Flosequinan in heart failure: acute haemodynamic and longer term symptomatic effects.

There is no single, simple test with which to evaluate new treatments for heart failure. Various methods need to be used, and a study of both the acute haemodynamic and longer term symptomatic effects of flosequinan, a new direct acting arteriolar and venous vasodilator, was therefore carried out in patients with heart failure. In one group of patients flosequinan increased cardiac output and caused a fall in pulmonary capillary wedge pressure, both effects lasting for 24 hours. In a double blind, placebo controlled study in another group flosequinan improved mean exercise tolerance from 9.9 to 12.7 minutes after four weeks of treatment. The drug also reduced perceived exertion during submaximal exercise and increased calf and therefore skeletal muscle blood flow. It reduced plasma renin activity and noradrenaline concentrations. Flosequinan possesses all the important properties of a drug likely to be of value in the treatment of heart failure.     

Reproducibility of the airway response to an exercise protocol standardized for intensity,duration, and inspired air conditions,in subjects with symptoms suggestive of asthma

Background

Exercise testing to aid diagnosis of exercise-induced bronchoconstriction (EIB) is commonly performed. Reproducibility of the airway response to a standardized exercise protocol has not been reported in subjects being evaluated with mild symptoms suggestive of asthma but without a definite diagnosis. This study examined reproducibility of % fall in FEV₁ and area under the FEV₁ time curve for 30 minutes in response to two exercise tests performed with the same intensity and duration of exercise, and inspired air conditions.

Methods

Subjects with mild symptoms of asthma exercised twice within approximately 4 days by running for 8 minutes on a motorized treadmill breathing dry air at an intensity to induce a heart rate between 80-90% predicted maximum; reproducibility of the airway response was expressed as the 95% probability interval.

Results

Of 373 subjects challenged twice 161 were positive (≥10% fall FEV₁ on at least one challenge). The EIB was mild and 77% of subjects had <15% fall on both challenges. Agreement between results was 76.1% with 56.8% (212) negative (< 10% fall FEV₁) and 19.3% (72) positive on both challenges. The remaining 23.9% of subjects had only one positive test. The 95% probability interval for reproducibility of the % fall in FEV₁ and AUC_0-30 min was ± 9.7% and ± 251% for all 278 adults and ± 13.4% and ± 279% for all 95 children. The 95% probability interval for reproducibility of % fall in FEV₁ and AUC_{0-30 min} for the 72 subjects with two tests ≥10% fall FEV₁ was ± 14.6% and ± 373% and for the 34 subjects with two tests ≥15% fall FEV₁ it was ± 12.2% and ± 411%. Heart rate and estimated ventilation achieved were not significantly different either on the two test days or when one test result was positive and one was negative.

Conclusions

Under standardized, well controlled conditions for exercise challenge, the majority of subjects with mild symptoms of asthma demonstrated agreement in test results. Performing two tests may need to be considered when using exercise to exclude or diagnose EIB, when prescribing prophylactic treatment to prevent EIB and when designing protocols for clinical trials.     

Effects of epinephrine, phenoxybenzamine, and propranolol on maximal exercise in sheep.

The mixed adrenergic agonist, epinephrine (10 micrograms/kg, i.v.), the beta-adrenergic receptor antagonist, propranolol (0.2 mg/kg, i.v.), or the alpha-adrenergic receptor antagonist, phenoxybenzamine (1 mg/kg, i.v.), were administered to sheep immediately before maximal incremental exercise. The effects of each of these drugs on hemoglobin (Hb) concentration during maximal exercise and on maximal exercise performance were investigated. The maximal incremental exercise protocol began at 4.0 km/h and 0% grade and finished at 5.6 km/h and 12% grade, with speed or grade increases every 1.5 minutes. Maximal exercise in control (untreated) sheep caused a mean 42% increase in hematocrit and 44% increase in Hb. This exercise-induced increase in Hb was unaffected by propranolol but was partially blocked by phenoxybenzamine. Epinephrine caused an immediate increase in Hb which abated during the early minutes of exercise and then subsequently increased toward the end of the exercise challenge. Maximum oxygen consumption (VO2) in control sheep was 47.6 +/- 6.7 ml/min per kilogram. Maximum VO2 after epinephrine, 51.6 +/- 8.7 ml/min per kilogram, was not significantly different from control. Maximum VO2 after propranolol and phenoxybenzamine, 35.4 +/- 15.3 and 40.8 +/- 8.2 ml/min per kilogram, respectively, were both significantly less than control exercise (P < 0.05).     

Utilité de l'épreuve d'effort sur tapis roulant peu après un infarctus du myocarde.

A program of reconditioning through walking was prescribed for 130 patients following an exercise test on a treadmill 3 weeks after a myocardial infarction. At 8 and at 12 weeks the patients again underwent an exercise test. The protocol is safe and permits the detection of angina, arrhythmias and dyspnea during the exercise, thus avoiding delays in treatment. The heart rate and the systolic blood pressure were measured at the end of each stage of the test and after 3 minutes of recuperation. About 75% of the patients attained the target energy output of the two submaximal tests (4 and 7 mets at 3 and 8 weeks respectively); an output of 7 mets permits a patient to resume his or her usual daily activities. The results of the tests at 3 and 12 weeks (the latter a maximal test) showed that the probability of an aerobic capacity of 7 mets or greater at 12 weeks is 86% if the 3-week test is completed. Clinical observations alone did not have the same prognostic value 3 weeks after the infarction.     

Haemodynamic effects of intravenous morphine in patients with acute myocardial infarction complicated by severe left ventricular failure.

The haemodynamic effects of intravenous morphine sulphate (0.2 mg/kg body weight) were measured in 10 patients with acute myocardial infarction complicated by severe left ventricular failure. Fifteen minutes after morphine injection there was a significant fall in mean heart rate (from 109 to 101 beats/min) and mean systemic arterial pressure (from 80 to 65 mm HG), and a small fall in mean cardiac index (from 2.4 to 2.21/min/m2). Haemodynamic changes at 45 minutes were similar. Neither stroke index nor indirect left ventricular filling pressure (measured as pulmonary artery end-diastolic pressure) were consistently improved 15 or 45 minutes after injection. The useful action of morphine in relieving distressing cardiac dyspnoea is not adequately explained by systemic venous blood pooling. These results suggest that the effects of morphine on the central nervous system are more important.     

A study of passive weight-bearing lower limb exercise effects on local muscles and whole body oxidative metabolism: a comparison with simulated horse riding,bicycle, and walking exercise

Background

We have developed an exercise machine prototype for increasing exercise intensity by means of passively exercising lower limb muscles. The purpose of the present study was to compare the passive exercise intensity of our newly-developed machine with the intensities of different types of exercises. We also attempted to measure muscle activity to study how these forms of exercise affected individual parts of the body.

Methods

Subjects were 14 healthy men with the following demographics: age 30 years, height 171.5 cm, weight 68.3 kg. They performed 4 types of exercise: Passive weight-bearing lower limb exercise (PWLLE), Simulated horse riding exercise (SHRE), Bicycle exercise, and Walking exercise, as described below at an interval of one week or longer. Oxygen uptake, blood pressure, heart rate, and electromyogram (EMG) were measured or recorded during exercise. At rest prior to exercise and immediately after the end of each exercise intensity, the oxygenated hemoglobin levels of the lower limb muscles were measured by near-infrared spectroscopy to calculate the rate of decline. This rate of decline was obtained immediately after exercise as well as at rest to calculate oxygen consumption of the lower limb muscles as expressed as a ratio of a post-exercise rate of decline to a resting one.

Results

The heart rate and oxygen uptake observed in PWLLE during maximal intensity were comparable to that of a 20-watt bicycle exercise or 2 km/hr walking exercise. Maximal intensity PWLLE was found to provoke muscle activity comparable to an 80-watt bicycle or 6 km/hr walking exercise. As was the case with the EMG results, during maximal intensity PWLLE, the rectus femoris muscle consumed oxygen in amounts identical to that of an 80-watt bicycle or a 6 km/hr walking exercise.

Conclusion

Passive weight-bearing lower limb exercise using our trial machine could provide approximately 3 MET of exercise and the thigh exhibited muscle activity equivalent to that of 80-watt bicycle or 6 km/hr walking exercise. Namely, given the same oxygen uptake, PWLLE exceeded bicycle or walking exercise in muscle activity, thus PWLLE is believed to strengthen muscle power while reducing the load imposed on the cardiopulmonary system.

     

Exercise Asthma and Disodium Cromoglycate

Exercise-induced asthma (defined as a fall in PEF of at least 25% of the pre-exercise value) was studied in adult patients with uncomplicated asthma. This was found to occur in 22 out of 52 patients. Pre-exercise inhalation of disodium cromoglycate reduced the mean fall in PEF after maximal exercise from 50% of the pre-exercise value to 23% (open assessment in 11 cases). After submaximal exercise for eight minutes the reduction was from 18% to 10% (double-blind crossover study in 28 cases). It is concluded that disodium cromoglycate partly inhibits the increase of airways resistance after exercise in asthmatic patients.     

The relative influences of exercise and coat-type on the thermoregulatory responses of cattle

Field and climatic chamber studies revealed that walking at 4.5 km/h elicited greater thermoregulatory responses in Hereford cattle than did the possession of a wooly hair coat.Under mild field conditions, walking caused sweating rate to increase to 150–200 g/m²/h within one hour (P<0.001); no significant differences were recorded between wooly-coated and clipped cattle.Walking at 4.5 km/h on a treadmill in a climate chamber at 38°C and 34 mm Hg water vapour pressure elevated rectal (P<0.001) and skin (P<0.05) temperatures to levels considerably above those in stationary controls. There were no differential effects on sweating or respiratory rates, though the latter were generally higher in the exercising group.Differences in skin temperature, sweating and respiratory rates between coat-types and exercise groups in the climate chamber were similar, but exercise resulted in a much greater rectal temperature response.Overall, exercise represented a more potent thermoregulatory stimulus than a wooly hair coat.     

Leptin, gastrointestinal and stress hormones in response to exercise in fasted or fed subjects and before or after blood donation.

Leptin, an ob gene product of adipocytes, plays a key role in the control of food intake and energy expenditure but little is known about leptin response to strenuous exercise in fasted and fed subjects or before and after blood donation. This study was designed to determine the immediate effects of strenuous exercise in healthy volunteers under fasting or fed conditions and before and one day after blood donation (450 ml) on plasma levels of leptin and gut hormones [gastrin, cholecystokinin (CCK), pancreatic polypeptide (PP) and insulin], as well as on "stress" hormones (cortisol, catecholamines and growth hormone. Two groups (A and B) of healthy non-smoking male volunteers were studied. All subjects performed incremental exercise tests until exhaustion (up to maximal oxygen uptake--VO2max), followed by 2 h of rest session. Group A perfomed the tests on a treadmill, while group B on a cycloergometer. In group A, one exercise was performed under fasting conditions and the second following ingestion of a standard liquid meal. In group B, one exercise test was performed as a control test and the second 24 h after blood donation (450 ml). Blood samples were withdrawn 5 min before the start of the test, at the VO2max, and 2 h after finishing the exercise. No significant change in plasma teptin were observed both immediately and 2 h after the exercise in fasted subjects, but after the meal the plasma leptin at VO2max and 2 h after the test was significantly higher, while after blood donation was significantly reduced. The postprandial rise in plasma leptin was accompanied by a marked increment in gut hormones; gastrin, CCK and PP and stress hormones such as norepinephrine, cortisol and GH. These hormonal changes could contribute to the postprandial rise in plasma leptin concentrations, while the fall of leptin after blood donation could be attributed to the inadequate response of stress hormones and autonomic nervous system to exhausting exercise. We conclude that strenuous physical exercise; 1) fails to affect plasma leptin level but when performed after meal but not after blood withdrawal it results in an increase and fall in plasma leptin, and 2) the release of gut hormones (gastrin, CCK and PP) and stress hormones (norepinephrine, cortisol, GH) increase immediately after exercise independently of feeding or blood donation and 3) following blood donation the strenuous exercise resulted in a marked reduction in the plasma leptin, cortisol and GH concentrations, possibly due to the impairment in the autonomic nervous control of these hormones.     

A comparison of the immediate effects of resistance, aerobic, and concurrent exercise on postexercise hypotension

A comparison of the immediate effects of resistance, aerobic, and concurrent exercise on postexercise hypotension. The influence of resistance exercise (RE), aerobic exercise (AE), and concurrent exercise (CE) on postexercise hypotension (PEH) is not known. We investigated the immediate blood pressure (BP) lowering effects of exercise after RE, AE, and CE sessions among healthy subjects. Twenty-one men (20.7 ± 0.7 years) performed 4 experimental sessions each in a within-subject design: control (CTL-seated rest for 60 minutes), RE (3 sets at 80% 1RM for 8 exercises, including upper and lower limbs), AE (7-minutes warm-up followed by 50 minutes of cycle ergometer exercise at 65% VO?peak and 3-minute cooldown), and CE (2 sets at 80% 1RM for 6 exercises among those which composed the RE session, plus 20 minutes of cycle ergometer exercise at 65% VO?peak, 7-minute warm-up and 3-minute cooldown, exactly in this order). The total duration of each exercise session was approximately 60 minutes. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were assessed by ambulatory monitoring at rest (20 minutes) and every 10 minutes after the exercise during 120 minutes while in the laboratory. The duration of the decrease in SBP was longer after AE and CE (120 minutes) compared to RE (80 minutes); and for DBP after AE (50 minutes) compared to CE (40 minutes) and RE (20 minutes) (p < 0.05). The magnitude of the decrease in SBP and DBP was similar after all exercise sessions and significantly different from CTL (p < 0.05) (SBP: RE = 4.1 ± 2.0 mm Hg, AE = 6.3 ± 1.3 mm Hg, CE = 5.1 ± 2.2 mm Hg; DBP: RE = 1.8 ± 1.1 mm Hg, AE = 1.8 ± 1.0 mm Hg, CE = 1.6 ± 0.6 mm Hg). It was concluded that exercise sessions combining aerobic and resistance activities are as effective as AE sessions and more effective than RE sessions to promote PEH.     

Diaphragmatic perfusion heterogeneity during exercise with inspiratory resistive breathing

Regional distribution of diaphragmatic blood flow (Q; 15-microns-diam radionuclide-labeled microspheres) was studied in normal (n = 7) and laryngeal hemiplegic (LH; n = 7) ponies to determine whether the added stress of inspiratory resistive breathing during maximal exercise may cause 1) redistribution of diaphragmatic Q and 2) crural diaphragmatic Q to exceed that in maximally exercising normal ponies. LH-induced augmentation of already high exertional work of breathing resulted in diminished locomotor exercise capacity so that maximal exercise in LH ponies occurred at 25 km/h compared with 32 km/h for normal ponies. The costal and crural regions received similar Q in both groups at rest. However, exercise-induced increments in perfusion were significantly greater in the costal region of the diaphragm. At 25 km/h, costal diaphragmatic perfusion was 154 and 143% of the crural diaphragmatic Q in normal and LH ponies. At 32 km/h, Q in costal diaphragm of normal ponies was 136% of that in the crural region. Costal and crural diaphragmatic Q in LH ponies exercised at 25 km/h exceeded that for normal ponies but was similar to the latter during exercise at 32 km/h. Perfusion pressure for the three conditions was also similar. It is concluded that diaphragmatic perfusion heterogeneity in exercising ponies was preserved during the added stress of inspiratory resistive breathing. It was also demonstrated that vascular resistance in the crural and costal regions of the diaphragm in maximally exercised LH ponies remained similar to that in maximally exercising normal ponies.     

Do compression garments enhance the active recovery process after high-intensity running?

Lovell, DI, Mason, DG, Delphinus, EM, and McLellan, CP. Do compression garments enhance the active recovery process after high-intensity running? J Strength Cond Res 25(12): 3264-3268, 2011-This study examined the effect of wearing waist-to-ankle compression garments (CGs) on active recovery after moderate- and high-intensity submaximal treadmill running. Twenty-five male semiprofessional rugby league players performed two 30-minute treadmill runs comprising of six 5-minute stages at 6 km·h, 10 km·h, approximately 85% VO(2)max, 6 km·h as a recovery stage followed by approximately 85% VO(2)max and 6 km·h wearing either CGs or regular running shorts in a randomized counterbalanced order with each person acting as his own control. All stages were followed by 30 seconds of rest during which a blood sample was collected to determine blood pH and blood lactate concentration [La]. Expired gases and heart rate (HR) were measured during the submaximal treadmill tests to determine metabolic variables with the average of the last 2 minutes used for data analysis. The HR and [La] were lower (p ≤ 0.05) after the first and second 6 km·h recovery bouts when wearing CGs compared with when wearing running shorts. The respiratory exchange ratio (RER) was higher and [La] lower (p ≤ 0.05) after the 10 km·h stage, and only RER was higher after both 85% VO(2)max stages when wearing CGs compared with when wearing running shorts. There was no difference in blood pH at any exercise stage when wearing the CGs and running shorts. The results of this study indicate that the wearing of CGs may augment the active recovery process in reducing [La] and HR after high-intensity exercise but not effect blood pH. The ability to reduce [La] and HR has important consequences for many sports that are intermittent in nature and consist of repeated bouts of high-intensity exercise interspersed with periods of low-intensity exercise or recovery.     

CRASH-3 - tranexamic acid for the treatment of significant traumatic brain injury: study protocol for an international randomized, double-blind, placebo-controlled trial

Background

Single-limb knee extension exercises have been found to be effective at improving lower extremity exercise capacity in patients with chronic obstructive pulmonary disease (COPD). Since the positive local physiological effects of exercise training only occur in the engaged muscle(s), should upper extremity muscles also be included to determine the effect of single limb exercises in COPD patients.

Methods/design

Trial design: a prospective, assessor-blind, block randomized controlled, parallel-group multicenter trial. Participants: stage II-IV COPD patients, > 40?years of age, ex-smokers, with stable medical treatment will be included starting May 2011. Recruitment at three locations in Sweden. Interventions: 1) high-repetitive single limb exercise (HRSLE) training with elastic bands, 60 minutes, three times/week for 8?weeks combined with four sessions of 60 minutes patient education, or 2) the same patient education alone. Outcomes: Primary: determine the effects of HRSLE on local muscle endurance capacity (measured as meters walked during 6-minute walk test and rings moved on 6-minute ring and pegboard test) and quality of life (measured as change on the Swedish version of the Chronic Respiratory Disease Questionnaire). Secondary: effects on maximal strength, muscular endurance, dyspnea, self-efficacy, anxiety and depression. The relationship between changes in health-related variables and changes in exercise capacity, sex-related differences in training effects, feasibility of the program, strategies to determine adequate starting resistance and provide accurate resistance for each involved movement and the relationship between muscle fatigue and dyspnea in the different exercise tests will also be analyzed. Randomization: performed by a person independent of the recruitment process and using a computer random number generator. Stratification by center and gender with a 1:1 allocation to the intervention or control using random block sizes. Blinding: all outcome assessors will be blinded to group assignment.

Discussion

The results of this project will contribute to increase the body of knowledge regarding COPD and HRSLE.

Trial registration

ClinicalTrials.gov Identifier: NCT01354067. Registration date: 2011-05-11. First participant randomized: 2011-09-02     

Relation of pressure and flow of pulmonary circulation in patients with chronic obstructive pulmonary disease

A series of 31 patients with various degrees of chronic obstructive pulmonary disease underwent right heart catheterization using flow-directed thermodilution catheters. Both rest and supine exercise values were obtained. The patients were divided into two groups on the basis of their reduction in forced expiratory volume in 1 s (FEV1). In patients with FEV1 values of greater than or equal to 1,300 ml (group 1), the arterial oxygen partial pressure (PaO2) did not significantly change with exercise, while in patients with FEV1 of less than or equal to 1,200 ml (group 2) PaO2 significantly (p less than 0.05) fell in response to exercise. In group 2, a significant increase of total pulmonary resistance (TPR) with exercise was found (p less than 0.01). Pulmonary vascular resistance (PVR) remained unchanged in both subgroups. It is suggested that the value of PVR for subgroup 2 is artificially low because an important variable, namely pulmonary artery wedge pressure, is influenced by alveolar pressure in patients with an uneven distribution of perfusion and ventilation at pulmonary venous pressures lower than alveolar pressure. The steeper slope of the pressure-flow relationship in these patients is probably due to an increased vascular tone caused by chronic hypoxia at rest and further fall of PaO2 and rise of arterial CO2 partial pressure in response to exercise.     

Effect of chronic pulmonary denervation on ventilatory responses to exercise

To assess the role of intrapulmonary receptors on the ventilatory responses to exercise we studied six beagle dogs before and after chronic pulmonary denervation and five dogs before and after sham thoracotomies. Each exercise challenge consisted of 6 min of treadmill exercise with measurements taken during the third minute at 3.2 km/h, 0% grade, and during the third minute at 5.0 km/h, 0% grade. Inspiratory and expiratory airflows were monitored with a low-dead-space latex mask and pneumotachographs coupled to differential pressure transducers. Both pre- and postsurgery, all dogs exhibited a significant arterial hypocapnia and alkalosis during exercise. Denervation of the lungs had no significant effect on minute ventilation at rest or during exercise, although there was a lower frequency and higher tidal volume in the lung-denervated dogs at all measurement periods. Breathing frequency increased significantly during exercise in lung-denervated dogs but to a lesser magnitude than in the control dogs. The changes that occurred in breathing frequency in all animals were due predominantly to the shortening of expiratory time. Inspiratory time did not shorten significantly during exercise following lung denervation. We conclude from these data that intrapulmonary receptors which are deafferented by sectioning the vagi at the hilum are not responsible for setting the level of ventilation during rest or exercise but are involved in determining the pattern of breathing.     

Liver-derived endocrine IGF-I is not critical for activation of skeletal muscle protein synthesis following oral feeding

Background

Like humans, fish can be classified according to their athletic performance. Sustained exercise training of fish can improve growth and physical capacity, and recent results have documented improved disease resistance in exercised Atlantic salmon. In this study we investigated the effects of inherent swimming performance and exercise training on disease resistance in Atlantic salmon. Atlantic salmon were first classified as either poor or good according to their swimming performance in a screening test and then exercise trained for 10 weeks using one of two constant-velocity or two interval-velocity training regimes for comparison against control trained fish (low speed continuously). Disease resistance was assessed by a viral disease challenge test (infectious pancreatic necrosis) and gene expression analyses of the host response in selected organs.

Results

An inherently good swimming performance was associated with improved disease resistance, as good swimmers showed significantly better survival compared to poor swimmers in the viral challenge test. Differences in mortalities between poor and good swimmers were correlated with cardiac mRNA expression of virus responsive genes reflecting the infection status. Although not significant, fish trained at constant-velocity showed a trend towards higher survival than fish trained at either short or long intervals. Finally, only constant training at high intensity had a significant positive effect on fish growth compared to control trained fish.

Conclusions

This is the first evidence suggesting that inherent swimming performance is associated with disease resistance in fish.     

Effects of exercise with or without light exposure on sleep quality and hormone reponses

[Purpose]

The objectives of the present study were to determine the effect of sun exposure and aerobic exercise on quality of sleep and investigate sleep-related hormonal responses in college-aged males.

[Methods]

In this study, the cross-over design was utilized. The subjects (N = 10) without any physical problems or sleep disorders participated in the experimental performed 4 protocols in only sun exposure (for 30 minutes, EG1) protocol, only aerobic exercise (walking and jogging for 30 minutes, EG2) protocol, aerobic exercise with sun exposure (EG3) protocol, and control (no exercise and no sun exposure, EG4) protocol. Each protocol was 5 times per week with one-week break (wash-out period) between protocols to prevent the effects of the previous protocol. Total test period was should be 7 weeks (one week of protocol and one week of break). Before and after each aerobic exercise session, the subjects completed stretching to warm up for 5 to 10 minutes. Surveys consisting of (bedtime, wake-up time, sleep onset latency, and (Pittsburgh Sleep Quality Index (PSQI) were obtained before the test and after each protocol. After each protocol, the following sleep-related hormonal responses were measured: blood concentrations of melatonin, cortisol, epinephrine, and norepinephrine. One-way ANOVA was used to determine differences between protocols. Statistical significance was set at p < 0.05.

[Results]

Bedtime of EG4 was significantly later than that of the EG1 or EG3. Wake-up time in the EG4 was significantly later than that of the EG1 or the EG3. Sleep onset latency in the EG4 was longer than that of the EG3. The quality of sleep in the EG4 was lower than that of the EG3. Sleep cycle in the EG4 was significantly shorter than that of the EG1. Blood melatonin concentrations of the EG3 was significantly higher than that of the EG4. There were no significant differences in blood concentrations of cortisol, epinephrine, or norepinephrine among protocols, with the order from the lowest to the highest values of EG1 < EG2 < EG3 < EG4.

[Conclusion]

The present data found that EG1 and EG3 showed positive sleep-related hormonal responses, sleep habits, and quality of sleep, indicating that sun exposure or exercise with sun exposure may improve the physical status and quality of life.     

Effects of chronic and acute exercise on cardiovascular beta-adrenergic responses.

beta-Adrenergic receptor density and responsiveness may be increased in experimental animals by physical conditioning, and the opposite effects have been observed after a single bout of exercise. To determine whether the chronic and acute effects of exercise include similar alterations in cardiovascular function in humans, we characterized heart rate, blood pressure, and distal lower extremity blood flow responses to graded-dose isoproterenol infusion in 15 young healthy subjects before and after exercise training and with and without a single preceding bout of prolonged exercise of either low or high intensity (61 +/- 1 or 82 +/- 1% maximal heart rate). VO2max was increased 18% after exercise training (43.2 +/- 2.7 to 51.1 +/- 3.3 ml.kg-1.min-1; P less than 0.001). Despite a concomitant fall in resting heart rate (59 +/- 3 to 50 +/- 2 beats/min; P less than 0.001), chronotropic and lower extremity blood flow responses to isoproterenol remained unchanged. Similarly, 1 h of acute high-intensity treadmill exercise altered baseline heart rate (58 +/- 4 to 74 +/- 5 beats/min; P less than 0.02), but neither low- nor high-intensity acute exercise influenced heart rate or lower extremity blood flow responses to isoproterenol. In contrast, the systolic pressure response to isoproterenol was blunted after high- but not low-intensity prolonged exercise (P less than 0.02). These data indicate that cardiac chronotropic (primarily beta 1) and vascular (beta 2) adrenergic agonist responses are not altered in humans by training or acute exercise. The systolic blood pressure response to beta-adrenergic stimulation is decreased by a single bout of high-intensity prolonged exercise by mechanisms that remain to be defined.     

Cold pressor test in diagnosis of coronary artery disease: echophonocardiographic method.

The cold pressor test was used to induce myocardial ischaemia in patients with coronary artery disease and the rise in left ventricular filling pressure used as the index of myocardial ischaemia. Left ventricular filling pressure was derived from a non-invasive echophonocardiographic method. A study group of 19 consecutive patients with chest pain underwent the cold pressor test before coronary angiography. Eighteen responded with a rise in filling pressure exceeding 30% and, of these, 17 had serious coronary artery disease (three single vessel, one two vessel, and 13 triple vessel disease; one had coronary artery spasm only). The remaining patient, who showed no rise in filling pressure, did not have coronary artery disease. None of 15 normal controls showed a rise greater than 5% (patients with coronary artery disease versus normal controls p less than 0.001). The cold pressor test would be suitable for patients who cannot or should not exercise and may be combined with exercise electrocardiograms to improve the information content, as it uses a different marker of myocardial ischaemia.