The relationship of hematocrit to cardiovascular states of health in the Negro and white population of Evans County, Georgia

Abstract

1. 1. Hematocrit data from a study in Evans County, Georgia, show significantly lower hematocrit values for Negroes than whites for both sexes and at all ages except males aged 15–34 years. 2. 2. Hematocrit was significantly correlated with age for both males and females. The correlation was inverse for males but direct for females. The principal age-association for females consisted of an increase in hematocrit between age-groups 35–44 and 45–54; and this appeared consistent with a menopausal influence upon hematocrit. 3. 3. The racial difference in hematocrit could not be explained by differences in hook-worm infestation, current nutritional intake, social class, occupation, glucose-6-phosphate dehydrogenase deficiency, sickle cell disease, parity, or cigarette smoking. The reasons for the racial difference in hematocrit remain unknown. 4. 4. A significant association between hematocrit and coronary heart disease could not be found in either of two studies: living coronary compared with non-coronary population segments in Evans County, Georgia, and deceased compared with surviving coronary patients from the North Carolina Memorial Hospital. First hematocrit was found to be significantly higher than last hematocrit in hospitalized coronary patients; under certain circumstances this could be an important source of bias in studies of hematocrit among hospital populations. 5. 5. Hematocrit was found to be significantly associated with blood pressure, serum cholesterol and body weight; but the degree of association was not large. 6. 6. Cigarette smokers had significantly higher hematocrit values than had non-smokers.