John E. Hall

Hypertension-Related Morbidity and Mortality in the Southeastern United States

Stroke mortality is higher in the Southeast compared with other regions of the United States. The prevalence of hypertension is also higher (black men = 35%, black women = 37.7%, white men = 26.5%, white women = 21.5%), and the proportion of patients whose hypertension is being controlled is poor, especially in white and black men. The prevalence of hypertension-related complications other than stroke is also higher in the Southeast. The five states with the highest death rates for congestive heart failure are all in the southern region. Of the 15 states with the highest rates of end-stage renal disease, 10 are in the Southeast. Obesity is very prevalent (24% to 28%) in the Southeast. Although Michigan tops the ranking for all states, 6 of the top 15 states are in the Southeast, as are 7 of the 10 states with the highest reported prevalence regarding no leisure-time physical activity. Similar to other areas of the United States, dietary sodium and saturated fat intake are high in the Southeast; dietary potassium intake appears to be relatively low. Other factors that may be associated with the high prevalence, poor control, and excess morbidity and mortality of hypertension-related complications in the Southeast include misperceptions of the seriousness of the problem, the severity of the hypertension, lack of adequate follow-up, reduced access to health care, the cost of treatment, and possibly, low birth weights. The Consortium of Southeastern Hypertension Control (COSEHC) is a nonprofit organization created in 1992 in response to a compelling need to improve the disproportionate hypertension-related morbidity and mortality throughout this region. The purpose of this position paper is to summarize the data that document the problem, the consequences, and possible causative factors.

Obesity, physical inactivity, and risk for cardiovascular disease.

Despite considerable progress in understanding disease mechanisms and risk factors, improved treatments, and public education efforts, cardiovascular disease (CVD) remains the leading cause of death in the United States. Obesity and physical inactivity, 2 important lifestyle-related risk factors for CVD, are prevalent in the southeastern United States and are becoming more prevalent in all racial groups and areas of the country. In reviewing these risk factors, we explored topics including prevalence and trends in population data; associated psychosocial and environmental factors; and some of the mechanisms through which these risk factors are thought to contribute to CVD. We identified significant, but as yet poorly understood, racial disparities in prevalence of obesity, low levels of physical activity, and correlates of these risk factors and examined important differences in the complex relationship between obesity, diabetes, and cardiovascular disease risk between African American and European American women. The Jackson Heart Study will provide important and unique information relevant to many unanswered questions about obesity, physical inactivity, and obesity in African Americans.

Mechanism of the blood pressure and renal hemodynamic effects of captopril

THis study was designed to investigate the mechanisms of captoprils chronic effect on arterial pressure and renal function. In dogs maintained on high sodium intake (250 mEq/day), 6 days of captopril infusion caused no change in arterial pressure, renal hemodynamics, sodium excretion or plasma aldosterone concentration. Infusion of captopril for 7 days also caused no significant changes in arterial pressure or renal function in dogs made hypertensive by chronic infusion of angiotensin II and high sodium intake, a model of hypertension in which plasma renin activity is undetectable and prostaglandin and bradykinin formation may be elevated. In dogs maintained on low sodium intake, chronic infusion of captopril decreased arterial pressure and plasma aldosterone concentration markedly while increasing effective renal plasma flow. Infusion of aldosterone (200 micrograms/day) for 8 days during captopril infusion restored plasma aldosterone concentration but did not significantly change arterial pressure or renal function, indicating that decreased plasma aldosterone concentration did not play a major role in the hypertensive and renal effects of captopril. However, angiotensin II infusion (10 ng/kg/min) for 8 days during captopril infusion restored arterial pressure, plasma aldosterone concentration and renal function toward control levels. These data suggest that the effects of captopril on arterial pressure, renal hemodynamics and electrolyte excretion are mediated primarily by decreased angiotensin II formation.

Hypertension in Blacks: Unanswered Questions and Future Directions for the JHS (Jackson Heart Study)

This report resulted from a working group assembled by the JHS (Jackson Heart Study) coordinating center as part of a symposium to identify, discuss, and refine key questions, related to hypertension in blacks, that can be addressed in the National Heart, Lung and Blood Institute (NHLBI)–sponsored study. The symposium and working group were assembled to assist in the preparation for the next phase of the JHS. The JHS is a longitudinal observational study designed to identify cardiovascular disease (CVD) risk factors among blacks and to develop the infrastructure for training the next generation of health disparities researchers.1 Between 2000 and 2004, 5306 community-dwelling blacks, aged ≥21 years, were enrolled from the tricounty area of Jackson, MS. In addition to a baseline study visit, follow-up visits were conducted in 2005 to 2008 and 2009 to 2013. JHS participants are contacted annually by telephone to identify potential CVD events that are adjudicated by trained clinicians.2nnHypertension is more common in blacks than any other race/ethnic group in the United States.3 In addition, blacks have a higher incidence of hypertension-related CVD and end-stage renal disease than other race/ethnic groups in the United States.4,5 The hypertension working group thought broadly about essential research questions related to hypertension in blacks. We considered research questions that could be addressed through continued observational follow-up of the JHS cohort or by conducting interventions among JHS participants.nnThe working group benefited from reviewing the NHLBI Strategic Vision and a recently published report from an NHLBI working group addressing research needs to improve hypertension treatment and control in blacks.6,7 Also, this report builds on the published work in the area of hypertension from the JHS (Table 1). Some of the suggestions from the working group require new study visits and are …

Position Paper: The Concept of Whole Body Autoregulation and the Dominant Role of the Kidneys for Long-term Blood Pressure Regulation

This paper addresses two different topics: a) the concept of whole body autoregulation; and b) the role of the kidneys for long-term blood pressure regulation. In the minds of most persons in the field of hypertension research, these are interdependent phenomena. However, this is quite untrue. One of the purposes of this paper will be to point out the independence of these two phenomena, to show that each one of them can function independently of the other—though, at times, they do function together.

The Infinite Gain Principle for Arterial Pressure Control by the Kidney-Volume-Pressure System

About ten years ago, one of the authors (ACG) coined the term ‘infinite gain principle’ for pressure control that applies to the kidney-volume-pressure control mechanism. The purpose of the present chapter is to elaborate on this principle and to explain it in more detail, especially because it has been misunderstood by many if not most workers in hypertension research. There have always been special qualifiers to this principle that in the main have been overlooked by others in their application of it. But, even more important, only a few have understood the universal applicability of the principle for the control of arterial pressure under all long-term stabilized pressure conditions. Please bear with us in the hope that we will be able to explain this principle so that it will be meaningful and useful.

Associations between height and blood pressure in the United States population

Abstract The mechanisms linking short stature with an increase in cardiovascular and cerebrovascular disease risk remain elusive. This study tested the hypothesis that significant associations are present between height and blood pressure in a representative sample of the US adult population. Participants were 12,988 men and women from a multiethnic sample (ageu200a≥u200a18 years) evaluated in the 1999 to 2006 National Health and Nutrition Examination Survey who were not taking antihypertensive medications and who had complete height, weight, % body fat, and systolic and diastolic arterial blood pressure (SBP and DBP) measurements; mean arterial blood pressure and pulse pressure (MBP and PP) were calculated. Multiple regression models for men and women were developed with each blood pressure as dependent variable and height, age, race/ethnicity, body mass index, % body fat, socioeconomic status, activity level, and smoking history as potential independent variables. Greater height was associated with significantly lower SBP and PP, and higher DBP (all Pu200a<u200a.001) in combined race/ethnic–sex group models beginning in the 4th decade. Predicted blood pressure differences between people who are short and tall increased thereafter with greater age except for MBP. Socioeconomic status, activity level, and smoking history did not consistently contribute to blood pressure prediction models. Height-associated blood pressure effects were present in US adults who appeared in the 4th decade and increased in magnitude with greater age thereafter. These observations, in the largest and most diverse population sample evaluated to date, provide support for postulated mechanisms linking adult stature with cardiovascular and cerebrovascular disease risk.