Risk Factors for Stroke in Blacks: A Critical Review

Abstract

Stroke is the third leading cause of death in US Blacks and is an important cause of mortality and morbidity worldwide. Mortality rates are higher in Blacks than in Whites in the United States at ages below 70 years. In Blacks, advanced age, elevated blood pressure, diabetes mellitus, and smoking are the only risk factors for stroke whose status has been firmly established by published data. More data are needed to assess other likely risk factors of importance for risk stratification and intervention and to determine the fraction of racial differences in stroke that may be explained by risk factor differences. Higher prevalences of hypertension, diabetes, obesity (in women), elevated lipoprotein(a) level, smoking (in men), and low socioeconomic status may contribute to the higher stroke incidence and mortality in US Blacks as compared with Whites. However, further environmental influences must be studied and candidate genes identified before assuming that racial differences can be attributed to inborn susceptibility linked to inheritance of specific genes.

The relationship between blood pressure and blood lead in NHANES III

“…Candidate susceptibility genes remain the source of speculation, but differences in sodium sensitivity, cation transport, vascular injury, insulin resistance or adrenergic activity have been postulated as being important. 23,25 In the present analysis, blood pressure was corrected for body-mass index, dietary calcium, dietary sodium, dietary potassium, poverty index and the use of antihypertensive drugs, but the relation between blood pressure and blood lead remained significant in blacks. Though blood lead levels were lower in whites, the overlap in blood lead levels between blacks and whites was large, so that it seems unlikely that there is a threshold value for an effect of lead on blood pressure that was exceeded in blacks but not in whites.…”

“…Differences in food consumption patterns (higher sodium, lower potassium and calcium intake), higher prevalence of obesity, lower socio-economic status (resulting for example in less access to antihypertensive treatment) may contribute to the higher blood pressure in blacks. 23,24 Genetic differences also may be the cause of a higher inborn susceptibility to hypertension in blacks. Candidate susceptibility genes remain the source of speculation, but differences in sodium sensitivity, cation transport, vascular injury, insulin resistance or adrenergic activity have been postulated as being important.…”

Anestesia na população negra

“…As diferenças raciais de maior susceptibilidade podem ser inatas pela presença de HAS, diabetes tipo II, obesidade, tabagismo e elevado nível de liproteína (a), mas também podem funcionar em conjunto com o estado sócio-econômico desfavorável e a baixa qualidade de vida da população negra idosa. Ao lado da maior propensão ao AVC, o paciente negro é menos sensível ao t-PA (ativador do plasminogênio) no tratamento trombolítico 60 .…”

“…A terapêutica anti-hipertensiva inadequada é o achado mais comum na história clínica do negro nefropata, candidato à transplante renal. A taxa mais alta de rejeição do rim transplantado no receptor negro está mais relacionada à procura tardia do atendimento médico e à não aderência à terapêuti-ca anti-rejeição [60][61][62][63] . Implicação Anestésica: O controle laboratorial da função renal e vascular é indispensável para levar a anestesia a bom termo no negro nefropata.…”

“…Racial differences with more susceptibility may be innate by the presence of SAH, diabetes type II, obesity, smoking and high lipoprotein (a) levels, but they may also act together with the unfavorable socio-economic status and the low quality of life of elderly blacks. Together with a higher susceptibility to stroke, black patients are less sensitive to t-PA (plasminogen activator) during thrombolytic treatment 60 . Anesthetic Implication: race should be taken into consideration when controlling anesthetic depth with remifentanil associated to propofol, especially in intravenous continuous infusion anesthesia and also during the treatment of acute or chronic pain.…”