Navigation Links
Night Shift Work Hard on the Heart
Date:3/2/2009

Study finds it alters levels of hormones, could raise risk of obesity, diabetes and heart disease

MONDAY, March 2 -- Working the night shift might lead to hormonal and metabolic changes that raise risks for obesity, diabetes and heart disease, researchers say.

"In the long run, the physiological impact of shift work on several markers involved in the regulation of body weight -- leptin, insulin, cortisol -- seems to contribute to the increased risk for the development of diabetes, cardiovascular disease and obesity," said study author Frank Scheer, an instructor of medicine in the division of sleep medicine at Brigham and Women's Hospital and Harvard Medical School, in Boston.

Scheer and his team report the findings in the March 2 online issue of the Proceedings of the National Academy of Sciences.

The authors point out that about 8.6 million Americans perform shift work, which the National Sleep Foundation defines as any type of schedule that falls outside the standard nine-to-five norm for business hours. In the United States, factory workers, hospital staff, policemen, firefighters, pilots, road crews and truck drivers are some of the positions that commonly entail some degree of shift work.

This type of work has been previously associated with gastrointestinal problems, fatigue and poor sleep, the researchers noted. Such complications are thought to arise from a chronic disconnect between the waking and eating habits the work demands and the body's innate 24-hour sleep/wake clock, commonly known as the circadian rhythm.

To explore how such a misalignment might raise the risk for developing serious health issues, Scheer and his colleagues conducted a laboratory test designed to mimic the acute effects of jet lag and/or the chronic impact of regular shift work.

In the experiment, the bodily responses of five men and five women were tracked as they stuck to an ever-changing sleep/eat schedule for 10 days.

By the study's conclusion, all the volunteers had eaten and slept across all phases of the circadian cycle, as they followed a daily schedule artificially fashioned along 28-hour blocks.

The results: circadian misalignment provoked a drop in levels of the weight-regulating hormone leptin. Plummeting leptin levels could hasten the onset of obesity and heart disease by prompting increases in appetite and decreases in activity, the researchers said.

Furthermore, changes in blood sugar levels and insulin levels also occurred, resulting in impaired glucose tolerance and decreased insulin sensitivity.

In particular, three participants with no prior history of diabetes developed glucose levels that resembled those of pre-diabetic people after eating on the misaligned schedule. Daytime blood pressure levels were also found to be elevated among these volunteers.

The degree of hormonal change was highest when participant schedules were set 12 hours off the normal sleep/wake cycle -- that is, when participants were asked to sleep throughout the day and stay awake through the night.

Yet despite the strength of the findings, Scheer cautioned that more research is needed before drawing too many conclusions.

"First of all, this is an in-laboratory study of short duration," he observed. "So we don't yet know if circadian misalignment has a similar impact in the long run in a real-life setting where people are performing night shift work."

"We also need to look at how different people might respond differently," Scheer noted. "Because shift work typically affects people's alertness levels, and GI functioning, and those who don't cope well with this are likely to drop out. Which means that those who continue with this kind of work might not be so susceptible to such problems, and may be less sensitive to this kind of misalignment. These are all questions for the future."

For the time being, Dr Joseph Bass, an assistant professor of medicine at Northwestern University's Feinberg School of Medicine in Chicago, agreed it is too soon to draw direct connections between shift work and specific health risks.

"However, having said that, this isn't smoke and mirrors," he said. "Our internal biological clocks represent a whole area of biology that is as critical as blood pressure or breathing. And this work does provide us with a plausible biological mechanism that may underlie and cumulatively contribute to the occurrence of metabolic disorders in certain individuals, because of their work patterns, or because of traveling, or simply because they ignore the normal light cycle."

More information

For more on night shift work and sleep, visit the National Sleep Foundation.



SOURCE: Frank Scheer, Ph.D, instructor, medicine, division of sleep medicine, department of medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston; Joseph Bass, M.D., Ph.D., assistant professor, medicine, Northwestern University Feinberg School of Medicine, Chicago; March 2, 2009, Proceedings of the National Academy of Sciences, online


'/>"/>
Copyright©2009 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Obesity: A Musculoskeletal Nightmare
2. GIVE IT A REST: Delta Dental of Illinois Encourages Routine Dental Exams to Help Detect Nighttime Teeth Grinding
3. Cancer Patients Often Stranded in Health Insurance Nightmares
4. Wake Up Your Relationship With a Good Night in Bed This Valentines Day
5. Nightmares increase risk of further suicide attempts
6. Knights of Columbus Ultrasound Program Assists Pregnant Women
7. Immune System Works Better at Night
8. Leahy Slams Midnight Bid to Relax Mercury-in-Fish Warnings to Women and Children
9. Holland & Knight Welcomes MARC Associates - Experts in Health Care and Intergovernmental Policy - to the Firms Public Policy & Regulation Practice
10. Citing Midnight Rules to Erode Health and Safety, Nurses Unveil New Website to Send Bush Packing
11. Nurture(R) by Steelcase Wins Second Consecutive Nightingale Award for SYNC(TM) Caregiver Workspace Solution
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Night Shift Work Hard on the Heart
(Date:12/6/2016)... ... December 06, 2016 , ... ... authorized OSHA Training Institute Education Center headquartered in Northern California, has announced the ... providing occupational safety and health training to public sector employees. , “The primary ...
(Date:12/5/2016)... , ... December 05, 2016 , ... "FCPX Overlay Glare ... but natural lighting effect without heavy rendering or complicated compositing," said Christina Austin - ... media to create an organic spectrum of lights that simulates the look of a ...
(Date:12/5/2016)... (PRWEB) , ... December 05, 2016 , ... ... announced it has been featured in SuperbCrew magazine, a leading online tech news ... world. This interview, now featured on SuperbCrew.com, explores the state of enterprise mobility ...
(Date:12/5/2016)... ... December 05, 2016 , ... “Epilepsy Awareness,” ... tomorrow, December 6th, sparks a conversation about epilepsy, bearing down on the social ... people will be diagnosed with epilepsy within their lifetime. With such a large ...
(Date:12/5/2016)... ... December 05, 2016 , ... ... lines. The goal of Castlewood Treatment Centers has always been to promote the ... as many people as possible. In that spirit, Castlewood has announced two new ...
Breaking Medicine News(10 mins):
(Date:12/5/2016)... , Dec 5, 2016 Research and ... by Product (Instruments, Consumables), Application (Biomedical & Biochemical Research, Disease Diagnostics), ... Global Forecasts to 2021" report to their offering. ... , , ... 730.7 Million in 2021 from USD 574.8 Million in 2016, growing ...
(Date:12/5/2016)... 5, 2016 According to a new market ... Transplantation, Growth Factor Technology, Tissue Scaffolds, Cell-free composites), Application (Hyaline Cartilage, ... market is projected to reach USD 779.8 Million by 2021 from ... during the forecast period of 2016 to 2021. ... ...
(Date:12/5/2016)... India , December 5, 2016 According to a ... Type and by Application - Global Opportunity Analysis and Industry Forecast, 2014 - ... is expected to reach $5,255 million by 2022, growing at a CAGR of ... with more than four-fifths share. Continue Reading ... ...
Breaking Medicine Technology: