MAY 15, 2019 4:29 PM PDT

In Their First Stressful Year, New Doctors Age Rapidly at the Cellular Level

WRITTEN BY: Carmen Leitch

Some jobs are especially stressful. For example, when new doctors enter their first year of training as interns, they work very long hours in a demanding environment. New research indicates that the protective caps that sit on the ends of chromosomes, called telomeres, will shorten six times faster than average in these new doctors' first year. As the hours they work grow longer, the shortening gets worse. The study, reported in Biological Psychiatry may also provide insight into the biological effects of lengthy and stressful work days in other fields. 

Image credit: Pxhere

"Research has implicated telomeres as an indicator of aging and disease risk, but these longitudinal findings advance the possibility that telomere length can serve as a biomarker that tracks effects of stress, and helps us understand how stress gets 'under the skin' and increases our risk for disease," said the senior author of the study Srijan Sen, M.D., Ph.D., a University of Michigan (UM) neuroscientist, psychiatrist and head of the Intern Health Study.

"It will be important to study how telomere changes play out in larger groups of medical trainees, and in other groups of people subjected to specific prolonged stresses such as military training, graduate studies in the sciences and law, working for startup companies, or pregnancy and the first months of parenting,” he added.

The 2009 Nobel Prize in Medicine was awarded for research that showed that telomeres protect chromosomal DNA from damage (one of the researchers that got the award discusses telomeres and aging in the video below). Most research on telomeres has been done in older adults. Short telomeres are linked to disease and depression.

This work included 250 recent graduates of medical school that participated in the Intern Health Study and a control group of UM college students. DNA was contributed at the beginning and end of the intern year, along with a series of lengthy questionnaires.

The scientists found that some of these new doctors started with shorter telomeres; some of them had indicated that they had very stressful childhoods, while others had personality traits like neuroticism, pessimism, and difficulty relaxing. By the end of the year, however, the researchers found that the number of hours worked by the interns was the only factor correlated with telomere shrinkage. The interns in the study worked an average of 64.5 hours per week, but as individuals worked more hours, their telomeres shrank faster. In the control group of 85 undergraduates, no telomere shrinkage was observed.

"The responses given by some of the interns in these surveys indicated that some were averaging more than 80 hours of work a week, and we found that those who routinely worked that many hours had most telomere attrition," said Sen. "Those whose hours were at the lower end of the range had less telomere attrition."

Sen wants to know more about how work schedules can impact telomere length; findings have already indicated that lots of changes in work hours disrupt circadian rhythm and mood. He also wants to investigate ways to stop the shrinkage or potentially, lengthen short telomeres.

"Residency directors should do as much as they can to keep their interns' work hours and workload towards the lower end of the current range,” he suggested. He also encourages interns to try to relieve stress and get enough sleep.


Sources: AAAS/Eurekalert! via University of Michigan, Biological Psychiatry

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JAN 24, 2020
Cell & Molecular Biology
JAN 24, 2020
New Insight Into Chronic Pain May Help Create Novel Therapeutics
Acute pain can progress to chronic pain, which can cause other problems including depression, loss of motivation and sensory dysfunction....
JAN 24, 2020
Genetics & Genomics
JAN 24, 2020
Learning More About How Gene Variants Impact Cystic Fibrosis
Cystic fibrosis is caused by a genetic mutation, but small changes other genes appear to influence the severity of the disease....
JAN 24, 2020
Genetics & Genomics
JAN 24, 2020
A New Type of Muscle Cell That Could be a Target for Gene Therapy is ID'ed
Muscles have a supply of restorative stem cells called satellite cells, and now they have identified a new type....
JAN 24, 2020
Cell & Molecular Biology
JAN 24, 2020
A Molecular Switch for Modulating Gene Therapy Doses
  Genetic errors cause many different kinds of diseases, and gene therapy has aimed to relieve those symptoms by addressing the root cause....
JAN 24, 2020
Health & Medicine
JAN 24, 2020
Consider Skipping The Post-Workout Ice Bath
In an effort to get heart-healthy, many people have experienced the painful after-effects of an intense workout. Weather cardiovascular or strength trainin...
JAN 24, 2020
Microbiology
JAN 24, 2020
Scientists Engineer a New Kind of Life Form
Usig cells harvested from frogs, researchers created tiny robots....
Loading Comments...