Exercise and hypertension

Cardiovascular Fitness and Absenteeism in 8,301 Employed Adults

The purpose of this study was to determine the extent of the relationship between cardiovascular fitness and absenteeism in the workplace. A total of 8,301 adult males and females who were employed by corporations which participated in a health screening program were used in the study. Absenteeism due to illness, demographic variables, and smoking status were assessed using a written questionnaire, while body fat was measured using skinfold calipers and cardiovascular fitness was assessed using a step test. Results indicated that high levels of cardiovascular fitness were associated significantly with low levels of absenteeism. The relationship remained strong after adjusting for differences in age, gender, income, cigarette smoking, and percent body fat. The association was stronger in females than males.

Reduced risk of intracerebral hemorrhage with dynamic recreational exercise but not with heavy work activity

BACKGROUND AND PURPOSE

It is unclear whether intracerebral hemorrhage (ICH) is associated with dynamic or static exercise. Our aim was to assess whether such an association exists.

METHODS

A case-control study was undertaken involving 331 consecutive cases of primary ICH and 331 age- and sex-matched community-based neighborhood controls. Cases, verified by CT or autopsy, were identified from 13 major hospitals in Melbourne, Australia. A questionnaire was used to elicit information about lifetime physical activity at leisure and work and other potentially confounding factors.

RESULTS

Individuals undertaking recent regular dynamic exercise exhibited an odds ratio (OR) for ICH of 0.63 (95% CI 0.39 to 1.01) when adjustment was made for all potential confounding factors, except hypertension, cholesterol, and body mass index. Among men and women separately, the ORs were 0.51 (95% CI 0.27 to 0.97) and 1.22 (95% CI 0.52 to 2.87), respectively. When hypertension, cholesterol, and body mass index were also included in the multivariate model, the OR among men was 0.57 (95% CI 0.28 to 1.14). There was no association between physical activity at work and ICH (OR 1.14, 95% CI 0.58 to 2.25).

CONCLUSIONS

These results provide preliminary evidence for a role of exercise in reducing the likelihood of ICH among men. In women, the CI was wide, and the association was not statistically significant. There was further support that factors other than blood pressure status, cholesterol, and body mass index may play a role in the observed inverse association between dynamic exercise and ICH among men.

Integrated effects of the vasodilating beta-blocker nebivolol on exercise performance, energy metabolism, cardiovascular and neurohormonal parameters in physically active patients with arterial hypertension

OBJECTIVE

The present study was designed to investigate the integrated effects of the beta-1-selective blocker with vasodilator properties, nebivolol, on systemic haemodynamics, neurohormones and energy metabolism as well as oxygen uptake and exercise performance in physically active patients with moderate essential hypertension (EH).

DESIGN AND METHODS

Eighteen physically active patients with moderate EH were included: age: 46.9 +/- 2.38 years, weight: 83.9 +/- 2.81 kg, blood pressure (BP): 155.8 +/- 3.90/102.5 +/- 1.86 mm Hg, heart rate: 73.6 +/- 2.98 min(-1). After a 14-day wash-out period a bicycle spiroergometry until exhaustion (WHO) was performed followed by a 45-min submaximal exercise test on the 2.5 mmol/l lactate-level 48 h later. Before, during and directly after exercise testing blood samples were taken. An identical protocol was repeated after a 6-week treatment period with 5 mg nebivolol/day.

RESULTS

Nebivolol treatment resulted in a significant (P < 0.01) decrease in systolic and diastolic BP and heart rate at rest and during maximal and submaximal exercise. Maximal physical work performance, blood lactate and rel. oxygen uptake (rel. VO(2)) before and after nebivolol treatment at rest and during maximal and submaximal exercise remained unaltered. Free fatty acid, free glycerol, plasma catecholamines, beta-endorphines and atrial natriuretic peptide (ANP) increased before and after treatment during maximal and submaximal exercise but remained unaltered by nebivolol treatment. In contrast, plasma ANP levels at rest were significantly higher in the presence of nebivolol, endothelin-1 levels were unchanged.

CONCLUSIONS

Nebivolol was effective in the control of BP at rest and during exercise in patients with EH. Furthermore, nebivolol did not negatively affect lipid and carbohydrate metabolism and substrate flow. The explanation for the effects on ANP at rest remain elusive. This pharmacodynamic profile of nebivolol is potentially suitable in physically active patients with EH.

Hypertensive men who exercise regularly have lower rate of cardiovascular mortality

BACKGROUND

Regular exercise has been associated in prospective studies with reduced incidence of cardiovascular disease (CVD) and death.

OBJECTIVE

To assess in a cohort study whether there is a similar protective effect of regular exercise among hypertensive individuals.

DESIGN

Population-based prospective cohort study. Spare time physical activity was assessed by structured interview.

SETTING

Malmo, Sweden.

PARTICIPANTS

Healthy men (n = 642) born in 1914. A baseline examination took place in 1969-1970.

MAIN OUTCOME MEASURES

All-cause and cardiovascular mortality rates during 25 years of follow-up in relation to blood pressure and other risk factors for atherosclerosis.

RESULTS

One-hundred (16%) men reported vigorous spare time physical activity. In this group, 31 had hypertension (blood pressure >160/95 mm Hg or treatment for hypertension), 47 were smokers and 39 had hyperlipidaemia. Among the 173 men with hypertension, vigorous physical activity was associated with markedly reduced rates of all-cause (17.3 versus 40.0 deaths per 1000 person-years) and cardiovascular mortality (6.3 versus 21.0 deaths per 1000 person-years). The risk reductions associated with exercise remained statistically significant after adjustment for smoking, systolic blood pressure and antihypertensive therapy. The relative risk was 0.43 (confidence interval 0.22-0.82) for total mortality and 0.33 (confidence interval 0.11 -0.94) for CVD mortality.

CONCLUSION

People who regularly perform physical activity constitute a heterogeneous group with regard to their exposure to known cardiovascular risk factors. Our results support the view that regular physical activity is associated with a reduced incidence of cardiovascular disease and death and suggest that this protective effect may be enhanced among hypertensive individuals.

Effects of long-term training on the progression of chronic renal failure in rats

To evaluate the effects of long-term exercise on the progression of chronic renal failure (CRF), adult Munich-Wistar rats with 5/6 renal mass ablation were submitted to treadmill exercise for 30 min 5 times/wk for 60 d. Whole kidney function and glomerular hemodynamics, proteinuria, and glomerular sclerosis were evaluated in 4 groups: Control, Sham trained (Sham + Ex), rats submitted to 5/6 nephrectomy (CRF) and maintained sedentary, and rats with 5/6 nephrectomy and trained (CRF + Ex). The groups with chronic renal failure (sedentary and trained) presented a reduction in total glomerular filtration rate (GFR) and in renal plasma flow (RPF), accompanied by an increase in single nephron GFR (SNGFR) and glomerular plasma flow (QA). However, the CRF + EX group did not show the glomerular hypertension observed in the CRF group. Despite the normalization of glomerular hypertension, proteinuria and sclerosis index were not different from the CRF sedentary group. Physical training provoked a vasodilatation of efferent arterioles, which induced the normalization of glomerular hypertension. These results suggest that the reduction alone of glomerular hypertension induced by exercise does not prevent the progression of renal disease, indicating the participation of other associated factors in this experimental model.

Exercise prescription for hypertensive patients

Physical conditioning has been suggested as a useful adjunct or alternative to pharmacologic therapy in the treatment of borderline or mild hypertension. This recommendation stems from numerous studies that have demonstrated modest decreases in blood pressure in hypertensive individuals. Exercise guidelines should be based on preliminary exercise testing and modified to accommodate those patients who are taking a variety of antihypertensive medications. Although pure isometric exercise is generally contraindicated in hypertensive patients, potentially valuable training activities that involve a substantial static component, including arm crank ergometry and mild-to-moderate load weight training, probably requires individual assessment.

Effects of endurance training on baroreflex sensitivity and blood pressure in borderline hypertension

Physical training offers a potential nonpharmacological strategy for control of mild and borderline hypertension, but its effect on blood pressure is controversial. We investigated the effects of endurance training on waking and sleeping blood pressure and on baroreflex sensitivity in 16 borderline hypertensive patients. First, 8 patients were assessed before and after a 6-month endurance training programme. Then, when it was clear that blood pressures were lower after training, a further 8 patients were studied not only at the end of the training programme but also after 4 months' abstention from exercise (detraining). Measurements were taken of baroreflex sensitivity (response to iv phenylephrine), blood pressure, R-R interval, and blood pressure and R-R variability. Ambulatory blood pressures were measured in 13 patients (7 trained, 6 detrained) and sleep blood pressures in 6 patients (3 trained, 3 detrained). Increased fitness was associated with a decline in resting arterial blood pressure of 9.7 (SE 2.0) mm Hg systolic and 6.8 (1.2) mm Hg diastolic, and with a decline in ambulatory blood pressure of 4.8 (1.4) mm Hg and 7.5 (2.1) mm Hg, respectively; both p less than 0.05. Baroreflex sensitivity was 14.0 (1.8) ms/mm Hg in the unfit and 17.5 (2.0) ms/mm Hg in the fit; p less than 0.05. Sleep blood pressures were not lower in the fit despite longer sleep R-R intervals. These findings indicate that, in some subjects with borderline or mild hypertension, a physical training programme is sufficient to bring the blood pressure within normal limits.

Effect of endurance training on blood pressure at rest, during exercise and during 24 hours in sedentary men

The effect of 4 months of physical training on resting, exercise and 24-hour blood pressure (BP) was studied using a randomized crossover design in 26 healthy, sedentary men, with an average age of 39 +/- 10 (standard deviation) years. Peak oxygen uptake increased by 14% (p less than 0.001) and the physical working capacity at a heart rate of 130 beats/min by 25% (p less than 0.001). The heart rate was reduced by 7 beats/min at night (p less than 0.01) and by 6 beats/min during the day (p less than 0.001). Training-induced changes of BP varied according to measuring conditions. A decrease in BP at rest while sitting in the morning in the laboratory was significant for diastolic (-5 mm Hg, p less than 0.01) but not for systolic BP. During exercise, systolic BP was significantly lower after training, when measured at the same submaximal workloads. However, when workload was expressed as a percentage of peak oxygen uptake, systolic BP was not different before and after training. When measured during 24 hours, the training-induced change in BP was not significant at night either for systolic or diastolic BP. During the day the decrease in diastolic BP was significant (-5 mm Hg, p less than 0.001), but the change in systolic BP was not.