Reduce Sedentary Behavior at Work

Interventions to Reduce Sedentary Behavior at Work: Pilot Study

Prior research suggests that sedentary behavior is detrimental to health, independent of exercise activity. Sedentary behavior is defined as behaviors that involve low levels of energy expenditure ≤1.5 metabolic equivalents (including sitting, watching TV, reading, and driving). Due to the high burden of sedentary behaviors in modern-day societies, this has potential implications for novel intervention strategies to reduce sitting (outside of regular exercise activity) and improve health. In addition, the modern workplace fosters sedentary behavior, and sedentary jobs now make up more than 80% of the workforce. The goal of this project is to implement interventions to reduce sedentary behavior at work and evaluate their impact on physiologic parameters and markers of disease. Specifically, the investigators/study team will use direct measurement of vascular endothelial function as one of our outcomes. This is important since conduit artery endothelial function, assessed by arterial flow-mediated dilation (FMD), is a powerful indicator of vascular inflammation and predictor of future cardiovascular events.

Study Overview

• Status: Completed
• Conditions: Obesity; Sedentary Lifestyle; Cardiovascular Risk Factor

Detailed Description

The hypothesis is that obese subjects with sedentary jobs at the Medical College of Wisconsin, when assigned use of a standing desk to encourage movement, will reduce their daily sedentary time and demonstrate improvement in physiologic parameters and disease markers from baseline through the end of the intervention.

Prior intervention studies are limited and not randomized, but have shown a reduction in waist circumference and improvements in cholesterol when overall sitting time is reduced over a 3-6 month interval (with a standing or treadmill desk). None of these intervention studies have directly measured vascular endothelial function, as assessed by arterial flow-mediated dilation (FMD), an early indicator of cardiovascular disease, and a powerful predictor of future cardiovascular events and vascular inflammation. Improvements in arterial FMD (or endothelial function) are known to reduce the future risk of cardiovascular events.

Due to differences in the energy requirement of lying down, sitting, and standing, there has been increased research interest in activity type classification based on posture. In the science of sedentary behaviors, this is an important distinction to consider when evaluating health outcomes, such as in the present study. Accelerometers (physical activity monitors) utilize piezoelectric crystal sensor technology to provide a measure of accelerations of the body during movement and have the advantage of capturing frequency, duration, and intensity of physical movement minute by minute. Accelerometer technology will be used to analyze the primary outcome of interest (sedentary time). The study team will collect information on standing time, sedentary bouts, daily steps, cadence (walking speed in steps/minute), and exercise activity. The study team will employ a compact and re-usable physical activity monitor that adheres to the subject's thigh. This will provide objective assessments of activity levels at baseline and during the intervention. This data can be translated into energy expenditure or activity intensity categories (METs) and even position (sitting verses standing). The monitor output is Excel-compatible and is ideal for comparing each subject's activity and physiological parameters from baseline to intervention.

• Study Type: Observational
• Enrollment (Actual): 16

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Sedentary office workers at the Medical College of Wisconsin who spend greater than 75% of their (8 hours or longer) work-day sitting at a desk.

Description

Inclusion Criteria:

• Sedentary office workers the Medical College of Wisconsin who spend greater than 75% of their (8 hours or longer) work-day sitting at a desk. This includes at least 1 period of 2 hours or longer of uninterrupted sitting time per work day.
• Body mass index of 26.0-44.9
• Willing and able to sign Informed consent
• Permission from the subject's supervisor to participate in the intervention

Exclusion Criteria:

• Known history of atherosclerotic cardiovascular disease, including myocardial infarction, stroke, coronary stent, coronary artery bypass grafting, angina and peripheral vascular disease
• Diabetics on insulin or other diabetic medications (pre-diabetes would be acceptable, defined as a HbgA1c of 5.7 to 6.4%, and not on medications)
• Elevated blood pressure (SBP≥150 mm Hg or DBP ≥90 mm Hg) or on medication for hypertension; or SBP < 100 mm Hg.
• On cholesterol-lowering medication or LDL-C cholesterol ≥190 mg/dL
• Pregnancy, lactating or planning to get pregnant within the next 6 months
• Current tobacco use within previous 12 months. Tobacco use included cigarettes, cigars, and all forms of smokeless tobacco.
• Current excessive alcohol use (defined as more than 14 drinks/week for women, more than 28 drinks/week for men)
• Current illicit drug use, defined as overuse of prescription medications, or of any illegal mind altering substances.
• Known thyroid disease
• Taking diet pills, or supplements other than those contained in a multi-vitamin
• History of musculoskeletal surgery/injury that would interfere with prolonged periods of standing
• History of use of PDE-5 inhibitors for any reason within the last 5 days of screening visit, and the inability to hold use of PDE-5 inhibitors for 5 days prior to each of the FMD evaluations.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The feasibility of implementing workplace interventions to reduce sedentary time, specifically using a sit-stand desk. We will survey the subjects regarding the feasibility and likability of the sit-stand workstation	Ten Questions using a Likert Scale. Each question has the same 5 options: strongly agree, agree, neutral, disagree, strongly disagree.	through study completion, an average of 6 months
The feasibility of implementing workplace interventions to reduce sedentary time, specifically using a sit-stand desk. We will survey the subjects regarding the feasibility and likability of the sit-stand workstation	Objectively quantify sitting, standing and walking times (sedentary vs. non-sedentary) using an accelerometer device that adheres to the subjects thigh	Change from baseline sedentary behaviors after 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Impact of reducing sedentary time on physiological outcomes	Measure Flow Mediated Dilation (FMD)	Change from baseline after use of a standing desk, through study completion, an average of 6 months
The Impact of reducing sedentary time on physiological outcomes	Measure Near-infrared spectroscopy is a spectroscopic (NIRS)	Change from baseline after use of a standing desk, through study completion, an average of 6 months
The Impact of reducing sedentary time on physiological outcomes	anthropometrics: Change from baseline body mass index after use of a standing desk	Through study completion, an average of 6 months
The Impact of reducing sedentary time on physiological outcomes	measure cardiac hemodynamics: Change from baseline systolic and diastolic blood pressure after use of a standing desk,	Through study completion, an average of 6 months
The Impact of reducing sedentary time on physiological outcomes	measure cardiac hemodynamics: Change from heart rate after use of a standing desk,	Through study completion, an average of 6 months
The Impact of reducing sedentary time on physiological outcomes	Measure blood lab results: Change from baseline fasting lipids, insulin resistance, hemoglobin A1c and C-reactive protein (CRP)	At baseline after use of a standing desk, through study completion, an average of 6 months

Collaborators and Investigators

• Sponsor: Medical College of Wisconsin

Study record dates

Study Major Dates

• Study Start (Actual): June 13, 2016
• Primary Completion (Actual): September 18, 2020
• Study Completion (Actual): November 30, 2020

Study Registration Dates

• First Submitted: January 17, 2019
• First Submitted That Met QC Criteria: January 21, 2019
• First Posted (Actual): January 25, 2019

Study Record Updates

• Last Update Posted (Actual): September 30, 2021
• Last Update Submitted That Met QC Criteria: September 24, 2021
• Last Verified: September 1, 2021

More Information

Terms related to this study

• Other Study ID Numbers: 25912

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No