Essential Hypertension: Part I: Definition and Etiology

Abstract

HomeCirculationVol. 101, No. 3Essential Hypertension Free AccessOtherPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyRedditDiggEmail Jump toFree AccessOtherPDF/EPUBEssential Hypertension Part I: Definition and Etiology Oscar A. Carretero and Suzanne Oparil Oscar A. CarreteroOscar A. Carretero From the Hypertension and Vascular Research Division, Heart and Vascular Institute, Henry Ford Hospital, Detroit, Mich (O.A.C.), and the Division of Cardiovascular Disease, Vascular Biology and Hypertension Program, University of Alabama School of Medicine, Birmingham (S.O.). and Suzanne OparilSuzanne Oparil From the Hypertension and Vascular Research Division, Heart and Vascular Institute, Henry Ford Hospital, Detroit, Mich (O.A.C.), and the Division of Cardiovascular Disease, Vascular Biology and Hypertension Program, University of Alabama School of Medicine, Birmingham (S.O.). Originally published25 Jan 2000https://doi.org/10.1161/01.CIR.101.3.329Circulation. 2000;101:329–335Essential hypertension remains a major modifiable risk factor for cardiovascular disease (CVD) despite important advances in our understanding of its pathophysiology and the availability of effective treatment strategies. High blood pressure (BP) increases the risk of CVD for millions of people worldwide, and there is evidence that the problem is only getting worse. In the past decade, age-adjusted rates of stroke incidence have risen, and the slope of the age-adjusted rate of decline in coronary disease has leveled off. The incidence of end-stage renal disease and the prevalence of heart failure have also increased. A major contributor to these trends is inadequate control of BP in the hypertensive population. This review of current concepts regarding the definition, etiology, and treatment of essential hypertension is intended to aid the clinician in identifying those individuals at high risk who need to undergo evaluation and treatment, as well as in selecting optimal treatment strategies for hypertensive patients with comorbid conditions and/or target organ damage. The part of the review that deals with the genetic basis of hypertension and the gene/environment interaction that may lead to elevated BP is still a work in progress. Information gained from the Human Genome Project and from ongoing studies of the genetic basis of hypertension both in animal models and human populations may revolutionize the treatment of hypertension by replacing current empirical therapy with more effective, targeted treatments based on the genotype of the patient. Concepts introduced in this review form the basis for such "pharmacogenomic" approaches to antihypertensive therapy.Definition of Essential or Primary HypertensionBP is a quantitative trait that is highly variable1 ; in population studies, BP has a normal distribution that is slightly skewed to the right. There is a strong positive and continuous correlation between BP and the risk of CVD (stroke, myocardial infarction, heart failure), renal disease, and mortality, even in the normotensive range. This correlation is more robust with systolic than with diastolic BP.2 There is no specific level of BP where cardiovascular and renal complications start to occur; thus the definition of hypertension is arbitrary but needed for practical reasons in patient assessment and treatment.The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) defined and classified hypertension in adults, as shown in Table 1.3 The diagnosis of hypertension is made when the average of 2 or more diastolic BP measurements on at least 2 subsequent visits is ≥90 mm Hg or when the average of multiple systolic BP readings on 2 or more subsequent visits is consistently ≥140 mm Hg. Isolated systolic hypertension is defined as systolic BP ≥140 mm Hg and diastolic BP <90 mm Hg. Individuals with high normal BP tend to maintain pressures that are above average for the general population and are at greater risk for development of definite hypertension and cardiovascular events than the general population. With the use of these definitions, it is estimated that 43 million people in the United States have hypertension or are taking antihypertensive medication, which is ≈24% of the adult population. This proportion changes with (1) race, being higher in blacks (32.4%) and lower in whites (23.3%) and Mexican Americans (22.6%); (2) age, because in industrialized countries systolic BP rises throughout life, whereas diastolic BP rises until age 55 to 60 years and thus the greater increase in prevalence of hypertension among the elderly is mainly due to systolic hypertension; (3) geographic patterns, because hypertension is more prevalent in the southeastern United States; (4) gender, because hypertension is more prevalent in men (though menopause tends to abolish this differen