White Blood Cell Count and Total and Cause-Specific Mortality in the Women's Health Initiative

• Published in: American journal of epidemiology Vol. 186; no. 1; pp. 63 - 72
• Main Authors: Kabat, Geoffrey C, Kim, Mimi Y, Manson, JoAnn E, Lessin, Lawrence, Lin, Juan, Wassertheil-Smoller, Sylvia, Rohan, Thomas E
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01.07.2017
• Subjects: Age Factors; Aged; Cause of Death; Coronary Disease - mortality; Female; Health Behavior; Health Status; Humans; Leukocyte Count - statistics & numerical data; Middle Aged; Mortality; Neoplasms - mortality; Original Contributions; Postmenopause; Proportional Hazards Models; Prospective Studies; Risk Factors; Smoking - epidemiology; Socioeconomic Factors; United States; Women's Health; cause-specific mortality; C-reactive protein; comorbidity; reverse causality; total mortality; smoking; white blood cell count
• ISSN: 0002-9262; 1476-6256
• DOI: 10.1093/aje/kww226

White blood cell (WBC) count appears to predict total mortality and coronary heart disease (CHD) mortality, but it is unclear to what extent the association reflects confounding by smoking, underlying illness, or comorbid conditions. We used data from the Women's Health Initiative to examine the associations of WBC count with total mortality, CHD mortality, and cancer mortality. WBC count was measured at baseline in 160,117 postmenopausal women and again in year 3 in 74,375 participants. Participants were followed for a mean of 16 years. Cox proportional hazards models were used to estimate the relative mortality hazards associated with deciles of baseline WBC count and of the mean of baseline + year 3 WBC count. High deciles of both baseline and mean WBC count were positively associated with total mortality and CHD mortality, whereas the association with cancer mortality was weaker. The association of WBC count with mortality was independent of smoking and did not appear to be influenced by previous disease history. The potential clinical utility of this common laboratory test in predicting mortality risk warrants further study.