# The effects of upper and lower limb exercise on the microvascular reactivity in limited cutaneous systemic sclerosis patients

PMID: 29871697
Journal: Arthritis research & therapy
Published: 2018 Jun 5
Authors: Mitropoulos A, Gumber A, Crank H, Akil M, Klonizakis M

## Question

Can upper-limb or lower-limb aerobic HIIT improve microvascular reactivity and fitness in limited cutaneous systemic sclerosis patients?

## Summary

This randomized trial tested whether 12 weeks of twice-weekly supervised HIIT using either arm cranking or cycling could improve vascular function, fitness, and quality of life in people with limited cutaneous systemic sclerosis. Both exercise modes were feasible, highly compliant, and produced high heart-rate responses with no exercise-related complications. Arm-crank HIIT showed the clearest signal for improved digital microvascular endothelial-dependent function, while both exercise groups improved VO2peak and life satisfaction and reported less Raynaud's pain.

## Population

- Limited cutaneous systemic sclerosis patients with disease duration 1-10 years, mostly women, able to exercise.
- Sample size: 34
- Age: Group means 62.2 to 69.1 years
- Sex: 31 women, 3 men
- Fitness level: Low clinical-population VO2peak
- Health status: Limited cutaneous systemic sclerosis with Raynaud's phenomenon; higher-risk cardiopulmonary disease excluded.

## Methodology

- Randomized three-group exercise trial comparing arm-crank HIIT, cycle-ergometer HIIT, and no-exercise control.
- 12 weeks
- Supervised sessions at the Centre of Sport and Exercise Science at Sheffield Hallam University.
- Randomized and controlled study design.

## Protocol

- Arm-crank or cycling 30:30 HIIT.
- Modality: Arm crank ergometer or cycle ergometer.
- Work intervals: 30 s.
- Recovery: 30 s passive recovery.
- Sets or repetitions: 30 min of repeated intervals.
- Intensity: 100% peak power output.
- Session duration: 40 min including warm-up/cool-down.
- Frequency: 2 sessions/week.
- Program length: 12 weeks.
- No-exercise control.
- Modality: No physical activity intervention.
- Program length: 12 weeks.

## Outcomes

### VO2peak
Status: improved
Both ACE and CE improved VO2peak after training; ACE improved significantly compared with control.

Both exercise groups p<0.01 versus baseline; ACE post 21.9 +/- 7.1 ml/kg/min.

### Microvascular endothelial function
Status: improved
Arm-crank exercise showed improved acetylcholine CVCmax while control declined.

ACE ACh CVCmax 1.28 to 1.56; control 1.40 to 0.82; table marks ACE post change p<0.05.

### Feasibility and tolerance
Status: improved
Both exercise groups had high compliance, high heart-rate responses, positive affect, and no exercise-related complications.

Compliance 92% ACE and 88% CE; HR 92.1% and 90.8% peak HR.

## Practical Insights

- Upper-body HIIT may be useful when the target adaptation involves upper-limb or digital circulation.
- A 30:30 work-rest structure can drive high heart-rate responses even with RPE around 13 in a supervised clinical population.
- Clinical translation requires strict screening for systemic sclerosis complications.

## Limitations

- Small clinical sample.
- No long-term follow-up.
- Specialized equipment and supervision.
- Some vascular findings were exploratory or trends.

## Safety And Adherence

- No exercise-related complications were reported.
- Control group had digital-ulcer/iloprost complications, including one amputation, but these were not exercise events.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/29871697/) (pubmed)
- [DOI](https://doi.org/10.1186/s13075-018-1605-0) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5989435/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.