Researchers at deCODE Genetics Inc. in Iceland identified the gene by screening a nationwide genealogical database of Icelanders. The database takes advantage of the small, inbred population that dates back to immigrants who settled the island 1,100 years ago.

Already known to be involved in bone development, the gene has several versions. The researchers found that about 30 percent of those tested had one of three versions of the gene that gave them three times the risk of osteoporosis compared to others.

The team double-checked using data from Danish women and confirmed their findings, they report in this week's issue of the Public Library of Science.

"There are over a million osteoporotic fractures per year in the United States, with a total direct medical cost exceeding $10 billion dollars annually," deCODE said in a statement.

"By identifying those at elevated risk before they begin to lose bone mass, it may be possible to more closely monitor bone density and implement more targeted and effective prevention strategies, involving lifestyle changes and-or existing medications," it added.

"A better understanding of the genetics of osteoporosis may also contribute to a better understanding of the biology of the disease, and thus to the development of new and more effective drugs."

WASHINGTON (Reuters) Nov 03/2003

Question:
How important is sunlight exposure to activate vitamin D? Is it even necessary to "activate" vitamin D taken as a supplement?

Vitamin D synthesis from sunlight exposure is an intriguing and complex area, and considerable debate continues about the definition of thresholds for vitamin D insufficiency and its subsequent consequences for bone health.

In the aging population (65 years and older), and in particular in those populations living in a northern latitude, vitamin D requirements are unlikely to be met sufficiently by exposure to sunlight. This is for 2 principle reasons: (1) skin pigmentation deteriorates with age, and thus the conversion of the UV light on the skin is much less efficient; (2) less surface skin is exposed to sunlight, as the elderly do not spend as much time out of doors and are often covered up so that sunlight cannot penetrate the skin sufficiently. [1]

From the data currently available, it would appear that in the aging population, sunlight exposure is not required to "activate" vitamin D and that vitamin D supplements (with Ca) are sufficient. The level of supplementation that is beneficial with respect to fracture reduction is somewhat controversial, but it seems that 1200 mg of Ca and 800 IU (20 micrograms [mcg]) of cholecalciferol is effective in fracture reduction. [2]

Vitamin D and Ca supplementation studies have been shown to significantly reduce fracture rates in both institutionalized [3] and free-living elderly populations. [4] However, intriguing is the finding that vitamin D supplementation alone is not effective [5] ; the most recent study found that cod liver oil containing 10 mcg (400 IU) of vitamin D did not prevent fracture in 1144 nursing home residents. [6] A point of note is the difference between vitamin D supplementation levels used in the various studies. In the studies by Chapuy [3] and Dawson-Hughes, [4] 20 mcg/d and 17.5 mcg/d of vitamin D were supplemented, respectively, whereas in the studies by Lips [5] and Meyer, [6] only 10 mcg/d was used, without additional Ca.

Less information is available concerning the requirement of vitamin D in the younger population. A 4% difference in the adjusted 3-year bone mineral density (BMD) accumulation from baseline between young girls who had a normal vitamin D status (> 37.5 nmol/L) and those who had severe hypovitaminosis (< 20 nmol/L) (actual values were 16.7% vs 12.7%) have been reported. [7] Furthermore, in girls of advanced sexual maturation, the adjusted 3-year change of BMD at the lumbar spine was 27% greater in the highest vitamin D intake tertile than in the lowest tertile. These and other data clearly suggest that pubertal adolescent females with hypovitaminosis D are at a significant risk of not reaching maximum peak bone mass, particularly at the lumbar spine. This is certainly an area that requires further investigation.

Response from Susan A. New, BA, MSc, PhD, RPHNutr
Center for Nutrition & Food Safety, School of Biomedical & Life Sciences, University of Surrey, Guildford, Surrey, United Kingdom

Fluoroquinolone use is associated with increased risk of Achilles tendon rupture, and that increase is "true across the board for exposure to any fluoroquinolone," according to results of nested case-control study reported last week at the 41st annual meeting of the Infectious Diseases Society of America.

Lead author John Seeger, PharmD, PhD, from Ingenix Epidemiology, a pharmaceutical research company in Auburndale, Massachusetts, said the study "puts a quantitative estimate on the elevation in risk of Achilles tendon rupture after exposure to fluoroquinolone antibiotics.... We were able to quantify the association and found that the elevation in risk was on the order of 20% to 30%. This was true across the board for exposure to any fluoroquinolone."

Animal studies demonstrated that "the fluoroquinolone antibiotics weaken tendons," Dr. Seeger said. Case reports show that this increased risk also occurs in humans and that the increased risk was greatest among the elderly.

Dr. Seeger and colleagues used the Ingenix Research Database — a health insurance claims database — to identify 947 cases of Achilles tendon rupture. A random sample of controls matched for time at risk were also selected from the database. Fluoroquinolone exposure specific incidence rates (IR) and rate ratios (RR) were estimated using logistic regression with covariates for age, sex, obesity, fluoroquinolone use, other antibiotic use, corticosteroid use, infection, arthritis, diabetes, and trauma.

Exposure to a fluoroquinolone was associated with an apparent increased risk of Achilles tendon rupture. Moreover, the increase was observed in each fluoroquinolone used. A case-control study published in the Aug. 11, 2003, issue of the Archives of Internal Medicine suggested that the increased risk of Achilles tendon rupture associated with fluoroquinolones was greatest during the first month of treatment, but Dr. Seeger said his study suggests the risk is constant over the entire course of treatment.

Moreover, the risk associated with fluoroquinolones was about the same as the increased risk associated with azithromycin and combined nonfluoroquinolone antibiotics.

"Just looking at this study, fluoroquinolones alone don't appear to be an independent risk factor for Achilles tendon rupture," Kelly Randell, DPharm, a research fellow at the University of Illinois, Chicago, College of Pharmacy, told Medscape. Dr. Randell was not involved in the study.

"However, they do seem to increase the risk," she said. "Most patients who develop Achilles tendon rupture on a fluoroquinolone appear to have other risk factors that probably contribute to the [rupture]."

IDSA 41st Annual Meeting: Poster 195. Presented Oct. 10, 2003.
Reviewed by Gary D. Vogin, MD

A Weight Loss Story

My roommates often watch The Learning Channel (TLC) when I'm in the living room working on my computer. In the background I hear fantastic stories about the perfect wedding or the perfect date and it makes my heart feel all warm and fuzzy inside. Well, I have the perfect weight loss story that I hope warms your heart and brings you hope if your challenge right now is weight loss.

Here's the story in her own words…

“About a year ago I decided to go after all my dreams. I realized that I was only striving for excellence in certain areas in my life and not in others. One of those areas that was lacking was my health. I have lost over 100 pounds in the last year. If you want it bad enough you will get it. At first I was so heavy I could only go for long walks but soon I was heading to the gym on a regular routine. I went with a personal trainer, Katrina Lewis. Katch Life Health & Wellness helped to build my knowledge and confidence. I will continue to include vigorous activity in my life and I love it… Life is so much better living in a fit body. I am so glad I realized that I was worth this and that I am responsible for making my dreams come true.” Kelly Kirby, Teacher Langley School District

~ This Month's Special Offer ~

CHECK OUT OUR WEBSITE!!! www.KatchLife.com