Vitamin D and Elderly Woman!

A new study by researchers at the University of Colorado Denver and Massachusetts General Hospital (MGH) shows vitamin D plays a vital role in reducing the risk of death associated with older age. The research, just published in the Journal of the American Geriatrics Society, evaluated the association between vitamin D levels in the blood and the death rates of those 65 and older. The study found that older adults with insufficient levels of vitamin D die from heart disease at greater rates that those with adequate levels of the vitamin (see also Massachusetts General Hospital).

"It's likely that more than one-third of older adults now have vitamin D levels associated with higher risks of death and few have levels associated with optimum survival," said Adit Ginde, MD, MPH, an assistant professor at the University of Colorado Denver School of Medicine's Division of Emergency Medicine and lead author on the study. "Given the aging population and the simplicity of increasing a person's level of vitamin D, a small improvement in death rates could have a substantial impact on public health."

Older adults are at high risk for vitamin D deficiency because their skin has less exposure to the sun due to more limited outdoor activities as well as reduced ability to make vitamin D.

The study analyzed data from the Third National Health and Nutrition Examination Survey conducted by the National Center for Health Statistics. The research team analyzed vitamin D in blood samples of more than 3,400 participants that were selected to be representative of the 24 million older adults in the United States. Compared to those with optimal vitamin D status, those with low vitamin D levels were 3 times more likely to die from heart disease and 2.5 times more likely to die from any cause.

Dr. Ginde says the findings suggest that current daily recommendations of vitamin D may not be enough for older adults to maintain optimal health. The research team has applied for research funding from the National Institutes of Health to perform a large, population-based clinical trial of vitamin D supplementation in older adults to see if it can improve survival and reduce the incidence of heart disease.

"Confirmation of these results in large randomized trials is critically important for advancing public health," says Carlos Camargo, MD, DrPH, of the MGH Department of Emergency Medicine, the senior author of the study and an associate professor of medicine at Harvard Medical School.

The study looking at elderly death rates is the second of two studies by the same team of researchers on vitamin D and general health. The first study, published in Archives of Internal Medicine earlier this year, identified vitamin D as playing a significant role in boosting the immune system and warding off colds and flu.

"Vitamin D has health effects that go beyond strong bones," says Ginde. "It's likely that it makes a vital contribution to good health."

Vitamin K forLong Term Health Benefits!

An analysis conducted by Joyce C. McCann, PhD and Bruce N. Ames, PhD at Children's Hospital Oakland Research Institute provides support for Dr Ames' triage hypothesis, which proposes that our bodies have evolved to allocate often scarce micronutrients to functions that are critical to short term survival rather than to those which protect long term health.

Chronic insufficient intake of many vitamins, minerals, amino acids and fatty acids causes DNA damage, mitochondrial decay and cellular aging, which, while not affecting immediate survival, can lead to degenerative diseases later in life. "Natural selection favors short-term survival at the expense of long-term health," explained Dr Ames in an introduction to his hypothesis published in the Proceedings of the National Academy of Sciences in 2006. "I hypothesize that short-term survival was achieved by allocating scarce micronutrients by triage, in part through an adjustment of the binding affinity of proteins for required micronutrients. If this hypothesis is correct, micronutrient deficiencies that trigger the triage response would accelerate cancer, aging, and neural decay but would leave critical metabolic functions, such as ATP production, intact."

Drs Ames and McCann reviewed hundreds of articles concerning vitamin K and its 16 known dependent proteins for the current analysis. Studies of mice in which vitamin K-dependent proteins were rendered inoperative revealed that five of these proteins have functions that are essential to survival, and 5 are less critical. The body preferentially distributes vitamin K to the liver to preserve coagulation when vitamin K levels are reduced; however, suboptimal vitamin K intake and anticoagulant-induced vitamin K deficiency have been linked with such age related conditions as bone fragility, arterial and kidney calcification, cardiovascular disease, and possibly cancer. "A triage perspective reinforces recommendations of some experts that much of the population and warfarin/coumadin patients may not receive sufficient vitamin K for optimal function of vitamin K-dependent proteins that are important to maintain long-term health," the authors write.

The report, which appeared online on August 19 in the American Journal of Clinical Nutrition, was published in the October, 2009 issue. The analysis is the first in a series conducted by Drs Ames and McCann to test the triage hypothesis. "Encouraging support for the triage theory from our vitamin K analysis suggests that experts aiming to set micronutrient intake recommendations for optimal function and scientists seeking mechanistic triggers leading to diseases of aging may find it productive to focus on micronutrient-dependent functions that have escaped evolutionary protection from deficiency," Dr McCann stated.

Waist-hip ratio better than BMI for gauging obesity in elderly

NewsRx.com

09-11-09

Body mass index (BMI) readings may not be the best gauge of obesity in older adults, according to new research from UCLA endocrinologists and geriatricians. Instead, they say, the ratio of waist size to hip size may be a better indicator when it comes to those over 70 (see also University of California - Los Angeles).

In a new study published online in the peer-reviewed journal Annals of Epidemiology, researchers from the David Geffen School of Medicine at UCLA found that the waist-to-hip circumference ratio was a better yardstick for assessing obesity in high-functioning adults between the ages of 70 and 80, presumably because the physical changes that are part of the aging process alter the body proportions on which BMI is based.

"Basically, it isn't BMI that matters in older adults - it's waist size," said Dr. Preethi Srikanthan, UCLA assistant professor of endocrinology and the study's lead investigator. "Other studies have suggested that both waist size and BMI matter in young and middle-aged adults and that BMI may not be useful in older adults; this is one of the first studies to show that relative waist size does matter in older adults, even if BMI does not matter."

Using data from the MacArthur Successful Aging Study - a longitudinal study of high-functioning men and women between the ages of 70 and 79 - researchers examined all-cause mortality risk over 12 years by BMI, waist circumference and waist-hip ratio. They adjusted for gender, race, baseline age and smoking status. The average age of participants was 74.

Obesity is often associated with premature mortality because it leads to an increased risk of diabetes, heart attack, stroke and other major health problems, the study authors say.

The researchers found no association between all-cause mortality and BMI or waist circumference; the link was only with waist-hip ratio. In women, each 0.1 increase in the waist-hip ratio was associated with a 28 percent relative increase in mortality rate (the number of deaths per 100 older adults per year) in the group sampled. Thus, if the waist-hip ratio rose from 0.8 to 0.9 or from 0.9 to 1.0, it would mean a 28 percent relative increase in the death rate. Put another way, if hip size is 40 inches, an increase in waist size from 32 to 36 inches signaled a 28 percent relative death-rate increase.

The relationship was not graded in men. Instead there was a threshold effect: The rate of dying was 75 percent higher in men with a waist-hip ratio greater than 1.0 - that is, men whose waists were larger than their hips - relative to those with a ratio of 1.0 or lower. There was no such relationship with either waist size or BMI.

The study may have some limitations, the authors noted. For instance, participants' BMI may be underestimated because height and weight were self-reported and older adults tend to report those numbers from their younger, peak years. Also, waist-hip ratios, waist circumference and BMI numbers were based on single measurements, limiting the researchers' ability to gauge how changing body size in old age can affect mortality risk.