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News Tips

IU Health & Wellness

Research and insights from Indiana University

FOR IMMEDIATE RELEASE
May 19, 2008

IU Health and Wellness for May discusses the following topics:

Firefighters and poor sleep
Iodine deficiencies resulting from low-salt diets, sea salt
Regular eye exams can prevent problems down the road

A restful night's sleep in the firehouse? Not likely. Charged with determining and measuring the physiological rigors faced by firefighters on the fire scene, Indiana University researchers embedded with urban firefighters are finding that a regular staple of the firehouse -- a poor night's sleep -- has a tremendous impact on the firefighters. Firefighters in their study not only sleep poorly in the firehouse, where rarely a night passes without multiple fire or emergency medical calls, but the dysfunctional sleep pattern appears to follow them home for at least one night following their shift. Other research has found that dysfunctional sleep can contribute to heart disease, cancer risk, diabetes and obesity. "These men and women are spending a significant portion of their lives poorly rested," said Jim Brown, visiting scientist in IU Bloomington's School of Health, Physical Education and Recreation. "Just after our study began, I was speaking with a veteran firefighter and told him, 'I'll be glad when I get used to this sleep pattern.' He said, 'I've been doing this for 30 years, and I'll be glad when I get used to it, too.'"

• Background: Researchers in the School of HPER's Department of Kinesiology received a $1 million grant from the U.S. Department of Homeland Security's Federal Emergency Management Agency to examine the toll firefighting takes on firefighters' cardiovascular and respiratory health. The results eventually could improve firefighter health and safety, and reduce the number of firefighter deaths that occur in the line of duty. Each year, says Brown, around 100 firefighters die in the line of duty, with around half of these deaths resulting from heart attacks caused by overexertion and stress. No studies, however, have documented how demanding the job actually is. For the IU study, 56 firefighters from the Indianapolis Fire Department, ranging in age from 27 to 62 and including four women, have agreed to wear special vests embedded with sensors that continually monitor cardiovascular and respiratory systems. During fire calls, two firefighters wear thermal imaging cameras mounted on their helmets to collect video, recorded onto a device inside the helmet. Researchers travel to fire scenes to record a variety of information, such as weather conditions and types of buildings encountered. The data, collected over six months, will be combined to produce a mathematical model for how firefighters respond physiologically to fire scenes and the physiological "load" those tasks represent. Training also will be recommended based on this model. Researchers are more than halfway done with the project and have begun analyzing data.

Brown said some firefighters will wear the LifeShirts® off-duty so researchers can gather more information about the impact their sleep patterns have on their health. He said fire services use many different "duty cycles" -- not all have firefighters working one day and taking two days off. These schedules are based on firefighters' feedback about how they feel, not on significant scientific studies that examine the best way to recuperate from poor sleep.

Brown can be reached at 317-215-4449 and jbbrown@indiana.edu. Top

Are you getting enough iodine in your diet? Adult men and women should get 100-200 micrograms of iodine per day but many are not reaching that goal, says Sara Blackburn, registered dietician at Indiana University-Purdue University Indianapolis. "We are being told we are taking in too much salt, yet low salt diets are associated with increased blood pressure," says Blackburn. Blackburn, clinical associate professor in IUPUI's Department of Nutrition and Dietetics in the School of Health and Rehabilitation Sciences, says restricting sodium intake to reduce blood pressure works if a person is salt sensitive. "If they are salt sensitive, then salt restriction will drop blood pressure. If not, then I recommend using medication, changing the diet and working with a registered dietician to guide them," she said. Experts in the health field have sent the message for some time now that low-sodium diets are associated with low blood pressure. This message has worked well and Americans are now consuming less salt. According to Blackburn, this has had the unintended consequence of an increased risk for iodine deficiencies. Why this concern? Iodine is an essential component of thyroid hormones and the developing nervous system. "In the Midwest, the most consistent source of iodine in the diet is iodized table salt," says Blackburn. The problem of low iodine intake was identified during World War I. Salt became the first functional food when, in 1924, iodine was added to table salt. According to data from the National Health and Nutrition Examination Surveys I and III (NHANES), urinary iodine levels in the United States have dropped since 1974. "This means that the use of iodized salt and iodine in the diet has decreased, increasing the risk of iodine deficiencies," says Blackburn.

Blackburn notes the following reasons for the increase of iodine deficiencies in the U.S.:

• Changes in food manufacturing
• Food manufacturers are decreasing the amount of sodium in foods which, in turn, reduces the iodine in these commercial food products
• Food grown in iodine deficient soil
• The amount of iodine in food can be affected by the cogent in the soil, irrigation and fertilizers. Marine foods (fish and seaweed) can be a rich source of iodine as they concentrate the iodine in seawater
• Increase in use of kosher or sea salt

Blackburn can be reached at 317-278-1385 and sblackb@iupui.edu. Top

Keeping an Eye on Your Health. Those blessed with natural 20/20 vision have no reason to have regular eye exams once they become adults, right? Think again. Many eye and vision conditions that develop later in life have no obvious symptoms before they become a problem, and early diagnosis is key in preventing vision loss. According to Dr. Jeff Perotti of the Indiana University School of Optometry, getting regular eye exams could easily save a life. "Many health conditions can be diagnosed through eye exams including diabetes, high blood pressure and even brain tumors," said Perotti.

Perotti recommends regular eye exams based on a schedule published by the American Academy of Optometry, which are as follows:

• Infants -- at 6 months and 3-years-old
• Preschool to high school -- before first grade and every two years after, or as recommended
• Ages 20 to 60 -- every two years or as recommended
• Ages 60 and above -- every year or as recommended

Children in grade school are at risk, particularly to the development and progression of nearsightedness, which could cause them to struggle in the classroom. "Of course, those who are at greater risk of eye conditions, such as those who are diabetic or have high blood pressure, or family history of glaucoma, should get an examination at least once a year," said Perotti. Additionally, those whose work causes constant eye strain, and those on certain systemic medications, such as Plaquenil for autoimmune disorders, are encouraged to go to the optometrist every year, no matter their age.

Perotti can be reached at 812-855-4979 and jperotti@indiana.edu. Top

For additional assistance with these media tips, contact Tracy James, University Communications, at 812-855-0084 and traljame@indiana.edu.

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