Walking and Blood Pressure in Older Adults With Respiratory Impairment.

The purpose of this study is to evaluate the effect of an 8-week walking program on blood pressure in inactive older adults with respiratory impairment, a condition where lung function is sub-optimal for a person's age. Older adults with respiratory impairment have greater risks of death by cardiovascular disease (CVD) compared to those without respiratory impairment, and this may be partly driven by higher resting blood pressure. One way to lower blood pressure is to increase the number of daily steps achieved throughout the course of everyday life ('lifestyle steps'), and previous research shows that an additional 3,000 lifestyle steps/day is effective for achieving this. However, whether an increase in daily lifestyle steps is effective for reducing blood pressure in senior-community dwelling older adults with respiratory impairment is unknown. Understanding how increasing daily steps impacts blood pressure in this understudied population is important for informing future strategies for tackling cardiovascular disease risk in those with lung dysfunction.

Older adults are particularly susceptible to respiratory impairment (a condition of lung dysfunction) due in part to longer lifetime exposures to air pollutants, tobacco smoke, and physical inactivity. Older adults with respiratory impairment have greater long-term risks of death by cardiovascular disease (CVD) when compared to individuals without respiratory impairment. Impaired lung function tends to run parallel with high blood pressure, and high blood pressure is a determinant of CVD mortality in this population. One approach to lowering blood pressure across the lifespan is by increasing physical activity (PA) behavior. Walking is the most commonly practiced modality of PA in older adulthood, and previous studies show that accumulating an additional 3,000 steps/day over 5-days a week through activities of daily living (i.e., 'lifestyle stepping') reduces blood pressure in inactive older adults free from respiratory impairment. This step-based PA prescription roughly equates to 150-minutes of moderate-intensity aerobic PA/week for most inactive older adults, and therefore satisfies the minimum aerobic PA recommendations for substantial health benefits. However, the impact of such an intervention on blood pressure in older adults with respiratory impairment is unclear. The 'Physical Activity Guidelines for Americans: Midcourse Report' (2023) indicates that senior centers are key settings for successful PA interventions. Senior-living communities are traditionally well-designed and well-resourced to support PA (e.g., safe outdoor walking spaces; access to indoor exercise facilities; social support, etc.), making them highly suitable locations for lifestyle walking. Additionally, the prescription of PA using lifestyle step counts rather than time-based prescriptions is intuitive and arguably easier to integrate into activities of daily living. However, no study has yet evaluated the effect of increasing daily lifestyle step counts on blood pressure in older adults with respiratory impairment. Addressing this gap in knowledge will provide support for the utility of lifestyle walking as a therapeutic approach to CVD risk management in older adults with lung dysfunction.

Eligibility Criteria:
Inclusion Criteria:

* Men and women aged 65 years and above.
* Elevated systolic blood pressure (120mmHg - 159 mmHg), and/or individuals taking medications for high blood pressure with a systolic pressure less than or equal to 159mmHg.
* Respiratory impairment as assessed by abnormal spirometry (a lung function test). Abnormal spirometric phenotypes include obstructive pattern, restrictive pattern, mixed obstructive/restrictive, and preserved ratio impaired spirometry (PRISm).
* Non-smoker (defined as being tobacco-free for at least the previous 12-months).
* Body mass index (BMI) \<42kg/m2.
* Physically inactive (determined by a 7-day day assessment of step counts using a pedometer, and defined as having an average daily step count \<7,000).
* Willingness to increase daily steps.

Exclusion Criteria:

* History of stroke, heart attack, or cancer diagnosis in the last 6-months.
* Admission to hospital for a respiratory-related illness (e.g., COPD exacerbation, pneumonia, lung injury, etc.) within the last 3 months.
* The use of supplemental oxygen.
* Neurological conditions such as Alzheimer's or Parkinson's disease.
* Significant mobility limitation (e.g., severe arthritis) that would hinder the ability to increase daily steps.
* The use of a cane or walker.
* Participants engaged in another walking study or structured walking program.