Vascular Dysfunction During Physical Inactivity

Study Summary

Prolonged periods of reduced activity are associated with decreased vascular function and muscle atrophy. Physical inactivity due to a sedentary lifestyle or acute hospitalization is also associated with impaired recovery, hospital readmission, and increased mortality. Older adults are a particularly vulnerable population as functional (vascular and skeletal muscle mitochondrial dysfunction) and structural deficits (loss in muscle mass leading to a reduction in strength) are a consequence of the aging process. The combination of inactivity and aging poses an added health threat to these individuals by accelerating the negative impact on vascular and skeletal muscle function and dysfunction. The underlying factors leading to vascular and skeletal muscle dysfunction are unknown, but have been linked to increases in oxidative stress. Additionally, there is a lack of understanding of how vascular function is impacted by inactivity in humans and how these changes are related to skeletal muscle function. It is the goal of this study to investigate the mechanisms that contribute to disuse muscle atrophy and vascular dysfunction in order to diminish their negative impact, and preserve vascular and skeletal muscle function.

Primary Outcome

The flow rate of brachial artery measured by flow-mediated dilation (FDM). Doppler ultrasound will be used to determine brachial artery vascular function. Specifically, this assessment will include the measurement of flow rate and artery diameter at rest and in response to flow mediated dilation.

Conditions Studied

Interventions

• BEHAVIORAL Step Count Reduction

Study Locations (1)