonged the depressant effect of alcohol on testosterone secretion. This seemed to be mainly a consequence of direct inhibition at the testicular level, even though the role of luteinizing hormone as a contributory regulatory factor cannot be totally ruled out. Cortisol response to exercise was not modified by alcohol under any of the experimental conditions.     

Physical activity and sarcopenia

Physical activity can be a valuable countermeasure to sarcopenia in its treatment and prevention. In considering physical training strategies for sarcopenic subjects, it is critical to consider personal and environmental obstacles to access opportunities for physical activity for any patient with chronic disease. This article presents an overview of current knowledge of the effects of physical training on muscle function and the physical activity recommended for sarcopenic patients. So that this countermeasure strategy can be applied in practice, the authors propose a standardized protocol for prescribing physical activity in chronic diseases such as sarcopenia.     

Effects of obesity, physical activity, and cardiorespiratory fitness on blood pressure, inflammation, and insulin resistance in the National Health and Nutrition Survey 1999–2002

Background and aimsThis study was designed to elucidate the effects of obesity, self-reported physical activity and cardiorespiratory fitness on blood pressure, inflammation, and insulin resistance.Methods and resultsData from 950 Caucasian subjects ranging in age from 19 to 49 years from the National Health and Nutrition Survey (NHANES), 1999–2002, were included to construct a population-based observational study. Cardiorespiratory fitness (VO₂ max) was predicted from a submaximal exercise stress test. Self-reported physical activity was measured by metabolic equivalent score transformed from a questionnaire. A structural equation model (SEM) was developed to examine the relationship between obesity, cardiorespiratory fitness, self-reported physical activity, and hypertension, inflammation, and insulin resistance. The model showed that obesity was positively linked to hypertension (B = 0.50, P < 0.001) and C-reactive protein (CRP; B = 0.15, p < 0.05), which in turn led to insulin resistance (B = 0.44, P < 0.05). Increased cardiorespiratory fitness was negatively associated with CRP (Γ = ?0.23, P < 0.01), but not correlated to hypertension after adjustment for potential confounding factors. No significant association was found between self-reported physical activity and hypertension, insulin resistance, and CRP.ConclusionObesity contributes to the development of hypertension, inflammation, and insulin resistance. Improved cardiorespiratory fitness might lead to clinical and biochemical improvement in insulin resistance by reducing the inflammatory state.     

Associations Between Exercise, Quality of Life, and Fatigue in Colorectal Cancer Survivors

Purpose  This study was designed to examine quality of life and fatigue in colorectal cancer survivors meeting and not meeting public health exercise guidelines. Methods  A Canadian provincial cancer registry identified colorectal cancer survivors who were mailed a questionnaire that assessed self-reported exercise, quality of life (Functional Assessment of Cancer Therapy - Colorectal), fatigue, medical, and demographic variables. Results  Completed questionnaires were received from 413 (61.3 percent) eligible colorectal cancer survivors. Only 25.9 percent of colorectal cancer survivors reported meeting exercise guidelines. Colorectal cancer survivors meeting public health exercise guidelines reported clinically and significantly better quality of life (mean difference, 6; 95 percent confidence interval, 2.3–9.8; P = 0.002) and fatigue (mean difference = 5.2; 95 percent confidence interval, 2.9–7.5; P < 0.001). Differences remained after adjusting for medical and demographic factors. Cancer site (i.e., colon vs. rectal) was the only variable to moderate this association (P < 0.05 for interaction). Conclusions  Colorectal cancer survivors meeting public health exercise guidelines reported significantly and meaningfully better quality of life and fatigue scores than colorectal cancer survivors who did not meet guidelines. Prospective observational studies and randomized, controlled trials are needed to further assess the causal nature of these relationships. Poster presentation at the Canadian Society for Psychomotor Learning and Sport Psychology, Halifax, Nova Scotia, Canada, November 1 to 4, 2006. Supported by the University of Alberta - Social Sciences Research Grant Program. This funding agency had no role in study design, collection, analysis, and interpretation of the data, writing the report, or the decision to submit the paper for publication. Ms. Peddle is supported by Full Time Health Research Studentships from the Alberta Heritage Foundation for Medical Research. Dr. Courneya is supported by the Canada Research Chairs Program and a Research Team Grant from the National Cancer Institute of Canada with funds from the Canadian Cancer Society and the Sociobehavioral Cancer Research Network.     

Occupational, commuting, and leisure-time physical activity in relation to cardiovascular mortality among finnish subjects with hypertension

BACKGROUND: The association between different types of physical activity and cardiovascular risk among hypertensive subjects is not fully understood. The purpose of this study was to determine the association of occupational, commuting, and leisure-time physical activity on cardiovascular mortality among hypertensive patients. METHODS: Study cohorts included 26,643 hypertensive Finnish men and women who were aged 25 to 64 years and free of coronary heart disease, stroke, and Type 1 diabetes. RESULTS: During a mean follow-up of 19.9 years (range, 6.6 to 31.7 years), 3743 subjects died because of cardiovascular disease. The multivariate-adjusted (age, study year, education, alcohol consumption, smoking, body mass index, systolic blood pressure, total cholesterol, use of antihypertensive drugs, and diabetes at baseline or during follow-up, and the other two kinds of physical activity) hazard ratios of cardiovascular mortality associated with low, moderate, and high occupational physical activity were 1.00, 0.84, and 0.86 (P for trend = .006), respectively, for hypertensive men, and 1.00, 0.85, and 0.84 (P for trend = .014), respectively, for hypertensive women. The multivariate-adjusted hazard ratios of cardiovascular mortality associated with low, moderate, and high leisure-time physical activity were 1.00, 0.84, and 0.73 (P for trend < .001), respectively, for hypertensive men, and 1.00, 0.78, and 0.76 (P for trend < .001), respectively, for hypertensive women. Active commuting to and from work was significantly associated with reduced cardiovascular mortality in hypertensive women. CONCLUSIONS: Moderate or high levels of occupational or leisure-time physical activity reduce cardiovascular mortality among both men and women with hypertension. Walking or cycling to and from work daily reduces cardiovascular mortality among hypertensive women.