Original Investigation 

Nutrition, Obesity, and Exercise

March 27, 2024

Sitting Time Reduction and Blood Pressure in Older Adults: A Randomized Clinical Trial

Dori E. Rosenberg, Weiwei Zhu, Mikael Anne Greenwood-Hickman, et al

JAMA Netw Open. 2024;7(3):e243234. doi:10.1001/jamanetworkopen.2024.3234

Key Points

Question  Is sitting time reduction an effective strategy for improving blood pressure?

Findings  In this randomized clinical trial of 283 older adults, there were greater reductions in sitting time and systolic blood pressure during 6 months in the intervention arm compared with the control condition.

Meaning  Reducing sitting time could be a practical strategy for promoting cardiometabolic health in older populations.

Abstract

Importance  Practical health promotion strategies for improving cardiometabolic health in older adults are needed.

Objective  To examine the efficacy of a sedentary behavior reduction intervention for reducing sitting time and improving blood pressure in older adults.

Design, Setting, and Participants  This parallel-group randomized clinical trial was conducted in adults aged 60 to 89 years with high sitting time and body mass index of 30 to 50 from January 1, 2019, to November 31, 2022, at a health care system in Washington State.

Intervention  Participants were randomized 1:1 to the sitting reduction intervention or a healthy living attention control condition for 6 months. Intervention participants received 10 health coaching contacts, sitting reduction goals, and a standing desk and fitness tracker to prompt sitting breaks. The attention control group received 10 health coaching contacts to set general healthy living goals, excluding physical activity or sedentary behavior.

Main Outcomes and Measures  The primary outcome, measured at baseline, 3 months, and 6 months, was sitting time assessed using accelerometers worn for 7 days at each time point. Coprimary outcomes were systolic and diastolic blood pressure measured at baseline and 6 months.

Results  A total of 283 participants (140 intervention and 143 control) were randomized (baseline mean [SD] age, 68.8 [6.2] years; 186 [65.7%] female; mean [SD] body mass index, 34.9 [4.7]). At baseline, 147 (51.9%) had a hypertension diagnosis and 97 (69.3%) took at least 1 antihypertensive medication. Sitting time was reduced, favoring the intervention arm, with a difference in the mean change of −31.44 min/d at 3 months (95% CI, −48.69 to −14.19 min/d; P < .001) and −31.85 min/d at 6 months (95% CI, −52.91 to −10.79 min/d; P = .003). Systolic blood pressure change was lower by 3.48 mm Hg, favoring the intervention arm at 6 months (95% CI, −6.68 to −0.28 mm Hg; P = .03). There were 6 serious adverse events in each arm and none were study related.

Conclusions and Relevance  In this study of a 6-month sitting reduction intervention, older adults in the intervention reduced sedentary time by more than 30 min/d and reduced systolic blood pressure. Sitting reduction could be a promising approach to improve health in older adults.

Trial Registration  ClinicalTrials.gov Identifier: NCT03739762