Associations of Baseline and Changes in Leukocyte Counts with Incident Cardiovascular Events: The Dongfeng-Tongji Cohort Study

Aim: The aim of the present study was to investigate the associations of baseline and longitudinal changes in leukocyte counts with incident cardiovascular disease (CVD). Methods: We conducted a prospective study to investigate the associations of baseline and 5-year changes in leukocyte counts with incident CVD and its subtypes in middle-aged and elderly Chinese. We estimated the hazard ratios (HRs) and 95% confidence intervals (CIs) for CVD using the Cox proportional-hazards models. Results: In the analyses of baseline total leukocyte count of 26,655 participants, compared with the lowest quartile (＜4.71×10⁹/L), participants in the fourth quartile (＞6.70×10⁹/L) had 11% higher risk for CVD. Consistent with total leukocyte count, neutrophil count also exhibited a significant positive association with the risk of CVD. In the analyses of 5-year changes in total leukocyte count of 11,594 participants, the changes in leukocyte count were categorized into three groups, i.e., the decreased group (＜25%), stable group (25%–75%), and increased group (＞75%). Compared with participants in the stable group (−1.18 to 0.44×10⁹/L), participants in the increased group (＞0.44×10⁹/L) had 14% higher risk for CVD. We also observed significant positive associations of the changes in neutrophil and monocyte counts with the risk of CVD. Furthermore, the total leukocyte count in the second or third tertile at the first follow-up with a 5-year increase was related to higher CVD risk. Conclusion: High baseline total leukocyte count and a 5-year increase in total leukocyte count were related to higher CVD risk.