Clinically speaking

Friday, February 28, 2003

SAN DIEGO - The long suspected causal link between hypertension and sleep disordered breathing both weakened and strengthened in new studies published in leading clinical journals in January.

In Circulation, a peer review journal published by the American Heart Association, a study conducted in Germany and Australia showed that effective CPAP therapy can reduce blood pressure by 10 mm of mercury. Lowering blood pressure by that amount can cut coronary heart disease risk by 37% and stroke risk by 56%, according to the study.

But another study in Chest that surveyed English-language clinical literature between 1972 and 2000 found the link to be far less definitive and “very difficult to demonstrate.”

If a definitive causal link were established, the market for sleep therapy products would grow significantly.

ResMed’s Walter Flicker characterized the Circulation study as the most significant validation to date of the link between sleep disordered breathing and heart disease.

HME providers “should get every home care physician and cardiologist to be asking their patients about sleep disordered breathing, particularly all those who have hypertension,” said Flicker.

Joe Lewarski, a home respiratory provider and chairman of the AARC’s home care section, takes a more sober view of the link.

“The summary, as I read it suggests that there still is not enough objective scientific evidence to establish proof of a clear and specific cause and effect relationship between SDB and” hypertension, he said. HME