BMI may not be the right tool to measure health risks

The BMI is easy to measure, cheap to compile and track, and simple to convey to patients, but it was never meant to be a predictor of an individual's health risks. It was intended as a useful metric to track changes in the health and nutrition of large populations. For patients who are very muscular, and for African Americans, BMI is often a poor gauge of body composition. For Asians and people who are sedentary but slim, a reliance on BMI can lead a physician to overlook signs of elevated disease risk. A child's BMI, which is calculated differently than that of an adult, is also an imperfect predictor of illness or early death.

The BMI continues to dominate research on obesity and guide physicians' advice to patients. But some researchers have launched a rear-guard effort to knock the measure from its place atop the public-health pedestal. To replace — or at least supplement — the BMI, they are searching for measures that might offer individual patients a better gauge of their health risks, as well as a wider range of options to better their odds of staying healthy.

They'll also need tools to do so that are as cheap and simple as the BMI. Most techniques that measure body composition, including the Bod-Pod, the dual-energy X-ray absorption test (DEXA), and hydrostatic underwater weigh-in, are costly and time-consuming. Bioelectrical Impedance Analysis, an inexpensive and reliable gauge of body composition increasingly used in weight-management programs, may be practical in some general medical practices. But researchers are increasingly looking for ways to capture such information with tools as simple and inexpensive as tape measures.

One of the easiest alternatives to the BMI is waist measurement. With growing evidence that fat girdling the waist and visceral organs disturbs metabolism, the circumference of a patient's midsection has been shown to be a better predictor of Type 2 diabetes risk than the BMI.

Finally, an increasing number of researchers cite a major gap in the BMI: its inability to reflect the health effects of an individual's exercise habits. At least seven high-profile studies in the last decade have established that even for people with high BMIs, cardiovascular risk and the likelihood of early death are driven down significantly by maintaining a high level of fitness or at least regular physical activity. The risk of Type 2 diabetes also falls, although in that case, studies suggest that whittling waist circumference is a better strategy still.

Source: L.A. Times

BMI in adolescence, a substantial risk factor for obesity-related disorders

What you weigh in your teen years can have far-reaching effects on your heart health in the future, suggests new research.

The higher your body mass index (BMI) in your late teens, even if it is well within the normal range, the greater your risk of heart disease decades later, according to a large study published in the April 7 issue of the New England Journal of Medicine.

For every one unit increase in BMI in the teen years, the study found a 12 percent increase in the risk of heart disease around 20 years later. And, for every one unit increase in BMI, the study found a nearly 10 percent increase in the risk of type 2 diabetes, though this risk may largely be related to a higher BMI in adulthood as well.

Data for the study came from a large group of young men entering the Israeli army. The researchers followed 37,674 males from the time they were first examined for military service at the age of 17, until an average of 17.4 years later, according to the study.

Overall, men with the highest BMIs in their teens were 2.76 times more likely to develop type 2 diabetes and 5.43 times more likely to have coronary heart disease later in life compared to those with the lowest BMIs, reported the study.

However, when a normal adult BMI was factored into the analysis, the increased risk of type 2 diabetes disappeared, suggesting that weight in adulthood is far more of a risk factor for the development of type 2 diabetes than weight status in your teens.

But, the researchers found that the risk of heart disease was elevated whether or not someone was heavy in their teens or heavy as an adult, suggesting that extra weight at any age affects cardiovascular health.

Education on healthy lifestyle factors should start as early as possible in schools and at home, he said. Parents should make healthy eating and exercise part of the family routine. And, he said, it's important to start as early as possible.

Source: Serena Gordon, Health Day. 

Cardiovascular Continuum (VIDEO)

Voyage into your body to see an amazing creation you're born with: the perfect cardiovascular system. A lifetime of poor health habits can destroy that system and lead to major medical problems and a shortened lifespan, but it doesn't have to be that way. You have the power to keep your body and mind healthy, strong, and alive. See how you can live longer and live better.

The Cardiovascular Continuum
The cardiovascular continuum links various risk factors, like hypertension and high cholesterol levels, with different types of heart disease that become progressively more severe throughout a person's life. By treating risk factors that occur early on in the cardiovascular continuum, like hypertension, it may be possible to prevent or slow the development of heart disease and to prolong life.

http://www.thevisualmd.com/health_centers/cardiovascular_health/cardiovascular_continuum