"People criticize the concept of reducing sodium because not everyone's blood pressure goes up," says Flack. "While everyone may not need to restrict sodium intake in the short term, buried within that group of people is a subset of people who are really salt-sensitive."
The exact cause of high blood pressure is not completely understood, says Flack. It has been well documented that when exposed to usual and customary levels of dietary salt intake, blood pressure rises in some people considered to be salt-sensitive.
"High blood pressure damages the kidneys, brain, heart, and other vital organs," says Flack. "The rise in blood pressure causes the kidneys to leak protein and also contributes to an abnormal increase in heart size."
Flack says that salt-sensitivity has been documented in all racial and ethnic groups, and even in people with normal blood pressure levels, but he adds that heredity is an important influence on whether an individual is salt-sensitive or not.
"This study is consistent with findings in Japanese and Spanish populations," says Flack. "We're not quite ready to recommend widespread screening for the ACE gene, but we may be getting close to the point where it might be a reasonable thing to do."
Currently, mass screening for the gene variant is not recommended. However, Flack says African Americans who have high blood pressure, diabetes, kidney disease or who are obese have been found to be most likely to have the ACE gene variant.
Co-authors are Beth A. Staffileno, D.N.Sc., Marwan Hamaty, M.D., Amanda Dudley,
B.S., Gerard Tromp, Ph.D., and Helena Kuivaniemi, M.D., Ph.D., of Wayne State
University; Carla Yunis, M.D., of Wake Forest School of Medicine, Winston
Contact: Carole Bullock
American Heart Association