Monthly Archives: June 2016

Hostility could be harmful to women

images-33Hostility is linked to poor heart health, and a new study reveals what may happen in women’s bodies that may explain this link.

Scientists have known that, in women, optimism is associated with a reduced risk for heart disease, and that “cynical hostility” — or a general mistrust of other people — has been linked to a higher risk for heart disease, according to a previous study.

What has been unclear, however, is what mechanism optimism and hostility act through to influence women’s heart health. In other words, why do these traits have such effects on heart disease risk?

In the new study, the researchers showed that the missing link could be something called heart rate variability, said Dr. Elena Salmoirago-Blotcher, an epidemiologist and assistant professor of medicine at Brown University School of Medicine and the lead author of the study. Salmoirago-Blotcher is also a research scientist at the Miriam Hospital Centers for Behavioral and Preventive Medicine.

The study revealed that women with higher levels of hostility had a lower heart rate variability, on average, compared with women with lower levels of hostility.

Heart rate variability is a measure of how much the time interval between heart beats varies from moment to moment, Salmoirago-Blotcher told Live Science. A person’s heart rate is not steady, rather, there can be tiny variations in the interval between beats, Salmoirago-Blotcher said.

In general, a higher heart rate variability is a good thing, Salmoirago-Blotcher said. It shows that the part of the nervous system that speeds up the heart rate and the part that slows it down are working in balance, she said. For example, research has shown that women with depression have a lower heart rate variability, Salmoirago-Blotcher said. Salmoirago-Blotcher presented her findings here Monday (Nov. 14) at the American Heart Association’s Scientific Sessions annual meeting.

Hostility and heart health

In the new study, the researchers looked at data on more than 2,600 women who were enrolled in a study called the Myocardial Ischemia and Migraine Study (MIMS). MIMS was a part of the Women’s Health Initiative (WHI). The women in the study were, on average, 63 years old.

As a part of the MIMS study, the women had their heart’s electrical activity measured an electrocardiogram (ECG or EKG) test. In the new study, the researchers used this data to calculate their heart rate variability. In addition, the researchers had data from the WHI about how optimistic and hostile the women were, based on their answers to two questionairres.

Hostility may increase the activity of the part of the nervous system that revs up a person’s fight or flight response, Salmoirago-Blotcher said.

Salmoirago-Blotcher noted that the researchers found that the women in the study who were more hostile were also more likely to have high blood pressure, high cholesterol and obesity, compared with those who were less hostile.

Risk when intersections

Bicycle riders are more likely to be seriously injured in vehicle crashes at intersections where streets don’t meet at right angles, according to a study in New York City.

Planners could factor in this added risk when designing bike lanes and other protections for cyclists, the study authors write in Injury Prevention.

Bicycling offers great health benefits but issues of safety are a huge barrier to people choosing bikes as their transportation, lead author Morteza Asgarzadeh of Harvard T.H. Chan School of Public Health in Boston told Reuters Health.

In the U.S., most bicycle-vehicle crashes occur at intersections, “yet we still don’t have proper protective bicycling infrastructure at intersections across the country,” Asgarzadeh said by email.

It would be very expensive for cities to overhaul all intersections, so the research team sought to identify which intersections might pose the greatest risk, Asgarzadeh said.

The researchers mapped the location of 3,266 bicycle and car crashes using GPS information recorded by New York police in 2011. They used police records and Geographic Information Service (GIS) maps to determine intersection angles, street width, presence of bike lanes, speed limits and average traffic level at the crash locations.

The study team also collected details about the accidents including the age and sex of the bicyclist, time of day, road conditions, type of vehicle involved in the crash and severity of the bikers’ injury.

The majority – 60 percent – of bike and car crashes happened at street intersections.

Compared with crashes at right-angle intersections, crashes at non-right angle intersections were 37 percent more likely to results in severe injury for cyclists.

Crashes that didn’t happen at intersections were also 31 percent more likely to cause serious injury compared with crashes at right-angle intersections.

When crashes were not at an intersection, they were more likely to happen on narrow streets less than 100 feet wide, although street width wasn’t linked to the severity of cyclist injuries.

Pancreas safe for hospitalized diabetics

unduhan-56An automatic insulin delivery system that has performed well in type 1 diabetes patients also proved safe and feasible for type 2 diabetes patients on a general hospital ward, according to a U.K. study.

The so-called artificial pancreas, or closed-loop insulin delivery system, monitors blood sugar levels and increases or decreases insulin delivery in response – approximating how a healthy pancreas would work, researchers write in The Lancet Diabetes and Endocrinology.

The system eliminates the skin-pricks and manual insulin injections that many type 2 diabetes patients currently rely on, the authors note.

The artificial pancreas “allows more responsive insulin delivery and the expectation, so far supported by clinical studies, is that health outcomes can be improved,” said senior author Dr. Roman Hovorka of the University of Cambridge Metabolic Research Laboratories.

But it costs more than injections and requires patients to wear a device around the clock, Hovorka told Reuters Health by email.

For the study, the researchers enrolled 40 adults with type 2 diabetes who were receiving insulin therapy in general wards at Addenbrooke’s Hospital in Cambridge. Half received closed-loop insulin delivery and half received conventional insulin injections for three days.

The artificial pancreas includes a glucose sensor inserted into the skin, which took measurements every 1 to 10 minutes and used the information to determine how much insulin to deliver.

Patients with the artificial pancreas spent about 60 percent of the three-day study period in their target blood sugar range, compared to an average 38 percent of the time in the comparison group. There were no incidents of severe high or low blood sugar in either group and no other adverse events related to the devices.

“We presently use the closed loop system in people with type 2 diabetes staying in hospital,” Hovorka said. “Glucose control in hospital is often suboptimal and our aim is to improve it while people with type 2 diabetes are staying in hospital for various reasons such as treating diabetes complications.”

At the moment, Hovorka and his colleagues are not planning to try the system outside the hospital, he said.

Before all people with type 2 diabetes can obtain one, “the major issue will be demonstrating cost effectiveness, through larger clinical trials, given the continual push on health care expenditure,” he said. “Development of commercial systems specifically for type 2 diabetes is also a necessity.”

This was a small study; a larger one may have found that the artificial pancreas helps reduce the risk of dangerously low or high blood sugar, writes Gerry Rayman of Ipswitch Hospital NHS Trust in Suffolk, U.K., in a commentary accompanying the study.