Effect of acute aerobic exercise on vaccine efficacy in older adults

The most effective way of avoiding influenza is through influenza vaccination. However, the vaccine is ineffective in about 25% of the older population. Immunosenescence with advancing age results in inadequate protection from disease because of ineffective responses to vaccination. Recently, a number of strategies have been tested to improve the efficacy of a vaccine in older adults. An acute bout of moderate aerobic exercise may increase the efficacy of the vaccine in young individuals, but there are limited efficacy data in older adults who would benefit most.

PURPOSE

This study sought to evaluate whether acute moderate-intensity endurance exercise immediately before influenza vaccination would increase the efficacy of the vaccine.

METHODS

Fifty-nine healthy volunteers between 55 and 75 yr of age were randomly allocated to an exercise or control group. Antibody titers were measured at baseline before exercise and 4 wk after vaccination. C-reactive protein (CRP) and interleukin-6 (IL-6) were measured at 24 and 48 h after vaccination.

RESULTS

Delta CRP and IL-6 at 24 and 48 h were significantly higher after vaccination as compared to the sham injection. There were no differences in the levels of antibody titers against the H3N2 influenza strain between groups. However, women in the exercise group had a significantly higher antibody response against the H1N1 influenza strain as compared to the men, probably because of lower prevaccine titers. There were no significant differences in seroprotection between groups.

CONCLUSIONS

Acute moderate aerobic exercise was not immunostimulatory in healthy older men but may serve as a vaccine adjuvant in older women.

Blood pressure changes following aerobic exercise in Caucasian and Chinese descendants

Acute aerobic exercise produces post-exercise hypotension (PEH). Chinese populations have lower prevalence of cardiovascular disease compared to Caucasians. PEH may be associated cardiovascular disease through its influence on hypertension. The purpose of this study was to compare PEH between Caucasian and Chinese subjects following acute aerobic exercise. 62 (30 Caucasian and 32 Chinese, 50% male) subjects underwent measurement of peripheral and central hemodynamics as well as arterial and cardiac evaluations, 30 min and 60 min after 45 min of treadmill exercise. Caucasians exhibited significantly higher baseline BP than the Chinese. While the reduction in brachial artery systolic BP was greater in Caucasian than in the Chinese, there was no difference in changes in carotid systolic BP between the groups. The increase in cardiac output and heart rate was greater in the Chinese than Caucasians, but total peripheral resistance and leg pulse wave velocity decreased by a similar magnitude in the Chinese and Caucasian subjects. We conclude that acute aerobic exercise produces a greater magnitude of PEH in peripheral systolic BP in Caucasian compared to Chinese subjects. The different magnitude in PEH was caused by the greater increase in cardiac output mediated by heart rate, with no change in stroke volume. It is possible that initial BP differences between races influenced the findings.

Sex differences in ventricular-vascular coupling following endurance training

Introduction

Ventricular and vascular coupling is defined as the ratio of arterial elastance (Ea) to ventricular elastance (Elv) and describes the interaction between the heart and arterial system. There are sex differences in both arterial and ventricular function in response to both acute exercise and aerobic exercise training.

Purpose

To examine the effects of aerobic exercise training on elastances and the coupling ratio in young adult men and women. We hypothesized a reduction in the coupling ratio in both sexes due to a decrease in Ea that would be more pronounced in men and an increase in Elv that would be larger in women.

Methods

Fifty-three healthy, young adults completed the study. Central pulse wave velocity and heart volumes were measured before and after an 8-week aerobic training intervention. Elastances were calculated as Ea = end-systolic pressure/stroke volume and Elv = end-systolic pressure/end-systolic volume and indexed to body surface area.

Results

After the intervention, women augmented indexed and un-indexed Elv from 2.09 ± 0.61 to 2.52 ± 0.80 mmHg/ml, p < 0.05, and reduced the coupling ratio from 0.72 ± 18 to 0.62 ± 15, p < 0.05, while men maintained their pre-training ratio (from 0.66 ± 0.20 to 0.74 ± 0.21, p > 0.05). Women also reduced end-systolic pressure (from 91 ± 10 to 87 ± 10 mmHg), and both groups reduced central pulse wave velocity (from 6.0 ± 1.0 to 5.6 ± 0.6 m/s, p < 0.05).

Conclusion

We conclude that after 8 weeks of aerobic training, only women reduced their coupling ratio due to an increase in Elv. This suggests that aerobic exercise training elicits sex-dependent changes in the coupling ratio in young, healthy individuals.

Effect of sex on wasted left ventricular effort following maximal exercise

Wasted left ventricular effort (∆Ew) refers to work required of the left ventricle to eject blood that does not result in increased stroke volume and is related to left ventricular hypertrophy. Literature shows that men and women have differing ventricular and vascular responses to and following exercise. Our purpose was to determine how ∆Ew changes post-exercise in men and women and examine potential mechanisms. We hypothesized a reduction in ∆Ew that would be greater in men and that central pulse wave velocity and wave intensity (WIA) would be related to ∆Ew. Blood pressures, central pulse wave velocity (cPWV), and WIA were obtained at rest, 15 and 30 min after maximal exercise. Both sexes reduced ∆Ew post-maximal exercise (p>0.05 for interaction), but women had higher ∆Ew at each time point (p<0.05). The first peak of WIA increased 15 min post-exercise only in women (p<0.05). cPWV was attenuated (p<0.05) in women at 15 min and men at 30 min (p<0.05) post-exercise with a significant time by sex interaction (p<0.05). WIA (1st peak) was correlated (p<0.05) to ∆Ew in both sexes before and 15 min post-exercise, but cPWV was only associated with ∆Ew in men at 30 min post-exercise. We conclude that both sexes decrease ∆Ew after maximal exercise, but vascular and ventricular changes associated with the attenuation of ∆Ew are not uniform between sexes.

Comparison of the acute impact of maximal arm and leg aerobic exercise on arterial stiffness

Acute aerobic exercise decreases arterial stiffness based on the intensity of the exercise and the arterial segment studied. Arm exercise may differentially affect arterial stiffness compared to leg exercise but this has not been studied. We hypothesized that maximal aerobic exercise would reduce local peripheral pulse wave velocity i.e. femoral-dorsalis pedis (LPWV) following leg exercise and carotid-radial (APWV) following arm exercise without any crossover effect. The main purpose of the study is to compare the effects of maximal arm versus leg aerobic exercise on peripheral and central arterial stiffness. Fifteen healthy participants (9 males and 6 females, 25 ± 5 years) performed maximal arm-ergometer and leg-ergometer exercise in a randomized, crossover design. Peripheral and central pulse wave velocities (PWV) were obtained using applanation tonometry before and 10 min after each maximal exercise bout. 2 × 2 repeated measures analysis of variance was used to detect differences between conditions. There was a significant interaction in the APWV between the two exercise modes. However, there was no condition or interaction effect on LPWV following maximal arm versus leg exercise. There was no significant difference in central PWV between conditions or with time. There was no change in MAP (75 ± 6-77 ± 3) after maximal arm exercise as compared to the maximal leg exercise (73 ± 6-80 ± 2). Arm exercise produced a more generalized effect on arterial stiffness than leg exercise. The prescription of upper limb exercise may be considered for purposes of eliciting post-exercise systemic changes in arterial stiffness.