Second-hand smoke implicated for adolescent hearing loss

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Secondhand smoke linked
to teen hearing loss

Secondhand (SHS) smoke has received a significant amount of attention for harming health. Now a study shows adolescents exposed to SHS are at increased risk for hearing loss, in addition to other health issues that include respiratory ailments, behavior problems and low birth weight. 

The finding, published in the July issue of Archives of Otolaryngology–Head and Neck Surgery, one of the JAMA/Archives journals, cites statistics that 60 percent of children are exposed to secondhand smoke in the United States.

How second hand smoke leads to hearing loss in youth

The link is seen from recurrent ear infections, or otitis media. The chance of ear damage and sensorineural hearing loss (SNHL) increased with higher levels of exposure to secondhand smoke in adolescents studied.

The authors says hearing loss may occur from "suppression or modulation of the immune system" or from "impairment of the respiratory mucociliary apparatus" that would normally act as a defense against bacteria and infection. Without defenses, bacteria can more easily adhere to structures in the ear. 

The study

The finding was extracted from data that was part of the National Health and Nutrition Examination Survey from 2005 to 2006. Researcher Anil K. Lalwani, M.D., and colleagues from NYU Langone Medical Center in New York City examined hearing loss risk factors among 1,533 individuals from 12 years to 19 years of age who were part of the study.

The study showed teens exposed to secondhand smoke were more likely to experience hearing loss affecting low and high frequencies.

Levels of cotinine, a byproduct of nicotine, correlated with higher rates of hearing loss and were measured in the bloodstream.

The study authors concluded:

"Adolescents who are exposed to SHS may need to be more closely monitored for hearing loss. In addition, they should be educated about risk factors for hearing loss, such as recreational or occupational noise exposure and SHS."

The authors note the finding that secondhand smoke leads to more ear infections and hearing loss in adolescents has public health implications. Loss of hearing can have a negative impact on normal childhood growth and development.


The study is believed to be the first to link hearing loss in adolescents to secondhand smoke exposure in the U.S.  If further studies support the finding, the authors say exposure to secondhand smoke might be considered a risk factor that would prompt screening for hearing loss in teens.


Arch Otolaryngol Head Neck Surg. 2011;137:655-662.

Stored blood for transfusion becomes less safe with aging, finds new study

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Stored blood can cause complications, finds new study

New research shows current methods of storing blood may be unsafe. Findings from scientists at Wake Forest University and the University of Pittsburgh School of Medicine found some complications associated with blood transfusion comes from the breakdown of red blood cells that happens during storage.


The finding means it may be necessary to find new ways to preserve blood for transfusion.


According to background information from the study, someone in the United States needs a blood transfusion every two seconds.


The finding, published in the journal  Circulation, found nitric oxide (NO) interacts with stored red blood cells, breaking down blood flow. For transfusion recipients, vital tissues can be damaged from blood stored for long periods of time.


Higher rates of infection risk, kidney, lung or multi-organ failure and death have been observed among patients given transfusions from blood stored for longer periods of time, leading the researchers to try to understand why.


Stored blood can restrict blood flow, leading to organ damage
Mark T. Gladwin, M.D., chief, Division of Pulmonary, Allergy and Critical Care Medicine, Pitt School of Medicine, and director of Pitt’s Vascular Medicine Institute explains:

“When blood sits for a while, some of the cells break down and release their contents, which include molecules of hemoglobin and red blood cell microparticles. These accumulate in the stored bag of blood and are transfused into the patient with the blood. In the bloodstream, the hemoglobin and microparticles bind to and destroy NO, a very important molecule that is used by the body to keep blood vessels dilated for normal blood flow.”

NO in stored blood then constricts blood flow, depriving organs of oxygen and promoting inflammation, Gladwin explains.

Daniel B. Kim–Shapiro, Ph.D., professor of physics and director of the Translational Science Center at Wake Forest said, 

“Transfusion of stored blood is one of the most common medical therapies. By understanding the mechanism of the storage lesion, we can design methods to make blood transfusion safer. For example, perhaps we can restore nitric oxide activity that is lost upon transfusion, use preservation solutions that better limit the degradation of blood cells, or develop agents that scavenge free hemoglobin.”

According to current guidelines, blood can be stored up to 42 days for transfusion. The new finding suggests blood stored for transfusion may not be safe, leading to complications if inflammation and impaired oxygen to organs. 


Citation:


Impaired adenosine-5′-triphosphate release from red blood cells promotes their adhesion to endothelial cells: A mechanism of hypoxemia after transfusion.; Hongmei Zhu, Rahima Zennadi, Bruce X. Xu, Jerry P. Eu, Jordan A. Torok, Marilyn J. Telen, Timothy J. McMahon.; Critical Care Medicine, 2011; DOI: 10.1097/CCM.0b013e318225754f


Duke researchers also warned of the dangers to patients from storing blood in 2007 in this video.

Study: Bigger forks stop diners from ‘pigging out’

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When it comes to the battle of the bulge, new research shows simply using a bigger fork stopped restaurant diners from 'pigging out'. Using a bigger fork helped diners eat less in an experiment.


According a July 14. 2011 news release, putting a bigger bite of food on your fork leads to less eating from important visual cues that otherwise seemed to be overlooked by food consumers.

The finding, which appears in the Journal of Consumer Research, is an interesting note for women who may not find a big fork so delicate.

But for weight loss, a bigger fork gives visual cues that could help with setting goals.

The study authors, from University of Utah, Salt Lake City, write:

"The fork size provided the diners with a means to observe their goal progress. The physiological feedback of feeling full or the satiation signal comes with a time lag. In its absence diners focus on the visual cue of whether they are making any dent on the food on their plate to assess goal progress."

Why using a bigger fork to eat less makes sense

Past studies have shown dieters are often unaware of visual cues that can influence higher food consumption. Examples include using smaller plates and just putting calorie laden foods out of sight.

The current study looked at individuals eating in a restaurant. When diners had a full plate of food and a small fork, they ate more than those with large forks.

According to the authors,”… it is very important to understand how small versus large bite sizes in a meal would influence the overall quantity of food consumed.”

But when serving sizes were small, fork size had no impact on the amount of food consumed in the experiment.

In the lab, fork size had no impact on food consumption. The authors suspect the reason is the goal of satisfying hunger when eating in a restaurant may have differed from the lab study participants.

Eating too much all boils down to paying attention to hunger cues, say the authors. “Mindful eating” has received much attention as a way to lose weight and help curb the obesity epidemic.


The study, according to the authors, is proof that it’s hard for people to know how much food they’re eating. "They allow external cues, such as fork size, to determine the amount they should consume."


Hint: When dining out, the big fork is the one next to the dinner plate. Keep it for dessert. Try it and see if you eat less food. The new study suggests it works.

Citation:

"Journal of Consumer Research; The Influence of Bite Size on Quantity of Food Consumed: A Field Study"; Arul Mishr, et al.; July 13 2011