Shift Work is Associated with an Elevated White Blood Cell Count: A Systematic Review and Meta-Analysis

Area of Science:

• Occupational Health
• Hematology
• Epidemiology

Background:

• Shift employment is associated with chronic inflammation and disease progression.
• White blood cell (WBC) counts are indicators of infection and disease.
• Understanding WBC changes in shift workers is crucial for health monitoring.

Purpose of the Study:

• To systematically review and meta-analyze evidence on total and differential WBC counts in shift employees.
• To compare WBC profiles between shift workers and day workers.

Main Methods:

• A comprehensive literature search was conducted across PubMed, Web of Science, and Scopus databases.
• Meta-analysis using a random-effects model was performed on data from 25 studies.
• Included studies comprised 37,708 participants from diverse geographical regions.

Main Results:

• Shift workers showed significantly higher total WBC counts (MD = 0.43; P < 0.001).
• Elevated levels of lymphocytes (MD = 0.16; P = 0.02), monocytes (MD = 0.04; P = 0.03), and eosinophils (MD = 0.01; P = 0.03) were observed in shift workers.
• No significant differences were found in neutrophil or basophil counts.

Conclusions:

• Shift work leads to a significant increase in total and differential WBC counts.
• WBC counts can serve as accessible biomarkers for disease diagnosis and prognosis in shift workers.