Common seasonal allergy symptoms, such as watery eyes, sneezing and fatigue, can significantly impair driving ability, says a study in the July issue of Allergy. Allergy symptoms' effect on driving was comparable to having a blood-alcohol concentration nearing impaired levels, according to the researchers. Allergy medications weren't wholly effective at reducing the symptoms' effects.
Allergic rhinitis, or hay fever, has been linked to car accidents but the effects on a driver's performance weren't known, researchers said.
The study, in the Netherlands, involved 19 people in their early 30s with grass- and tree-pollen allergies. During the off-season, when they were free of symptoms, subjects were each treated in turn with an antihistamine, steroid nasal spray or a placebo pill or spray in four testing sessions on separate days. After each treatment, they were given grass and tree allergens or a placebo through a nasal spray to provoke allergy symptoms.
The subjects then did a 60-minute driving test in a vehicle with a camera that recorded how often they veered toward the center lane. The technique, called standard deviation of lateral position (SDLP), is commonly used to assess drunken driving. The higher the SDLP score, the greater the impairment. During the last 15 minutes of driving, subjects were given verbal memory tests where they were asked to recall as many words as possible from a list presented through the car audio system.
The greatest impairment occurred in participants with allergic symptoms who had received a placebo treatment. SDLP scores for this group were comparable to driving with a blood-alcohol level of 0.03%, just under the legal limit of 0.05% in most countries, researchers said. (The U.S. limit is 0.08%.) Both the antihistamine and nasal spray reduced SDLP scores to nonsignificant levels.
Driving scores of allergy sufferers deteriorated further during the memory tests. In this case, only treatment with nasal spray improved SDLP scores. The antihistamine's effects were comparable to placebo, possibly because of additional mild sedation due to the drug, the researchers said.
Caveat: Participants were tested in easy driving conditions, without distraction from cellphones, radios, or bad weather. The study was partially funded with a grant from GlaxoSmithKline.
Signs of teen obesity: How teenagers decorate their bedrooms provides important information about their weight and possible future health risks, says a study in the July issue of the Journal of Adolescence.
The study found overweight adolescents tended to accumulate objects that weren't associated with physical activity compared with peers who had a body-mass index that was normal or below normal. Teen BMIs increased with each additional object.
The study, at Utah State University, involved 234 students in grades 8 and 9. About 30% of both sexes had above-average BMIs. Students were given a checklist of 66 electronic and decorative objects and asked if they had the item in their bedroom and were satisfied with it, or if they wanted to have the item.
Bedrooms of boys with above-average BMIs had significantly more TVs, electronic games and magazines. Bedrooms of boys with average or below-average BMIs had more souvenirs from other places, computers, religious items and artwork or pictures.
Girls with above-average BMIs had more board games, dolls, and stereos. Girls with lower BMIs were more likely to have objects associated with physical activity, such as calendars, schedules and spinning disco balls.
Caveat: The influence of parents and peers wasn't assessed.
Prenatal insomnia: Mothers' loss of sleep in late pregnancy may trigger abnormal cellular activity in the fetal brain that could be associated with memory and behavioral problems in childhood, says a report in the August issue of Neurobiology of Disease. Prenatal stress has been shown to have harmful effects on fetal development, but the impact of sleep disturbances hasn't been explored, researchers said.
Disturbed sleep in late pregnancy appeared to overactivate microglia, brain cells involved in nervous-system development, and inflammatory proteins called cytokines, the study found.
Experiments in China subjected three groups of pregnant rats to 72 hours of sleep disruption in the early, middle and late stages of gestation. Controls weren't sleep-deprived. Memory and spatial-recognition tests were administered to the rats' offspring on the first day after birth and every week for three weeks. Intake of plain water or water containing 1% sucrose was compared among offspring groups. Tissue samples from the hippocampus, the brain's memory center, were also analyzed.
Rat offspring from the late sleep-deprived group took significantly longer to find an underwater platform than controls. Offspring from the early and middle sleep-deprived groups also took longer than controls to find the platform but the difference wasn't statistically significant. When the platform was removed and later returned to its original location, the late-deprived offspring spent significantly longer finding it than other groups, suggesting memory and spatial learning were impaired researchers said.
The late sleep-deprived group had lower birth weights and were smaller as adults than other groups. These rats exhibited a markedly reduced preference for the sucrose solution, an indication of anhedonia, or the inability to experience pleasure.
Caveat: The experiments were conducted on rats and would be difficult or impossible to perform on humans, researchers said.
Boater behavior: Public-education programs that promote the use of life jackets do little to alter boaters' behavior—but changing the law might, a study suggests.
Wearing of life jackets increased 41% in canoes, kayaks, dinghies and small motorboats after a new law in the state of Victoria, Australia, mandated their use, according to a study published online in Injury Prevention.
In the U.S., where life-jacket use is voluntary, about 22% of all boaters wore the flotation vests in 2013, according to the nonprofit health consulting firm JSI Research & Training Institute, Inc. of Boston.
In the current study, researchers compared life-jacket use before and after the 2005 law came into effect, requiring life jackets be worn in boats up to 16 feet long. (Noncompliance resulted in $250 fines.) Trained observers stationed at boat ramps recorded life-jacket use.
Life-jacket usage by occupants of small boats increased to 63% from 22% after the law took effect. The largest increase of 56% was recorded in boaters age 60 and older; the smallest increase of 23% was in infants and children under age 9.
On larger boats, only children and teens increased their use of life jackets, by as much as 10%. Life-jacket use on yachts decreased by 17% after the law took effect.
A study published on Monday in Injury Prevention reported that boating-related drowning deaths in the six years after the 2005 legislation took effect fell to 16 from 59 recorded in the six years before it was introduced. Of the 16 boaters, 56% weren't wearing life jackets.
Caveat: Observers may have miscalculated boat lengths and children's ages. Observation rates varied slightly from region to region within the province.
Belted waists: Wearing belted clothing may cause physiological changes in the lower esophagus that increase the risk of inflammation and cancer, suggests a study in the July issue of Gut. Cancers of the lower esophagus are increasing, particularly among men. Acid reflux disease is a risk factor for esophageal cancers but many patients never experience reflux symptoms, such as heartburn, researchers said.
The study suggests pressure from waist belts, especially worn over a large waistline, can cause pockets of silent acid reflux to develop in the lower esophagus without noticeable symptoms.
Researchers at the University of Glasgow in Scotland recruited 24 volunteers, 12 men and 12 women, in their mid-30s. Half had a normal weight and half were obese. The subjects swallowed a probe that recorded changes in the squamocolumnar junction, the area where the cells of the lower esophagus start to resemble stomach cells, during two experiments. In one, subjects consumed fish and chips in an upright position until full. In the other, they consumed the same meal wearing a wrestler's belt.
After eating, wearing a belt and having a large waist were more likely to cause the squamo-columnar junction to move higher in the esophagus and closer to the sphincter muscle that stops the backward flow of stomach contents.
The displaced junction caused a partial hiatus hernia, in which part of the stomach protrudes into the diaphragm, the study found. The belt was also associated with a short section of acid reflux above the junction that was more pronounced in subjects with larger waists.
Caveat: The long-term effects of wearing a belt aren't known. Weightlifter belts aren't typical belts worn by most people.
Nordic Poles Boost Artery-Disease Patients' Walking
People with peripheral artery disease, or narrowed leg arteries, were able to walk significantly farther using Nordic walking poles than when they didn't use poles, according to a study in the June issue of the British Journal of Surgery. Poles work the body 23% harder than normal walking, but the participants didn't seem aware of the extra exertion, the researchers said.
Peripheral artery disease (PAD), a risk factor for heart attack and stroke, affects an estimated 8 million Americans, according to the Centers for Disease Control and Prevention.
U.K. researchers recruited 52 patients with PAD, 39 to 84 years old. The subjects were asked to walk at a normal pace three times a week for 30 minutes. About half used walking poles. Walking tests were administered at the start of the study and every four weeks for 12 weeks and consisted of walking a 55-yard circuit as fast and as long as possible. The pole group performed the test twice at each session, once with poles and once without poles.
Claudication distance, the distance covered before experiencing leg pain, increased immediately in the pole group to approximately 162 yards from 136 yards. After 12 weeks, maximum walking distance had more than doubled in the pole group and claudication distance had increased by 60%.
Without poles, the subjects' walking distances also increased significantly. Controls had longer walking and claudication distances, but the change wasn't statistically significant.
Caveat: The study involved a small number of subjects.