US Pharm. 2007;1:20-22.

Body Fluid Displacement Can Lead to Sleep Apnea
It is widely believed that obesity is a major cause of obstructive sleep apnea, a condition in which a blockage in the throat or upper airway causes breathing to stop long enough to decrease the amount of oxygen in the blood and increase the amount of carbon dioxide. In its severest form, obstructive sleep apnea can lead to death. But data from a study recently published in the American Journal of Respiratory and Critical Care Medicine show that nonobese persons can also suffer from sleep apnea while lying on their backs.

This is generally due to a small amount of fluid displaced from the legs to the base of the neck, which can narrow soft tissue around the throat and increase airflow resistance in the pharynx by more than 100%, predisposing patients to the disorder.

While the National Heart, Lung, and Blood Institute estimates that 18 million Americans suffer from sleep apnea, according to T. Douglas Bradley, MD, of the Toronto General Hospital, "obesity and neck circumference are important risk factors in obstructive sleep apnea, but altogether only account for approximately one third of the variability in the apnea-hypopnea index." He added, "A factor not ordinarily considered is fluid accumulation at the nape of the neck and around the pharyngeal soft tissue. Obstructive sleep apnea is very common in fluid-retaining states such as heart failure, renal failure, and peripheral edema of unknown cause."

Gut Bacteria May Be Cause of Obesity
The inability to lose weight may not be in your head after all; it may be bacteria in the stomach, according to researchers at Washington University, St. Louis. Investigator Jeffrey I. Gordon, MD, noted that when an overweight person goes on a diet, one group of efficient bacteria moves out of the gut, and another, less efficient group moves in to fill the void.

Based on research published in the journal Nature, Dr. Gordon and his colleagues wrote that manipulation of intestinal microbes might someday lead to a treatment for obesity. The investigators conducted a census of intestinal flora in obese people while they lost weight. They found that the proportion of Bacteroidetes and Firmicutes bacteria, species of which comprise more than 90% of intestinal microbes in humans, changed in tandem with the drop in excess poundage. While it is not clear whether change in the bacteria drives the weight loss or puts pressure on the bacterial composition of the gut, the researchers believe that it raises intriguing questions about the nature of
obesity.

Many Colonoscopy Exams Are Too Short
Anyone who has ever undergone a colonoscopy exam can attest that it seems like a lifetime before it is completed. But a study published in the New England Journal of Medicine concludes that doctors who perform colonoscopy would get better results if they spent more time looking for abnormal growths.

The study recorded the results of 12 experienced gastroenterologists performing nearly 8,000 colonoscopy procedures over a 15-month period. The investigators compared rates of detection of neoplastic lesions among the physicians who had a mean colonoscopic withdrawal time of six minutes or more. As compared with colonoscopies with mean withdrawal times of less than six minutes, the withdrawal times of six minutes or more had higher rates of detection of any neoplasia and of advanced neoplasia.

Cold Therapy for Migraine Patients
Migraine headaches are one of the most difficult types of headache to treat. While they are generally treated with antimigraine drugs, analgesics, and antiemetics, many patients also resort to nonpharmacologic methods such as massage, trigger point therapy, reflexology, spinal manipulation, acupuncture, or therapeutic heat or cold therapy.

A relatively small, nonrandomized study from Turkey indicated that cold application alone may be effective in some patients suffering from migraine attacks. The study showed that approximately 50% of patients treated for migraine with cold therapy found some relief after onset of the headache. There was also consistency in the cold applications. The study showed that 76% of patients who had a response in their first attack benefited from the cold therapy in the second attack. But the investigators noted that 60% of the patients who did not respond to the first cold application had no response during the second attack either.

Cancer-Causing Stem Cells Resistant to Treatment Identified
While the debate concerning stem cell research continues to swirl in political circles, a report from Cedars-Sinai Medical Center's Maxine Dunitz Neurosurgical Institute, Los Angeles, offers a positive perspective. According to the report, published in the journal Molecular Cancer, researchers identified "cancer stem cells," a small population of cells that appear to be the source of cells comprising a malignant brain tumor. The investigators believe that if these mother cells can be destroyed, in theory the tumor will not be able to sustain itself. On the other hand, if they are not removed or destroyed, even if the tumor is almost completely obliterated, the cancer will regenerate from the surviving cancer stem cells and be even more resistant to cancer-killing therapies.

"If one believes in the cancer stem cell hypothesis, it may guide the way we research tumors and the way we look for therapeutic approaches to treat these tumors, because all of our efforts will need to be directed at killing these cells," said Keith L. Black, MD, Director of the Institute and Chair of Cedars-Sinai's Department of Neurosurgery.

Cancer stem cells were first found in certain leukemias and in breast carcinomas. In 2004, shortly after stem cells were identified in pediatric brain tumors, researchers at Cedars-Sinai's neurological institute reported the first isolation of cancer stem cells in adult brain tumors. "In this study, we provide the first evidence that cancer stem cells have a significant resistance to conventional chemotherapeutic agents. We also link this resistance to genes that are known to inhibit a cell death," said John S. Yu, MD, Codirector of the Comprehensive Brain Tumor Program at Cedars-Sinai and senior author of the journal article.

Posttraumatic Stress Increases Risk of Heart Disease in Older Veterans
While a link between posttraumatic stress syndrome (PTSD) and heart disease has long been suspected, a study by Laura Kubzansky, PhD, and her colleagues from the Harvard School of Public Health in Boston contend that their study appears to be the first to demonstrate a prospective association between PTSD and heart disease.

The study suggests that individuals with more severe PTSD run a greater risk for coronary heart disease. The authors said their findings may imply a dose-response relationship and that the results were consistent with a model of prolonged stress reaction that suggests impaired adaptation and increased wear and tear on the body, which may lead to atherosclerosis and cardiovascular damage, although a biological pathway between PTSD and heart disease has yet to be determined.

Cough and Phlegm in the Young Causes Increased COPD Incidence
The results of a 10-year respiratory study published recently in the American Journal of Respiratory and Critical Care Medicine shows that young adults (ages 20 to 44) with normal lung function who later develop chronic cough and phlegm have a fourfold higher risk of chronic obstructive pulmonary disease (COPD).

According to Isa Cerveri, MD, Division of Respiratory Diseases at San Matteo Hospital and University of Pavia in Italy, where the study was done, chronic cough and phlegm among the study participants was an independent and statistically significant predictor of COPD. "COPD is a major health problem even in young adults who are usually not considered to be at risk," said Dr. Cerveri. COPD is the fourth leading cause of death in the United States.

Quitting Smoking Early May Reverse Damage
A clinical investigation reported in the Journal of Nuclear Medicine suggests that damage done to coronary arteries by smoking may be reversed in healthy young smokers.

According to investigators at Hokkaido University Graduate School of Medicine, Sapporo, Japan, smoking negatively impacts the lining of the arteries, known as the endothelium, and leads to atherosclerosis. This results in abnormal peripheral and coronary vascular vasomotion, which raises the risk of heart attack and stroke.

The researchers examined the blood flow in the coronary arteries of 15 men in their 20s and 30s who reported a smoking history of, on average, 20 cigarettes per day for more than five years; each agreed to stop smoking for at least six months. They found that in young smokers, artery damage may be reversible within one month of smoking cessation.

To comment on this article, contact editor@uspharmacist.com.