Genetic epidemiology of hypertension: an update on the African diaspora

Hypertension is a serious global public health problem, affecting approximately 600 million people worldwide. The lifetime risk of developing the condition exceeds 50% in most populations. Despite considerable success in the pharmacological treatment of hypertension in all-human populations, the health-care community still lacks understanding of how and why individuals develop chronically elevated blood pressure. This gap in knowledge, and the high prevalence of hypertension and associated complications in some populations of African descent, have led some to conclude that hypertension is a "different disease" in people of African descent. Despite considerable evidence from epidemiologic studies showing that blood pressure distribution in populations of the African diaspora spans the known spectrum for all human populations, theories in support of unique "defects" among populations of African descent continue to gain wide acceptance. To date, no known environmental factors or genetic variants relevant to the pathophysiology of human hypertension have been found to be unique to Black populations. However, available genetic epidemiologic data demonstrate differential distributions of risk factors that are consistent with current environmental and geographic origins. This review summarizes the available evidence and demonstrates that as the exposure to known risk factors for hypertension (eg, excess consumption of salt and calories, stress, sedentary lifestyle, and degree of urbanization) increases among genetically susceptible individuals, the prevalence of hypertension and associated complications also increases across populations of the African diaspora. This observation is true for all human populations.