Risk factors for stroke have been classified as ‘non-modifiable’ or ‘modifiable’ (Goldstein et al 2001). Modifiable risk factors are those factors that can be managed or treated and include high blood pressure, smoking, diabetes, atrial fibrillation and hyperlipidaemia (an inherited blood disorder associated with high serum cholesterol) (Wolf and D’Agostino 1993). Non-modifiable risk factors include age, gender, race and ethnicity and family history (Gillum 1998; Gorelick 1998).
Studies have shown that stroke incidence in the USA is higher in blacks than in whites (Gorelick 1998; Howard et al 1994). In a study investigating risk factors in stroke, Gillum (1999) found that blacks had a 38 per cent greater incidence of strokes than whites. This may be because the incidence of high blood pressure, obesity and diabetes mellitus is higher in the black population than the white population (Gillum 1999).
Cigarette smoking Several studies have shown that cigarette smoking is a major risk factor for stroke (Shaper et al 1991; Wannamethee et al 1995; Wishant, 1997) In a population of 7,735 British men monitored for eight years, cigarette smoking was found to be associated with a risk of having a stroke (Shaper et al 1991). Shinton and Beevers (1989) found that cigarette smoking increased the risk of cerebral infarction among smokers compared to non-smokers. However, the risk of stroke disappeared two to four years after stopping smoking (Kawachi, Colditz and Stampfer 1993). In the only study in Saudi Arabia, El Sayed et al (1999) found that 1.8 per cent of stroke survivors who been admitted to hospital were smokers, although these results should be carefully interpreted because there were no comparisons between smokers and non-smokers.