Poisonous bean may benefit OSA suffers

Sunday, November 23, 2003

November 24, 2003

YARMOUTH, Maine - A bevy of sleep apnea studies have linked the disorder with everything from depression to acid reflux, but the newest theory is full of beans.

The main ingredient of the poisonous African Calabar bean, once used in African rituals, may prove effective in treating obstructive sleep apnea, according to researchers at Sahlgrenska University in Sweden.

The team treated 10 OSA patients with a continuous infusion of the drug physostigmine. When drug concentrations reached a steady plateau, the frequency of apnea events decreased significantly, with the biggest drop during the REM stage of sleep.

The researchers believe that physostigmine counteracts the chemical imbalance in the brain that causes certain kinds of sleep-disordered breathing. The drug also helps muscles contract.

Physostigmine has been used to treat certain types of glaucoma.

In separate OSA findings, some ophthalmologists have noted a correlation between OSA and glaucoma, and many believe the association is great enough to include questions on sleep disorders when evaluating a patient's medical history.

The study was conducted because OSA is believed to affect oxygenation and other factors that may have an effect on the optic nerve.

One ophthalmologist, Dr. Rick Bendel, noted that of 83 of his patients with OSA, 33% also had glaucoma.

It is well known that people with sleep apnea run an increased risk of car accidents and a host of other events, said Bendel, "but perhaps we should now be adding the risk of glaucoma to the list and telling them that their sleep apnea could be having a significantly detrimental impact on their eyes."