Background and purpose: A higher total leukocyte count has been reported to predict all-cause mortality in men, but data are limited for this relation in women and for the relation between differential leukocyte counts and all-cause mortality in both men and women. This study was designed to analyze these relationships in Taiwanese.
Methods: A total of 8447 subjects were enrolled from participants in a physical check-up program at National Taiwan University Hospital from 1995 to 1997. Information on mortality was obtained from a national mortality databank that was updated to the end of 2001. Data were analyzed by Student's t test and Cox regression analysis.
Results: Among the 245 deaths, 88 were due to cancer and 62 were due to cardiovascular diseases. Cox regression analysis revealed an inverse association between lymphocyte count and all-cause mortality in the study group as a whole (all subjects, p < 0.01, hazard ratio = 0.73). This inverse association was mainly due to an inverse association between lymphocyte count and cancer mortality (p < 0.05, hazard ratio = 0.64), especially the mortality from hepatoma (p = 0.010, hazard ratio = 0.29). The latter hazard ratio of 0.29 indicates that, in all subjects, every decrease of 1.0 x 10(9)/L in lymphocyte count increased the risk of mortality from hepatoma by 3.45-fold during an average follow-up period of 65.5 months. There was a positive association between total leukocyte count and all-cause mortality in men (p < 0.05, hazard ratio = 1.10), mainly due to both the neutrophil and monocyte counts having positive associations with the cardiovascular mortality (both p < 0.05, hazard ratio = 1.23 and 1.22, respectively). The latter hazard ratio of 1.22 indicates that, in men, every increase of 0.1 x 10(9)/L in monocyte count increased the risk of cardiovascular mortality by 1.22-fold.
Conclusions: In Taiwanese adults of both genders, a lower lymphocyte count is associated with cancer mortality, especially mortality from hepatoma. In Taiwanese men, higher neutrophil and monocyte counts are associated with cardiovascular mortality.