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Hypertension Watch

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Race Plays Role in Conversion from Prehypertension to High Blood Pressure 

African Americans with prehypertension develop high blood pressure 1 year sooner than Caucasians and have a 35% greater risk of progressing to hypertension, according to analysis of the health records of 18,865 adults.

Previous research has shown that coronary heart disease, stroke, and hypertension are more common among African Americans. In a study published in the September 2011 issue of Hypertension: Journal of the American Heart Association, a team of researchers from the Medical University of South Carolina led by Anbesaw Selassie, DrPH, analyzed electronic health records from patients at 197 community-based clinics in the southeastern United States from 2003 to 2009. The goal, according to the study, was to determine whether progression from prehypertension is accelerated in African American patients.

The researchers found that in addition to race, a number of other conditions are strongly associated with a faster conversion from prehyptertension to hypertension, including age (75 years and older), systolic blood pressure (130 to 139 mm Hg), being overweight or obese, and having type 2 diabetes.

Dr. Selassie and colleagues recommend several lifestyle changes to reduce risk for prehypertension, including weight loss, physical activity, a diet high in fruits and vegetables and low in salt and fat, and moderate alcohol consumption. Treatment guidelines do not call for using medications to lower the risk of high blood pressure for people with prehypertension, they noted.

The study results, according to Dr. Selassie, suggest a strong need for more aggressive early interventions and lifestyle changes for African Americans with prehypertension. “I firmly believe that without early therapeutic interventions such as medication, we cannot narrow the gap between blacks and whites on these outcomes,” he said.

Diabetes and Hypertension Linked to Glaucoma

Individuals with diabetes and hypertension may have an increased risk of developing open-angle glaucoma (OAG), according to research published in the July 2011 issue of Ophthalmology.

In the study, Joshua D. Stein, MD, MS, of the University of Michigan Kellogg Eye Center, and colleagues examined the possible associations between various components of metabolic syndrome, and how each component increased or decreased the risk of glaucoma.

Analysis of the billing records of more than 2 million people 40 years and older who were enrolled in a managed care network in the United States and who visited an eye care provider at least once from 2001 to 2007 showed that individuals with diabetes alone had a 35% higher chance of developing OAG, and those with hypertension alone had a 17% greater risk. In patients with both diabetes and hypertension, there was a 48% increased risk of developing OAG, the most common form of glaucoma in the country.

“Patients who have diabetes and hypertension are already known to be at elevated risk for eye conditions like diabetic retinopathy, a condition that harms the blood vessels in the retina,” says Dr. Stein. “This study and others suggest that, for these patients, an increased likelihood of glaucoma is also a concern.” PT

Slow Wave Sleep Can Predict Hypertension Risk

Reduced slow wave sleep (SWS) is a powerful predictor for developing high blood pressure in older men, according to study published online August 29, 2011, in Hypertension: Journal of the American Heart Association.

Researchers from the Outcomes of Sleep Disorders in Older Men Study found that individuals with the lowest level of SWS—a deep stage of sleep characterized by nonrapid eye movement—had an 80% increased risk of developing hypertension.

“Our study shows for the first time that poor quality sleep, reflected by reduced slow wave sleep, puts individuals at significantly increased risk of developing high blood pressure, and that this effect appears to be independent of the influence of breathing pauses during sleep,” said study coauthor Susan Redline, MD, of Harvard Medical School.

Evaluation of sleep characteristics related to hypertension in 784 men showed that men who spent less than 4% of their sleep time in SWS were significantly more likely to develop hypertension during the 3-year study, whereas men with reduced SWS had generally poorer sleep quality and had more severe sleep apnea than men with higher levels of SWS. However, of all measures of sleep quality, decreased SWS was the most strongly linked to the development of hypertension.

“People should recognize that sleep, diet and physical activity are critical to health, including heart health and optimal blood pressure control,” said Dr. Redline, adding that “Poor sleep may be a powerful predictor for adverse health outcomes. Initiatives to improve sleep may provide novel approaches for reducing hypertension burden.”