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Hypertension in minorities: Blacks
AJH 1995; 8:115S-119S
Hypertension in Minorities: Blacks Elijah Saunders
Hypertension is k n o w n to occur much more frequently in blacks than in the general population, roughly 33% to 50% more frequently. In addition, severe hypertension occurs 3 to 7 times more commonly in blacks than whites and is associated with an excessive amount of target organ damage. Thus, damage to the heart, kidneys, and cerebral structures may occur as much as three to five times more frequently in blacks than the general population and is associated with a much greater mortality. Because of differences in clinical presentation, delays in entering the medical care system, and some pathophysiologic features specific for the black population, treatment becomes somewhat more challenging and should be tailored for this population. Because of economic factors often found in minority populations, inexpensive effective drugs such as diuretics and ~-blockers, which are preferred drugs according to the JNC-V, often
should be given first consideration in this population. However, calcium channel blockers seem to be quite effective in this group, equal to in the white population, although they are somewhat more expensive. Angiotensin converting enzyme inhibitors, if given in proper dosage and especially with low dose diuretics, are also quite effective in this population. Tissue specific angiotensin converting enzyme inhibitors may be more effective, but further studies are needed. Studies have shown that effective treatment of the black population, in spite of the differences and the more challenging situation, can result in improved survival and reduction in morbidity and mortality from the various complications. Am J Hypertens 1995;8:115S--119S
ardiovascular disease, being the most common cause of mortality in the Western world, has been shown over the past several years to have ethnic differences in epidemiology, clinical behavior, and outcome. Blacks have been shown to have a disproportionate amount of hypertension and recent data suggests that the mortality from coronary heart disease is also excessive in blacks compared to their white counterparts. Most of the differences that have been appreciated between black and white hypertensives have been epidemiological and point to the fact that the mean
systolic and diastolic blood pressures are higher in blacks at all ages compared to their white counterparts. More recent studies have continued to show these differences but it appears that factors other than genetics may contribute to such differencesJ "2 More important than just the higher levels of blood pressure in blacks is the fact that the pathophysiology of the black hypertensive contributes to increased morbidity and mortality from hypertensive-related complications of the kidney, heart and cerebrovascular structures.99
C
m
KEY WORDS: Race, blacks, essential hypertension, drug treatment.
PATHOPHYSIOLOGY OF HYPERTENSION IN BLACKS
Address correspondence and reprint requests to Elijah Saunders, MD, FACC, Division of Hypertension, 419 West Redwood Specific hormonal, hemodynamic, and biochemical Street, Suite 620, Baltimore, MD 21201-1734. Department of Medicine, Division of Hypertension, University factors (Table 1) that may have some genetic basis are of Maryland School of Medicine, Baltimore, Maryland. frequently associated with hypertension in blacks. 2 © 1995 by the American Journal of Hypertensi(m, Ltd.
089547061/95/$9.50 0895-7061(95)00309-6
116S
SAUNDERS
AJH-DECEMBER 1995-VOL. 8, NO. 12, PART 2
TABLE 1. PATHOPHYSIOLOGIC CHARACTERISTICS OF HYPERTENSION IN BLACKS
effective blood pressure control in the individual patient.
Low cardiac output Expanded plasma volume Increased peripheral vascular resistance Decreased renal blood flow Increased salt sensitivity Decreased plasma renin levels Decreased sympathetic nervous function Decreased natriuretic vasodilatory kinins and prostaglandins Increased sodium-potassium ratio Abnormal sodium-potassium cotransport and sodium-lithium countertransport Abnormal cellular handling of calcium or magnesium
H y p e r t e n s i v e C o m p l i c a t i o n s in Blacks Because blacks seem to develop more severe hypertension at an earlier point in life and remain undiagnosed for a longer period of time, it stands to reason that they are more likely to suffer excessively the catastrophic consequences of longstanding hypertension. However, one cannot rule out increased susceptibility to the ravages of hypertension in this population. Black hypertensives have been shown to be at a greater risk for target organ damage with higher rates of stroke, left ventricular hypertrophy, 12 and renal disease. 13"14 It is of some interest that cardiovascular and renal disease, which are indicated by such conditions as left ventricular hypertrophy, microalbuminuria, and elevated creatinine, may also develop independently of blood pressure levels in many blacks. In formulating effective therapeutic strategies, therefore, clinicians need to recognize the effects of agents on blood pressure as well as other disease markers. In addition, clinicians should be aware of the presence of concomitant diseases, and other cardiovascular risk factors that may further aggravate the disease and frequently can be influenced by treatment. As will be stated in the next section on treatment, the clinician, when treating black patients, should be aware of the experiences of the antihypertensive response to various agents and should consider whether or not racial factors may dictate which agents may be efficacious. This seems to have special relevance in the black population. Although there are a number of concomitant conditions that occur in hypertensive individuals, particularly important in the black population are diabetes mellitus and various forms of insulin resistant syndromes. These two conditions, both separately and together, are the most frequent causes of end-stage renal disease in blacks, 15 and extremely costly in clinical and economic terms. It is, therefore, the hope of students of hypertension that bringing d o w n the blood pressure with the appropriate agent will be efficacious in preventing or reducing the likelihood of end-stage renal disease, especially in conjunction with diabetes mellitus.
As a group, blacks tend to have hypertension characterized by diminished activity of the neurohormonal systems, such as the sympathetic nervous system and the renin-angiotensin system, low cardiac output, expanded plasma volume, and increased peripheral resistance. It had been considered that these factors were the foundation for selecting antihypertensive drug therapy, but more recent data suggests that one cannot accurately predict the clinical response to an antihypertensive agent by these pathophysiological observations. However, they do seem to form a basis for suggesting that there may be some underlying genetic cause that might be responsible for these differences that contribute to increased blood pressure. In addition, considerable modification might have occurred over generations because of environmental exposure to factors such as psychosocial stress, dietary habits, obesity, and various metabolic syndromes, such as diabetes and glucose intolerance. Also, high levels of psychosocial stress related to p o v e r t y , crime, d e n s i t y of h o u s i n g , residential mobility, and marital instability, have been correlated with elevated blood pressure among black men. 1° Limited access to primary care physicians compounds the problem resulting not only in lower opportunities for detection and treatment, but in lower compliance rates as well. Benefit From Treatment Evidence suggests that hypertensive blacks can achieve similar reduction in blood pressure and cardiovascular morbidity and mortality as hypertensive whites when given equal access to appropriate care. 11 Therefore, while clinicians need to be familiar with the pathophysiologic and socioeconomic differences of hypertension in blacks compared to whites, successful management is clearly dependent upon instituting and maintaining
TREATMENT OF HYPERTENSION IN BLACKS
The treatment of blacks with antihypertensive agents can be challenging because of a somewhat different efficacy profile of a variety of a n t i h y p e r t e n s i v e agents, compared to whites. 16 The treatment algorithm offered by the Fifth Joint National Committee Report on Detection, Evaluation and Treatment of
HYPERTENSION IN BLACKS 117S
AJH-DECEMBER 1995-VOL. 8, NO. 12, PART 2
TABLE 2. PHARMACOLOGIC TREATMENT OF HYPERTENSION IN BLACK PATIENTS Nonpharmacologic treatment of hypertension in blacks
A. B. C. D. E.
Dietary sodium restriction (and possibly increased dietary potassium and calcium) Weight loss (calorie restriction) Increased physical exercise Restriction of alcohol (and probably tobacco) use Stress reduction 1. Personal, family 2. Racial (relations) 3. Poverty, low education (environmental)
Pharmacologic treatment of hypertension in black patients
A. Diuretics • Low dose • Combined with other agents • Possibly better response in blacks than whites • Less expensive than other antihypertensives • Demonstrated reduction in cardiovascular morbidity and mortality B. Calcium channel blockers • Response comparable to whites • All types are effective • Relatively expensive C. Angiotensin converting enzyme (ACE) inhibitors • Less effective in blacks at lower doses • Higher doses required for ideal response in blacks • Better tissue penetrating angiotensin converting enzyme inhibitors may be more effective in blacks • Synergistic and additive with diuretics • Renal protection (especially in diabetics) • Useful in congestive heart failure or impaired myocardial function • Relatively expensive D. [3-Blockers • Somewhat less effective in blacks at lower doses • Cardioprotective • Additive with diuretics • Demonstrated reduction in cardiovascular morbidity and mortality E, c,,-Blockers • Response in blacks comparable to whites • Higher doses usually required in blacks • Possible benefit with dyslipidemia F. c~,,~-Blockers • More effective than B-blockers in blacks • Additive with diuretics G. Centrally acting antihypertensives • Less well-tolerated as monotherapy • More effective in combination therapy in blacks (and whites) H. Angiotensin II receptor inhibitors • More data needed for blacks • Probably associated with less cough and angioedema • Efficacy profile probably similar to ACE inhibitors
H i g h Blood P r e s s u r e s h o u l d g e n e r a l l y be a p p l i e d to all h y p e r t e n s i v e s , i n c l u d i n g blacks. H o w e v e r , a few m o d i f i c a t i o n s s h o u l d be a p p l i e d t h a t m o r e specifically a d d r e s s s o m e of t h e p r o b l e m s of the black hyp e r t e n s i v e . T h u s , the n o n p h a r m a c o l o g i c t r e a t m e n t of h y p e r t e n s i o n in blacks is s h o w n in Table 1. N o t e that in this p o p u l a t i o n , i n c r e a s e d e m p h a s i s is p l a c e d o n m o r e d i e t a r y p o t a s s i u m a n d c a l c i u m b e c a u s e of the s u g g e s t i o n t h a t t h e s e ions are t a k e n in insufficient quantities in m a n y black individuals. T h e i m p o r t a n c e of w e i g h t loss, b e c a u s e of t h e h i g h rate of o b e s i t y in the black p o p u l a t i o n , s h o u l d also be e m p h a s i z e d . A
s t r o n g e m p h a s i s s h o u l d be p l a c e d o n stress r e d u c t i o n b e c a u s e of the a s s o c i a t i o n of h y p e r t e n s i o n w i t h l o w s o c i o e c o n o m i c status, l o w e d u c a t i o n a l levels, a n d p s y c h o s o c i a l issues, s u c h as racism. The Fifth Joint N a t i o n a l C o m m i t t e e R e p o r t t h e n s u g g e s t s , w h i l e c o n t i n u i n g lifestyle m o d i f i c a t i o n s , that if the b l o o d p r e s s u r e h a s n o t r e a c h e d goal levels, the a p p r o p r i a t e p h a r m a c o l o g i c a g e n t s h o u l d be a p plied. A special c h a l l e n g e in t h e black h y p e r t e n s i v e is to p r o v i d e the m o s t cost effective, safe, a n d b e s t tole r a t e d t h e r a p y . L i m i t e d financial r e s o u r c e s a n d access to care r e m a i n particularly i m p o r t a n t barriers to
118S
SAUNDERS
treatment in this population. Experience in the black community has shown that special techniques relative to the delivery of hypertensive care to the population, can often be used and improve control rates (ie, church-based and worksite programs, barber shop programs, etc). Several studies have emerged showing different efficacy profiles to antihypertensive agents in blacks compared to the white population. 17"1s These studies have suggested that the calcium channel blockers have a high degree of efficacy in blacks, and with proper dosing have comparable effects as in the white population. It is interesting that even though some of the earlier studies suggest that the angiotensin converting enzyme (ACE) inhibitors were not very effective in the black population, a recent study shows a far better response in the black patient, especially if the proper dose of these agents is applied, is Additionally, early results from a few clinical trials suggest that ACE inhibitors that act both in the plasma and at the tissue level may be particularly effective in blacks. 19 This was demonstrated in a large multicenter population-based study of over 12,000 patients. 19 The Fifth Joint National Committee recommended that diuretics and ~-blockers be used as first-line therapy for hypertensives because of the reduced morbidity and mortality from clinical trials seen with these agents. In blacks thiazide diuretics are often the drugs of choice because of their high response rate (volume expansion and increased salt sensitivity) and their lower cost compared to other drugs. Thiazide diuretics generally are quite safe when lower doses are used and many of the metabolic adverse side effects are not seen. However, the black patient often will require higher doses of pharmacologic agents because of more severe hypertension. Therefore, the black patient is more likely to experience metabolic adverse effects, such as hypokalemia, hyperglycemia, and, possibly, hypercholesterolemia. Many blacks will require two drug therapy. The use of a low dose thiazide diuretic with another antihypertensive agent (eg, an ACE inhibitor) is very effective, and, therefore, not likely to produce the adverse effects that may be experienced when larger doses of either of the agents is used alone. This was also pointed out in the report of the Fifth Joint National Committee. Finally, the ~-blockers have been shown not to be as effective in blacks as in their white counterparts, as was demonstrated in a study done by Saunders et al. 13 Unlike the ACE inhibitors in this study, larger doses of the ~-blockers did not show a statistically significant increase in responsiveness in blacks. Table 2 summarizes the pharmacologic treatment of hypertension in black patients, indicating the advantages and disadvantages of the various agents as
AJH-DECEMBER 1995-VOL. 8, NO. 12, PART 2
applied to the general population and blacks in particular. REFERENCES 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Roberts J, Maurer K: National Center for Health Sta-
tistics: blood pressure levels of persons 6-74 years, United States, 1971-1974. DHEW Pub HRA 78-1648. Vital and Health Statistics, Series 11, No. 203. U.S. Government Printing Office, Washington, DC, 1977, p 72. Saunders E. Special techniques for managements in blacks, in Hall WD, Saunders E, Shulman NB (eds): Hypertension in Blacks: Epidemiology, Pathophysiology and Treatment. Year Book Medical Publishers, Chicago, 1985, Chapter 14, pp 209-236. Kannel WB: Role of blood pressure in cardiovascular morbidity and mortality. Prog Cardiovasc Dis 1974; 17:5. Hypertension Detection and Follow-up Program Cooperative Group: Race, education and prevalence of hypertension. Am J Epidemiol 1977;106:351. Rostand SG, Kirk KA, Rutsky EA, et al: Racial differences in the incidence of treatment for end-stage renal disease. N Engl J Med 1982;306:1276. Frolich E. Hemodynamics and other determinants in development of left ventricular hypertrophy. Fed Proc 1983;42:2709. Prineas RJ, Castle CH, Curb JD, et al: Baseline electrocardiographic characteristics of the hypertensive participants, in Doughtery SA, Entwisle G (eds): Hypertension Detection and Follow-Up Program: Baseline Characteristics of the Enumerated, Screened, and Hypertensive Participants. Hypertension 1983;6(suppl IV):160. Savage DD, et al: New perspectives on the evaluation of cardiac target-organ damage in hypertensive patients. J Hypertens 1987;27. Hypertension Detection and Follow-Up Program Cooperative Group: Five year findings of the hypertension detection and follow-up program. III. Reduction in stroke incidence among persons with high blood pressure. JAMA 1982;247:633. Haarburg E, Erfurt JC, Hauenstein LS, et al: Socioecological stress, suppressed hostility, skin color, and black-white male blood pressure, Detroit. Psychol Med 1973;35:276-296. Ooi WL, Budner NS, Cohen H, et al: Impact of race on treatment response and cardiovascular disease among hypertensives. Hypertension 1989;14:227-234. Beaglehole R, Tyroler HA, Cassel JC, et al: An epidemiological study of left ventricular hypertrophy in the biracial population of Evans County, Georgia. J Chronic Dis 1975;28:549-559. Saunders E: Special techniques for management in blacks, in Hall WD, Saunders E, Shulman NB (eds): Hypertension in Blacks: Epidemiology, Pathophysiology, and Treatment. Year Book, Chicago, 1985. Rostand SG, Kirk KA, Rutsky EA, et al: Racial differences in the incidence of treatment for end-stage renal disease. N Engl J Med 1982;306:1276-1289.
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15.
16.
17.
Whelton PK, Klag MJ: Hypertension as a risk factor for renal disease. Review of clinical and epidemiological evidence. Hypertension 1989;13(suppl):l-19-1-27. Saunders E: The safety and efficacy of terazosin in the treatment of essential hypertension in blacks. Am Heart J 1991;122:936-942. Materson RJ, Reda DJ, Cushman WC, et al: Singledrug therapy for hypertension in men. N Engl J Med 1993;328:914-921.
18.
Saunders E, Weir MR, Kong BW, et al: A comparison of the efficacy and safety of a f~-blocker, a calcium channel blocker, and a converting enzyme inhibitor in hypertensive blacks. Arch Intern Med 1990;150:17071713. 19. Weber MA: Recent clinical trials in hypertension: ACE inhibitor treatment in the community. Curr Topics Hypertens May, 1994.
Hypertension in Minorities: Blacks Elijah Saunders
Hypertension is k n o w n to occur much more frequently in blacks than in the general population, roughly 33% to 50% more frequently. In addition, severe hypertension occurs 3 to 7 times more commonly in blacks than whites and is associated with an excessive amount of target organ damage. Thus, damage to the heart, kidneys, and cerebral structures may occur as much as three to five times more frequently in blacks than the general population and is associated with a much greater mortality. Because of differences in clinical presentation, delays in entering the medical care system, and some pathophysiologic features specific for the black population, treatment becomes somewhat more challenging and should be tailored for this population. Because of economic factors often found in minority populations, inexpensive effective drugs such as diuretics and ~-blockers, which are preferred drugs according to the JNC-V, often
should be given first consideration in this population. However, calcium channel blockers seem to be quite effective in this group, equal to in the white population, although they are somewhat more expensive. Angiotensin converting enzyme inhibitors, if given in proper dosage and especially with low dose diuretics, are also quite effective in this population. Tissue specific angiotensin converting enzyme inhibitors may be more effective, but further studies are needed. Studies have shown that effective treatment of the black population, in spite of the differences and the more challenging situation, can result in improved survival and reduction in morbidity and mortality from the various complications. Am J Hypertens 1995;8:115S--119S
ardiovascular disease, being the most common cause of mortality in the Western world, has been shown over the past several years to have ethnic differences in epidemiology, clinical behavior, and outcome. Blacks have been shown to have a disproportionate amount of hypertension and recent data suggests that the mortality from coronary heart disease is also excessive in blacks compared to their white counterparts. Most of the differences that have been appreciated between black and white hypertensives have been epidemiological and point to the fact that the mean
systolic and diastolic blood pressures are higher in blacks at all ages compared to their white counterparts. More recent studies have continued to show these differences but it appears that factors other than genetics may contribute to such differencesJ "2 More important than just the higher levels of blood pressure in blacks is the fact that the pathophysiology of the black hypertensive contributes to increased morbidity and mortality from hypertensive-related complications of the kidney, heart and cerebrovascular structures.99
C
m
KEY WORDS: Race, blacks, essential hypertension, drug treatment.
PATHOPHYSIOLOGY OF HYPERTENSION IN BLACKS
Address correspondence and reprint requests to Elijah Saunders, MD, FACC, Division of Hypertension, 419 West Redwood Specific hormonal, hemodynamic, and biochemical Street, Suite 620, Baltimore, MD 21201-1734. Department of Medicine, Division of Hypertension, University factors (Table 1) that may have some genetic basis are of Maryland School of Medicine, Baltimore, Maryland. frequently associated with hypertension in blacks. 2 © 1995 by the American Journal of Hypertensi(m, Ltd.
089547061/95/$9.50 0895-7061(95)00309-6
116S
SAUNDERS
AJH-DECEMBER 1995-VOL. 8, NO. 12, PART 2
TABLE 1. PATHOPHYSIOLOGIC CHARACTERISTICS OF HYPERTENSION IN BLACKS
effective blood pressure control in the individual patient.
Low cardiac output Expanded plasma volume Increased peripheral vascular resistance Decreased renal blood flow Increased salt sensitivity Decreased plasma renin levels Decreased sympathetic nervous function Decreased natriuretic vasodilatory kinins and prostaglandins Increased sodium-potassium ratio Abnormal sodium-potassium cotransport and sodium-lithium countertransport Abnormal cellular handling of calcium or magnesium
H y p e r t e n s i v e C o m p l i c a t i o n s in Blacks Because blacks seem to develop more severe hypertension at an earlier point in life and remain undiagnosed for a longer period of time, it stands to reason that they are more likely to suffer excessively the catastrophic consequences of longstanding hypertension. However, one cannot rule out increased susceptibility to the ravages of hypertension in this population. Black hypertensives have been shown to be at a greater risk for target organ damage with higher rates of stroke, left ventricular hypertrophy, 12 and renal disease. 13"14 It is of some interest that cardiovascular and renal disease, which are indicated by such conditions as left ventricular hypertrophy, microalbuminuria, and elevated creatinine, may also develop independently of blood pressure levels in many blacks. In formulating effective therapeutic strategies, therefore, clinicians need to recognize the effects of agents on blood pressure as well as other disease markers. In addition, clinicians should be aware of the presence of concomitant diseases, and other cardiovascular risk factors that may further aggravate the disease and frequently can be influenced by treatment. As will be stated in the next section on treatment, the clinician, when treating black patients, should be aware of the experiences of the antihypertensive response to various agents and should consider whether or not racial factors may dictate which agents may be efficacious. This seems to have special relevance in the black population. Although there are a number of concomitant conditions that occur in hypertensive individuals, particularly important in the black population are diabetes mellitus and various forms of insulin resistant syndromes. These two conditions, both separately and together, are the most frequent causes of end-stage renal disease in blacks, 15 and extremely costly in clinical and economic terms. It is, therefore, the hope of students of hypertension that bringing d o w n the blood pressure with the appropriate agent will be efficacious in preventing or reducing the likelihood of end-stage renal disease, especially in conjunction with diabetes mellitus.
As a group, blacks tend to have hypertension characterized by diminished activity of the neurohormonal systems, such as the sympathetic nervous system and the renin-angiotensin system, low cardiac output, expanded plasma volume, and increased peripheral resistance. It had been considered that these factors were the foundation for selecting antihypertensive drug therapy, but more recent data suggests that one cannot accurately predict the clinical response to an antihypertensive agent by these pathophysiological observations. However, they do seem to form a basis for suggesting that there may be some underlying genetic cause that might be responsible for these differences that contribute to increased blood pressure. In addition, considerable modification might have occurred over generations because of environmental exposure to factors such as psychosocial stress, dietary habits, obesity, and various metabolic syndromes, such as diabetes and glucose intolerance. Also, high levels of psychosocial stress related to p o v e r t y , crime, d e n s i t y of h o u s i n g , residential mobility, and marital instability, have been correlated with elevated blood pressure among black men. 1° Limited access to primary care physicians compounds the problem resulting not only in lower opportunities for detection and treatment, but in lower compliance rates as well. Benefit From Treatment Evidence suggests that hypertensive blacks can achieve similar reduction in blood pressure and cardiovascular morbidity and mortality as hypertensive whites when given equal access to appropriate care. 11 Therefore, while clinicians need to be familiar with the pathophysiologic and socioeconomic differences of hypertension in blacks compared to whites, successful management is clearly dependent upon instituting and maintaining
TREATMENT OF HYPERTENSION IN BLACKS
The treatment of blacks with antihypertensive agents can be challenging because of a somewhat different efficacy profile of a variety of a n t i h y p e r t e n s i v e agents, compared to whites. 16 The treatment algorithm offered by the Fifth Joint National Committee Report on Detection, Evaluation and Treatment of
HYPERTENSION IN BLACKS 117S
AJH-DECEMBER 1995-VOL. 8, NO. 12, PART 2
TABLE 2. PHARMACOLOGIC TREATMENT OF HYPERTENSION IN BLACK PATIENTS Nonpharmacologic treatment of hypertension in blacks
A. B. C. D. E.
Dietary sodium restriction (and possibly increased dietary potassium and calcium) Weight loss (calorie restriction) Increased physical exercise Restriction of alcohol (and probably tobacco) use Stress reduction 1. Personal, family 2. Racial (relations) 3. Poverty, low education (environmental)
Pharmacologic treatment of hypertension in black patients
A. Diuretics • Low dose • Combined with other agents • Possibly better response in blacks than whites • Less expensive than other antihypertensives • Demonstrated reduction in cardiovascular morbidity and mortality B. Calcium channel blockers • Response comparable to whites • All types are effective • Relatively expensive C. Angiotensin converting enzyme (ACE) inhibitors • Less effective in blacks at lower doses • Higher doses required for ideal response in blacks • Better tissue penetrating angiotensin converting enzyme inhibitors may be more effective in blacks • Synergistic and additive with diuretics • Renal protection (especially in diabetics) • Useful in congestive heart failure or impaired myocardial function • Relatively expensive D. [3-Blockers • Somewhat less effective in blacks at lower doses • Cardioprotective • Additive with diuretics • Demonstrated reduction in cardiovascular morbidity and mortality E, c,,-Blockers • Response in blacks comparable to whites • Higher doses usually required in blacks • Possible benefit with dyslipidemia F. c~,,~-Blockers • More effective than B-blockers in blacks • Additive with diuretics G. Centrally acting antihypertensives • Less well-tolerated as monotherapy • More effective in combination therapy in blacks (and whites) H. Angiotensin II receptor inhibitors • More data needed for blacks • Probably associated with less cough and angioedema • Efficacy profile probably similar to ACE inhibitors
H i g h Blood P r e s s u r e s h o u l d g e n e r a l l y be a p p l i e d to all h y p e r t e n s i v e s , i n c l u d i n g blacks. H o w e v e r , a few m o d i f i c a t i o n s s h o u l d be a p p l i e d t h a t m o r e specifically a d d r e s s s o m e of t h e p r o b l e m s of the black hyp e r t e n s i v e . T h u s , the n o n p h a r m a c o l o g i c t r e a t m e n t of h y p e r t e n s i o n in blacks is s h o w n in Table 1. N o t e that in this p o p u l a t i o n , i n c r e a s e d e m p h a s i s is p l a c e d o n m o r e d i e t a r y p o t a s s i u m a n d c a l c i u m b e c a u s e of the s u g g e s t i o n t h a t t h e s e ions are t a k e n in insufficient quantities in m a n y black individuals. T h e i m p o r t a n c e of w e i g h t loss, b e c a u s e of t h e h i g h rate of o b e s i t y in the black p o p u l a t i o n , s h o u l d also be e m p h a s i z e d . A
s t r o n g e m p h a s i s s h o u l d be p l a c e d o n stress r e d u c t i o n b e c a u s e of the a s s o c i a t i o n of h y p e r t e n s i o n w i t h l o w s o c i o e c o n o m i c status, l o w e d u c a t i o n a l levels, a n d p s y c h o s o c i a l issues, s u c h as racism. The Fifth Joint N a t i o n a l C o m m i t t e e R e p o r t t h e n s u g g e s t s , w h i l e c o n t i n u i n g lifestyle m o d i f i c a t i o n s , that if the b l o o d p r e s s u r e h a s n o t r e a c h e d goal levels, the a p p r o p r i a t e p h a r m a c o l o g i c a g e n t s h o u l d be a p plied. A special c h a l l e n g e in t h e black h y p e r t e n s i v e is to p r o v i d e the m o s t cost effective, safe, a n d b e s t tole r a t e d t h e r a p y . L i m i t e d financial r e s o u r c e s a n d access to care r e m a i n particularly i m p o r t a n t barriers to
118S
SAUNDERS
treatment in this population. Experience in the black community has shown that special techniques relative to the delivery of hypertensive care to the population, can often be used and improve control rates (ie, church-based and worksite programs, barber shop programs, etc). Several studies have emerged showing different efficacy profiles to antihypertensive agents in blacks compared to the white population. 17"1s These studies have suggested that the calcium channel blockers have a high degree of efficacy in blacks, and with proper dosing have comparable effects as in the white population. It is interesting that even though some of the earlier studies suggest that the angiotensin converting enzyme (ACE) inhibitors were not very effective in the black population, a recent study shows a far better response in the black patient, especially if the proper dose of these agents is applied, is Additionally, early results from a few clinical trials suggest that ACE inhibitors that act both in the plasma and at the tissue level may be particularly effective in blacks. 19 This was demonstrated in a large multicenter population-based study of over 12,000 patients. 19 The Fifth Joint National Committee recommended that diuretics and ~-blockers be used as first-line therapy for hypertensives because of the reduced morbidity and mortality from clinical trials seen with these agents. In blacks thiazide diuretics are often the drugs of choice because of their high response rate (volume expansion and increased salt sensitivity) and their lower cost compared to other drugs. Thiazide diuretics generally are quite safe when lower doses are used and many of the metabolic adverse side effects are not seen. However, the black patient often will require higher doses of pharmacologic agents because of more severe hypertension. Therefore, the black patient is more likely to experience metabolic adverse effects, such as hypokalemia, hyperglycemia, and, possibly, hypercholesterolemia. Many blacks will require two drug therapy. The use of a low dose thiazide diuretic with another antihypertensive agent (eg, an ACE inhibitor) is very effective, and, therefore, not likely to produce the adverse effects that may be experienced when larger doses of either of the agents is used alone. This was also pointed out in the report of the Fifth Joint National Committee. Finally, the ~-blockers have been shown not to be as effective in blacks as in their white counterparts, as was demonstrated in a study done by Saunders et al. 13 Unlike the ACE inhibitors in this study, larger doses of the ~-blockers did not show a statistically significant increase in responsiveness in blacks. Table 2 summarizes the pharmacologic treatment of hypertension in black patients, indicating the advantages and disadvantages of the various agents as
AJH-DECEMBER 1995-VOL. 8, NO. 12, PART 2
applied to the general population and blacks in particular. REFERENCES 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Roberts J, Maurer K: National Center for Health Sta-
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