full pdf of issue - Middle East Journal of Family Medicine

ORIGINAL CONTRIBUTION AND CLINICAL INVESTIGATION
the corresponding shear rate that
has been used in its measurement
[1]. Factors that increase WBV
include haematocrit, total plasma
protein, erythrocyte aggregation and
erythrocyte deformability [9, 10]. The
present study showed that packed
cell volume and plasma viscosity were
increased and then subsequently
whole blood viscosity increased.
Hematocrit is the most important
determinant of blood viscosity under
bulk flow conditions (e.g., large
diameter vessels or large geometry
viscometers)[11]. The physiological
meaning of hematocrit value should
be carefully considered. On one
hand, the hematocrit value reflects
the oxygen carrying capacity of
blood since higher hematocrit usually
correlates with higher hemoglobin
concentration and higher oxygen
binding capacity. On the other hand,
the hematocrit value is logarithmically
related to blood viscosity, hence
a determinant of flow resistance.
Oxygen transfer to a given tissue
is a function of both blood flow to
that tissue and oxygen content of
blood flowing to that tissue. Above
this critical value of hematocrit,
increased blood viscosity and flow
resistance would dominate and the
main physiological function of blood
flow (i.e., supplying oxygen to tissues)
would be impaired[12]. Being related
to the physiological importance of
an optimal hematocrit value, RBC
production is a well-controlled
process [13]. The main control factor
of RBC production is the hormone
erythropoietin, and its secretion is,
in turn, controlled by the degree
of tissue oxygenation [13]. Among
the 4,000 or more toxic substances
absorbed during smoking, carbon
monoxide (CO) and glycoproteins
play a particularly important role in
the development of smoking related
arteriosclerotic changes, and the
severity of the changes produced
is influenced by the cigarette dose
and smoking duration [14]. Plasma
Viscosity unlike suspensions of
red cells in plasma or whole blood,
plasma and serum are Newtonian
fluids with their viscosity independent
of shear rate. This means that their
viscosity is an intrinsic property of the
liquid itself and there is no need to
measure plasma or serum viscosity
at defined shear rates [11]. Changes
in the concentration of one or more
plasma protein fractions will result in
a change in plasma viscosity. Plasma
viscosity (PV) depends primarily
on plasma protein concentration,
indicating that PV can vary in disease
[15]. As a result, the fluidity of the
blood is lowered and the viscosity of
whole blood and plasma is increased
[16, 17]. Plasma protein levels show a
dose dependent increase in smokers;
following smoking cessation, levels
decrease towards similar values in
those who have never smoked.
Conclusion
The percentage of cigarette smokers
is high compared to ex and never
smoked persons in Sakaka city,
Saudi Arabia. The common reason
for smoking was the influence of the
family which can be parent imitation,
family careless, family breakdown or
other reasons. The smoking leads
to a rise in hematocrit and alters the
rheological properties by increasing
whole blood viscosity and plasma
viscosity levels. Further prospective
and public health studies would
be required to deal with common
reasons which influence smoking
behavior as well as to deal with the
blood rheological changes. The
hematological and hemorheological
changes associated with long
standing cigarette smoking and to
assess whether any such changes
were reversible after smoking was
stopped, should be established.
References
[1] Baskurt, OK; Hardeman M,
Rampling MW, Meiselman HJ
(2007). Handbook of Hemorheology
and Hemodynamics. Amsterdam,
Netherlands: IOS Press. ISBN 978-1-
58603-771-1.
[2] Kwaan HC, Bongu A. The
hyperviscosity syndromes.
SeminThromb Hemostas 1999;
25:199-208.
[3] Craveri et al., 1987; Resch et al.,
1991; Lee et al., 1998; Kensey and
Cho, 2001
[4] Ross R: The pathogenesis of
atherosclerosis: a perspective for the
1990s. Nature 1993; 362:801-809.
[5] Doll R, Peto R, Boreham J,
Sutherland I:Mortality in relation to
smoking: 50 years’ observations on
male British doctors. Br Med J 2004;
328: 1519-1529.
[6] Lowe GDO, Donnan T, McColI
P et al. Blood viscosity, fibrinogen
and activation of coagulation and
leukocytes in peripheral arterial
disease: The Edinburgh Artery Study.
Br JHaematol 199I;77 (Suppl 1):27.
[7] Rogers RL, Meyers JS, Judd B et
al. Abstention from cigarette smoking
improves cerebral perfusion among
elderly chronic smokers.
[8] Lowe GD, Lee AJ, Rumley A,
Price JF, Fowkes FG. Blood viscosity
and risk of cardiovascular events:
the Edinburgh Artery Study. Br J
Haematol 1997; 96:168-173.
[9] Higgins C. Recurrence of venous
thromboembolism. The Biomedical
Scientist [Magazine], London 2006;
50:865-867.
[10] Tamariz LJ, Young JH, Pankow
JS et al. Blood viscosity and
hematocrit as risk factors for type 2
diabetes mellitus: the atherosclerosis
risk in communities (ARIC) study. Am
J Epidemiol. 2008; 168:1153-1160.
[11] Baskurt O.K., Yalcin O., Gungor F.
and Meiselman H.J., Hemorheological
parameters as determinants of
myocardial tissue hematocrit values,
Clin. Hemorheol.Microcirc. (2006),
45-50.
[12] Bogar L., Juricskay I., Kesmarky
G., Kenyeres P. and Toth K.,
Erythrocyte transport efficacy of
human blood: a rheological point of
view, Eur. J. Clin. Invest. (2005), 687-
690.
[13] Wintrobe M.M., Lee G.R., Boggs
D.R., Bithell T.C., Foerster J., Athens
J.W. and Lukens J.N. Erythropoiesis.
In: Clinical Hematology, Lea-Febiger,
Philadelphia, 1981, pp. 108-135.
[14] McBride PE. The health
consequences of smoking.
Cardiovascular diseases. Med
ClinNorth Am. 1992; 76(2):333-353.
[15] Rampling M.W.. Red cell
aggregation and yield stress. In:
Clinical blood rheology, G.D.O. Lowe,
Ed., CRC Press, Inc., Florida , 1988;.
45-64.
[16] Gudmundsson M, Bjelle A (1993)
Plasma, serum and whole-blood
viscosity variations with age, sex, and
smoking habits. Angiology 44(5):384-
391.
[17] Feher MD, Rampling MW,
Brown J, Robinson R, Richmond W,
Cholerton S ,et al. Acute changes
in atherogenic and thrombogenic
factors with cessation of smoking. J R
SocMed. 1990; 83(3):146-148
MIDDLE MIDDLE EAST EAST JOURNAL JOURNAL OF OF FAMILY MEDICINE VOLUME • VOLUME 10 ISSUE 7, ISSUE 6 10 17