Blood Pressure and Haematological Indices in Twelve Communities in Ashanti, Ghana

Abstract

Cardiovascular disease has become an important cause of premature death and disability in Sub-Saharan Africa [1, 2]. Hypertension is known to be the major contributor [3] and is itself a consequence of increasing urbanisation and an increasingly western lifestyle, exemplified by increasing obesity, higher salt intake, and a sedentary lifestyle. Another contributory factor to hypertension may be blood viscosity. Plasma and whole blood viscosity have been suggested as important determinants of arterial blood pressure [4–9] both in normotensive individuals and in those with untreated hypertension. Others, meanwhile, have suggested that both blood pressure and viscosity are themselves secondary to factors such as obesity, mental stress, smoking, and physical inactivity [10]. Nonetheless, it is possible that whole blood viscosity plays a part in the genesis of stroke and coronary artery disease [11–15] and cardiac hypertrophy [16]. Of the factors contributing to whole blood viscosity, haematocrit, red cell aggregability, red cell rigidity, and plasma viscosity, haematocrit is thought to be the most important, being responsible for at least 70% of the contribution [17]. However, others have not found a correlation between blood pressure and blood viscosity in normotensives [18, 19]. Most of the evidence relating blood pressure to blood viscosity is derived from studies from the developed world. There is very little data on the relationship between blood pressure and blood viscosity from Sub-Saharan Africa [20].