Effect of Reducing Sedentary Behavior on Blood Pressure
Condition: Hypertension; Prehypertension
MeSH terms: Prehypertension
Study type: Interventional

Summary: 
      This is a 2-arm, 3-month randomized trial comparing a novel sedentary behavior intervention
      vs. control in working adults (n=300). 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 300 adults (150 per group). 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.
    

Intervention name(s): Intervention
Intervention type(s): Behavioral
Intervention description(s): The intervention will be delivered by trained research staff who are exercise physiologists or behavioral lifestyle counselors. This target reflects a recent expert statement concluding that desk-based workers should reduce workday sedentary behavior by 2-4 hr (by increasing standing and movement). The approach will combine: 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. The initial in-person session will occur at the participant's office location. During months 2 and 3, one-on-one in-person meetings will occur at the research lab. Telephone intervention contacts will occur in the 3rd week of months 1-3.
Other intervention name(s): Sedentary Behavior Reduction
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: sedentary behavior; light intensity physical activity; behavioral intervention; office workers; blood pressure; pulse wave velocity; randomized clinical trial