Effect of Reducing Sedentary Behavior on Blood Pressure

Not Applicable

Completed

Conditions: Prehypertension
Hypertension

Interventions: Behavioral: Intervention

Registration Number: NCT03307343

Lead Sponsor: University of Pittsburgh

Brief Summary: This is a 2-arm, 3-month randomized trial comparing a novel sedentary behavior intervention vs. control in working adults (n=271). The primary outcome is resting systolic blood pressure (SBP) at 3 months; secondary outcomes will be resting diastolic blood pressure (DBP), ambulatory blood pressure (ABP), and carotid-femoral pulse wave velocity (cfPWV). Also, best practice objective activity monitoring will be leveraged in the analysis of ABP to account for recent activity and posture and will inform adherence and dose-response relationships.We will also measure plasma renin activity and aldosterone as a potential mechanism of blood pressure reduction, and insulin and glucose as exploratory outcomes.

Detailed Description: Hypertension (HTN) is the most common major risk factor for cardiovascular disease (CVD), affecting 1 in 3 American adults. Also, nearly another 1 in 3 adults has prehypertension (preHTN). Moderate-to-vigorous intensity physical activity (MVPA) is known to decrease BP. Guidelines recommend 150 min/week of MVPA performed in continuous bouts of ≥10 min (i.e., bouted MVPA). Sedentary behavior (SED), defined as sitting or reclining with low energy expenditure, has gained attention as a highly prevalent and distinct behavior from MVPA that is independently associated with higher BP, arterial stiffness, CVD, and mortality. These data, coupled with the fact that Americans spend more than half of the waking day in SED, suggest SED as a novel intervention target. Yet, despite heightened public perception of SED as a health risk, there is a dearth of randomized clinical trials demonstrating that SED reduction will lead to health benefits, including reduced BP. Decreasing SED more substantially could improve BP, but this remains unclear in the absence of larger randomized trials with effective SED interventions.

Thus, to test initial efficacy, the Effect of Reducing Sedentary Behavior on Blood Pressure (RESET-BP) has the following specific aims:

Specific aim 1: To evaluate the efficacy of our intervention targeting decreased sedentary behavior (SED) over 3 months. Outcomes include SBP (primary), DBP, ABP (nocturnal, daytime seated, daytime non-seated), and cfPWV. We hypothesize that the 3-month SED intervention will decrease SBP, DBP, ABP and cfPWV vs. controls

Specific Aim 2: To explore whether renin-angiotensin-aldosterone (RAAS) activation (increased plasma renin activity (PRA) and aldosterone) mediates changes in BP elicited by SED reduction

Specific Aim 3: To examine associations between achieved reductions in SED, increases in replacement behaviors (i.e., standing, other light-intensity physical activity (LPA), and BP reduction

These aims will be evaluated with a 2-arm, 3-month randomized trial comparing a novel SED intervention vs. control in 271 adults. The study will recruit adults with untreated, elevated blood pressure (SBP 120-159 mmHg or DBP 80-99 mmHg) and desk jobs that require prolonged SED to maximize the opportunity for SED reduction. The intervention will target currently recommended levels of SED reduction for desk-based employees (2-4 hours/day with frequent postural changes) and will use a behavioral intervention including individual in-person (1/month) and phone counselling (1/month) focused on goal setting, overcoming barriers, self-monitoring, social support, and stimulus control. In addition, the intervention will include environmental modification via provision of a sit-stand desk attachment and external prompting via text messaging and a wrist-worn inactivity prompter.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 271

Inclusion Criteria

Age 21-65 years
SBP 120-159 mmHg or DBP of 80-99
Inactive (Engages in less than 150 min/wk of moderate + 2 x vigorous intensity physical activity)
Currently perform deskwork for ≥ 20 hr/week at a desk compatible with the sit-stand attachment
Employment within an approximate 25-mile radius of the University of Pittsburgh
Stable employment (≥ 3 months in current job, plan to be in current job for the next 3 months)
Supervisor approval to join the intervention
Possession of a cellular phone able to receive text messages

Exclusion Criteria

SBP ≥ 160 mmHg, DBP ≥ 100 mmHg
Use of antihypertensive or glucose controlling medication
Comorbid condition that would limit ability to reduce sedentary behavior (e.g. musculoskeletal condition, current chemotherapy)
History of ischemic heart disease, chronic heart failure, stroke, or chronic kidney disease
Unable to obtain consent from primary care provider or physician to participate
Current use of sit-stand/standing desk, sedentary behavior prompting device, enrollment in a weight loss or exercise study or program, recent (< 1 year) or planned bariatric surgery
Currently pregnant or pregnant in that last 6 months; breastfeeding currently or in the last 3 months
Plans to be away from your desk for an extended period (>1 week) during the study period

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Intervention	Intervention	The intervention will use behavioral strategies (self-monitoring, goal setting, problem solving, social support, stimulus control), environment modification (sit-stand attachment), and proximal (activity prompter) and distal (text messages) external prompts to target a 2-4 hour/day reduction in sedentary behavior.

Primary Outcome Measures

Name	Time	Method
Resting Systolic Blood Pressure	Baseline and Follow-Up (3 months)	Resting systolic blood pressure will be measured at baseline and follow-up using an oscillometric device after a 10-minute rest on two occasions

Secondary Outcome Measures

Name	Time	Method
Resting Diastolic Blood Pressure	Baseline and Follow-Up (3 months)	Resting diastolic blood pressure will be measured at baseline and follow-up using an oscillometric device after a 10-min rest on two occasions
24-Hour Systolic/Diastolic Ambulatory Blood Pressure	Baseline and Follow-Up (3 months)	Ambulatory blood pressure will be measured at baseline and 3-month follow-up during a workday and overnight (24 hours total) at the beginning and end of the study
Pulse Wave Velocity	Baseline and Follow-Up (3 months)	Carotid-femoral and carotid-radial pulse wave velocity will be measured at baseline and follow-up following a 10-min supine rest via tonometry.
Plasma Renin Activity	Baseline and Follow-Up (3 months)	Plasma Renin Activity (PRA) will be measured at baseline and 3 month follow-up.
Aldosterone	Baseline and Follow-Up (3 months)	Aldosterone will be measured at baseline and 3 month follow-up.