Nurses

Details

• Alternative Title:
  Cancer Epidemiol Biomarkers Prev
• Personal Author:
  Razavi, Pedram ; Devore, Elizabeth E. ; Bajaj, Archna ; Lockley, Steven W. ; Figueiro, Mariana G. ; Ricchiuti, Vincent ; Gauderman, W. James ; Hankinson, Susan E. ; Willett, Walter C. ; Schernhammer, Eva S.
• Description:
  Background:
  
  Previous studies associated night-shift work with melatonin disruption, with mixed evidence regarding the modulating effects of chronotype (i.e., diurnal preference).
  
  Methods:
  
  130 active nurses (84 rotating-shift and 46 day-shift workers) in the Nurses’ Health Study II wore a head-mounted light meter and collected spontaneous urine voids over three days. 6-sulfatoxymelatonin (aMT6s), the major urinary metabolite of melatonin, was assessed.
  
  Results:
  
  Rotating-shift workers on night shifts had more light exposure and lower urinary melatonin levels during the night, and urinary melatonin rhythms with smaller peaks (14.83, 95% confidence interval [CI], 11.72–18.75 versus 11.81 ng/mg-creatinine/hour, 95%CI, 9.49–14.71) and later peak onset (4.10, 95%CI, 3.37–4.99 versus 5.71 hours, 95%CI, 4.76–6.85), compared to day-shift workers. Further, evening chronotypes’ melatonin rhythms had later peak onset compared to morning types (4.90 hours, 95%CI, 3.94–6.09 versus 3.64 hours, 95%CI, 2.99–4.43). However, among day-shift workers, morning chronotypes had melatonin rhythms with greater mean levels, larger peaks, and earlier peak onset compared to evening chronotypes; patterns were similar comparing evening versus morning chronotypes among rotating-shift workers on night shifts. The interaction of rotating-shift work and chronotype was significant across all parameters (p<0.05).
  
  Conclusions:
  
  As expected, rotating-shift workers on night shifts had greater light exposure and lower urinary melatonin levels during the night compared to day-shift workers. Intriguingly, melatonin rhythms were dependent on both chronotype and rotating-shift work type, and better alignment of rotating-shift work and chronotype appeared to produce less disrupted melatonin rhythms.
  
  Impact:
  
  The joint effects of shift-work type and chronotype require attention in future studies.
  
  
• Subjects:
  Article Chronotype Circadian Light Melatonin Shift Work
• Source:
  Cancer Epidemiol Biomarkers Prev. 28(7):1177-1186
• Pubmed ID:
  31142495
• Pubmed Central ID:
  PMC6750706
• Document Type:
  Journal Article
• Funding:
  R01 OH008171/OH/NIOSH CDC HHS/United States ; R01 OH009803/OH/NIOSH CDC HHS/United States ; U01 CA176726/CA/NCI NIH HHS/United States ; UM1 CA176726/CA/NCI NIH HHS/United States
• Volume:
  28
• Issue:
  7
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:2296ccb3be3a52b06ce809c84597df39926a614396d208eba6231dbb87de6a14
• Download URL:
  https://stacks.cdc.gov/view/cdc/90002/cdc_90002_DS1.pdf
• File Type:
  [PDF - 758.93 KB ]