Factors Explaining Excess Stroke Prevalence: The Spanish Stroke Belt
To the Editor:
We have read with interest the article of Liao et al on factors explaining excess stroke prevalence in the US stroke belt.1 Identifying the factors contributing to stroke disparities is clearly an important question, as long as the precise reason for this has been a topic of debate and controversy for decades. Moreover, we consider that when these results are also congruent with the data published in other countries, the key role of these factors on stroke disparity is reinforced.
Stroke remains a major health care problem in Spain.2 In addition, as in the United States, rates of stroke prevalence and mortality also differ largely among different parts of the country. Likewise, an area in southeastern Spain has an unusually high rate of strokes and other forms of cardiovascular disease, particularly the area of Andalusia, with ≈50% higher stroke mortality rates.2 Remarkably, and according to Liao et al data, in this area, we also find the highest incidence of prevalent chronic diseases (hypertension, diabetes, and coronary heart disease), risk factors (overweight, obesity, and smoking),3 and the worst socioeconomic status (education and income).4 Thus, for instance, in Andalusia, among the population ≥60 years of age, the prevalence of diagnosed hypertension and the prevalence of ECG–left ventricular hypertrophy are 79.4% and 19.6%, respectively, the highest values in the Spanish population (with a mean of 73% and 12.9%, respectively).3,5 Furthermore, the control rate of hypertension in this population is 28.5%, which is the lowest in the country.3 As expected, a direct relationship between stroke mortality rates and the prevalence and control rates of hypertension has been demonstrated.3,5
Therefore, the effect of these factors on the total burden of stroke in different countries is similar and substantial. Additional global efforts are needed to understand and reduce these huge disparities and finally eliminate these stroke belts.
Liao Y, Greenlund KJ, Croft JB, Keenan NL, Giles WH. Factors explaining excess stroke prevalence in the US Stroke Belt. Stroke. 2009; 40: 3336–3341.
Ministerio de Sanidad y Consumo. Estadisticas y publicaciones. Disponible en: http://www.msc.es/estadEstudios/estadisticas/inforRecopilaciones/mortalidad/tablasSeleccion.htm. Accessed on: October 14, 2009.
Redón J, Cea-Calvo L, Lozano JV, Martí-Canales JC, Llisterri JL, Aznar J, González-Esteban J. PREV-ICTUS Study. Differences in blood pressure control and stroke mortality across Spain: the Prevención de Riesgo de Ictus (PREV-ICTUS) study. Hypertension. 2007; 49: 799–805.
Ministerio de Sanidad y Consumo. Estadisticas y publicaciones. Disponible en www.ine.es/daco/daco42/daco4211/epapro0209.pdf. Accessed on: October 14, 2009.
Redón J, Cea-Calvo L, Lozano JV, Martí-Canales JC, Llisterri JL, Aznar J, González-Esteban J. Investigators of the PREV-ICTUS study. Blood pressure and estimated risk of stroke in the elderly population of Spain: the PREV-ICTUS study. Stroke. 2007; 38: 1167–1173.