[Relationship between the white blood cell count and development of electrocardiographic ST-T abnormalities. Insights from annual health examinations of urban residents].
OBJECTIVE
Inflammation has been shown to play a role in atherosclerosis and coronary heart disease. This study was designed to examine the relationship between the baseline white blood cell (WBC) count and development of electrocardiographic ST-T abnormalities.


METHODS
The results of annual health examinations conducted in the city of A, Osaka Prefecture, from 1985 to 1997 were evaluated. At the initial examination, carried out during the period 1985-1988, 1,213 women and 201 men, who were current non-smokers without hypertension, were free from ST-T abnormalities. We focused on cases with new ST-T abnormalities identified during the 12-year period. WBC counts were categorized as low (< 50th percentile) or high (> or = 50th percentile), and were divided into quintiles. Cox proportional hazards models were used to test for correlations.


RESULTS
The age-adjusted mean WBC count in both men and women were higher for cases with new ST-T abnormalities than for those with normal ECG findings. For men, the percentage of positive cases with a high WBC count was significantly greater. Multivariate models showed that the relative risk (RR) of new ST-T abnormalities for cases with a high WBC count as compared with those with a low WBC count was 7.16 (P<0.001) for men and 1.50 (P< 0.001) for women. The quintiles for men showed a step-wise increment in the rate per 1,000 person-years but no such tendency was observed for women. The higher the quintile in men, the higher the RR was, and the RR in the highest quintile was approximately ten times that in the lowest quintile. For women, a similar trend was observed, but the association between the RR and the WBC count was weaker.


CONCLUSIONS
These results confirm that the WBC count is significantly associated with development of ST-T abnormalities, and that an elevated WBC count is a marker for an increased risk of ST-T abnormalities. In women, this relationship appears less prevalent than in men.
Nishina
Kazue
K
Department of Social and Environmental Health, Osaka University Graduate School of Medicine F2.
D003327:Coronary Disease / Q000175:diagnosis; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D014505:Urban Population