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CORONARY HEART DISEASE IN THE AMERICAN BLACK POPULATION
148 in determining the likely "career pathways" of individuals moving through that system. Can we profitably continue to operate public health policies on the assumption that the drug ecology is made up of a set of distinct domains rather than an interacting whole? The pointer to the reality of period effects is also very important. We know too little about the nature of the social groundswell that influences the ebb and flow of drug use, and the American work is an example of the epidemiological research that is required in Britain and elsewhere.
advantage
CORONARY HEART DISEASE IN THE AMERICAN BLACK POPULATION DEATHS from coronary heart disease (CHD) are now as in black Americans as in their white compatriots. in Indeed, some states the age-specific mortality in men under 60 years and women under 70 years seems to be higher in Blacks. The CHD death rate increased rapidly in black adults during the 1950s and 1960s such that towards the end of this period figures for black males were close to those for white males and those for black females exceeded those for white females. Since then, CHD mortality has declined in men and women of both groups in all 34 (largely eastern) states with a sizeable black community, with one exception. West Virginian black males showed a small increase in CHD mortality in the 1970s. Regional differences in CHD mortality affect both ethnic groups similarly. Thus in the men the correlation between age-adjusted rates in Blacks and Whites across the 34 states was about 0.7in 1968-72, increasing to 0 - 8 in 1978. The proceedings of two meetings (published under single cover of the American Heart Journal1 present these and other data to refute the prevailing belief that CHD is predominantly a disease of the white American. The
common
mortality statistics, although probably subject to greater inaccuracy of census data and death certification in Blacks than in Whites, were judged broadly reliable for ethnic comparison. Considerable reservations were expressed about the quality of other pertinent data. Estimates of CHD incidence and prevalence have probably suffered from sampling error. The diagnostic criteria for CHD have evolved mainly through epidemiological and clinical experience within white communities, and may differ in sensitivity and specificity when applied to black populations. Without validation, the responses to standard questionnaires, electrocardiographic classifications, and even serum enzyme levels may lead to biased estimates of CHD incidence and prevalence in Blacks. A case in point is the remarkably high frequency with which black adults (particularly women) in some studies have given a positive response to the Rose questionnaire for symptoms compatible with angina. Primary prevention of CHD through the risk-factor approach is obviously as relevant for Blacks as for Whites. Certainly the risk-factor status of Blacks is cause for concern. National data for the early 1970s showed that in both sexes raised blood-pressure and cigarette smoking were more common in Blacks than in Whites (though black smokers consumed fewer cigarettes). Hypercholesterolaemia was if anything slightly more frequent in black males than in white 1.
Report of N.H.L.B.I. working conference on populations, and proceedings of a symposium populations Am Heart J 1984; 108: 633-862.
coronary heart disease in black coronary heart disease in black
on
males, and obesity was much more prevalent in black women. Some have asked how it
came
about that in these years CHD
mortality was not higher in black males than in white males, since the data available, albeit open to criticism, suggest that blood-pressure and tobacco consumption operate much the same way as risk factors in both ethnic groups. In fact, in 23 of the 34 states for which the comparison could be made the ageadjusted CHD death rate in black males was higher than that in white males, and in three of those remaining it was identical to that for Whites. Could it be that the favourable distribution of cholesterol within the plasma lipoproteius of the black American male offsets some of his disadvantages with respect to CHD risk? Plasma high-density lipoprotein cholesterol (HDLCh) tends to be higher and low-density lipoprotein (LDLCh) lower in black males than in white males. In females the difference in HDLCh is less impressive, maybe because of the high prevalence of obesity in the black female. The suggestion that this increase in HDLCh in black adults is due to genetic factors is highly speculative. In Trinidad Miller and co-workers2 have found urban men of African descent to have a significantly lower HDLch concentration than that of rural men of this ethnic group, but a similar concentration to that of urban men of European descent.2 Alternative explanations such as an ethnic difference in dietary habit in the USA cannot be discounted. Attempts have been made to account for ethnic differences in CHD mortality and risk-factor distributions in the USA in terms of traditional indicators of socioeconomic status. They have met with little success, not least because skin colour is a unique determinant of status in American society (though less so than formerly). Thus when factors such as education, employment, and income are allowed for, differences in important concomitants of socioeconomic status are likely to persist between Blacks and Whites, some of which may have physical and psychological consequences that are detrimental to cardiovascular health. What these concomitants may be, and how they operate, is poorly understood. Adverse socioeconomic factors, combined with in Blacks, seem to have about CHD misconceptions prejudiced primary health care, diagnosis, and treatment of CHD of Blacks in the past. The pathology of the disease does not differ appreciably with ethnic group, the responses to medical and surgical therapy are apparently similar in Blacks and Whites, yet survival after myocardial infarction is poorer in the black patient. Relatively few black adults with CHD seem to be offered coronary arteriography, and, of those who are, relatively few come to surgery in comparison with Whites. This difference in the proportion offered surgery is not apparently explained by an ethnic difference in the severity of disease. There was also suspicion that death within a few hours of the onset of symptoms was a more common event in Blacks than in Whites, and concern that restricted access to emergency medical care may have had a hand in this. A general call is made in the meeting reports for more study to bring information about CHD in Blacks on a par with that in Whites. There is, however, a broader message in this American experience. Many populations around the world are rapidly relinquishing traditional lifestyles and adopting instead those living habits held responsible for the high rates of CHD in America and elsewhere. In such communities, now-not after the event-is the time for careful surveillance and introduction of preventive measures. GJ, Beckles GLA, Byam NTA, et al. Serum relation to ethnic composition and urbanisation in West Indies Int J Epidemiol 1984, 13: 413-21
2. Miller
lipoprotein men
and
concentrations in
women
of Trinidad.
advantage
CORONARY HEART DISEASE IN THE AMERICAN BLACK POPULATION DEATHS from coronary heart disease (CHD) are now as in black Americans as in their white compatriots. in Indeed, some states the age-specific mortality in men under 60 years and women under 70 years seems to be higher in Blacks. The CHD death rate increased rapidly in black adults during the 1950s and 1960s such that towards the end of this period figures for black males were close to those for white males and those for black females exceeded those for white females. Since then, CHD mortality has declined in men and women of both groups in all 34 (largely eastern) states with a sizeable black community, with one exception. West Virginian black males showed a small increase in CHD mortality in the 1970s. Regional differences in CHD mortality affect both ethnic groups similarly. Thus in the men the correlation between age-adjusted rates in Blacks and Whites across the 34 states was about 0.7in 1968-72, increasing to 0 - 8 in 1978. The proceedings of two meetings (published under single cover of the American Heart Journal1 present these and other data to refute the prevailing belief that CHD is predominantly a disease of the white American. The
common
mortality statistics, although probably subject to greater inaccuracy of census data and death certification in Blacks than in Whites, were judged broadly reliable for ethnic comparison. Considerable reservations were expressed about the quality of other pertinent data. Estimates of CHD incidence and prevalence have probably suffered from sampling error. The diagnostic criteria for CHD have evolved mainly through epidemiological and clinical experience within white communities, and may differ in sensitivity and specificity when applied to black populations. Without validation, the responses to standard questionnaires, electrocardiographic classifications, and even serum enzyme levels may lead to biased estimates of CHD incidence and prevalence in Blacks. A case in point is the remarkably high frequency with which black adults (particularly women) in some studies have given a positive response to the Rose questionnaire for symptoms compatible with angina. Primary prevention of CHD through the risk-factor approach is obviously as relevant for Blacks as for Whites. Certainly the risk-factor status of Blacks is cause for concern. National data for the early 1970s showed that in both sexes raised blood-pressure and cigarette smoking were more common in Blacks than in Whites (though black smokers consumed fewer cigarettes). Hypercholesterolaemia was if anything slightly more frequent in black males than in white 1.
Report of N.H.L.B.I. working conference on populations, and proceedings of a symposium populations Am Heart J 1984; 108: 633-862.
coronary heart disease in black coronary heart disease in black
on
males, and obesity was much more prevalent in black women. Some have asked how it
came
about that in these years CHD
mortality was not higher in black males than in white males, since the data available, albeit open to criticism, suggest that blood-pressure and tobacco consumption operate much the same way as risk factors in both ethnic groups. In fact, in 23 of the 34 states for which the comparison could be made the ageadjusted CHD death rate in black males was higher than that in white males, and in three of those remaining it was identical to that for Whites. Could it be that the favourable distribution of cholesterol within the plasma lipoproteius of the black American male offsets some of his disadvantages with respect to CHD risk? Plasma high-density lipoprotein cholesterol (HDLCh) tends to be higher and low-density lipoprotein (LDLCh) lower in black males than in white males. In females the difference in HDLCh is less impressive, maybe because of the high prevalence of obesity in the black female. The suggestion that this increase in HDLCh in black adults is due to genetic factors is highly speculative. In Trinidad Miller and co-workers2 have found urban men of African descent to have a significantly lower HDLch concentration than that of rural men of this ethnic group, but a similar concentration to that of urban men of European descent.2 Alternative explanations such as an ethnic difference in dietary habit in the USA cannot be discounted. Attempts have been made to account for ethnic differences in CHD mortality and risk-factor distributions in the USA in terms of traditional indicators of socioeconomic status. They have met with little success, not least because skin colour is a unique determinant of status in American society (though less so than formerly). Thus when factors such as education, employment, and income are allowed for, differences in important concomitants of socioeconomic status are likely to persist between Blacks and Whites, some of which may have physical and psychological consequences that are detrimental to cardiovascular health. What these concomitants may be, and how they operate, is poorly understood. Adverse socioeconomic factors, combined with in Blacks, seem to have about CHD misconceptions prejudiced primary health care, diagnosis, and treatment of CHD of Blacks in the past. The pathology of the disease does not differ appreciably with ethnic group, the responses to medical and surgical therapy are apparently similar in Blacks and Whites, yet survival after myocardial infarction is poorer in the black patient. Relatively few black adults with CHD seem to be offered coronary arteriography, and, of those who are, relatively few come to surgery in comparison with Whites. This difference in the proportion offered surgery is not apparently explained by an ethnic difference in the severity of disease. There was also suspicion that death within a few hours of the onset of symptoms was a more common event in Blacks than in Whites, and concern that restricted access to emergency medical care may have had a hand in this. A general call is made in the meeting reports for more study to bring information about CHD in Blacks on a par with that in Whites. There is, however, a broader message in this American experience. Many populations around the world are rapidly relinquishing traditional lifestyles and adopting instead those living habits held responsible for the high rates of CHD in America and elsewhere. In such communities, now-not after the event-is the time for careful surveillance and introduction of preventive measures. GJ, Beckles GLA, Byam NTA, et al. Serum relation to ethnic composition and urbanisation in West Indies Int J Epidemiol 1984, 13: 413-21
2. Miller
lipoprotein men
and
concentrations in
women
of Trinidad.