Relationship between Poor Sleep Quality and High White Blood Cell Count in Korean Adults

Abstract

Objective: This study aimed to investigate the relationship between sleep quality and white blood cell (WBC) count among Korean adults. Methods: This cross-sectional study included 136 participants who attended the medical health check programs of two tertiary medical institutions from December 2019 to March 2021. Sleep quality was measured using the Korean version of the Pittsburgh Sleep Quality Index (PSQI-K). The participants were divided into the poor sleep quality group (n=94) and the good sleep quality group (n=42) according to the global PSQI-K score. A high WBC count was defined as that greater than the 75th percentile in the current sample. The odds ratios (ORs) and 95% confidence intervals (CIs) for high WBC count were calculated using multivariable logistic regression analyses after adjusting for confounding variables. Results: The mean WBC count was significantly lower in individuals with good sleep quality than in those with poor sleep quality. The prevalence of high WBC count was significantly higher in participants with poor sleep quality than in those with good sleep quality (p=0.018). Compared with the ORs (95% CIs) in individuals with good sleep quality, the ORs (95% CIs) for high WBC count in individuals with poor sleep quality were 3.83 (1.09-13.41) after adjusting for age, sex, alcohol consumption, coffee consumption, physical activity, marital status, hypertension, diabetes mellitus, depressive symptoms, body mass index, and homeostatic model assessment of insulin resistance. Conclusion: Poor sleep quality was positively associated with an increased risk of high WBC count among Korean adults.