Heart at Work Study

Completed

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

• Registration Number: NCT04075279
• Lead Sponsor: University of Pittsburgh

Brief Summary

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

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 Timeline

• Study First Submitted: 2019-08-28
• Study First Submitted QC: 2019-08-29
• Study First Posted: 2019-08-30
• Study Start: 2019-10-17
• Primary Completion: 2020-04-20
• Study Completion: 2020-07-24
• Status Verified: 2021-04
• Results First Submitted: 2021-04-06
• Results First Submitted QC: 2021-04-06
• Last Update Submitted: 2021-04-06
• Results First Posted: 2021-05-03
• Last Update Posted: 2021-05-03

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 19

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 & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
24-hour Heart Rate	24 hours	We will calculate the average heart rate over each 24 hour period throughout a one week monitoring period.

Secondary Outcome Measures

Name	Time	Method
Nocturnal Heart Rate Variability, SDNN	approximately 8 hours (sleep time)	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).
Nocturnal Heart Rate Variability, LF	approximately 8 hours (sleep time)	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).
Physical Activity Pattern. MVPA	1 week	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
Nocturnal Heart Rate Variability, RMSSD	approximately 8 hours (sleep time)	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).
Physical Activity Pattern. LPA	1 week	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
24-hour Ambulatory Diastolic Blood Pressure	24 hours	We will calculate the average diastolic blood pressure over a 24-hour period on two separate days (workdays versus non-workdays).
24-hour Ambulatory Systolic Blood Pressure	24 hours	We will calculate the average systolic blood pressure over a 24-hour period on two separate days (workdays versus non-workdays).
Physical Activity Pattern. Steps Per Day	1 week	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
Nocturnal Heart Rate Variability, HF	approximately 8 hours (sleep time)	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).
Physical Activity Pattern. Sedentary	1 week	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
Physical Activity Pattern. Upright	1 week	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

Trial Locations

Locations (1)

Physical Activity and Weight Management Research Laboratory; 🇺🇸 Pittsburgh, Pennsylvania, United States