Senior author Michael D. Brown of Temple University’s College of Health Professions, said the hormone aldosterone influences the kidney’s regulation of blood pressure, but too much of it can contribute to the development of hypertension because it causes the kidney to retain salt. Forty percent of African-Americans have hypertension, but there is little data about what makes them more susceptible to this condition.

The six-month study involving 35 Caucasians and African-Americans with hypertension found that aerobic exercise training program reduced aldosterone levels in Caucasians by 32 percent, but levels African-Americans dropped by 8 percent. Total body fat was reduced only in Caucasians, reported the study published in Experimental Physiology.

Brown said that although study the showed exercise did not lower aldosterone in African-Americans, exercise still has many other benefits for this population.