title: Hematocrit is associated with carotid atherosclerosis in men but not in women.
abstract: BACKGROUND
  It is known that blood and plasma viscosities are associated with clinical manifestations of atherosclerosis, though evidence is not conclusive particularly in women.
  
  
  OBJECTIVE
  To verify whether hematocrit and blood and plasma viscosities are independently associated with carotid atherosclerosis and whether their measurement can improve the definition of the global coronary heart disease (CHD) risk.
  
  
  METHODS
  Eight hundred and ninety-two participants in a cardiovascular disease prevention campaign were examined with regard to conventional CHD risk factors (age, blood pressure, lipids, glucose, body mass index, waist/hip ratio, cigarette smoking and diabetes), hematocrit and blood and plasma viscosities. According to the degree of carotid atherosclerosis, investigated by echo-Doppler, participants were divided in three groups: those without atherosclerosis, those with a low degree of atherosclerosis and those with a high degree of atherosclerosis.
  
  
  RESULTS
  In men, age, blood pressure, intima-media thickness (IMT), hematocrit (47.4+/-3.7%, 47.8+/-3.7%, 48.4+/-3.7%, P<0.05) and blood viscosity (4.69+/-0.51 cP, 4.77+/-0.55 cP, 4.82+/-0.51 cP, P=0.05) increased with increasing degree of carotid atherosclerosis. In women, age, blood pressure, total cholesterol and low-density lipoprotein-cholesterol, IMT and plasma viscosity (1.42+/-0.12 cP, 1.44+/-0.11 cP, 1.46+/-0.13 cP, P<0.05) increased with increasing carotid score. Analysis of covariance (ANCOVA) showed that after adjusting for hematocrit, blood viscosity was no longer different in the three groups. In discriminant analysis, hematocrit, among the hemorheological variables investigated, was independently associated with carotid score in men (F=3.66, P<0.05). Neither hematocrit nor blood and plasma viscosities were significantly associated with carotid score in women.
  
  
  CONCLUSIONS
  These findings suggest that in men, both hematocrit and blood viscosity are related to carotid atherosclerosis but hematocrit would appear to have an independent effect over and above that mediated by viscosity.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Catanzaro Magna Graecia, Italy.
authors.forename: Concetta
authors.initials: C
authors.lastname: Irace
authors.forename: Monica
authors.initials: M
authors.lastname: Ciamei
authors.forename: Andrea
authors.initials: A
authors.lastname: Crivaro
authors.forename: Elio
authors.initials: E
authors.lastname: Fiaschi
authors.forename: Angela
authors.initials: A
authors.lastname: Madia
authors.forename: Claudio
authors.initials: C
authors.lastname: Cortese
authors.forename: Agostino
authors.initials: A
authors.lastname: Gnasso
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001161:Arteriosclerosis / Q000097:blood* / Q000000981:diagnostic imaging / Q000209:etiology; D001809:Blood Viscosity; D002340:Carotid Artery Diseases / Q000097:blood* / Q000000981:diagnostic imaging / Q000209:etiology; D015150:Echocardiography, Doppler; D005260:Female; D006400:Hematocrit; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012737:Sex Factors