Presentation on theme: "WHITE BLOOD CELL COUNT SECULAR TREND AND MORTALITY: THE BALTIMORE LONGITUDINAL STUDY OF AGING C.Ruggiero; E.J.Metter; A.Cherubini; M.Maggio; R.Sen; S.S.Najjar;"— Presentation transcript:
WHITE BLOOD CELL COUNT SECULAR TREND AND MORTALITY: THE BALTIMORE LONGITUDINAL STUDY OF AGING C.Ruggiero; E.J.Metter; A.Cherubini; M.Maggio; R.Sen; S.S.Najjar; G.B.Windham; A.Ble; U.Senin; L.Ferrucci. The Gerontological Society of America’s The 59 ° Annual Scientific Meeting
White Blood Cell (WBC) count is a marker of inflammation - risk factor for morbidity and specific and all- cause mortality - strong predictor of incident cardiovascular and cerebrovascular events - negative prognostic factor in CHD patients (Wheeler JG, 2004) White Blood Cell (WBC) count is a marker of inflammation - risk factor for morbidity and specific and all- cause mortality (Coller BS, 2005; Margolis KL, 2005; Brown DW, 2004) - strong predictor of incident cardiovascular and cerebrovascular events (Danesh J,1998) - negative prognostic factor in CHD patients (Wheeler JG, 2004) BACKGROUND
Does WBC count directly enhance the a Does WBC count directly enhance the atherothrombotic process? - macrophages and phagocytes activation - platelet aggregation - microvascular resistance and obstruction -Does WBC count simply mark a negative cardiovascular risk profile? - smoking behavior - sedentary lifestyle - infective agents and sanitary conditions BACKGROUND
AIMS OF THE STUDY 1) Investigate the trend in WBC count in the BLSA participants from 1958 to ) Estimate the relationship between WBC count and mortality 3) Examine the relationship between WBC count and mortality over successive decades
2803 persons (1083 women and 1720 men) Women Men STUDY POPULATION Evaluation time: 2 years Follow-up time Men: 22 ± 13.6 years (6 visits median) Women: 13 ± 7.9 years (3 visits median) Total Evaluations: >16.000
WBC count (cells/mm 3 ): standard automated method in the same clinical laboratory; differential WBC count in a subgroup (40% of visits) Vital status (died or alive): telephone follow-up, correspondence with inactive participants or their relatives, searches of the National Death Index Cause of death : consensus of 3 physicians based on revision of death certificates, medical records, correspondences and other available information METHODS
Men Women RESULTS (1) A downward trend in WBC count was observed over the period in men and women enrolled in successive decades -114 cells/year - 48 cells/year - 6 cells/year - 48 cells/year
RESULTS (1) Secular WBC downward trend according to age at the initial evaluation in successive cohorts The secular WBC count decline was independent of age, gender, race, smoking, BMI and physical activity. Men
RESULTS (2) Non linerar relationship between WBC count and all-cause mortality Linear relationship between WBC count and cardiovascular mortality WBC count has no effect on cancer mortality
RESULTS (2) 1.62 (0.9, 2.8) 1.28 (1.0, 1.6) 1.0 (Ref) - Adjusted Risk Ratio (95% C.I.) ‡ 1.76 (1.3, 2.3) 1.24 (1.1,1.4) 1.0 (Ref) 1.53 (0.6, 3.7) Adjusted Risk Ratio (95%C.I.) * 1.99 (1.5, 2.6) 1.54 (1.3, 1.8) 1.0 (Ref) 1.40 (0.6, 3.4) Risk Ratio (95%C.I.) Rate/1000 person-years 2,547 26,73018,726345Person-Years, (n) White Blood Cell Count, (group) >10,0006,001-10,0003,501-6,000<3,500 Time to event * Cox proportional hazard model adjusted for age, sex, race, BMI and smoking; ‡ Cox proportional hazard model adjusted for age, sex, race, BMI, smoking, physical activity, systolic and diastolic blood pressure, cholesterol, triglyceride and diabetes.
RESULTS (2)Time-dependent Model 1Model 2Model 3 WBC<3, (1.6,5.3) 3.3 (1.4,8.0) 1.9 (1.2,3.1) 3,50110, (1.6,2.5) 2.1 (1.4,3.1) 0.9 (0.6,1.3) Neutrophils (cells/mm 3 )1.2 (1.1,1.3) Model 1: adjusted for age, date, sex, race; Model 2: adjusted for all covariates in Model 1 and BMI, physical activity, smoking, blood pressure, cholesterol, triglycerides, diabetes; Model 3: adjusted for all covariates in Model 2 and neutrophils.
Age-adjusted mortality rate in each WBC group across successive decades RESULTS (3) ,500-6,000 6,001-10,000 >10,000 Rate/1000 persons
RESULTS (3) Mortality risk ratios among the WBC groups across decades Mortality risk ratio ,5 1 1,5 2 2,5 (Ref) 3,500-6,000 6,001-10,000 >10, Risk ratios adjusted for age, sex, smoking, race, BMI, blood pressure, cholesterol, diabetes.
CONCLUSION (1) A WBC count downward trend was observed in the BLSA participants from 1958 to 2002 The relationship between WBC count and all-cause mortality was non-linear Participants with WBC 3,500-6,000 cells/mm 3 had the lowest mortality risk and it significantly increased above WBC >6,000 cells/mm 3 The downward secular trend in WBC count was not a strong determinant of the mortality decline