• Change from baseline actigraphic wake after sleep onset (WASO) at 3 months [ Time Frame: 3 months ]
  Primary outcome for Aim 1: actigraphy-assessed wake after sleep onset, averaged over 7 nights
• Change from baseline activPAL-assessed sedentary behavior (SED) at 3 months [ Time Frame: 3 months ]
  Primary outcome for Aim 2: SED, assessed via activPAL inclinometer, averaged over 7 days
• Change from baseline resting systolic blood pressure (SBP) at 3 months [ Time Frame: 3 months ]
  Primary outcome for Aim 2: resting SBP, measured via oscillometric device following a 10-minute rest averaged over two separate occasions

• Change from baseline total sleep time (TST) at 3 months [ Time Frame: 3 months ]
  Secondary outcome for Aim 1: actigraphy-assessed TST, averaged over 7 nights
• Change from baseline apnea-hypopnea index (AHI) at 3 months [ Time Frame: 3 months ]
  Secondary outcome for Aim 1: polysomnography-assessed AHI, assessed over 1 night of home-based recording
• Change from baseline slow-wave sleep (SWS) at 3 months [ Time Frame: 3 months ]
  Secondary outcome for Aim 1: polysomnography-assessed slow-wave sleep, assessed over 1 night of home-based recording
• Change from baseline 24-hour blood pressure at 3 months [ Time Frame: 3 months ]
  Secondary outcome for Aim 2: blood pressure, assessed by an ambulatory monitor during a workday and overnight for 24 hours total
• Change from baseline pulse wave velocity (PWV) at 3 months [ Time Frame: 3 months ]
  Secondary outcome for Aim 2: carotid-femoral and carotid-radial PWV, assessed via tonometry following a 10-minute rest

• Change from baseline self-reported sleep patterns at 3 months [ Time Frame: 3 months ]
  Self-reported sleep patterns will be assessed via a daily diary; mean and measures of variability will be obtained from 7 nights of data
• Change from baseline Epworth Sleepiness Scale (ESS) scores at 3 months [ Time Frame: 3 months ]
  The ESS, a measure of daytime sleepiness, will be administered at baseline and 3 months; total score will be used
• Change from baseline Insomnia Severity Index (ISI) scores at 3 months [ Time Frame: 3 months ]
  The ISI, a measure of insomnia symptom severity, will be administered at baseline and 3 months; total score will be used
• Change from baseline Functional Outcomes of Sleep Questionnaire (FOSQ) scores at 3 months [ Time Frame: 3 months ]
  The 10-item version of the FOSQ, a measure of daytime dysfunction due to poor sleep, will be administered at baseline and 3 months; total score will be used
• Change from baseline PROMIS Sleep-related Impairment scale scores at 3 months [ Time Frame: 3 months ]
  The PROMIS (Patient-Reported Outcomes Measurement Information System) Sleep-related Impairment Scale, a measure of daytime impairment, will be administered at baseline and 3 months; total score will be used
• Change from baseline Pittsburgh Sleep Quality Index (PSQI) scores at 3 months [ Time Frame: 3 months ]
  PSQI will be administered at baseline and 3 months; global score and 3 factors (sleep efficiency, perceived sleep quality, daily disturbances) will be used
• Change from baseline actigraphic sleep patterns at 3 months [ Time Frame: 3 months ]
  Actigraphic sleep patterns will be assessed with the Actiwatch Spectrum Plus; mean and measures of variability will be obtained from 7 nights of data
• Change from baseline polysomnography (PSG)-assessed sleep patterns at 3 months [ Time Frame: 3 months ]
  Polysomnography will be performed in the participant's home at baseline and 3 months
• Change from baseline weight at 3 months [ Time Frame: 3 months ]
  Weight will be measured by digital scale at baseline and 3 months
• Change from baseline glucose at 3 months [ Time Frame: 3 months ]
  Glucose will be measured from a fasting blood draw at baseline and 3 months
• Change from baseline insulin at 3 months [ Time Frame: 3 months ]
  Insulin will be measured from a fasting blood draw at baseline and 3 months
• Change from baseline accelerometer-assessed physical activity at 3 months [ Time Frame: 3 months ]
  Physical activity will be assessed via waist-worn ActiGraph GT3X accelerometer at baseline and 3 months

Disturbed sleep, most notably insomnia and obstructive sleep apnea (OSA), is highly prevalent and associated with increased risk for elevated blood pressure (BP) and cardiovascular disease. Unfortunately, despite the substantial public health burden of disturbed sleep, standard treatments are often limited by poor adherence, inadequate availability, and/or significant side effects. As such, identification of alternative approaches to mitigate disturbed sleep is greatly needed. In contrast to increasing engagement in exercise, we propose that reducing sedentary behavior (SED), or time spent sitting, is a novel and feasible approach to reduce sleep disturbance. We also propose that the presence of disturbed sleep during the intervention could blunt the adherence to attempted SED reduction and impact its cardiovascular health benefits. Therefore, the goal of this ancillary study is to test the hypotheses that SED reduction will improve sleep and that the presence of baseline sleep disturbance will reduce the effectiveness of SED reduction efforts. We will test this hypothesis by adding comprehensive sleep assessments to an ongoing randomized clinical trial (NCT03307343) that is examining the effect of SED reduction on BP. In this parent trial, 300 desk workers with elevated BP are randomized to a 3-month multicomponent behavioral intervention aimed at replacing 2-4 hr/day of SED with light-intensity activity or a 3-month no-contact control condition.

Anticipating the ability to enroll 150 participants from the remaining sample of the parent trial (estimated N~210), we will assess sleep at baseline and post-intervention using 7 nights of wrist-worn actigraphy and 1 night of home-based polysomnography (PSG), yielding objective measures of sleep quality (WASO), total sleep time (TST), OSA severity (apnea-hypopnea index [AHI]), and sleep depth (slow-wave sleep [SWS]. These data will allow us to efficiently address the following specific aims:

Aim 1: To evaluate the effect of a 3-month SED reduction intervention on objective measures of sleep quality, depth, duration, and OSA severity.

Hypothesis: Participants randomized to the SED reduction intervention will have greater reduction than control participants in actigraphy-assessed WASO (primary outcome [hypothesis 1.1]), PSG-assessed AHI and SWS, and greater increase in actigraphy-assessed TST (secondary outcomes [hypothesis 1.2]).

Aim 2: To examine the effect of baseline disturbed sleep on SED reduction and BP improvement.

Hypothesis: Intervention-induced reductions in SED (hypothesis 2.1) and BP (hypothesis 2.2) will be smaller among individuals with disturbed sleep (e.g., elevated WASO or AHI) at baseline.

• Sleep
• Obstructive Sleep Apnea
• Insomnia

• Experimental: Behavioral 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.
  Intervention: Behavioral: Behavioral Intervention
• No Intervention: Control Condition
  Participants randomized to the control condition will receive no intervention during the study. After the 3-month assessment, control participants will be provided with a wrist-worn activity monitor and will be offered the 3-month delayed intervention if desired to aid in retention and recruitment.

Inclusion Criteria:

1. Age 21-65 years
2. SBP of 120-159 mmHg or DBP of 80-99 mmHg
3. Physically inactive or insufficiently active (i.e., not meeting current aerobic MVPA recommendations [≥150 min/wk])
4. Currently perform deskwork for ≥ 20 hr/wk at a desk compatible with a sit-stand desk attachment
5. Employment within 25-mi radius of University of Pittsburgh
6. Stable employment (≥ 3 mo at current job, plan to be in current job for at least the next 3 mo)
7. Supervisor approval to join intervention
8. Possession of cellular phone able to receive text messages

Exclusion Criteria:

1. SBP ≥ 160 mmHg or DBP ≥ 100 mmHg
2. Use of anti-hypertensive or glucose-controlling medication
3. Comorbid condition that would limit ability to reduce sedentary behavior (e.g., musculoskeletal condition)
4. History of ischemic heart disease, chronic heart failure, stroke, or chronic kidney disease
5. Inability to obtain consent from primary care provider/physician to participate
6. Current use of a sit-stand desk or sedentary behavior prompting device
7. Current enrollment in a weight loss or exercise program, recent (< 1 yr) or planned bariatric surgery
8. Plans to be away from work for an extended period (>1 wk) during the study period
9. Current or recent (within last 6 mo) pregnancy; current or recent (within last 3 mo) breastfeeding
10. Undiagnosed severe OSA (AHI ≥ 30) or insomnia (ISI ≥ 22)