Physician-Training Stress and Accelerated Cellular Aging.
Level 3 - non-randomized controlled study
Prospective longitudinal cohort study evaluating within-subject changes over time.
PubMed 31230727 · doi:10.1016/j.biopsych.2019.04.030
What was done
A prospective multicenter longitudinal cohort study tracked 250 first-year medical residents (interns) across 55 United States hospital systems during the 2015–2016 academic year. Investigators measured salivary telomere length before and at the conclusion of the internship year and assessed associations with baseline factors (early family environment, neuroticism) and residency work hours.
What was found
Telomere length shortened significantly over the year from 6465.1 ± 876.8 base pairs pre-internship to 6321.5 ± 630.6 base pairs post-internship (t246 = 2.69, p = .008). This observed mean attrition rate was approximately six times greater than typical annual attrition rates reported in prior meta-analytic literature. Longer weekly work hours were significantly associated with greater telomere attrition (p = .002). Shorter pre-internship telomere length was significantly associated with neuroticism and stressful early family environments.
Why it matters
This study provides prospective within-subject evidence that severe occupational stress and extended work hours directly correlate with accelerated cellular aging biomarkers in humans.
Limits
The study lacked a concurrent, non-intern control cohort followed under the same assay conditions over the same time frame. Telomere length was measured in saliva rather than isolated leukocyte subsets, and unmeasured lifestyle confounders (e.g., changes in diet, physical activity, sleep architecture, substance use) were not fully isolated.
Cited by
- supports Stress accelerates telomere shortening.