Clinical

Jacqueline Kerr, PhD
Clinical Project of the UCSD AHA Women’s Health Program will assess 3-month changes in sitting time, standing time, physical activity and blood pressure in a randomized control trial. This 2-arm randomized controlled trial (RCT) will occur in the community with post menopausal Latina women (N=250) who spend at least 8 hrs/day sitting and have increased risk for cardiovascular disease through high BMI and borderline hypertension. Women will be identified through the San Ysidro Clinic and assessed at the South Bay Latino Research Center.

To date, there have been no sitting reduction interventions in Latinas who have a high prevalence of poor lifestyle behaviors and cardiovascular disease risk. A recent review demonstrated that physical activity interventions do not impact sitting time to the same extent as targeted sitting reduction interventions. Several sitting reduction trials in children, workplaces, and older adults have now been conducted; demonstrating that we can reduce sitting, with tools such as standing desks and feedback from thigh worn inclinometers. Our own research has shown that a physical activity intervention can reduce sitting time by 20 minutes, but that a sitting reduction intervention can reduce it by 2 hours. Guidelines recently published suggest we should be targeting a 2 hour reduction in sitting time. This intervention will target a 2 hour (25%) reduction in sitting time through a standing intervention.

Only a few randomized control studies to date, with 3-6 month assessment periods, have included health outcomes. These preliminary trials indicate that cardiovascular biomarkers and blood pressure can be improved. Project 1 will assess novel biomarkers on this intervention cohort and subsequently study candidate molecular transducers of sedentary behavior in vitro. This intervention evidence compliments the growing laboratory and epidemiological evidence of a relationship between sitting time and cardiovascular risk factors, events and mortality including evidence from the HCHS/SOL cohort that objectively measured sitting time is related to cardiovascular disease risk factors.

The RCT will deliver healthy aging materials to 125 control participants. The 125 intervention participants will receive a novel but already piloted intervention to increase standing time, drawing on identified behavior change strategies, using a thigh worn inclinometer to support self-monitoring and provide feedback about when to break up sitting. In person and phone call counseling from a trained health educator will help participants plan more standing in their day, identify barriers, and provide tools and cues to prompt standing including standing desks. Participants will be assessed at baseline and 3 months.

Clinical Project will address the following aims:

  1. Investigate the 3 month effect of the intervention to impact the primary behavioral outcomes of sitting, standing and stepping time assessed objectively by a thigh worn inclinometer (ActivPAL) in Latinas at risk for heart disease.

    Hypotheses: Compared to control participants who receive standard AHA lifestyle materials, women randomized to the sitting reduction intervention arm will significantly reduce their sitting time (by about 25%), increase their standing time and increase their stepping time (by a small amount).
  2. Investigate the 3 month effect of the intervention to impact the secondary health outcomes of blood pressure, depressive symptoms, and anthropometrics.

    Hypotheses: Compared to control participants who receive standard AHA lifestyle materials, women randomized to the sitting reduction intervention arm will significantly reduce their systolic and diastolic blood pressure, reduce their depressive symptoms score, and improve their BMI and waist circumference.
  3. Explore the psychosocial & environmental mediators & moderators of changes in sitting time.

    Hypotheses: Participants with more supportive social & physical environments will have greater change in behaviors.