The slavery hypertension hypothesis proposes that disproportionately high rates of hypertension among black people in the New World are due to selective pressure preferring individuals who retain more sodium among black slaves during the Middle Passage. [1]
It was originally proposed in 1983 by Clarence Grim and Thomas W. Wilson, who subsequently promoted it heavily during the remainder of the 1980s. It gained considerable media attention when Grim presented it at a conference in 1988. [2] In 1990, the first medical textbook mentioning the hypothesis was published. The first peer-reviewed paper advancing the hypothesis was published by Wilson and Grim in 1991. [3] This study also received considerable media attention. [4]
In December 2004, a paper titled CYP3A Variation and the Evolution of Salt-Sensitivity Variants was published which drew attention to the importance of the CPY3A5*1 and CPY3A5*3 alleles of cytochrome P450 CYP3A5 in hypertensive disease. [5] The paper showed a substantial correlation between geographical latitude and the CPY3A5 allele distribution, with African Americans descended from the slave trade having retained the equatorial haplotype.
In 2005 the thesis that black Americans who trace their immigration to the slave era experience lower life expectancy due to hypertensive disease associated with the slave trade was revisited by the academic team of David Cutler, Roland G. Fryer Jr. and Nathan Glazer. [6] This paper was circulated in mimeo, was presented at a conference, and received 12 citations in the literature despite never being published in a formal journal. The paper shows that Black Americans having descended from the slave trade have largely retained the allele associated with equatorial populations, have higher sodium retention than other populations in America (including black people who later emigrated to America after the slave trade had ended), and have correspondingly higher hypertensive disease. [7]
The thesis gained renewed media attention when Oprah Winfrey mentioned the hypothesis in an interview with Dr. Oz in 2007. [8]
Since it was originally proposed, the hypothesis has been challenged, [9] and it has been described as a "myth". [8] [10] Detractors argue that the hypothesis is inconsistent with historical evidence regarding salt deficiency in Africa or the causes of death aboard slave ships. [11] Grim and Robinson responded to Kaufman and Hall, maintaining the validity of the hypothesis and its consistency with historical descriptions of slavery. [12]
Hypertension, also known as high blood pressure, is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major risk factor for stroke, coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, vision loss, chronic kidney disease, and dementia. Hypertension is a major cause of premature death worldwide.
Tacrolimus, sold under the brand name Prograf among others, is an immunosuppressive drug. After allogenic organ transplant, the risk of organ rejection is moderate. To lower the risk of organ rejection, tacrolimus is given. The drug can also be sold as a topical medication in the treatment of T-cell-mediated diseases such as eczema and psoriasis. For example, it is prescribed for severe refractory uveitis after a bone marrow transplant, exacerbations of minimal change disease, Kimura's disease, and vitiligo. It can be used to treat dry eye syndrome in cats and dogs.
Pre-eclampsia is a multi-system disorder specific to pregnancy, characterized by the onset of high blood pressure and often a significant amount of protein in the urine. When it arises, the condition begins after 20 weeks of pregnancy. In severe cases of the disease there may be red blood cell breakdown, a low blood platelet count, impaired liver function, kidney dysfunction, swelling, shortness of breath due to fluid in the lungs, or visual disturbances. Pre-eclampsia increases the risk of undesirable as well as lethal outcomes for both the mother and the fetus including preterm labor. If left untreated, it may result in seizures at which point it is known as eclampsia.
Antihypertensives are a class of drugs that are used to treat hypertension. Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke, heart failure, kidney failure and myocardial infarction. Evidence suggests that reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34% and of ischaemic heart disease by 21%, and can reduce the likelihood of dementia, heart failure, and mortality from cardiovascular disease. There are many classes of antihypertensives, which lower blood pressure by different means. Among the most important and most widely used medications are thiazide diuretics, calcium channel blockers, ACE inhibitors, angiotensin II receptor antagonists (ARBs), and beta blockers.
Essential hypertension is a form of hypertension without an identifiable physiologic cause. It is the most common type affecting 85% of those with high blood pressure. The remaining 15% is accounted for by various causes of secondary hypertension. Essential hypertension tends to be familial and is likely to be the consequence of an interaction between environmental and genetic factors. Hypertension can increase the risk of cerebral, cardiac, and renal events.
Hypertensive kidney disease is a medical condition referring to damage to the kidney due to chronic high blood pressure. It manifests as hypertensive nephrosclerosis. It should be distinguished from renovascular hypertension, which is a form of secondary hypertension, and thus has opposite direction of causation.
Hypertensive heart disease includes a number of complications of high blood pressure that affect the heart. While there are several definitions of hypertensive heart disease in the medical literature, the term is most widely used in the context of the International Classification of Diseases (ICD) coding categories. The definition includes heart failure and other cardiac complications of hypertension when a causal relationship between the heart disease and hypertension is stated or implied on the death certificate. In 2013 hypertensive heart disease resulted in 1.07 million deaths as compared with 630,000 deaths in 1990.
Race and health refers to how being identified with a specific race influences health. Race is a complex concept that has changed across chronological eras and depends on both self-identification and social recognition. In the study of race and health, scientists organize people in racial categories depending on different factors such as: phenotype, ancestry, social identity, genetic makeup and lived experience. "Race" and ethnicity often remain undifferentiated in health research.
The health of slaves on American plantations was a matter of concern to both slaves and their owners. Slavery had associated with it the health problems commonly associated with poverty. It was to the economic advantage of owners to keep their working slaves healthy, and those of reproductive age reproducing. Those who could not work or reproduce because of illness or age were sometimes abandoned by their owners, expelled from plantations, and left to fend for themselves.
John Henryism is a strategy for coping with prolonged exposure to stresses such as social discrimination by expending high levels of effort, which results in accumulating physiological costs.
Endothelial NOS (eNOS), also known as nitric oxide synthase 3 (NOS3) or constitutive NOS (cNOS), is an enzyme that in humans is encoded by the NOS3 gene located in the 7q35-7q36 region of chromosome 7. This enzyme is one of three isoforms that synthesize nitric oxide (NO), a small gaseous and lipophilic molecule that participates in several biological processes. The other isoforms include neuronal nitric oxide synthase (nNOS), which is constitutively expressed in specific neurons of the brain and inducible nitric oxide synthase (iNOS), whose expression is typically induced in inflammatory diseases. eNOS is primarily responsible for the generation of NO in the vascular endothelium, a monolayer of flat cells lining the interior surface of blood vessels, at the interface between circulating blood in the lumen and the remainder of the vessel wall. NO produced by eNOS in the vascular endothelium plays crucial roles in regulating vascular tone, cellular proliferation, leukocyte adhesion, and platelet aggregation. Therefore, a functional eNOS is essential for a healthy cardiovascular system.
Cytochrome P450 3A5 is a protein that in humans is encoded by the CYP3A5 gene.
Cytochrome P450, family 3, subfamily A, also known as CYP3A, is a human gene locus. A homologous locus is found in mice.
Corin, also called atrial natriuretic peptide-converting enzyme, is a protein that in humans is encoded by the CORIN gene.
Seasoning, or the Seasoning, was the period of adjustment that slave traders and slaveholders subjected African slaves to following their arrival in the Americas. While modern scholarship has occasionally applied this term to the brief period of acclimatization undergone by European immigrants to the Americas, it most frequently and formally referred to the process undergone by enslaved people. Slave traders used the term "seasoning" to refer to the process of adjusting the enslaved Africans to the new climate, diet, geography, and ecology of the Americas. The term applied to both the physical acclimatization of the enslaved person to the environment, as well as that person's adjustment to a new social environment, labor regimen, and language. Slave traders and owners believed that if slaves survived this critical period of environmental seasoning, they were less likely to die and the psychological element would make them more easily controlled. This process took place immediately after the arrival of enslaved people during which their mortality rates were particularly high. These "new" or "saltwater" slaves were described as "outlandish" on arrival. Those who survived this process became "seasoned", and typically commanded a higher price in the market. For example, in eighteenth century Brazil, the price differential between "new" and "seasoned" slaves was about fifteen percent.
Pathophysiology is a study which explains the function of the body as it relates to diseases and conditions. The pathophysiology of hypertension is an area which attempts to explain mechanistically the causes of hypertension, which is a chronic disease characterized by elevation of blood pressure. Hypertension can be classified by cause as either essential or secondary. About 90–95% of hypertension is essential hypertension. Some authorities define essential hypertension as that which has no known explanation, while others define its cause as being due to overconsumption of sodium and underconsumption of potassium. Secondary hypertension indicates that the hypertension is a result of a specific underlying condition with a well-known mechanism, such as chronic kidney disease, narrowing of the aorta or kidney arteries, or endocrine disorders such as excess aldosterone, cortisol, or catecholamines. Persistent hypertension is a major risk factor for hypertensive heart disease, coronary artery disease, stroke, aortic aneurysm, peripheral artery disease, and chronic kidney disease.
Complications of hypertension are clinical outcomes that result from persistent elevation of blood pressure. Hypertension is a risk factor for all clinical manifestations of atherosclerosis since it is a risk factor for atherosclerosis itself. It is an independent predisposing factor for heart failure, coronary artery disease, stroke, kidney disease, and peripheral arterial disease. It is the most important risk factor for cardiovascular morbidity and mortality, in industrialized countries.
Salt consumption has been extensively studied for its role in human physiology and impact on human health. Chronic, high intake of dietary salt consumption is associated with hypertension and cardiovascular disease, in addition to other adverse health outcomes. Major health and scientific organizations, such as the World Health Organization, US Centers for Disease Control and Prevention, and American Heart Association, have established high salt consumption as a major risk factor for cardiovascular diseases and stroke.
20-Hydroxyeicosatetraenoic acid, also known as 20-HETE or 20-hydroxy-5Z,8Z,11Z,14Z-eicosatetraenoic acid, is an eicosanoid metabolite of arachidonic acid that has a wide range of effects on the vascular system including the regulation of vascular tone, blood flow to specific organs, sodium and fluid transport in the kidney, and vascular pathway remodeling. These vascular and kidney effects of 20-HETE have been shown to be responsible for regulating blood pressure and blood flow to specific organs in rodents; genetic and preclinical studies suggest that 20-HETE may similarly regulate blood pressure and contribute to the development of stroke and heart attacks. Additionally the loss of its production appears to be one cause of the human neurological disease, Hereditary spastic paraplegia. Preclinical studies also suggest that the overproduction of 20-HETE may contribute to the progression of certain human cancers, particularly those of the breast.
The genetic history of the African diaspora is composed of the overall genetic history of the African diaspora, within regions outside of Africa, such as North America, Central America, the Caribbean, South America, Europe, Asia, and Australia; this includes the genetic histories of African Americans, Afro-Canadians, Afro-Caribbeans, Afro-Latinos, Afro-Europeans, Afro-Asians, and African Australians.
The observation of a significant rank correlation between the frequency of the CYP3A5*3 allele that defines this haplotype class and distance from the equator further suggests the action of spatially varying selective pressures.
The only data set that allows us to compare health outcomes for a representative sample of African-Americans versus black immigrants is the National Longitudinal Mortality Study (NLMS), a national population sample drawn from the Current Population Surveys (CPS) [circa 1980]
[...] if that were so, a sizable number of today's West Africans would similarly exhibit hypertension as their own salt consumption increased in modern times. This has not been the case. Epidemiologist Dr. Richard Cooper has shown, for example, that the prevalence of hypertension among Nigerians is significantly lower than white Americans, while Germans and Finns have a higher prevalence than black Americans. Surely, much more is going on here than genes.