What question did this study set out to answer?

To investigate whether the blood pressure-lowering effect of endurance exercise training is mediated by organ-specific reductions in resting cardiac or renal sympathetic nervous activity.

November 1, 1991Hypertension

Exercise training lowers resting renal but not cardiac sympathetic activity in humans.

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Why the study?

Does regular bicycle exercise reduce resting sympathetic activity in habitually sedentary healthy normotensive men?

Population

8 habitually sedentary healthy normotensive men, mean age 36 +/- 3 years.

Comparison

1 month of regular bicycle exercise 3 times/wk. vs 1 month of sedentary activity (crossover design).

Design

RCT, randomized order

Follow-up

1 month

Authors

IMIan T. MeredithInterventional Cardiology PFPeter FribergPreventive Cardiology GJGarry JenningsPreventive Cardiology

Discussion

Member takes

Implication

Reinforces endurance exercise for BP control via renal sympathetic inhibition; extends total spillover data with organ-specific RCT measurements.

Key Points

To investigate whether the blood pressure-lowering effect of endurance exercise training is mediated by organ-specific reductions in resting cardiac or renal sympathetic nervous activity.
Randomized crossover trial in 8 habitually sedentary healthy normotensive men (mean age 36 ± 3 years) comparing 1 month of regular bicycle exercise (40 minutes, 3 times/week at 60–70% maximum work capacity) with 1 month of sedentary activity.
Resting total, cardiac, and renal norepinephrine spillover to plasma were measured using radiotracer dilution techniques alongside assessments of blood pressure and vascular conductance.
One month of exercise training reduced resting blood pressure by 8/5 mm Hg (p < 0.01), increased maximum oxygen consumption by 15% (p < 0.05), and increased total peripheral conductance by 12.1%.
Total norepinephrine spillover fell by 24% from 438.8 ng/min (p < 0.05), primarily driven by a 41% reduction in renal norepinephrine spillover from 169.4 ng/min (p < 0.05), with no change observed in cardiac norepinephrine spillover.
Renal vascular conductance increased by 10% (p < 0.05), accounting for 18% of the total peripheral conductance increase and 66% of the total reduction in norepinephrine spillover.

Structured PICO

Does regular bicycle exercise reduce resting sympathetic activity in habitually sedentary healthy normotensive men?

Population

8 habitually sedentary healthy normotensive men, mean age 36 +/- 3 years.

Intervention

1 month of regular bicycle exercise 3 times/wk (40 minutes at 60-70% maximum work capacity).

Comparator

1 month of sedentary activity (crossover design).

Outcome

Resting total, cardiac, and renal norepinephrine spillover to plasma.surrogate

Regular endurance exercise reduces resting sympathetic activity primarily in the kidney, though the resulting fall in renal vascular resistance does not fully account for the blood pressure-lowering effect.

Cite This Study

Meredith et al. (1991) studied this question.

synapsesocial.com/papers/6a7a8cb15968508e56f3ce02 https://doi.org/10.1161/01.hyp.18.5.575

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November 1, 1991Hypertension

Exercise training lowers resting renal but not cardiac sympathetic activity in humans.

View Full Paper

Ask AI

Bookmark

Why the study?

Does regular bicycle exercise reduce resting sympathetic activity in habitually sedentary healthy normotensive men?

Population

8 habitually sedentary healthy normotensive men, mean age 36 +/- 3 years.

Comparison

1 month of regular bicycle exercise 3 times/wk. vs 1 month of sedentary activity (crossover design).

Design

RCT, randomized order

Follow-up

1 month

Authors

IMIan T. MeredithInterventional Cardiology PFPeter FribergPreventive Cardiology GJGarry JenningsPreventive Cardiology

Discussion

Member takes

Implication

Reinforces endurance exercise for BP control via renal sympathetic inhibition; extends total spillover data with organ-specific RCT measurements.

Key Points

To investigate whether the blood pressure-lowering effect of endurance exercise training is mediated by organ-specific reductions in resting cardiac or renal sympathetic nervous activity.
Randomized crossover trial in 8 habitually sedentary healthy normotensive men (mean age 36 ± 3 years) comparing 1 month of regular bicycle exercise (40 minutes, 3 times/week at 60–70% maximum work capacity) with 1 month of sedentary activity.
Resting total, cardiac, and renal norepinephrine spillover to plasma were measured using radiotracer dilution techniques alongside assessments of blood pressure and vascular conductance.
One month of exercise training reduced resting blood pressure by 8/5 mm Hg (p < 0.01), increased maximum oxygen consumption by 15% (p < 0.05), and increased total peripheral conductance by 12.1%.
Total norepinephrine spillover fell by 24% from 438.8 ng/min (p < 0.05), primarily driven by a 41% reduction in renal norepinephrine spillover from 169.4 ng/min (p < 0.05), with no change observed in cardiac norepinephrine spillover.
Renal vascular conductance increased by 10% (p < 0.05), accounting for 18% of the total peripheral conductance increase and 66% of the total reduction in norepinephrine spillover.

Structured PICO

Does regular bicycle exercise reduce resting sympathetic activity in habitually sedentary healthy normotensive men?

Population

8 habitually sedentary healthy normotensive men, mean age 36 +/- 3 years.

Intervention

1 month of regular bicycle exercise 3 times/wk (40 minutes at 60-70% maximum work capacity).

Comparator

1 month of sedentary activity (crossover design).

Outcome

Resting total, cardiac, and renal norepinephrine spillover to plasma.surrogate

Cite This Study

Meredith et al. (1991) studied this question.

synapsesocial.com/papers/6a7a8cb15968508e56f3ce02 https://doi.org/10.1161/01.hyp.18.5.575

Also Consider

Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context:

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