Study: Humidity may help explain seasonality of flu virus
BLACKSBURG, Va. — Humidity may be the common denominator to help explain why flu viruses are most prevalent during the winter months in temperate climates like the United States, and most prevalent during the rainy season in many tropical regions close to the equator, according to a study released Tuesday by Virginia Tech researchers.
Possible explanations for the seasonality of the flu have been investigated in the past, such as the return of kids to school, people spending more time indoors in the winter and lower light levels that affect the immune system, but there has been no consensus among that research.
The Virginia Tech study presents for the first time the relationship between the influenza A virus viability in human mucus and humidity over a large range of relative humidities, from 17% to 100%. At low humidity, respiratory droplets evaporate completely and the virus survives well under dry conditions. But at moderate humidity, the droplets evaporate some, but not completely, leaving the virus exposed to higher levels of chemicals in the fluid and compromising the virus’ ability to infect cells.
Researchers found the viability of the flu A virus was highest when the relative humidity was either close to 100% or below 50%. “We added flu viruses to droplets of simulated respiratory fluid and to actual human mucus and then measured what fraction survived after exposure to low, medium, and high relative humidities,” stated Linsey Marr, associate professor of civil and environmental engineering at Virginia Tech.
The viruses survived best at low humidity, such as those found indoors in the winter, and at extremely high humidity. Humidity affects the composition of the fluid, namely the concentrations of salts and proteins in respiratory droplets, and this affects the survival rates of the flu virus.
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Survey: Consumer utilization of fitness technology on the rise
ARLINGTON, Va. — More than half (55%) of U.S. online consumers used a fitness technology in the past year, and more than one-third (37%) anticipate purchasing fitness technology in the next 12 months, according to new research by the Consumer Electronics Association. "Getting Connected with Emerging Fitness Technologies" shows the number of consumers who used a fitness technology in the past year increased 8% from 2010. Results from the study were released Wednesday at the mHealth Summit.
According to the study, 46% of consumers who do not exercise cite lack of motivation as the main reason for not exercising. For those who do exercise, the top reasons are to improve overall health (76%) and to lose weight (58%). The study found the primary benefits owners attribute to using fitness technologies are to stay motivated, monitor physical activity and make exercise more enjoyable.
“We continue to see technology play an increasingly important role in health and fitness,” stated Kevin Tillmann, senior research analyst, CEA. “Fitness technology is empowering consumers to assess their fitness levels, set achievable goals, track progress and make exercise more rewarding.”
Pedometers remain the most popular health and fitness device, but fitness video games saw the most dramatic increase in usage, almost doubling from 9% in 2010, to 16% in 2012. However, heart rate monitors and body mass index scales both saw a 6% decrease in usage from 2010.
“Wirelessly-connected devices have allowed for major strides within digital health and fitness,” Tillmann said. “Consumers already own devices, such as smartphones, that are capable of being used for exercise and fitness. This year we saw considerable growth in fitness apps. This enables the devices we already own to turn into pedometers, accelerometers and distance trackers.”
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Study: Patients once considered ‘aspirin resistant’ may only need to switch to an uncoated aspirin
PHILADELPHIA — Patients once considered "aspirin resistant" may not be resistant to aspirin after all, according to a study published online by Circulation, the journal of the American Heart Association. Rather, the protective coating around the aspirin to prevent stomach issues may be delaying the absorption of aspirin, leading clinicians to believe that patients are aspirin resistant.
Roughly one-fifth of Americans take low-dose aspirin every day for heart-healthy benefits. But based on either urine or blood tests of how aspirin blocks the stickiness of platelets — blood cells that clump together in the first stages of forming harmful clots — up to one-third of patients are deemed unlikely to benefit from daily use, or aspirin resistant.
In people who have suffered a heart attack, low-dose aspirin reduces the chances of a second event by about one-fifth, making it perhaps one of the most cost-effective drugs currently prescribed, noted study author Tilo Grosser, director of the Institute for Translational Medicine and Therapeutics. Although consumed widely by the worried well, the relative usefulness of low-dose aspirin in patients who have never had a heart attack is more controversial. According to previous primary prevention studies, low-dose aspirin reduces this group’s very low risk of a first attack by about the same number of serious stomach bleeds it causes.
In the study of 400 healthy volunteers scientists from the Perelman School of Medicine at the University of Pennsylvania, went looking for people who are truly resistant to the benefits of aspirin, such as might result from a particular genetic makeup. They failed to find one case of aspirin resistance; rather, they found “pseudoresistance,” due to the coating found on most brands of aspirin, often preferred by patients for the protection it is claimed to provide the stomach. What’s more, a urine biomarker of platelet stickiness was not able to find which volunteers were even pseudoresistant.
“When we looked for aspirin resistance using the platelet test, it detected it in about one-third of our volunteers,” Grosser said. “But, when we looked a second time at the incidence of aspirin resistance in the volunteers, the one-third that we measured who was now resistant was mostly different people. Nobody had a stable pattern of resistance that was specific to coated aspirin.”
To address the reason for this pseudoresistance, the researchers compared test results of coated aspirin with the same dose of regular uncoated aspirin in volunteer subgroups for coated versus immediate-release, uncoated aspirin. Resistance was absent in the group that took the uncoated aspirin.
The coating delayed absorption compared to immediate-release, uncoated aspirin. This led to a false impression of aspirin resistance in people taking coated aspirin. Platelets of such patients remained sensitive to aspirin when examined in a test tube, so they were not truly resistant to the action of aspirin.
Although supposedly easier on the stomach, coating of aspirin has never been shown to reduce the likelihood of serious stomach bleeds compared to the same dose of uncoated aspirin, Grosser noted. “These studies question the value of coated, low-dose aspirin,” commented Garret FitzGerald, director of the Institute for Translational Medicine and Therapeutics. “This product adds cost to treatment, without any clear benefit. Indeed, it may lead to the false diagnosis of aspirin resistance and the failure to provide patients with an effective therapy. Our results also call into question the value of using office tests to look for such resistance.”