Intervention reduces systolic BP, daily sitting time in older adults

Key takeaways:

• Systolic BP was 3.48 mm Hg lower in the intervention group vs. the control group.
• Decreased sitting could be a “gateway” to more physical activity, researchers noted.

An intervention reduced daily sitting time and systolic BP among older adults, according to results of a randomized controlled trial published in JAMA Network Open.

Dori E. Rosenberg, PhD, MPH, a senior scientific investigator at Kaiser Permanente, and colleagues noted that moderate to vigorous activity can help improve physical, emotional and cognitive health in older adults, but “their levels of meeting physical activity guidelines are low, with older adults typically sitting for 65% to 80% of waking hours.”

The researchers tested the effectiveness of a 6-month sitting reduction intervention called I-STAND, which is based on “social cognitive theory, habit formation and motivational interviewing,” they said. The researchers gave participants in the intervention 10 brief health coaching contacts — initially two were done in person and eight by telephone, but they were eventually all conducted over the telephone during the pandemic — along with a wrist-worn fitness tracker, a standing desk and workbook.

“Participants set individualized goals on reducing sitting time by standing more and taking frequent sitting breaks,” they explained. “Participants developed personalized reminder systems consisting of inner reminders (eg, noticing muscle stiffness), external reminders (eg, fitness band prompts), and habit reminders (eg, adding standing to habitual activities, such as reading the newspaper) to break automatic and habitual sitting patterns.”

Participants, aged 60 to 89 years, were randomly assigned to either the intervention (n = 140) or a control group (n = 143), with the latter only receiving 10 health coaching contacts.

The primary outcome of the trial — conducted between Jan. 1, 2019, through Nov. 31, 2022 — was change in mean daily sitting time, whereas co-primary outcomes were changes in systolic BP (SBP) and diastolic BP.

At baseline, 51.9% of the cohort had hypertension and 69.3% took at least one antihypertensive medication.

Overall, the mean change in sitting time decreased more in the intervention group vs. the control group by:

• 31.44 minutes a day at 3 months (95% 48.69 to 14.19); and by
• 31.85 minutes a day at 6 months (95% CI, 52.91 to 10.79).

The change in sitting time was larger among those who were randomly assigned during the COVID-19 pandemic, at 40.25 minutes a day (95% CI, 65.39 to 15.11).

The researchers also found that SBP was 3.48 mm Hg (95% CI, 6.68 to 0.28) lower in the intervention group compared with the control group.

SBP decreases were similar for those who were randomly assigned before (3.75 mm Hg; 95% CI, 7.27 to 0.23) and during (3.41 mm Hg; 95% CI, 9.47 to 2.66) the pandemic.

“Potential physiologic reasons for SBP reductions could include more frequent interruptions to the bent artery position, which could improve blood flow and vascular shear stress,” Rosenberg and colleagues suggested.

There were 87 and 57 adverse events reported in the intervention and control groups, respectively, although none were study related. The intervention group had more skin disorders and musculoskeletal events vs. the control group.

The researchers noted that the research had several limitations. For example, they had to rely on patient-measured outcomes during the pandemic

Still, “the promising finding of no significant effect modifiers indicated that people with lower physical function or physical activity or with chronic conditions, such as type 2 diabetes, can reduce their sitting time and reap BP benefits,” they concluded. “Decreased sitting could serve as a gateway to more physical activity as people gain strength and confidence.”