Shift Work and Risk of Cardio-vascular Disease

Study Overview
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Brief Summary
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The purpose of this research is to test the hypothesis that those with non-traditional work schedules (e.g. shift workers) have a higher cardio-metabolic risk than those with traditional work schedules (e.g. day workers), and that both accumulated sleep debt and the degree of circadian disruption predict the elevated cardio-metabolic risk. The findings of this research are expected to increase our understanding of physiologic tolerance to non-traditional work schedules and provide the basis for the development of methods for the early detection of adverse health effects and determine coping strategies for the millions of workers with non-traditional work schedules.

Official Title
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Impact of Shift Work on Risk of Cardiovascular Disease and Diabetes: A Cross-sectional Study

Conditions
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Shift-Work Sleep Disorder

Intervention / Treatment
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* Other: Sleep, Dietary and Cardio-metabolic Measurements


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18 and older Full-time workers- working between 7:00 a.m. and 7:00 p.m. employed full time at a medical center. Non-traditional full-time workers- working between 7:00 a.m. and 7:00 p.m and between 7:00 p.m. and 7:00 a.m., employed full time at a medical center. Exclusion criteria include: Acute illness or recent change in medication. Persons employed for less than 3 months at their current job -

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Traditional workers<br>Individuals who work 'traditional work hours, i.e., 9a-5p. | Other: Sleep, Dietary and Cardio-metabolic Measurements<br>* At home session: 2-weeks of wrist actigraphy and sleep diaries; a food diary for the three days preceding the lab session; 24-h period of ambulatory blood pressure on a non-work day for participant. Work schedules over a 4-week period will be collected and participants identified as traditional or non-traditional workers. Subjects will begin the stay in the research unit in the evening and will remain for about 16-20 hr. Saliva samples will be taken every 30 min from admission until bedtime. Bedtime with polysomnography will be from 11:00pm to 7:00am. Questionnaires will be administered; height, weight and waist/hip circumference and bioimpedance measurement; standard 3-h oral glucose tolerance test and blood tests (CBC, electrolytes, renal, liver and thyroid function , hemoglobin A1c, SHBG levels). For individuals with diabetes only fasting blood samples will be taken.<br>|
| Non-traditional workers<br>Individuals who have work hours outside the usual daytime period | Other: Sleep, Dietary and Cardio-metabolic Measurements<br>* At home session: 2-weeks of wrist actigraphy and sleep diaries; a food diary for the three days preceding the lab session; 24-h period of ambulatory blood pressure on a non-work day for participant. Work schedules over a 4-week period will be collected and participants identified as traditional or non-traditional workers. Subjects will begin the stay in the research unit in the evening and will remain for about 16-20 hr. Saliva samples will be taken every 30 min from admission until bedtime. Bedtime with polysomnography will be from 11:00pm to 7:00am. Questionnaires will be administered; height, weight and waist/hip circumference and bioimpedance measurement; standard 3-h oral glucose tolerance test and blood tests (CBC, electrolytes, renal, liver and thyroid function , hemoglobin A1c, SHBG levels). For individuals with diabetes only fasting blood samples will be taken.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cardio-metabolic risk | 24-h ambulatory blood pressure monitoring and 3-h oral glucose tolerance test | Once | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Obesity | height, weight, BMI and waist/hip circumference and bioimpedance measurement of body fat | Once |