Elevated mortality rates from circulatory disease in African American men and women of Los Angeles County, California - A possible genetic susceptibility?

Objective: Reports of higher mortality in African Americans have often focu sed on socioeconomic differences. Such differences do not explain the exces s mortality in African Americans compared with Hispanics in Los Angeles Cou nty. We suggest the existence of genetic factors to explain at least some o f the differences in mortality risk. Methods: We compared the mortality rat es from circulatory diseases in African American and Hispanic adults of Los Angeles County for 1988 to 1992 with the frequency of the angiotensinc-onv erting enzyme (ACE) genotype. Results: African American adults 45 to 74 yea rs old had a 2-fold higher overall mortality rate than Hispanics. The large st differences were seen for hypertensive disease and cardiomyopathy in men ; the most striking differences were seen in the youngest age group. Rates were lower in women than in men, but African American women also showed sub stantial excess compared with Hispanics. ACE genotype also showed a signifi cant difference between the Hispanic and African American population; the l atter had a significantly higher prevalence of the DD genotype, which is as sociated with a higher level of circulating enzyme, and lower prevalence of the II genotype, which is associated with a lower enzyme level. Conclusion : African American adults aged 45 to 74 years in Los Angeles County have a substantial excess mortality from hypertensive diseases compared with a sim ilar Hispanic population. The frequency of the ACE DD genotype was higher i n African Americans than in Hispanics. These studies may indirectly support the possibility of a genetic contribution to the excess hypertensive disea se mortality in African Americans.