BACKGROUND: Clinical studies suggest that hypertensives have lower mean corpuscular volume (MCVs) than do normotensives. Epidemiological studies show no relation or higher MCVs. In the present study of elderly men (71 to 93 years of age) of the Honolulu Heart Program, elements of both findings are confirmed. METHODS AND RESULTS: Three groups are identified: (1) those receiving no hypertension treatment, (2) those receiving treatment with any diuretic, and (3) those receiving treatment with nondiuretics only. MCV is lower in group 3 than in group 1 (-0.85 fL, P<.001) but the same in groups 1 and 2. Within groups 1 and 3, inverse relations of -0.22 and -0.09 mm Hg/fL (P<.05) are noted for systolic (SBP) and diastolic (DBP) blood pressures. No relations are observed in group 2. MCV and red blood cell count (RBC) are inversely correlated (r=-.45). In group 2, adjustment for RBC unmasks a direct relation between MCV and SBP (0.5 mm Hg/fL, P=.02) and DBP (0.3 mm Hg/fL, P=.02). In groups 1 and 3, relations between SBP and MCV are lost after adjustment for RBC (0.005 mm Hg/fL). For DBP, adding RBC plus an MCV x RBC interaction is significant (P<.001). DBP is 5 mm Hg greater in the highest RBC quartile than in the lowest. A +3 mm Hg difference between extreme MCV quartiles is noted only at high RBC levels. CONCLUSIONS: The relation between blood pressure and red cell measures is probably mediated by whole blood viscosity. Hematocrit is a determinant of whole blood viscosity. Viscosity affects peripheral resistance to blood flow, and peripheral resistance affects DBP. At high RBC levels, MCV may be "downregulated." This may lower whole blood viscosity and partially reduce DBP without compromising flow.
BACKGROUND: Clinical studies suggest that hypertensives have lower mean corpuscular volume (MCVs) than do normotensives. Epidemiological studies show no relation or higher MCVs. In the present study of elderly men (71 to 93 years of age) of the Honolulu Heart Program, elements of both findings are confirmed. METHODS AND RESULTS: Three groups are identified: (1) those receiving no hypertension treatment, (2) those receiving treatment with any diuretic, and (3) those receiving treatment with nondiuretics only. MCV is lower in group 3 than in group 1 (-0.85 fL, P<.001) but the same in groups 1 and 2. Within groups 1 and 3, inverse relations of -0.22 and -0.09 mm Hg/fL (P<.05) are noted for systolic (SBP) and diastolic (DBP) blood pressures. No relations are observed in group 2. MCV and red blood cell count (RBC) are inversely correlated (r=-.45). In group 2, adjustment for RBC unmasks a direct relation between MCV and SBP (0.5 mm Hg/fL, P=.02) and DBP (0.3 mm Hg/fL, P=.02). In groups 1 and 3, relations between SBP and MCV are lost after adjustment for RBC (0.005 mm Hg/fL). For DBP, adding RBC plus an MCV x RBC interaction is significant (P<.001). DBP is 5 mm Hg greater in the highest RBC quartile than in the lowest. A +3 mm Hg difference between extreme MCV quartiles is noted only at high RBC levels. CONCLUSIONS: The relation between blood pressure and red cell measures is probably mediated by whole blood viscosity. Hematocrit is a determinant of whole blood viscosity. Viscosity affects peripheral resistance to blood flow, and peripheral resistance affects DBP. At high RBC levels, MCV may be "downregulated." This may lower whole blood viscosity and partially reduce DBP without compromising flow.
Authors: Robert W Read; Karen A Schlauch; Gai Elhanan; William J Metcalf; Anthony D Slonim; Ramsey Aweti; Robert Borkowski; Joseph J Grzymski Journal: PLoS One Date: 2019-06-13 Impact factor: 3.240
Authors: Jundong Liu; Elizabeth L Chou; Kui Kai Lau; Peter Yat Ming Woo; Tsz Kin Wan; Ruixuan Huang; Kei Hang Katie Chan Journal: HGG Adv Date: 2022-08-10
Authors: Santhi K Ganesh; Neil A Zakai; Frank J A van Rooij; Nicole Soranzo; Albert V Smith; Michael A Nalls; Ming-Huei Chen; Anna Kottgen; Nicole L Glazer; Abbas Dehghan; Brigitte Kuhnel; Thor Aspelund; Qiong Yang; Toshiko Tanaka; Andrew Jaffe; Joshua C M Bis; Germaine C Verwoert; Alexander Teumer; Caroline S Fox; Jack M Guralnik; Georg B Ehret; Kenneth Rice; Janine F Felix; Augusto Rendon; Gudny Eiriksdottir; Daniel Levy; Kushang V Patel; Eric Boerwinkle; Jerome I Rotter; Albert Hofman; Jennifer G Sambrook; Dena G Hernandez; Gang Zheng; Stefania Bandinelli; Andrew B Singleton; Josef Coresh; Thomas Lumley; André G Uitterlinden; Janine M Vangils; Lenore J Launer; L Adrienne Cupples; Ben A Oostra; Jaap-Jan Zwaginga; Willem H Ouwehand; Swee-Lay Thein; Christa Meisinger; Panos Deloukas; Matthias Nauck; Tim D Spector; Christian Gieger; Vilmundur Gudnason; Cornelia M van Duijn; Bruce M Psaty; Luigi Ferrucci; Aravinda Chakravarti; Andreas Greinacher; Christopher J O'Donnell; Jacqueline C M Witteman; Susan Furth; Mary Cushman; Tamara B Harris; Jing-Ping Lin Journal: Nat Genet Date: 2009-10-11 Impact factor: 38.330
Authors: Keyue Ding; Mariza de Andrade; Teri A Manolio; Dana C Crawford; Laura J Rasmussen-Torvik; Marylyn D Ritchie; Joshua C Denny; Daniel R Masys; Hayan Jouni; Jennifer A Pachecho; Abel N Kho; Dan M Roden; Rex Chisholm; Iftikhar J Kullo Journal: G3 (Bethesda) Date: 2013-07-08 Impact factor: 3.154