News in brief - July 7, 2008

FDA seeks "black-box" warning for older antipsychotics - Some hearing loss tied to diabetes - Overall mortality goes down - Hormone increases eating during stressful times - Tracking changes in avian influenza virus strains

FDA seeks "black-box" warning for older antipsychotics

The Food and Drug Administration on June 16 exercised its new authority under a law enacted last fall to require manufacturers of older antipsychotic drugs to place a "black-box" warning on the drugs' labels. The warning cautioned about the increased risk of death associated with the off-label use of these drugs to treat behavioral problems in older people with dementia.

The so-called older antipsychotics, which are referred to as "conventional," include such drugs as Compazine, Haldol and Loxitane.

Newer antipsychotics, commonly called "atypical," already were required to have a black-box warning about the same risk. Among them are Clozaril, FazaClo and Risperdal. The drugs are approved for treating symptoms associated with schizophrenia.

Some hearing loss tied to diabetes

Hearing loss is about twice as common in adults with diabetes, according to a study in the July Annals of Internal Medicine. The study was published online June 17.

The researchers discovered the higher rate of loss after analyzing the results of hearing tests given to a nationally representative sample of 5,140 adults ages 20 to 69. Hearing loss in diabetics was evident across all frequencies -- low, middle and high. Researchers were unable to distinguish between type 1 and type 2 diabetes.

They suggested that people with diabetes consider having their hearing tested. "Our study found a strong and consistent link between hearing impairment and diabetes using a number of different outcomes," said author Catherine Cowie, PhD, MPH, director of the diabetes epidemiology program at the National Institute of Diabetes and Digestive and Kidney Diseases.

Overall mortality goes down

The age-adjusted death rates for the general population decreased from 2005 to 2006 and went down for 11 of the 15 leading causes of death, according to Deaths: Preliminary Data for 2006 issued by the Centers for Disease Control and Prevention last month.

The overall death rate declined from 799 per 100,000 to 776, and fewer died from heart disease, cancer, cerebrovascular issues, chronic respiratory conditions, accidents, diabetes, influenza and pneumonia, septicemia, suicide, chronic liver disease and hypertension. Life expectancy also increased to a record high of 78.1 years.

But death rates for Alzheimer's, kidney conditions, Parkinson's and homicide were unchanged, and patient advocates seek more resources to tackle them. Activists are particularly concerned about Alzheimer's because it has bypassed diabetes and become the sixth leading cause of death. The aging of the population is expected to continue to make this an increasingly common problem.

"It is vitally important that we increase Alzheimer's research funding to slow or stop the progression of this devastating disease," said William Thies, PhD, vice president of medical and scientific relations at the Alzheimer's Assn.

Hormone increases eating during stressful times

A hormone known to play a role in appetite regulation increases food intake while suppressing depression and anxiety during times of stress, according to a study published online in Nature Neuroscience last month and due to be in a future print edition.

Researchers stimulated production of ghrelin in mice by restricting what they ate. Some were also injected with the substance. They were then subjected to stressful situations such as running a maze, a forced swim test or encounters with more aggressive mice. Those with high levels of this hormone were less likely to experience depression or anxiety and tended to eat more for up to four weeks after the high-stress incident.

"Our findings support the idea that these hunger hormones don't do just one thing. They coordinate an entire behavioral response to stress and probably affect mood, stress and energy levels," said Michael Lutter, MD, PhD, lead author and instructor of psychiatry at University of Texas Southwestern Medical Center at Dallas.

Tracking changes in avian influenza virus strains

Some North American avian influenza strains -- specifically, certain A H7 virus strains -- have properties that may enhance their potential to infect humans as well as their potential to spread from human to human, according to study findings reported by Centers for Disease Control and Prevention researchers.

The study was published in the May 27 Proceedings of the National Academy of Sciences USA, and its lead author noted that its results underscore the importance of continued influenza virus surveillance.

These viruses infect humans by attaching to certain sugar receptor molecules on cells in the respiratory tract. The greater this ability to bind or attach, the more likely it is that the virus will cause illness in humans and possibly be transmitted from human to human, researchers said.

In this study, three recent H7N2 strains and two H7N3 strains from North America were tested and found to bind to both avian and human receptors in varying degrees.

One virus, an H7N2 strain isolated from an immune-compromised man in New York in 2003, was found to have the greatest binding to human sugar receptors. Overall, the findings suggest that these North American avian influenza A H7 viruses are partially adapted to recognize the sugar receptors preferred by human influenza viruses and found in the human upper respiratory tract.