Genetic and familial factors in essential hypertension and related traits

Abstract

The health significance of essential hypertension (high blood pressure of undefined origin) is well established. It is a major factor contributing to coronary heart disease, stroke, and kidney failure. It directly affects about one in five Americans. Factors which are known to be associated with blood pressure include: body composition as it relates to overall mass and fat mass; physiological variables involving the sympathetic and parasympathetic nervous systems; biochemical variables such as renin, aldosterone, kallikrein, lipids, and lipoproteins, etc.; environmental variables such as sodium intake, heavy metals, and noise; and psychological variables involving personality type and mental stress.There is a definite, well-established genetic involvement in hypertension, but specific genetic mechanisms remain a mystery. Familial aggregation occurs for many of the associated traits listed above. For some, specific polymorphic major genes have been identified, but for others genetic factors are unidentified. Essential hypertension is undoubtedly a heterogeneous group of diseases with the common end result of elevated blood pressure. Because of its health significance, there is considerable interest in identifying genetic mechanisms resulting in essential hypertension. One area that currently shows some potential for the identification of a specific genetic mechanism is related to the transmembrane transport of sodium and potassium cations.A genetic component has long been suspected in essential hypertension, but a clear and definitive genetic mechanism has yet to be identified. Since there are many variables that can affect blood pressure, this review of the genetics of essential hypertension necessarily involves a discussion of related traits. Before focusing on the genetic and familial aspects of hypertension a description of the normal course of human blood pressure is presented and some of the traits related to it are discussed. NATURAL HISTORY OF BLOOD PRESSUREUntil recently, reports describing blood pressure patterns during the neonatal period were relatively few, largely because of the difficulty of accurately measuring blood pressure in infants by noninvasive techniques. The ultrasonic technique utilizing the Doppler effect greatly facilitated noninvasive systolic blood pressure determination in infants (McLaughlin et al., 1971). Accurate automatic methods are currently available using the oscillometric principal coupled with a microcomputer and a standard limb blood presure cuff (Friesen and Lichtor, 1981). Even in adults newer methods are being developed (Wolthuis et al., 1981).© 1983 Alan R. Liss, Inc. [Vol.26,1983 Systolic blood pressure tends to increase sharply during the first two weeks of life from a mean of 70 mmHg at 2 days to 84 mmHg at 2 weeks. It continues to increase at a slightly slower rate over the next 4 weeks to a mean of about 93 mmHg at 6 weeks (Earley et aI., 1980); from 6 weeks to 1 year af age there is little change in systolic pressure (deSwiet et aI., 1975(deSwiet et ...

An epidemiological study of blood pressure and lipid levels among Marwaris of Calcutta, India

“…An understanding of how blood pressure is influenced by genetic and environmental factors is the key to understanding the role played by hypertension in cardiovascular complications. Blood pressure profiles and etiologic factors affecting blood pressure are different for traditional societies and Westernizedl urbanized societies (Epstein and Eckhoff, 1967;Siervogel, 1983;Ward, 1983). Further, while some of the factors that contribute to increased blood pressure seem to cut across cultural patterns and geographic regions, there are certain factors that seem to be population-specific (Marmot, 1979;Ward, 1983).…”

Relationship between parental hypertension and cardiometabolic risk factors in adolescents

“…The relationship between parental hypertension and increased cardiometabolic risk in offspring could result from both shared environmental and genetic factors. In terms of shared environmental factors, the offspring of hypertensive parents are particularly prone to a high intake of excess sodium . Moreover, it has been demonstrated that adolescents with parental hypertension tend to have lower levels of physical activity, which is possibly linked to an increased risk of obesity .…”

“…20 As a result, professional guidelines usually include the assessment of family prone to a high intake of excess sodium. 21 Moreover, it has been demonstrated that adolescents with parental hypertension tend to have lower levels of physical activity, which is possibly linked to an increased risk of obesity. 22 In our study, participants with parental hypertension had a significantly higher weight than those without parental hypertension at baseline.…”

Awareness of bp among outpatients

“…About 30 % of the blood pressure variance can be attributed to genetic factors [7] , and % in pedigree studies to 65 % in . Among various mechanisms proposed to explain the relation between hypertension and positive family history of hypertension, are the increased renal proximal , genetic traits related to high blood pressure such as high sodium-lithium counter-transport, low urinary kallikrein excretion, elevated uric acid level, high ng plasma insulin concentrations, high-density LDL subfractions, fat pattern index, oxidative stress and body mass index, as well as shared environmental factors such as sodium intake and heavy metal exposure [9][10][11][12] .…”