Using a hypertension model developed by the institute's associate director, Dr. Gregory Harshfield, Dr. Kapuku is first looking at those who might be most at risk: people with a genetic tendency to retain sodium and an elevated blood pressure following stress, such as a competitive video game.
The body naturally responds to stress by increasing blood vessel constriction and fluid volume inside vessels. The kidneys help with volume by retaining sodium. Natriuresis is the body's way of eliminating sodium so pressures can return to pre-stress levels. Dr. Harshfield's studies have shown certain populations, including young black males and overweight males, have a problem with pressure returning to normal because of reduced ability to eliminate sodium.
Dr. Kapuku wants to know if this impaired ability to regulate sodium also increases the risk for the early changes in the heart's ability to fill. He'll look at a cross- section of teens to determine the contribution of race and gender as well. "The purpose of this study is to tell you that before you have difficulty breathing, you show some signs that we could modify earlier and prevent you from going on to that," says Dr. Kapuku.
The many unknowns about heart disease prompted Dr. Kapuku to leave his practice in the Congo, complete training in clinical cardiology and cardiovascular physiology in Japan and three research fellowships, including one in interventional cardiology at the Montreal Heart Institute and two at MCG. He joined the MCG faculty in 2001.