Heart Rate Predicts Future Blood Pressure Rise In African American Boys

      HEART RATE PREDICTS FUTURE BLOOD PRESSURE RISE IN AFRICAN AMERICAN BOYS

      Does Not Work in African American Girls

      Or In White School Children, Study Finds

      NEW YORK, NY -- Heart rate predicted future diastolic blood pressure increases in African American boys, according to a study in October's American Journal of Hypertension, but not in African American girls or in white children.

      "This study of 800 schoolchildren gives physicians an important warning sign when examining young African American men," said Michael A. Weber, MD, an editor of the American Journal of Hypertension. "It suggests a means for

      identifying people at-risk and starting education programs for good heart health.

      "Certainly, the presence of an increased heart rate in young black men should alert physicians and other health providers to the possibility of impending hypertension," he continued. "Early education and intervention programs covering smoking cessation, reducing salt intake, following good

      dietary habits and making other lifestyle changes should benefit young African American males.

      "From a public health perspective," Dr. Weber said, "African American men are the most vulnerable to the consequences of hypertension, including kidney failure at a young age."

      Nearly 50 million Americans, including nearly 12 million African Americans, have high blood pressure. Commonly referred to as the silent killer, untreated hypertension prematurely ages the body's arteries and can lead to strokes, heart attacks and kidney failure, often without warning.

      Researchers from Indiana University School of Medicine, Indianapolis, studied a cohort of 344 African Americans (159 boys and 185 girls) and 456 white school children (230 boys and 226 girls), ages five to 19. Blood pressure was measured in follow-up every six months for up to 12.9 years.

      "The main observation of our study was the relationship of heart rate to the blood pressure level in the future, and here this was significant only in black males," the investigators said.

      They noted that while baseline heart rate predicted future diastolic blood pressure in the African American boys, "in the black girls there was a trend for a similar relationship. No relationship of baseline heart rate to

      future blood pressure was observed in the white subjects."

      Longitudinal systolic blood pressure was significantly higher in the boys than in the girls for both races. Longitudinal diastolic blood pressure was not significantly different in the boys and girls of either race, the

      researchers said.

      They found heart rate declined with age, with the boys showing the greatest decline. Differences between the African American boys and girls and between the white boys and girls were significant. African American girls showed the smallest decline, although the difference in the level between

      the black and white girls was only marginally significant.

      "We did find in both the whites and the blacks that concurrently measured heart rate and systolic blood pressure were significantly and positively related, although relationships to diastolic blood pressure were less consistent," the researchers reported.

      Authors of the study, "Heart Rate as a Predictor of Future Blood Pressure in Schoolchildren," are Lifen Zhou, MS; Walter T. Ambrosius, Ph.D.; Shirley A. Newman, RN; Mary Anne Wagner, BS; and J. Howard Pratt, MD. Dr. Pratt is also affiliated with the VA Medical Center, Indianapolis, IN.

      The American Society of Hypertension (ASH) is the largest US organization devoted exclusively to hypertension and related cardiovascular diseases. ASH is committed to alerting physicians, allied health professionals and the public about new medical options, facts, research findings and treatment

      choices designed to reduce the risk of cardiovascular disease.

      American Journal of Hypertension: October 2000; 13:1082-1087