Public Release: 

2003 HBP news tips

Stories are embargoed until times indicated

American Heart Association

News tips from the American Heart Association's 57th Annual High Blood Pressure Research Conference, September 23-26, 2003, Omni Shoreham, Washington, D.C.

Tuesday, Sept. 23, 2003

4 p.m.* - Abstract P10 - High-normal blood pressure increases risk for organ damage. In a study of 265 people with normal blood pressure -- less than 140/90 millimeters of mercury (mmHg) -- researchers found that kidney damage is already present in people whose blood pressures fell in the "high-normal" range. Among participants, 73 had optimal blood pressure (less than 120/80 mmHg), 84 had normal pressure (less than 130/85 mmHg) and 108 were high-normal (130-139/85-89 mmHg). Researchers evaluated renal (kidney) function by a test for glomerular filtration rate (GFR) and filtration fraction (FF). High GFR and FF indicate impaired kidney function. Cardiac morphology -- left ventricular mass index (LVMI) and relative wall thickness (RWT) -- was assessed with ultrasound. High LVMI and RWT indicate an enlarged heart. Kidney function and cardiac morphology worsened from the optimal to high-normal group. The proportion of subjects with target organ damage also increased from 7 percent in the optimal group to 13 percent in the normal group and 23 percent in the high-normal group. Further, in 28 patients who were followed for an average of six years, 13 of 16 with high-normal pressure became hypertensive. The scientists found that people with high normal blood pressure already had signs of target organ damage. Researchers also found a trend that people with high-normal blood pressure progressed to hypertension. Recently updated high blood pressure guidelines consider blood pressures measuring 120-139/80-89 mmHg as "pre-hypertension." Pre-hypertension is associated with significant and progressive increase in the risk of cardiovascular death. Pierre Fesler, Hospital Lapeyronie, Montpellier, France; 33-46-733-8443; pierre.fesler@bigfoot.com.
*presentation time is 5:50 p.m.

4 p.m. - Abstract P61 - High potassium diet may protect brain from stroke damage. In an animal study, researchers have shown for the first time that dietary potassium significantly reduced the size of a stroke. Scientists fed rats either a low-potassium (Low K) or high-potassium (High K) diet for six weeks. At the end of the diet, a stroke was induced. Later, the researchers measured the part of the brain that had lost blood supply during the stroke. They measured percentage of the hemisphere affected. Rats fed the High K diet showed damage in 37 percent of the affected hemisphere, while rats on the Low K diet had 56 percent damage. The researchers believe potassium protects the brain by affecting cellular processes that expand the blood vessels in the brain. Anne M. Dorrance, Medical College of Georgia, Augusta; (706) 721-8901; adorrance@mail.mcg.edu.
*presentation time is 5:50 p.m.

Wednesday, Sept. 24, 2003

4 p.m. - Abstract 21 - Hypertension genes pinpointed. Researchers say they have validated that two genes on chromosome 2 influence blood pressure in humans. Humans have 46 chromosomes (23 pairs) that contain genetic material. Chromosome 2 has been consistently identified as a region of the human genome that affects blood pressure levels, researchers said. The National Heart, Lung, and Blood Institute's Family Blood Pressure Program has concentrated its efforts to narrow down the area of chromosome 2 to identify gene(s) for high blood pressure. They looked at the genetic "map" of chromosome 2 from 1,411 non-Hispanic whites, 1,696 African Americans and 1,649 Hispanics. Their search turned up two genes called SLC4A5 and SLC9A2. Both of these genes are expressed in the kidney and are involved with transporting material across cell membranes -- one transports sodium bicarbonate, the other exchanges sodium and hydrogen. The researchers said their study validates evidence for two genes on chromosome 2 that influence hypertension status in the population.

Thursday, Sept. 25, 2003

1:30 p.m. - Abstract P182 - Blood pressure linked to total mineral intake. High sodium intake has been shown to increase, and low sodium intake to decrease, blood pressure in some people. However, based on a statistical analysis of data from National Health and Nutrition Examination Surveys (NHANES) between 1980-2000, researchers suggested that higher blood pressure was associated with a diet low in minerals such as calcium, potassium and magnesium, rather than high sodium intake. These researchers analyzed data from NHANES III and IV (NHANES I was done in 1970). The researchers divided participants' sodium, calcium and total mineral intake (calcium, potassium, magnesium) into four groups. While blood pressure did not vary significantly according to sodium intake, higher calcium intake was linked to lower blood pressure. In NHANES III, higher total mineral intake was associated with lower blood pressure. The researchers suggest that sodium's effects on blood pressure appear to depend on other mineral intake. Where sodium intake was associated with high blood pressure, mineral intake was poor. NHANES data is compiled from people who were asked to recall their daily or weekly eating habits in a national survey, and is subject to the limitations of such data. The American Heart Association recommends that healthy adults limit their sodium intake to no more than 2400 milligrams (about one teaspoon of table salt) per day.

1:30 p.m. - Abstract P199 - Treatment that talks: Cell phones transmit data to doctors. Cellular technology can help control high blood pressure by transmitting data from patients to their doctors, according to Japanese researchers. They said it is an improvement over standard telemedicine monitoring that relies on regular landline telephones. And, it provides two-way convenience with both patients and physicians being able to check data or send messages at any time of the day. Researchers studied 38 men and 22 women, average age 50, being treated for hypertension. Patients used home monitoring systems to collect blood pressure and heart rate data. They used cell phones that connected to an Internet Web site to transmit the data. The patients were monitored for three months. During that time they were asked to check blood pressure at least two times a day -- in the morning and before sleep. Participants also were asked to check blood pressure as often as they could, using the cellular system at different times and locations. Blood pressure data was accumulated at NTT DoCoMo data center. The researchers report that all patients achieved good blood pressure control using the cellular monitoring system, including patients who were managed without using blood pressure-lowering medicines. Moreover, the cost for the system was only about $1 a month.

1:30 p.m. - Abstract P221 - Black girls retain more sodium if calcium intake is low. Researchers measured sodium (Na) excretion in 40 black and 28 white adolescent girls 11-15 years old. The study was divided into two sessions of three weeks each. The girls ate diets with either 1.3 grams per day (g/d) or 4 g/d of dietary sodium, plus dietary calcium in one of three levels -- 800 milligrams per day (mg/d), 1300 mg/d or 1800 mg/d. Researchers measured daily urinary and fecal sodium levels. While consuming the low-calcium, high-sodium diet, blacks had lower urinary sodium excretion (2,671 mg/d) than whites (3,485 mg/d). However, at higher levels of calcium intake, urinary sodium was similar between blacks and whites even on the high-sodium diet (3,743 mg/d in blacks and 3,889 mg/d in whites). Sodium retention may increase risk for hypertension in this population.

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To complement our news releases, News Media Relations has reviewed nearly 400 abstracts and prepared news tips for selected studies. Note: Stories are embargoed until times indicated with each entry. For presentations after 4 p.m. ET, embargo lifts at 4 p.m. ET.

*** All times are Eastern ***

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