Mixed Race Studies

The Racial Distribution of Nephritis and Hypertension in Panama

The American Journal of Pathology
Volume 21, Number 6 (November 1945)
pages 1031-1046

Carl E. Taylor

In Panama a large scale natural experiment on the pathogenesis of human hypertension awaits scientific interpretation. The studies of Kean and of Marvin and Smith have demonstrated the presence of fairly distinct racial groups, living in contiguity and subjected to similar environmental factors, in which there is a striking difference in the incidence of hypertension. The native Panamanians, originally were Indian, but in the past 300 years there has been added to this stock the blood of Spaniards and other Europeans together with their Negro slaves. This apparently composite ethnologic group is actually fairly clearly defined in language, customs, and appearance. Relatively pureblooded Negroes were imported to Panama from the West Indian Islands for construction work on the Canal 30 to 40 years ago and with their descendants they form another rather distinct group. These racial groups were defined by Kean as follows: ‘A ‘Panamania’ is one born in Panama whose parents were both born in Panama,” and “a ”West Indian’ is a Negro who was either born in the West Indies of West Indian parentage or whose parents both were born in the West Indies.” A third racial group is made up of Caucasians, most of whom are United States citizens.

In examining 1,328 candidates for employment with the Panama Canal, Kean found that hypertension was seven times as common in the West Indians as in the Panamanians; this difference was especially marked in the younger age groups in which the ratio of Negro to Panamanian hypertensive patients ranged as high as 16 to 1. In a group of almost 2,000 pregnant females he found hypertension to be five times as frequent in the West Indians as in the Panamanians. In over 2,000 consecutive hospital admissions Marvin and Smith found that hypertension was about eight times as common in the West Indians as in the Panamanians.

Phillips found a high incidence of hypertension in Negroes in Jamaica. It is the consensus of studies 4-6 of the racial incidence of hypertension in the United States that American Negroes have about twice as much hypertension as whites. Many factors have been considered in attempting to explain this difference. Heredity has been discounted because of Donnison’s report of the relatively low blood pressure found in African Negroes living under primitive conditions. These authors suggested that hypertension in the Negro may be caused in some way by adjustment to a new civilization and a new environment.

Shattuck has reported that the Indians of Guatemala and of Yucatan have relative hypertension and that blood pressure in the mestizo or mixed racial groups was somewhat higher. Kean, in a survey of the relatively isolated Cuna Indians living on the San Blas Islands off the coast of Panama, observed that the average blood pressure of 407 adult Indians was 105mm. of Hg systolic and 69 diastolic; not a single case of hypertension was found.

The generally recognized correlation between hypertension and nephritis suggested that an analysis of the racial distribution of nephritis in Panama might contribute to our understanding of the problem…

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