Heart at Work Study

Cardiovascular Mechanisms of the Occupational Physical Activity Health Paradox: 24-hour Physical Activity, Blood Pressure, and Heart Rate

This is an observational study to examine the cardiovascular mechanisms of increased cardiovascular mortality in those with high activity occupations.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases; Occupational Diseases; Occupational Exposure; Cardiovascular Risk Factor

Detailed Description

The current proposal uses a repeated-measures, within-subject design to address our aims. Twenty male participants will report to the laboratory to provide informed consent, complete baseline assessments, and receive ambulatory monitors. Following this session, each participant will wear physical activity and ambulatory cardiovascular monitors for 7 days, including at least one non-work day and one work day. Characterization of work activity will use physical activity data from self-reported time at work (Specific Aim I). The 24-hour cardiovascular load (HR and BP) and nocturnal HRV will be compared across work and non-work days (Specific Aim II). Lastly, whether fitness level or job strain modify the difference in cardiovascular strain between work vs. non-work days will be evaluated (Specific Aim III).

• Study Type: Observational
• Enrollment (Actual): 19

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15261
      • Physical Activity and Weight Management Research Laboratory

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 35 years to 59 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

• Sampling Method: Non-Probability Sample

Study Population

Middle-aged male food service workers

Description

Inclusion Criteria:

• middle age (35-59 years)
• male
• self-report working full-time in the food service industry (≥30 hours/week)
• self-report predominantly completing light intensity activity job responsibilities (≥75% work time walking, light movement, or standing)

Exclusion Criteria:

• Resting blood pressure of ≥150 mmHg systolic and/or ≥95 mmHg diastolic
• currently taking medications that are known to affect blood pressure or heart rate (e.g. Beta-blockers, ACE inhibitors, etc.)
• greater than low risk to participate in physical activity as determined by PAR-Q (answer of yes to any of the 7 physical activity readiness questionnaire questions)
• report working a second job in addition to their primary full-time job
• report working overnight shifts (10pm-6am)
• reported physical dysfunction (inability to walk 2 city blocks or climb 2 flights of stairs)
• inability to complete the sub-maximal exercise test to completion (80% age-predicted heart rate maximum)
• Currently being treated for a serious medical condition such as kidney disease, liver disease, cancer, or heart disease.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Crossover
• Time Perspectives: Cross-Sectional

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
24-hour Heart Rate	We will calculate the average heart rate over each 24 hour period throughout a one week monitoring period.	24 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
24-hour Ambulatory Systolic Blood Pressure	We will calculate the average systolic blood pressure over a 24-hour period on two separate days (workdays versus non-workdays).	24 hours
Nocturnal Heart Rate Variability, RMSSD	We will calculate the average heart rate variability during each night's sleep for a total of one week. The specific HRV variable presented is root mean square successive differences (RMSSD).	approximately 8 hours (sleep time)
Physical Activity Pattern. Steps Per Day	This physical activity metric of steps per day was calculated as average number of steps during each day type (work versus non-workdays) throughout one week	1 week
Nocturnal Heart Rate Variability, SDNN	We will calculate the average heart rate variability during each night's sleep for a total of one week. The specific HRV variable presented is standard deviation of the normal to normal RR intervals (SDNN).	approximately 8 hours (sleep time)
Nocturnal Heart Rate Variability, LF	We will calculate the average heart rate variability during each night's sleep for a total of one week. The specific HRV variable presented is low frequency power (LF).	approximately 8 hours (sleep time)
Nocturnal Heart Rate Variability, HF	We will calculate the average heart rate variability during each night's sleep for a total of one week. The specific HRV variable presented is high frequency power (HF).	approximately 8 hours (sleep time)
Physical Activity Pattern. MVPA	This physical activity metric of minutes of moderate to vigorous physical activity was calculated as average minutes during each day type (work versus non-workdays) throughout one week	1 week
Physical Activity Pattern. LPA	This physical activity metric of minutes of light physical activity was calculated as average minutes during each day type (work versus non-workdays) throughout one week	1 week
Physical Activity Pattern. Sedentary	This physical activity metric of minutes of sedentary time was calculated as average minutes during each day type (work versus non-workdays) throughout one week	1 week
Physical Activity Pattern. Upright	This physical activity metric of minutes of upright time was calculated as average minutes during each day type (work versus non-workdays) throughout one week	1 week
24-hour Ambulatory Diastolic Blood Pressure	We will calculate the average diastolic blood pressure over a 24-hour period on two separate days (workdays versus non-workdays).	24 hours

Collaborators and Investigators

• Sponsor: University of Pittsburgh
• Investigators: Principal Investigator: Tyler D Quinn, MS, graduate student

Study record dates

Study Major Dates

• Study Start (Actual): October 17, 2019
• Primary Completion (Actual): April 20, 2020
• Study Completion (Actual): July 24, 2020

Study Registration Dates

• First Submitted: August 28, 2019
• First Submitted That Met QC Criteria: August 29, 2019
• First Posted (Actual): August 30, 2019

Study Record Updates

• Last Update Posted (Actual): May 3, 2021
• Last Update Submitted That Met QC Criteria: April 6, 2021
• Last Verified: April 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Occupational Diseases
• Other Study ID Numbers: STUDY19050097

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No
• IPD Plan Description: Upon completion of all data collection, data will be analyzed and summary conclusions will be published in a peer reviewed scientific journal.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No