Friday, January 29, 2010

Snus - Smokeless Tobacco Made Easy

Now available over the internet and in stores; Snus (rhymes with loose), a smokeless tobacco product containing nicotine that originated in Sweden. Snus comes in colorful tins and is packaged in small tea bag-like packets. It’s real advantage over traditional smokeless chewing tobacco is that no spitting is necessary - the small amount of juice produced can just be swallowed. It’s likely to become popular among teens who want their tobacco use to go undetected, patrons of bars and restaurants where smoking is not permitted, and smokers who want to quit.

The tobacco companies are looking to attract a whole new generation of tobacco users and to shore up profits in the face of declining cigarette sales. R.J. Reynolds launched a nationwide marketing campaign for “Camel Snus” in 2009. As usual, the company denies that it aims its marketing campaign toward underage users.

So far there is no evidence that Snus use may be a risk factor for cancers of the mouth and throat. Nevertheless, it is a tobacco product. It’s worth remembering that there were no clear health risks associated with cigarettes, either, when they first became popular in the 1940s.

Thursday, January 28, 2010

Living With Cystic Fibrosis

Sixty years ago, before doctors knew very much about cystic fibrosis, most children with the disease died before school age. Today people with the disorder are living well into their 30s. Today we know that cystic fibrosis is a genetic disorder and we know what causes the symptoms.

What we don’t have is a cure. Prolonging the life of cystic fibrosis patients is largely based on improvement of care, including medicines that alleviate some manifestations of the disease and physical therapy to keep the lungs clear. What works for one patient doesn’t always work as well for the next.

An effective tool in the improvement of care for cystic fibrosis patients has been the establishment of a national registry of patients. The registry, which is managed by the Cystic Fibrosis Foundation, currently collects and stores patient records from more than 100 cystic fibrosis treatment centers across the country. The pooled data has proven very useful in learning what works best for which kinds of patients, and why. It’s like having the collective experience of thousands of doctors right at your fingertips.

The concept of a using a national registry of patients to improve patient care has proven so successful that other patient groups are copying it.

Wednesday, January 13, 2010

Depo-Provera and Bone Loss

Around two million women use Depo-Provera as their contraceptive of choice. About 400,000 of them are teenagers. Depo-Provera is popular with teenagers because of its ease of use – just a single injection is required every three months.

However, Depo-Provera has one side effect not shared by oral contraceptives; it causes a slight but statistically significant bone loss. Researchers compared bone mineral density in young women aged 12-18 who used either Depo-Provera, oral contraceptives, or no birth control at all (the control group) for two years. Bone mineral density increased over the two-year period in the control group, as expected in young women still in their teens. It also increased in the oral contraceptives group by the same amount. However, bone mineral density decreased slightly but significantly in the Depo-Provera group.

The decrease in bone mineral density among Depo-Provera users was not sufficient to pose an immediate health risk, and any long-term risks are still unknown. Nevertheless, women’s health experts suggest that teenagers who are taking Depo-Provera should be sure to get enough calcium in their diet.

Reference: Cromer, Barbara A., et al. Bone mineral density in adolescent females using injectable or oral contraceptives; a 24-month prospective study. Fertility and Sterility 90: 2060-2067, 2008.

Tuesday, January 5, 2010

Combating Motion Sickness

What causes motion sickness? The main reason is that during certain kinds of involuntary motions the brain receives conflicting neural signals from visual receptors in the eyes, positional receptors in the inner ears and in muscles and tendons, and gravity receptors in the stomach. These conflicting signals confuse the brain, and nausea ensues.

Recently, researchers learned that the severity of motion sickness caused by a slow, cyclic motion can be reduced by deliberately breathing out of sync with the motion. Breathing either faster or slower than the cyclic motion allows the diaphragm to counteract the heaving movements of the stomach, thereby minimizing the neural disconnect between stomach gravity sensors and other motion and position receptors. The worst thing you can do is to take a breath with each heaving motion, although it’s the natural thing to do.

Reference: Denise, P. et al. Effect of temporal relationship between respiration and body motion on motion sickness. Autonomic Neuroscience 151:142-146, 2009.

Sunday, January 3, 2010

Quietus for Tinnitus?

Perhaps you’ve heard the ads for Quietus, an allegedly “unique homeopathic formula” containing “proven and effective ingredients” for treating tinnitus (ringing in the ears). The product’s website doesn’t list the ingredients, but I was told by a representative who answered the phone that it contains quinine sulfate, salicylates (a close relative of aspirin), and several other ingredients.

Quinine sulfate?! The FDA banned quinine sulfate in 2006 from all FDA-approved drug products except for products used in the treatment of malaria. The FDA lists a number of possible toxic effects of quinine including disorientation, cardiac arrhythmia, allergic reactions, and even death (there have been 93 deaths associated with quinine use in the past 40 years)

Why is quinine still allowed in a homeopathic remedy? Unlike pharmaceutical drugs, homeopathic remedies derived from natural products can stay on the market until they are proven to be unsafe. In other words, the makers of homeopathic remedies do not have to prove their products safe before marketing their products; they can just wait and see what happens to users. Users beware…..

Saturday, January 2, 2010

Myopia is on the Rise

According to a recent report, the prevalence of myopia (nearsightedness) in persons aged 12-54 years in the U.S. has increased from 25% to 41.6% in just the past 30 years. That’s too large a change in such a short a time to be due solely to a genetic factor; there must be an environmental component. A clue is that myopia is more common in people with more than 12 years of education, suggesting that close work such as reading and computer work might be a risk factor.

The good news is that myopia is relatively easy to correct with eyeglasses, contacts, or LASIK surgery. As health problems go, myopia is not the big one. Nevertheless, scientists are curious to know what might be causing the rise in myopia so that preventive measures could be undertaken if possible. Over 40% of the population with myopia is a lot of people! If nothing else, correction of myopia represents a significant national heath care expenditure, even if it's not a big deal to any one person.