Date of Award
Master of Science (MS)
Sandra Fowkes Godek, Ph.D., ATC
Katherine Morrison, Ph.D., ATC
Christine Karpinski, Ph.D., RD
Context: Racial differences in the renin-angiotensin-aldosterone system (RAAS) have been implicated in the disparity in the prevalence of hypertension in Americans. The RAAS is a primary mechanism for sodium conservation during exercise. Purpose: To investigate racial differences in the RAAS and its relationship to sweat and urine electrolyte losses during exercise. Methods: Data was collected before the first pre-season practice and during football and soccer practice on day 10 of practices. Eight Caucasian and 8 African-American male division II collegiate football and soccer players volunteered and did not differ in physical characteristics. Venous blood samples (8 mL) were drawn before the first pre-season practice (baseline) and on day 10 of practices. Sweat and urine electrolyte concentrations (mmol/L) were analyzed by ion-selective electrodes. Results: Significant differences were found in renin at baseline (Caucasian: 1.22 ± 0.56 ng/dL/hr, African-American: 0.57 ± 0.22 ng/dL/hr, p = 0.013) and at pre-practice (Caucasian: 1.30 ± 0.51 ng/dL/hr, African-American: 0.77 ± 0.34 ng/dL/hr, p = 0.042). Post-practice concentrations of urine sodium (Caucasian: 48.8 ± 33.7 mmol/L, African-American: 97.7 ± 40.1 mmol/L, p = 0.029) and chloride (Caucasian: 95.2 ± 49.7 mmol/L, African-American: 151.5 ± 42.7 mmol/L, p = 0.039) also differed. Correlations between between electrolyte losses and measurement of the RAAS were found to be significant in both races, but never simultaneously. Conclusions: These results suggest a potential racial difference in the influence of these hormones on the mechanism by which electrolytes are lost and need to be replaced in African-American versus Caucasian athletes.
McGinty, Shane, "Racial Differences in Renin and Aldosterone and Their Relationship to Sweat and Urine Electrolyte Losses in Male Collegiate Athletes During Pre-Season Practices" (2018). West Chester University Master’s Theses. 29.