Cardiovascular Diseases, Cardiovascular Risk Factor, Occupational Diseases, Occupational Exposure
Conditions
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).
Interventions
None listed
Sponsors
University of Pittsburgh
Study design
Observational model
CASE_CROSSOVER
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
MALE
Age
35 Years to 59 Years
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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). |
| 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. 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, 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). |
| 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. 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 |
| 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 |
| 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 |
| 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). |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Research Study Participation Participants who were enrolled in the study and completed all study procedures. | 19 |
| Total | 19 |
Baseline characteristics
| Characteristic | Research Study Participation |
|---|---|
| Age, Continuous | 46.6 years STANDARD_DEVIATION 7.9 |
| Occupational Industry Building and Grounds Maintenance | 1 Participants |
| Occupational Industry Food Service | 8 Participants |
| Occupational Industry Healthcare | 1 Participants |
| Occupational Industry Material Moving | 9 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 4 Participants |
| Race (NIH/OMB) More than one race | 2 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 13 Participants |
| Region of Enrollment United States | 19 participants |
| Sex: Female, Male Female | 0 Participants |
| Sex: Female, Male Male | 19 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 19 |
| other Total, other adverse events | 0 / 19 |
| serious Total, serious adverse events | 0 / 19 |
Outcome results
Primary
24-hour Heart Rate
We will calculate the average heart rate over each 24 hour period throughout a one week monitoring period.
Time frame: 24 hours
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | 24-hour Heart Rate | Workdays | 83.8 beats per minute | Standard Error 1.2 |
| Research Study Participation | 24-hour Heart Rate | Non-workdays | 78.5 beats per minute | Standard Error 1.4 |
Secondary
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).
Time frame: 24 hours
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | 24-hour Ambulatory Diastolic Blood Pressure | Workdays | 75.2 millimeters of Mercury | Standard Error 1 |
| Research Study Participation | 24-hour Ambulatory Diastolic Blood Pressure | Non-workdays | 72.6 millimeters of Mercury | Standard Error 1.1 |
Secondary
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).
Time frame: 24 hours
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | 24-hour Ambulatory Systolic Blood Pressure | Workdays | 126.0 millimeters of Mercury | Standard Error 1.7 |
| Research Study Participation | 24-hour Ambulatory Systolic Blood Pressure | Non-workdays | 124.0 millimeters of Mercury | Standard Error 1.8 |
Secondary
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).
Time frame: approximately 8 hours (sleep time)
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | Nocturnal Heart Rate Variability, HF | non-workdays | 5.56 log milliseconds | Standard Error 0.31 |
| Research Study Participation | Nocturnal Heart Rate Variability, HF | workdays | 5.22 log milliseconds | Standard Error 0.3 |
Secondary
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).
Time frame: approximately 8 hours (sleep time)
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | Nocturnal Heart Rate Variability, LF | workdays | 6.18 log milliseconds | Standard Error 0.2 |
| Research Study Participation | Nocturnal Heart Rate Variability, LF | non-workdays | 6.45 log milliseconds | Standard Error 0.21 |
Secondary
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).
Time frame: approximately 8 hours (sleep time)
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | Nocturnal Heart Rate Variability, RMSSD | workdays | 34.17 milliseconds | Standard Error 4.04 |
| Research Study Participation | Nocturnal Heart Rate Variability, RMSSD | non-workdays | 35.34 milliseconds | Standard Error 4.32 |
Secondary
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).
Time frame: approximately 8 hours (sleep time)
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | Nocturnal Heart Rate Variability, SDNN | workdays | 39.85 milliseconds | Standard Error 3.48 |
| Research Study Participation | Nocturnal Heart Rate Variability, SDNN | non-workdays | 42.14 milliseconds | Standard Error 3.71 |
Secondary
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
Time frame: 1 week
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | Physical Activity Pattern. LPA | Workdays | 391.5 minutes per day | Standard Error 19.9 |
| Research Study Participation | Physical Activity Pattern. LPA | Non-workdays | 285.2 minutes per day | Standard Error 23.3 |
Secondary
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
Time frame: 1 week
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | Physical Activity Pattern. MVPA | Workdays | 72.4 minutes per day | Standard Error 7.2 |
| Research Study Participation | Physical Activity Pattern. MVPA | Non-workdays | 41.5 minutes per day | Standard Error 8.9 |
Secondary
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
Time frame: 1 week
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | Physical Activity Pattern. Sedentary | Workdays | 492.5 minutes per day | Standard Error 18.4 |
| Research Study Participation | Physical Activity Pattern. Sedentary | Non-workdays | 629.7 minutes per day | Standard Error 22.5 |
Secondary
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
Time frame: 1 week
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | Physical Activity Pattern. Steps Per Day | Workdays | 12,772 steps per day | Standard Error 945 |
| Research Study Participation | Physical Activity Pattern. Steps Per Day | Non-workdays | 7,923 steps per day | — |
Secondary
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
Time frame: 1 week
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Research Study Participation | Physical Activity Pattern. Upright | Workdays | 462.4 minutes per day | Standard Error 18.4 |
| Research Study Participation | Physical Activity Pattern. Upright | Non-workdays | 325.2 minutes per day | Standard Error 22.5 |