SEATTLE, May 7 -- Sleep disturbances in older patients may signal gastroesophageal reflux, a panel of specialists said here.
Because aging dulls the classic daytime heartburn of gastroesophageal reflux disease (GERD), nighttime symptoms may herald continued "silent" damage, warned participants in an industry-sponsored satellite symposium held in conjunction with the American Geriatrics Society meeting.
Age-related physiologic changes increase older patients' risk from GERD, said James E. McGuigan, M.D., of the University of Florida in Gainesville.
For instance, peristalsis, which cleanses the esophagus of refluxed acid, progressively decreases with age, he said.
Medication plays a role, too. Some of the most common medications used by older patients are known to reduce lower esophageal pressure, Dr. McGuigan said. These include levodopa, opioid analgesics, and benzodiazepines.
Aging has also been associated with decreased sensory perception at striated muscle segments in the upper esophagus and at smooth muscle segments in the lower esophagus, Dr. McGuigan said. Thus, older patients have a longer lag time before sensation of esophageal pain in the presence of acid.
"If we have a situation in which we don't recognize sensation, we are less likely to do something about it pharmacologically," Dr. McGuigan said at the Wyeth-sponsored symposium.
"[GERD] is not less common because the disease is less severe," he said, "but because the sensation of pain -- heartburn -- is lessened in older patients."
The clinical presentation of GERD in older patients may be less typical than in younger patients, and more likely to include chest pain, vomiting, dysphagia, respiratory symptoms, and belching.
"Our index of suspicion has to be much higher than it would be otherwise," Dr. McGuigan said.
Older patients may also experience sleep disturbance as a symptom, said William C. Orr, Ph.D., a sleep expert at the Oklahoma University Health Sciences Center in Oklahoma City.
Three-quarters of adults with weekly GERD symptoms report nighttime heartburn, according to two epidemiologic studies that "turned the heads of a lot of gastroenterologists," Dr. Orr said.
Half of the patients in one study reported waking from sleep because of nocturnal symptoms; 40% of patients in the second study reported impaired functioning the next day.
During sleep, gravity impedes esophageal clearance and swallowing frequency drops, leading to prolonged acid contact time at night and changing the pattern of daytime symptoms, Dr. Orr said.
Previous studies have shown that nighttime reflux increases risk of GERD complications including erosive esophagitis, adenocarcinoma, asthma, and sleep deprivation.
"Acid mucosal contact during sleep will also produce arousals and sleep fragmentation," Dr. Orr said. "We've shown this time and time again in our laboratory."
In one of his laboratory experiments, exogenous infusion of acid into the esophagus while volunteers were asleep showed arousal from sleep both on electroencephalogram (EEG) and on submental electromyography (EMG).
A paper in press in the Journal of Clinical Sleep Medicine showed the same thing for 90% of spontaneous acid reflux events in patients, he said.
Older adults' attenuated esophageal sensory function could lead to longer reflux events and greater esophageal damage, Dr. Orr said. "It's adding insult to injury."
Sleep abnormalities could serve as "the needed clinical clue for identifying silent GERD," he said.
His 2005 study published in the American Journal of Gastroenterology indicated that 26% of older adults with no heartburn or other sleep disturbance actually had acid reflux during sleep.
Other studies have found so-called silent GERD in 6% to 23% of asymptomatic, healthy individuals screened using upper endoscopy.
Nighttime symptoms of GERD can be effectively treated with proton pump inhibitors (PPIs), said Denis M. McCarthy, M.D., Ph.D., of the University of New Mexico in Albuquerque.
In a small study in the American Journal of Gastroenterology in 2002, evening dosing of the PPI rabeprazole (Aciphex) reduced nighttime symptoms better than morning dosing.
It appears that PPIs have similar efficacy in daytime and nighttime symptoms, Dr. McCarthy said.
For patients who wake up at night with heartburn or have breakthrough symptoms, he suggested using an antacid rather than an H2 receptor antagonist, because these drugs inactivate PPIs.
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