Health Highlights: Feb. 12, 2007
Vasectomy May Increase Dementia Risk British Drug Store Chain to Sell Viagra Without Prescription Lack of Sleep Affects Brain Region Tied to New Memories: Study Genetic Risk for Type 2 Diabetes Mapped OutStillbirth Risk Increases for Women Older Than 40
Here are some of the latest health and medical news developments, compiled by editors of HealthDay:
Vasectomy May Increase Dementia Risk
Having a vasectomy may increase the risk of certain types of dementia, say researchers at Northwestern University in Chicago.
Their study of 106 men found that 40 percent of those with a form of dementia called primary progressive aphasia (PPA) had undergone a vasectomy, compared to 16 percent of the men without this form of dementia. The study was published in the journal Cognitive and Behavioral Neurology.
While the findings don't mean that having a vasectomy will directly cause PPA, it may be a risk factor for developing the condition, said principal investigator Sandra Weintraub, professor or psychiatry and behavioral sciences and of neurology at the university's Feinberg School of Medicine.
People with PPA have difficulty recalling and understanding words, resulting in the loss of their ability to express themselves and understand speech.
The researchers also found preliminary evidence that vasectomy may be associated with another form of dementia called frontotemporal dementia. Symptoms of this condition include personality changes, lack of judgment and bizarre behavior.
British Drug Store Chain to Sell Viagra Without Prescription
In a trial program to be launched on Valentine's Day, men will be able to buy Viagra without a prescription at a few stores operated by the British pharmacy chain Boots.
The company said the pilot program with the drug, used to treat erectile dysfunction, will be offered at three stores in Manchester and is expected to last six months, the Associated Press reported.
Men, ages 30 to 65, who want to purchase Viagra without a prescription will have to see a pharmacist, provide a medical history, and undergo tests for cholesterol, blood pressure and glucose levels. If men want a refill, they'll have to see a doctor.
After the initial trial, the company will consider whether to expand the program to other outlets. Boots has about 1,500 stores across Britain, the AP reported.
Lack of Sleep Affects Brain Region Tied to New Memories: Study
A lack of sleep disrupts the functioning of the hippocampus -- the area of the brain involved in forming new memories -- and this could explain why children who don't get enough sleep tend to do poorly in school, say Harvard Medical School researchers.
Their study included 28 volunteers who were randomly deprived of sleep for two days and a night or who were allowed to sleep normally. After that time, the volunteers were given a test that involved looking at and remembering a series of pictures, Agence France Presse reported.
While they did the test, the volunteers' cerebral activity was monitored using functional magnetic resonance imaging (fMRI). The sleep-deprived participants did slightly worse on the test than those who got their normal amount of sleep.
The fMRI revealed that the sleep-deprived volunteers had far lower levels of hippocampus activity during the test than the sleepers, and this affected other areas of the brain linked to alertness, AFP reported.
The findings were published Sunday in the journal Nature Neuroscience.
"These results demonstrate that an absence of prior sleep substantially compromises the neural and behavioral capacity for committing new experiences to memory," the study authors wrote. "It therefore appears that sleep before learning is critical in preparing the human brain for next-day memory formation -- a worrying finding considering society's increasing erosion of sleep time."
Genetic Risk for Type 2 Diabetes Mapped Out
British and Canadian researchers say they've mapped out a genetic mutation that may indicate whether a person will develop type 2 diabetes, the most common form of the disease.
In the United States, more than 17 million people are estimated to have type 2 diabetes, also known as adult onset diabetes. In the United Kingdom, where the research was conducted, almost 2 million people have type 2 diabetes, according to BBC News.
The gene mapping will be able to identify about 70 percent of the genetic makeup of type 2 diabetes, the news agency quoted the scientists as saying. The gene mutation is a zinc transporter involved in regulating insulin secretion, according to BBC News. The research is published in the current issue of the journal Nature.
"If we can tell someone that their genetics mean they are predisposed towards type 2 diabetes, they will be much more motivated to change things such as their diet to reduce their chances of developing the disorder," the news agency quoted researcher Philippe Froguel as saying. "We can also use what we know about the specific genetic mutations associated with type 2 diabetes to develop better treatments," he added.
Stillbirth Risk Increases for Women Older Than 40
It may be a finding that many will find disappointing, but pregnancy after age 40 is an independent risk factor for stillbirth, according to researchers from Yale Medical School.
And that's why it's important for older pregnant women to get antenatal testing on a regular basis after 38 weeks into their pregnancy, the researchers told those attending the Society for Maternal-Fetal Medicine Conference in San Francisco over the weekend.
According to a news release from the society, Yale scientists conducted a cross-sectional study of more than 11 million deliveries between 1995 and 1997 in a database provided by the U.S. Centers for Disease Control and Prevention. The results confirmed increased risks for older pregnant women, including gestational diabetes mellitus, preeclampsia, placenta previa and intrauterine growth restriction.
All of these conditions can contribute to a higher incidence of stillborn deliveries, the researchers said.