Stroke Belt
Encyclopedia
Stroke Belt or Stroke Alley is a name given to a region in the southeastern United States
that has been recognized by public health authorities for having an unusually high incidence of stroke
and other forms of cardiovascular disease
. It is typically defined as an 11-state region consisting of Alabama
, Arkansas
, Georgia
, Indiana
, Kentucky
, Louisiana
, Mississippi
, North Carolina
, South Carolina
, Tennessee
, and Virginia
.
Although many possible causes for the high stroke incidence have been investigated, the reasons for the phenomenon have not been determined.
s of Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia. In 1980 these eleven states had age-adjusted stroke mortality rate
s more than 10% above the national average. Some investigators also consider northern Florida
to be a part of the stroke belt, based on a stroke mortality rate higher than several states included in the region. East Texas
also is characterized as a stroke belt.
researchers who noted a concentration of high stroke death rate
s in the Atlantic coastal plain
counties of North Carolina
, South Carolina
and Georgia
. Similar high stroke rates were later observed in the Mississippi Delta
region as well.
Analysis by the CDC of U.S. mortality statistics
from the period 1991 to 1998 found that for both blacks
and white
s the counties with the highest stroke death rates were in the southeastern states and the Mississippi Delta
region. Stroke death rates for states ranged from a high of 169 per 100,000 in South Carolina to a low of 89 per 100,000 in New York
. While most observational studies have focused primarily on stroke incidence in adults, in 2004 researchers reported that children in the eleven stroke belt states also have an increased risk of death from ischemic and hemorrhagic stroke compared with children in other states. Glymour et al. (2007) reported that adults who had resided in the stroke belt during childhood and had moved outside the region had higher stroke risk at ages 50 and older than adults who grew up in areas with lower stroke incidence. A study reported in 2011 found that people over age 45 living in the eight "stroke belt" states of Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee had an 18 percent higher incidence of cognitive decline than people in other U.S. regions. Another researcher noted that, "Stroke by itself is a major contributor to cognitive impairment and dementia." Other researchers have made similar observations.
In 2011, CDC researchers mapped the occurrence of diabetes in the U.S. by county, finding that highest prevalence of diabetes is in a "diabetes belt" that has extensive overlap with the stroke belt.
, diet, cultural lifestyle, quality of healthcare facilities, smoking
, and infection
s. Among the specific factors that have been proposed or studied are the following:
programs specifically aimed at reducing stroke incidence and mortality in the stroke belt. In the 1990s the Stroke Belt Initiative operated in eleven stroke belt states, providing nutrition
education, blood pressure screening, smoking cessation
programs, weight loss
programs, and other health promotion and public education initiatives targeted at stroke risk factors. In 2004, the Stroke Belt Elimination Initiative of the U.S. Department of Health and Human Services awarded grant
s aimed at reducing the high incidence of stroke and high rates of stroke death and disability in the seven states with the highest rates of stroke (Alabama, Arkansas, Georgia, Mississippi, North Carolina, South Carolina, and Tennessee).
such as "snow belt" and "sun belt
." Extending the analogy to the belt as an article of clothing
, the coastal plain
counties of the Carolinas and Georgia, where the stroke belt phenomenon was first described and where stroke incidence is highest, are sometimes called the "buckle
of the stroke belt."
Southeastern United States
The Southeastern United States, colloquially referred to as the Southeast, is the eastern portion of the Southern United States. It is one of the most populous regions in the United States of America....
that has been recognized by public health authorities for having an unusually high incidence of stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
and other forms of cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
. It is typically defined as an 11-state region consisting of Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
, Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
, Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
, Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
, Kentucky
Kentucky
The Commonwealth of Kentucky is a state located in the East Central United States of America. As classified by the United States Census Bureau, Kentucky is a Southern state, more specifically in the East South Central region. Kentucky is one of four U.S. states constituted as a commonwealth...
, Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
, Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...
, North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
, South Carolina
South Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
, Tennessee
Tennessee
Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...
, and Virginia
Virginia
The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...
.
Although many possible causes for the high stroke incidence have been investigated, the reasons for the phenomenon have not been determined.
Geographic scope
The stroke belt is typically defined to include the stateU.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
s of Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia. In 1980 these eleven states had age-adjusted stroke mortality rate
Mortality rate
Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...
s more than 10% above the national average. Some investigators also consider northern Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
to be a part of the stroke belt, based on a stroke mortality rate higher than several states included in the region. East Texas
East Texas
East Texas is a distinct geographic and ecological area in the U.S. state of Texas.According to the Handbook of Texas, the East Texas area "may be separated from the rest of Texas roughly by a line extending from the Red River in north central Lamar County southwestward to east central Limestone...
also is characterized as a stroke belt.
History of observations
The stroke belt was first identified in 1962 by Centers for Disease Control (CDC)Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
researchers who noted a concentration of high stroke death rate
Mortality rate
Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...
s in the Atlantic coastal plain
Atlantic Coastal Plain
The Atlantic coastal plain has both low elevation and low relief, but it is also a relatively flat landform extending from the New York Bight southward to a Georgia/Florida section of the Eastern Continental Divide, which demarcates the plain from the ACF River Basin in the Gulf Coastal Plain to...
counties of North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
, South Carolina
South Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
and Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
. Similar high stroke rates were later observed in the Mississippi Delta
Mississippi Alluvial Plain
The Mississippi River Alluvial Plain is an alluvial plain created by the Mississippi River on which lies parts of seven states, from southern Louisiana to southern Illinois....
region as well.
Analysis by the CDC of U.S. mortality statistics
Mortality rate
Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...
from the period 1991 to 1998 found that for both blacks
African American
African Americans are citizens or residents of the United States who have at least partial ancestry from any of the native populations of Sub-Saharan Africa and are the direct descendants of enslaved Africans within the boundaries of the present United States...
and white
White people
White people is a term which usually refers to human beings characterized, at least in part, by the light pigmentation of their skin...
s the counties with the highest stroke death rates were in the southeastern states and the Mississippi Delta
Mississippi Delta
The Mississippi Delta is the distinctive northwest section of the U.S. state of Mississippi that lies between the Mississippi and Yazoo Rivers. The region has been called "The Most Southern Place on Earth" because of its unique racial, cultural, and economic history...
region. Stroke death rates for states ranged from a high of 169 per 100,000 in South Carolina to a low of 89 per 100,000 in New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
. While most observational studies have focused primarily on stroke incidence in adults, in 2004 researchers reported that children in the eleven stroke belt states also have an increased risk of death from ischemic and hemorrhagic stroke compared with children in other states. Glymour et al. (2007) reported that adults who had resided in the stroke belt during childhood and had moved outside the region had higher stroke risk at ages 50 and older than adults who grew up in areas with lower stroke incidence. A study reported in 2011 found that people over age 45 living in the eight "stroke belt" states of Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee had an 18 percent higher incidence of cognitive decline than people in other U.S. regions. Another researcher noted that, "Stroke by itself is a major contributor to cognitive impairment and dementia." Other researchers have made similar observations.
In 2011, CDC researchers mapped the occurrence of diabetes in the U.S. by county, finding that highest prevalence of diabetes is in a "diabetes belt" that has extensive overlap with the stroke belt.
Hypotheses on causation
The causes of the elevated incidence of stroke in the stroke belt region have not been determined. Numerous possible contributing factors have been identified, including hypertension, low socioeconomic statusSocioeconomic status
Socioeconomic status is an economic and sociological combined total measure of a person's work experience and of an individual's or family’s economic and social position in relation to others, based on income, education, and occupation...
, diet, cultural lifestyle, quality of healthcare facilities, smoking
Smoking
Smoking is a practice in which a substance, most commonly tobacco or cannabis, is burned and the smoke is tasted or inhaled. This is primarily practised as a route of administration for recreational drug use, as combustion releases the active substances in drugs such as nicotine and makes them...
, and infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
s. Among the specific factors that have been proposed or studied are the following:
- It has been suggested that the higher stroke death rates in the stroke belt are due to the region's high African AmericanAfrican AmericanAfrican Americans are citizens or residents of the United States who have at least partial ancestry from any of the native populations of Sub-Saharan Africa and are the direct descendants of enslaved Africans within the boundaries of the present United States...
population, because African Americans' stroke death rates are higher than the national average. However, because white people also have higher rates of stroke death in the stroke belt than in other parts of the country, the higher death rates in the stroke belt cannot be attributed solely to the region's higher proportion of African Americans. - In the early 1990s it was hypothesized that seleniumSeleniumSelenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...
deficiency in the soilSoilSoil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
s of the coastal plain might be a causative factor. The subsequent recognition of high stroke incidence in areas with different soil characteristics led researchers to reject this hypothesis. - Some observers have assumed that more stroke belt residents suffer from untreated hypertensionHypertensionHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
. However, researchers have found that residents of the southern United StatesSouthern United StatesThe Southern United States—commonly referred to as the American South, Dixie, or simply the South—constitutes a large distinctive area in the southeastern and south-central United States...
are as likely to be aware of hypertension and receiving treatment as residents of other U.S. regions. Additionally, researchers who documented the region's elevated incidence of pediatric stroke noted that "If the stroke belt is solely caused by regional differences in atherosclerotic stroke risk factors, it should not apply to children." - It has been suggested that one cause of higher mortality may be the predominantly rural character of the region, which increases the distances that patients must travel to obtain emergency medical treatment. Regional differences in standards of medical care have also been suggested as a contributing factor. In one study, researchers found that patients discharged from hospitals in the stroke belt after suffering acute myocardial infarctionMyocardial infarctionMyocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
were less likely to be treated with warfarinWarfarinWarfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...
than patients in most other U.S. regions.
- Glymour et al. (2007) suggested that the higher stroke incidence in the stroke belt is related to experiences or exposures in childhood.
- It has been proposed that povertyPovertyPoverty is the lack of a certain amount of material possessions or money. Absolute poverty or destitution is inability to afford basic human needs, which commonly includes clean and fresh water, nutrition, health care, education, clothing and shelter. About 1.7 billion people are estimated to live...
and malnutritionMalnutritionMalnutrition is the condition that results from taking an unbalanced diet in which certain nutrients are lacking, in excess , or in the wrong proportions....
in previous generations, which resulted in poor maternal prenatal nutritionPrenatal carePrenatal care refers to the medical and nursing care recommended for women before and during pregnancy. The aim of good prenatal care is to detect any potential problems early, to prevent them if possible , and to direct the woman to appropriate specialists, hospitals, etc...
and low birth weightLow birth weightLow birth weight is defined as a birth weight of a liveborn infant of less than 2,500 g. regardless of gestational age-Causes:LBW is either the result of preterm birth or of the infant being small for gestational age , or a combination of...
s, led to a predisposition to cardiovascular disease in adult life. - DietDiet (nutrition)In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
s high in fried and high-fatFatFats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
foods (such as fried chickenFried chickenFried chicken is a dish consisting of chicken pieces usually from broiler chickens which have been floured or battered and then pan fried, deep fried, or pressure fried. The breading adds a crisp coating or crust to the exterior...
, which are prevalent in the region, are thought to contribute to higher risk. - The same geographical area also has a higher than national average incidence of lung cancerLung cancerLung cancer is a disease characterized by uncontrolled cell growth in tissues of the lung. If left untreated, this growth can spread beyond the lung in a process called metastasis into nearby tissue and, eventually, into other parts of the body. Most cancers that start in lung, known as primary...
, as it is where much of the tobaccoTobaccoTobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...
in the United States is grown. SmokingSmokingSmoking is a practice in which a substance, most commonly tobacco or cannabis, is burned and the smoke is tasted or inhaled. This is primarily practised as a route of administration for recreational drug use, as combustion releases the active substances in drugs such as nicotine and makes them...
is reputed to be the strongest contributing factor of developing both diseases
Public health initiatives to reduce stroke incidence in the region
The U.S. federal government has conducted public healthPublic health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals" . It is concerned with threats to health based on population health...
programs specifically aimed at reducing stroke incidence and mortality in the stroke belt. In the 1990s the Stroke Belt Initiative operated in eleven stroke belt states, providing nutrition
Nutrition
Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....
education, blood pressure screening, smoking cessation
Smoking cessation
Smoking cessation is the process of discontinuing the practice of inhaling a smoked substance. This article focuses exclusively on cessation of tobacco smoking; however, the methods described may apply to cessation of smoking other substances that can be difficult to stop using due to the...
programs, weight loss
Weight loss
Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...
programs, and other health promotion and public education initiatives targeted at stroke risk factors. In 2004, the Stroke Belt Elimination Initiative of the U.S. Department of Health and Human Services awarded grant
Grant (money)
Grants are funds disbursed by one party , often a Government Department, Corporation, Foundation or Trust, to a recipient, often a nonprofit entity, educational institution, business or an individual. In order to receive a grant, some form of "Grant Writing" often referred to as either a proposal...
s aimed at reducing the high incidence of stroke and high rates of stroke death and disability in the seven states with the highest rates of stroke (Alabama, Arkansas, Georgia, Mississippi, North Carolina, South Carolina, and Tennessee).
Terminology
The term "stroke belt" is modeled on similar terms for U.S. regionsBelt regions of the United States
The belt regions of the United States are portions of the country that share certain characteristics. The "belt" terminology was first applied to growing regions for various crops, which often follow lines of latitude because those are more likely to have similar climates...
such as "snow belt" and "sun belt
Sun Belt
The Sun Belt or Spanish Belt is a region of the United States generally considered to stretch across the South and Southwest . Another rough boundary of the region is the area south of the 36th parallel, north latitude. It is the largest region which the U.S government does not recognize officially...
." Extending the analogy to the belt as an article of clothing
Belt (clothing)
A belt is a flexible band or strap, typically made of leather or heavy cloth, and worn around the waist. A belt supports trousers or other articles of clothing.-History:...
, the coastal plain
Coastal plain
A coastal plain is an area of flat, low-lying land adjacent to a seacoast and separated from the interior by other features. One of the world's longest coastal plains is located in eastern South America. The southwestern coastal plain of North America is notable for its species diversity...
counties of the Carolinas and Georgia, where the stroke belt phenomenon was first described and where stroke incidence is highest, are sometimes called the "buckle
Buckle
The buckle or clasp is a device used for fastening two loose ends, with one end attached to it and the other held by a catch in a secure but adjustable manner. Usually overlooked and taken for granted, the invention of the buckle has been indispensable in securing two ends before the invention of...
of the stroke belt."
External links
- Atlas of Stroke Mortality: Racial, Ethnic and Geographic Disparities in the United States, Centers for Disease Control and Prevention
- Stroke Statistics, Internet Stroke Center at Washington University