Michael J. Horan

Prevalence of Hypertension in the US Adult Population: Results From the Third National Health and Nutrition Examination Survey, 1988-1991

The purpose of this study was to estimate the current prevalence and distribution of hypertension and to determine the status of hypertension awareness, treatment, and control in the US adult population. The study used a cross-sectional survey of the civilian, noninstitutionalized population of the United States, including an in-home interview and a clinic examination, each of which included measurement of blood pressure. Data for 9901 participants 18 years of age and older from phase 1 of the third National Health and Nutrition Examination Survey, collected from 1988 through 1991, were used. Twenty-four percent of the US adult population representing 43,186,000 persons had hypertension. The age-adjusted prevalence in the non-Hispanic black, non-Hispanic white, and Mexican American populations was 32.4%, 23.3%, and 22.6%, respectively. Overall, two thirds of the population with hypertension were aware of their diagnosis (69%), and a majority were taking prescribed medication (53%). Only one third of Mexican Americans with hypertension were being treated (35%), and only 14% achieved control in contrast to 25% and 24% of the non-Hispanic black and non-Hispanic white populations with hypertension, respectively. Almost 13 million adults classified as being normotensive reported being told on one or more occasions that they had hypertension; 51% of this group reported current adherence to lifestyle changes to control their hypertension. Hypertension continues to be a common finding in the general population. Awareness, treatment, and control of hypertension have improved substantially since the 1976-1980 National Health and Nutrition Examination Survey but continue to be suboptimal, especially in Mexican Americans.(ABSTRACT TRUNCATED AT 250 WORDS)

Trends in the Prevalence, Awareness, Treatment, and Control of Hypertension in the Adult US Population: Data From the Health Examination Surveys, 1960 to 1991

The objective of this study was to describe secular trends in the distribution of blood pressure and prevalence of hypertension in US adults and changes in rates of awareness, treatment, and control of hypertension. The study design comprised nationally representative cross-sectional surveys with both an in-person interview and a medical examination that included blood pressure measurement. Between 6530 and 13,645 adults, aged 18 through 74 years, were examined in each of four separate national surveys during 1960-1962, 1971-1974, 1976-1980, and 1988-1991. Protocols for blood pressure measurement varied significantly across the surveys and are presented in detail. Between the first (1971-1974) and second (1976-1980) National Health and Nutrition Examination Surveys (NHANES I and NHANES II, respectively), age-adjusted prevalence of hypertension at > or = 160/95 mm Hg remained stable at approximately 20%. In NHANES III (1988-1991), it was 14.2%. Age-adjusted prevalence at > or = 140/90 mm Hg peaked at 36.3% in NHANES I and declined to 20.4% in NHANES III. Age-specific prevalence rates have decreased for every age-sex-race subgroup except for black men aged 50 and older. Age-adjusted mean systolic pressures declined progressively from 131 mm Hg at the NHANES I examination to 119 mm Hg at the NHANES III examination. The mean systolic and diastolic pressures of every sex-race subgroup declined between NHANES II and III (3 to 6 mm Hg systolic, 6 to 9 mm Hg diastolic). During the interval between NHANES II and III, the threshold for defining hypertension was changed from 160/95 to 140/90 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Do Borderline Hypertensive Patients Have Labile Blood Pressure

The 24-hour patterns of ambulatory blood pressure were investigated in borderline (labile) hypertensive patients (office blood pressures fluctuating about 140/90 mm Hg). Sixty-three patients (21 normotensive, 21 borderline hypertensive, and 21 fixed hypertensive) had blood pressures recorded every 7.5 to 15 minutes using noninvasive automatic recorders. The mean 24-hour blood pressures (normotensive, 115 +/- 14/74 +/- 12 mm Hg; borderline hypertensive, 127 +/- 16/81 +/- 13 mm Hg; fixed hypertensive, 143 +/- 17/91 +/- 12 mm Hg) were significantly different from each other (p less than 0.005), but the standard deviations were not significantly different. The percentages of elevated blood pressures on the 24-hour recordings of the borderline hypertensive patients were intermediate between those of the normotensive and fixed hypertensive patients, but within the borderline group there was a broad range in percentage of elevated blood pressures (7.9% to 81.2%). Thus, borderline hypertensive patients have blood pressures no more labile than those in normotensive or fixed hypertensive patients, but because of their broad range of percentage of elevated blood pressures, their pressures are best evaluated with multiple measurements.

Progress in the battle against hypertension. Changes in blood pressure levels in the United States from 1960 to 1980.

Intensive efforts by practicing physicians and public health workers to identify and treat persons with hypertension have been underway for many years. In this report, changes in blood pressure levels in the United States are assessed based on nationally representative health (and nutrition) examination surveys conducted by the National Center for Health Statistics in 1960 to 1962, 1971 to 1974, and 1976 to 1980. Analysis of age-adjusted data for adults aged 18 to 74 years (including those on antihypertensive medication) indicates that between the first and third surveys for whites and blacks, respectively, mean systolic blood pressure declined 5 and 10 mm Hg; the proportion of persons with systolic blood pressure of 140 mm Hg or higher fell 18 and 31%; the proportion with undiagnosed hypertension decreased 17 and 59%; and the proportion taking antihypertensive medications rose 71 and 31%. These differences between the first and third surveys were all statistically significant (p less than 0.05 or better). Changes in diastolic blood pressure levels were generally not significant among race-sex groups. The proportion of persons with definite hypertension (i.e., systolic blood pressure greater than or equal to 160 mm Hg, and/or diastolic blood pressure greater than or equal to 95 mm Hg, and/or taking antihypertensive medication) declined among blacks but rose slightly among whites. Study results are consistent with the recent decline in cardiovascular disease mortality.

Bypass Angioplasty Revascularization Investigation (BARI): Baseline clinical and angiographic data

This report presents baseline clinical and angiographic data from the Bypass Angioplasty Revascularization Investigation (BARI), a multicenter international trial assessing the relative efficacy of percutaneous transluminal coronary angioplasty (PTCA) versus coronary artery bypass graft surgery (CABG) in selected patients with multivessel coronary artery disease. PTCA is commonly performed in patients with multivessel coronary artery disease, yet its long-term efficacy in comparison to CABG is unknown. From August 1988 through August 1991, 1,829 qualifying patients with multivessel disease suitable for either procedure were randomized to PTCA or CABG; sample size estimates were based on anticipated 5-year mortality. Two registry populations were also defined for follow-up: (1) 2,013 patients eligible for randomization but not randomized; and (2) 422 patients considered by angiography as unsuitable for randomization. Patients randomized in BARI were at relatively high risk for subsequent cardiac events: 39% were > or = 65 years old, 55% had prior myocardial infarction, 69% presented with unstable angina or non-Q wave myocardial infarction, and 43% had 3-vessel coronary artery disease. Patients randomized to PTCA and CABG were equally matched in all the important baseline variables. The randomized and the eligible but not randomized groups were similar in most respects. However, the nonrandomized group had a higher proportion with college education; fewer with a history of myocardial infarction, heart failure, diabetes, and smoking; and a somewhat better average ejection fraction. At the 3-month follow-up, PTCA had been performed more commonly in the nonrandomized eligible patients, especially those with 2-vessel disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in hypertension awareness, treatment, and control rates 20-Year trend data

In the last 2 decades, public knowledge, awareness, treatment, and control of high blood pressure have changed remarkably. These changes are real, and have been associated with the activities of the National High Blood Pressure Education Program. Without a control group it is always difficult to attribute causality; however, the improving levels are remarkably large and consistent, and they have occurred concurrently with the decline in age-adjusted stroke mortality.

Access to Timely and Optimal Care of Patients with Acute Coronary Syndromes — Community Planning Considerations: A Report by the National Heart Attack Alert Program

Age-adjusted mortality due to cardiovascular disease (CVD) has declined by more than 50% over the past three decades; however, CVD continues to be the leading cause of death in the United States. In 1994, 1.25 million people experienced an acute myocardial infarction (AMI). Nearly 500,000 Americans died from CVD, and more than half of these deaths occurred suddenly, within 1 hour of symptom onset, outside the hospital setting. The National Heart Attack Alert Program (NHAAP) endorses the view of the American Heart Association that the community should be recognized as the “ultimate coronary care unit.” Rapid identification and early treatment are supported by research that demonstrates time is a fundamental factor in reducing morbidity and mortality from AMI and cardiac arrest. A dramatic relationship has been shown between the onset of AMI symptoms, reperfusion treatment, and outcome for patients treated within the first hour after the onset of symptoms. The golden hour has become a widely recognized term in the trauma field, and communities and states are encouraged to develop and implement regional and statewide plans to ensure that trauma patients receive appropriate care within 1 hour of injury. The primary premise of this report — that planning by communities for rapid recognition and triage of patients with symptoms and signs of acute coronary syndromes will result in better outcomes for patients with AMI, including sudden cardiac arrest — is largely based on experience with trauma patients, a population that is benefitting from similar community planning efforts. This NHAAP report reviews community planning considerations and the essential components of an effective community plan (i.e., action plans and protocols, equipment and resources, education and training, and continuous quality improvement evaluation and research) and provides recommendations for each component. The report also presents strategies to guide communities in developing community cardiac emergency action plans.

Epidemiologic considerations in defining hypertension.

Definitions of hypertension have historically been based on at least one of three concepts. The first approach identifies thresholds of hypertension based on the frequency of occurrence in the population. The statistical approach designates a point in the distribution (e.g., the 95th percentile), as the threshold for hypertension. This distribution method identifies different limits for hypertension depending on the age, sex, and race, of the population, all of which affect the average pressure. Although distribution curves do not by themselves identify thresholds for intervention, they are useful for examining changes in population groups over time. The second approach to defining hypertension relates pressures to the risk of morbidity and mortality and is characterized by a continuously graded curve with no clear categorical thresholds. Studies correlating both diastolic and systolic pressures with cardiovascular complications demonstrate continuous risks from lowest to highest values for both sexes, all ages, and both blacks and whites in the United States. The blood pressure-risk relationship provides a compelling rationale for treatment but does not by itself define thresholds for the initiation of therapy. The third approach uses data from clinical intervention trials to identify thresholds where the benefits of therapy outweigh the costs and side effects of long-term treatment. Although results of large randomized trials have clearly demonstrated reductions in morbidity and mortality by lowering blood pressures, consensus on the lowest threshold within the mild range for which antihypertensive drug treatment is recommended has not been reached. Because an optimal definition of hypertension must encompass all three approaches and the resultant classification scheme must be sufficient for all purposes, attempts to refine and improve upon the presently recommended thresholds will undoubtedly continue.

NIH Report on Research Challenges in Nutrition and Hypertension

O delineate the role of nutrition in the regulation of blood pressure and the pathogenesis of hypertension, the National Heart, Lung, and Blood Institute in conjunction with the National Institute on Aging and the National Institutes of Health Nutrition Coordinating Committee, sponsored a Workshop on Nutrition and Hypertension in Bethesda, Maryland, on March 12 to 14, 1984. The purpose of the workshop was to identify the research needed to strengthen the understanding of the relationships between nutrition, blood pressure regulation, and hypertension. This research is important for two reasons: first, there is still an enormous amount of knowledge to be gained about the pathogenesis of hypertension, and any insights that can be derived about nutritional influences are highly desirable. Second, because the majority of patients with elevated blood pressure fall in the borderline and mild hypertensive categories, there is a need to support research on nonpharmacological strategies for management of these patients, in particular, nutritional interventions. The format of the workshop consisted of two major activities: position papers on selected dietary nutrients that may influence blood pressure and working group sessions devoted to the specification of research objectives. In addition to touching on an overview of hypertension and nutrition research methods, the position papers expounded on the roles of sodium and other electrolytes; caloric intake and obesity; dietary proteins, amino acids, carbohydrates, alcohol, and trace metals; and dietary fats and prostaglandins. Nutritional considerations of special populations, including the young and the elderly,

Transgenic animals. New approaches to hypertension research.

The purpose of this article is to describe the procedures for generating transgenic animals, to discuss some major experimental opportunities that transgenic animals offer, to summarize a number of scientific advances outside the area of hypertension research, and to elaborate on the current state of the field and future directions as it partains to normal and altered blood pressure regulation