Racial Differences in Cardiorespiratory Fitness between Blacks and Whites: A Meta-Analysis

Abstract

PURPOSE: Cardiorespiratory fitness (CRF) is a major risk factor for cardiovascular disease (CVD), all-cause mortality and CVD mortality. Some researchers have speculated that Blacks have lower levels of CRF when compared to Whites, which may contribute to the health disparities in CVD. However, this racial difference in CRF has not been previously evaluated quantitatively across published clinical trials. The purpose of the present study is to perform a meta-analysis to quantify the CRF differences between Black and White Adults. We hypothesized that the analysis would find that Blacks' CRF values would significantly lower than the Whites Adults. METHODS: A systematic literature search was performed for studies that compared CRF values between Black and White Adults. Articles were included if: (1) CRF was assessed by an exercise test (submaximal or maximal); (2) CRF was assessed in Blacks and Whites; (3) examined adults only; and (4) published in a peer review journal. Studies were excluded if: (1) the study population was children or adolescents (2) the sample size had less than 15 participants per group and, (3) health conditions were not cardiovascular in nature or type two diabetes (e.g. neurological). The meta-analysis was performed using the R Studio Software (Boston, MA). RESULTS: Twenty-three studies (77,776 subjects; 17,314 Blacks; 60,462 Whites) were eligible out of the 47 studies identified. The first analysis (N=23) comparing CRF levels between Blacks and Whites from epidemiological and clinical studies quantifying fitness in maximal METs from exercise testing had a difference of 0.93 between the means. The second analysis comparing CRF levels between Blacks and Whites from studies only utilizing maximal oxygen consumption had a difference of 3.27 between the means. DISCUSSION: The present meta-analysis supports previous literature indicating that Blacks have a lower CRF levels when compared to Whites in many published clinical trials. The following results supports that exercise interventions should be specifically designed for Blacks to help combat the racial differences found in CRF and future researchers should investigate the potential mechanisms that may be contributing to lower CRF in Blacks.