Conference report on stroke mortality in the southeastern United States

Abstract

A workshop to describe and then seek possible causes for the increased stroke mortality in the southeastern United States briefly considered 30 suspected correlates and discussed in more detail the 10 thought to be most likely. Recent age-adjusted stroke mortality rates in adults from industrialized countries reveal marked geographic differences. Age-adjusted statewide stroke mortality rates also differ, and they are higher in the Southeast than elsewhere in the United States. For five southeastern coastal states in the heart of the "Stroke Belt," excess stroke mortality has been present at least since 1930. In a 20-year follow-up of 10,000 veterans, the Stroke Belt had a 25% increase in all-cause mortality and congestive heart failure. A potential cause of increased fatal stroke included hypertension, which was more frequent in the Stroke Belt. No consistent patterns of lifestyle differences or of differences in potassium or calcium intake seemed to explain the higher rates of fatal strokes in the Stroke Belt; however, detailed investigations of smaller populations in localized areas seem warranted. Some data suggest a relationship between socioeconomic status and the Stroke Belt effect. Other differences in the Southeast that could explain, at least partially, the Stroke Belt effect include presence of soft water throughout most of the area, decreased antioxidant intake, and differences in the use of medical care and in the response to antihypertensive drugs. On the basis of available information, the three most likely explanations or partial explanations for the Stroke Belt are increased levels of blood pressure, localized differences in socioeconomic status, and toxic environmental factor(s). Two major recommendations were made: (1) to encourage both patient and caregiver to use all currently available means of decreasing morbidity and mortality by controlling blood pressures at or below normal levels and by reducing other risk factors and (2) to seek precise information about relationships of identified possible causes of increased morbidity and mortality in the Stroke Belt.