Hypertension In Blacks: Dietary Salt Plays Key Role

Hypertension in BlacksDIETARY SALT PLAYS KEY ROLE

A study of first and second-generation African Caribbeans living in the West Midlands of England found many undiagnosed cases of high blood pressure and more whose blood pressure medications were not adequately controlling their hypertension.

The study is the first to focus on blood pressure, dietary salt intake and salt sensitivity among both first and second-generation African Caribbeans living in the United Kingdom. It is one of the largest studies ever to examine the effects of dietary salt on blood pressure in a black population.

Dr. Elijah Saunders, head of the Division of Hypertension at the University of Maryland School of Medicine, will present his preliminary findings on July 21 to the 12th International Conference on Hypertension in Blacks, in London, England. A co-founder and current chairman of the board of the society sponsoring the conference, he directed the six-week study of 150 African Caribbeans living in Birmingham and Wolverhampton.

Participants had their blood pressure, pulse rate, height and weight measured at a baseline screening prior to the study. Blood and 24-hour urine examinations were done at baseline. and then weekly for three weeks while the subjects ate their normal diets, usually high in salt. Blood pressure, pulse, weight and 24-hour urine exams (for salt) were repeated weekly for a total of six weeks. During the last three weeks the subjects ate diets containing 50 percent less salt than at baseline.

Preliminary results suggest that on the salt-restricted diets, most subjects lost weight and their blood pressure dropped.

"We were not surprised to see high blood-pressure rates nearly twice that of whites, and we were not surprised to find a significant amount of obesity and diets excessively high in salt—we have seen this phenomenon in African Americans," Saunders said.

Some surprises did await the researchers, though. "Not only was a significant amount of hypertension undiagnosed, but many people who were being treated had blood pressures that were not being very well controlled by their medication," Saunders said.

Another surprise, he said, was that some doctors and patients did not seem to be aware of just how serious a condition high blood pressure can be in blacks. With complications including diabetes, kidney disease, stroke and heart disease, untreated or inadequately treated hypertension is probably the number one killer in the Western world, Saunders said.

In other research reported at the London conference, Saunders and colleague, Dr. Matthew Weir, head of the Division of Nephrology at the University of Maryland School of Medicine, reported that certain kinds of high blood-pressure medications are less effective in black people when us