Introduction Kidney and Blood Pressure: Partners in Health and Disease

Abstract

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are linked not only to each other but are important causes of premature morbidity and mortality. Although prospective data on risk factors for CKD are lacking and limited to men, there appears to be a powerful graded relationship between the blood pressure (BP) levels and CKD.1Haroun M.K. Jaar B.H. Hoffman S.C. et al.Risk factors for chronic kidney disease A prospective study of 23,534 men and women in Washington County, Maryland.J Am Soc Nephrol. 2003; 14: 2934-2941Crossref PubMed Scopus (401) Google Scholar Systemic hypertension follows diabetes as a major contributing factor for the development of ESRD. Cardiovascular disease is more prevalent not only in patients with CKD but also advances more aggressively in this population.2Collins A.J. Li S. Gilbertson D.T. et al.Chronic kidney disease and cardiovascular disease in the Medicare population.Kidney Int Suppl. 2003; 87: S24-S31Crossref PubMed Scopus (280) Google Scholar Thus, CKD patients constitute a high-risk group.In the United States alone, more than 50 million adults have systemic hypertension. It is clear from epidemiologic and pathophysiologic dimensions that hypertension can be a cause as well as a consequence of CKD. Although the mortality rates from stroke and coronary disease are decreasing, the prevalence of hypertension as an undeniable contributor for CKD has increased paradoxically. The association between hypertension and CKD has been recognized since the days of a pioneering observation made by Bright3Bright R. Cases and observations illustrative of renal disease accompanied by albuminous urine. Longmans, Rees, Orme, Brown, and Green, London1836Google Scholar in 1836. Nearly 50 years ago it was shown that effective antihypertensive drug therapy stabilized renal function in patients with malignant hypertension, whereas in the untreated group renal function deteriorated rapidly.4Moyer J.H. Heider C. Pevey K. et al.The effect of treatment on the vascular deterioration associated with hypertension, with particular emphasis on renal function.Am J Med. 1958; 24: 177-192Abstract Full Text PDF PubMed Scopus (67) Google Scholar Because uncontrolled hypertension promotes renal deterioration, aggressive BP control should be pursued to interrupt this vicious cycle. Effective and sustained control of hypertension, therefore, is the foremost therapeutic principle in the prevention of CKD and in halting its relentless progression.Although normalizing the BP by itself offers significant nephroprotection, antihypertensive drugs that block the renin-angiotensin-aldosterone axis have been shown to be advantageous particularly because of their special effects on decreasing intraglomerular pressure and proteinuria. Nevertheless, most patients with diabetic or nondiabetic renal disease require multiple antihypertensive drugs to achieve and maintain goal BP levels. Although the beneficial effects of lowering BP have been well documented, the rates of achieving target BP goals are alarmingly low.5Coresh J. Weig L. McQuillan G. et al.Prevalence of high blood pressure and elevated serum creatinine level in the United States; findings from the third National Health and Nutrition Examination Survey (1998–1996).Arch Intern Med. 2001; 161: 1207-1216Crossref PubMed Scopus (493) Google Scholar Despite the unresolved issues6Locatelli F. Del Vecchio L. Pozzoni P. et al.Is it the agent or the blood pressure level that matters for renal and vascular protection in chronic nephropathies?.Kidney Int Suppl. 2005; 93: 515-519Google Scholar surrounding the choice of antihypertensive drugs, nephrologists (and others) should achieve target BP goals in their patients. These therapeutic interventions are relatively inexpensive and will result in the slowing down of renal disease progression and thereby reduce the burden of CKD, ESRD, and cardiovascular disease in the community.This issue of Seminars in Nephrology addresses selected aspects of systemic hypertension in relation to kidney function and CKD. The articles ranging from epidemiology and classification of hypertension to the management of patients should provide a clear insight to the readers about the pathophysiologic implications of uncontrolled hypertension including hypertensive crises. The readers also will benefit from reviewing the current understanding of renovascular disease discussed in this issue. Various aspects of analyses and discussions contained in the ensuing articles should equip the clinical nephrologist to gain an in-depth knowledge about the nexus between the systemic BP (dys)regulation and renal (dys)function. Dr. Daniel Lackland provides a succinct summary of the hypertension pandemic. The classification of hypertension continues to be modified every 3 to 5 years and an understanding of the evolving guidelines is discussed by Drs. Kenneth Choi and George Bakris, who offer a practical guide to the busy practitioner on the stratification of hypertensive disorders. Dr. Norman Kaplan offers an abbreviated overview of the implications of hypertension in the community. Is hypertension the same irrespective of the sex, age, and comorbidities? Dr. Shawna Nesbitt covers these unsettled concerns. The general and fundamental concepts of antihypertensive drugs are detailed by Drs. Addison Taylor and James Pool, followed by Dr. Dominic Sica’s analysis of special pathophysiologic considerations in the selection of antihypertensive drug therapy in patients with impaired renal function. Because the clinical trials of the past decade have at times raised more questions then answers, these and other controversies are covered by Drs. Franz Messerli and Ehud Grossman. A broad clinical approach to hypertensive disorders in patients with renal disease is provided by Drs. Michael Wiederkehr, Robert Toto, Andrew Z. Fenves, and C. Venkata S. Ram. Despite the strides we have made in the science of organ transplantation and immunosuppression, systemic hypertension after kidney transplantation is not only common, but exerts deleterious consequences. This complex subject is reviewed by Drs. Jose Castillo and Pedro Vergne-Marini. Occasionally (but not so rarely), some hypertensive patients present with a critical increase in blood pressure requiring immediate therapeutic intervention. Drs. Andrew Fenves and C. Venkata S. Ram discuss the clinical manifestations and management of hypertensive crises. We are grateful to the authors of this issue for their authoritative thoughts and masterful review of what is decidedly a common and evolving subject.In conclusion, although hypertension is easy to diagnose in patients with or without CKD, it remains undiagnosed, untreated, or poorly treated in many patients. This is truly a tragic fact in clinical medicine. Recent advances in the epidemiology, pathogenesis, and treatment of hypertensive orders have brought us to the prospect, in the next few years, of reducing the burden of hypertension, particularly in patients at risk for developing CKD.If we apply the current knowledge and therapeutic guidelines presented in this issue, for more aggressive treatment and close follow-up evaluation of hypertensive patients, lives can be saved and the community will obtain some relief from the treacherous burden imposed by hypertensive disorders in patients with renal insufficiency. We are sure that the readers will share our gratitude to the contributors for their time and effort in making this issue of Seminars in Nephrology possible. Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are linked not only to each other but are important causes of premature morbidity and mortality. Although prospective data on risk factors for CKD are lacking and limited to men, there appears to be a powerful graded relationship between the blood pressure (BP) levels and CKD.1Haroun M.K. Jaar B.H. Hoffman S.C. et al.Risk factors for chronic kidney disease A prospective study of 23,534 men and women in Washington County, Maryland.J Am Soc Nephrol. 2003; 14: 2934-2941Crossref PubMed Scopus (401) Google Scholar Systemic hypertension follows diabetes as a major contributing factor for the development of ESRD. Cardiovascular disease is more prevalent not only in patients with CKD but also advances more aggressively in this population.2Collins A.J. Li S. Gilbertson D.T. et al.Chronic kidney disease and cardiovascular disease in the Medicare population.Kidney Int Suppl. 2003; 87: S24-S31Crossref PubMed Scopus (280) Google Scholar Thus, CKD patients constitute a high-risk group. In the United States alone, more than 50 million adults have systemic hypertension. It is clear from epidemiologic and pathophysiologic dimensions that hypertension can be a cause as well as a consequence of CKD. Although the mortality rates from stroke and coronary disease are decreasing, the prevalence of hypertension as an undeniable contributor for CKD has increased paradoxically. The association between hypertension and CKD has been recognized since the days of a pioneering observation made by Bright3Bright R. Cases and observations illustrative of renal disease accompanied by albuminous urine. Longmans, Rees, Orme, Brown, and Green, London1836Google Scholar in 1836. Nearly 50 years ago it was shown that effective antihypertensive drug therapy stabilized renal function in patients with malignant hypertension, whereas in the untreated group renal function deteriorated rapidly.4Moyer J.H. Heider C. Pevey K. et al.The effect of treatment on the vascular deterioration associated with hypertension, with particular emphasis on renal function.Am J Med. 1958; 24: 177-192Abstract Full Text PDF PubMed Scopus (67) Google Scholar Because uncontrolled hypertension promotes renal deterioration, aggressive BP control should be pursued to interrupt this vicious cycle. Effective and sustained control of hypertension, therefore, is the foremost therapeutic principle in the prevention of CKD and in halting its relentless progression. Although normalizing the BP by itself offers significant nephroprotection, antihypertensive drugs that block the renin-angiotensin-aldosterone axis have been shown to be advantageous particularly because of their special effects on decreasing intraglomerular pressure and proteinuria. Nevertheless, most patients with diabetic or nondiabetic renal disease require multiple antihypertensive drugs to achieve and maintain goal BP levels. Although the beneficial effects of lowering BP have been well documented, the rates of achieving target BP goals are alarmingly low.5Coresh J. Weig L. McQuillan G. et al.Prevalence of high blood pressure and elevated serum creatinine level in the United States; findings from the third National Health and Nutrition Examination Survey (1998–1996).Arch Intern Med. 2001; 161: 1207-1216Crossref PubMed Scopus (493) Google Scholar Despite the unresolved issues6Locatelli F. Del Vecchio L. Pozzoni P. et al.Is it the agent or the blood pressure level that matters for renal and vascular protection in chronic nephropathies?.Kidney Int Suppl. 2005; 93: 515-519Google Scholar surrounding the choice of antihypertensive drugs, nephrologists (and others) should achieve target BP goals in their patients. These therapeutic interventions are relatively inexpensive and will result in the slowing down of renal disease progression and thereby reduce the burden of CKD, ESRD, and cardiovascular disease in the community. This issue of Seminars in Nephrology addresses selected aspects of systemic hypertension in relation to kidney function and CKD. The articles ranging from epidemiology and classification of hypertension to the management of patients should provide a clear insight to the readers about the pathophysiologic implications of uncontrolled hypertension including hypertensive crises. The readers also will benefit from reviewing the current understanding of renovascular disease discussed in this issue. Various aspects of analyses and discussions contained in the ensuing articles should equip the clinical nephrologist to gain an in-depth knowledge about the nexus between the systemic BP (dys)regulation and renal (dys)function. Dr. Daniel Lackland provides a succinct summary of the hypertension pandemic. The classification of hypertension continues to be modified every 3 to 5 years and an understanding of the evolving guidelines is discussed by Drs. Kenneth Choi and George Bakris, who offer a practical guide to the busy practitioner on the stratification of hypertensive disorders. Dr. Norman Kaplan offers an abbreviated overview of the implications of hypertension in the community. Is hypertension the same irrespective of the sex, age, and comorbidities? Dr. Shawna Nesbitt covers these unsettled concerns. The general and fundamental concepts of antihypertensive drugs are detailed by Drs. Addison Taylor and James Pool, followed by Dr. Dominic Sica’s analysis of special pathophysiologic considerations in the selection of antihypertensive drug therapy in patients with impaired renal function. Because the clinical trials of the past decade have at times raised more questions then answers, these and other controversies are covered by Drs. Franz Messerli and Ehud Grossman. A broad clinical approach to hypertensive disorders in patients with renal disease is provided by Drs. Michael Wiederkehr, Robert Toto, Andrew Z. Fenves, and C. Venkata S. Ram. Despite the strides we have made in the science of organ transplantation and immunosuppression, systemic hypertension after kidney transplantation is not only common, but exerts deleterious consequences. This complex subject is reviewed by Drs. Jose Castillo and Pedro Vergne-Marini. Occasionally (but not so rarely), some hypertensive patients present with a critical increase in blood pressure requiring immediate therapeutic intervention. Drs. Andrew Fenves and C. Venkata S. Ram discuss the clinical manifestations and management of hypertensive crises. We are grateful to the authors of this issue for their authoritative thoughts and masterful review of what is decidedly a common and evolving subject. In conclusion, although hypertension is easy to diagnose in patients with or without CKD, it remains undiagnosed, untreated, or poorly treated in many patients. This is truly a tragic fact in clinical medicine. Recent advances in the epidemiology, pathogenesis, and treatment of hypertensive orders have brought us to the prospect, in the next few years, of reducing the burden of hypertension, particularly in patients at risk for developing CKD. If we apply the current knowledge and therapeutic guidelines presented in this issue, for more aggressive treatment and close follow-up evaluation of hypertensive patients, lives can be saved and the community will obtain some relief from the treacherous burden imposed by hypertensive disorders in patients with renal insufficiency. We are sure that the readers will share our gratitude to the contributors for their time and effort in making this issue of Seminars in Nephrology possible.