Abstract 17302: Long-Term Association of Low-Risk Profile and White Blood Cell Count - The Chicago Healthy Aging Study (CHAS)

Abstract

Background: Low CVD risk factor (RF) burden at younger ages is associated with substantially lower risk of future clinical CVD events. White blood cell (WBC) count, a measure of systemic inflammation, also predicts CVD morbidity and mortality, and is cross-sectionally associated with CVD risk factors. No data exist on long-term associations of risk status at younger ages and WBC at older ages. Methods: Using data from CHAS, we assessed the association of baseline low risk (LR) status (1967-73) with follow-up WBC count (2007-10). Participants were classified as baseline LR, 0 RF high, only 1 RF high, and 2+RF high (see table footnote for definitions). WBC counts in the 5th quintile (≥7.5x10 9 cells/L) were classified as "high" compared to all others (<7.5x10 9 cells/L). Results: The sample consisted of 1389 participants (28% women, 9% African American, and 20% LR) baseline ages 25-45 (follow-up mean age 71), free of baseline major ECG abnormalities or myocardial infarction. With average follow-up 39 years, multivariate adjusted mean WBC count was higher in a linear fashion across baseline RF categories (P-trend <0.001) (see table footnote for adjustments). Greater number of baseline RFs was also associated with greater likelihood of high WBC count (P-trend= 0.001). Thus, for persons with baseline 0 RF high, 1 only RF high, and ≥2 RFs high, the odds of high WBC count were higher by 57%, 74%, and 81%, respectively, compared to those with baseline LR (see Table). Analyses with individual RFs instead of LR status showed that the above association was mostly due to baseline smoking status and BMI. The association was stronger in women compared to men: coefficient/p-trend was 0.30/<0.001 in women and 0.11/0.049 in men (results not shown). Conclusion: Low risk profile at younger ages is associated with lower WBC count in older age. A low risk profile early in life apparently leads to long-term decreased inflammation, as well as reduced risk of CVD events later in life.