Stories tagged mortality

Nov
12
2007


People who are overweight stand a greater risk of dying from some diseases, but not for othersCourtesy Roger Cullman

Pretty bad. People who are overweight are more likely to die from diabetes and kidney failure than the general population. And people who are obese are more likely to die from heart disease and certain types of cancer.

These common-sense truths were reconfirmed last week by a report from the Centers for Disease Control, which analyzed decades of data from 39,000 Americans. However, the news was not all bad. For instance, obese people had the same overall mortality rate from cancer as the population as a whole. Which means that while they were at greater risk of dying from cancers that attack fatty tissues (including the breast, uterus, ovaries, kidneys, colon, throat and pancreas), they were actually less likely to die from other forms of cancer.

For folks who are overweight but not obese, the picture is even more complicated. Neither cancer nor heart disease killed this group at higher-than-average rates. In fact, researchers found lower mortality in this group for all other causes of death, including infectious diseases and accidents.

The researchers aren’t sure why this should be. One theory is that carrying a little extra fat – but not too much – gives the bodies the energy reserves it needs to fight off illness.

Another possibility is raised by the way the study defined “overweight” and “obese.” They did not measure the patients’ body fat directly, but rather used a mathematical calculation known as the Body Mass Index or BMI. This widely-used tool gives doctors a rough estimate of a person’s body fat – a number over 25 classifies a person as “overweight.” A BMI 30 or higher qualifies as “obese.”

The trouble is, BMI basically divides weight by height (with a couple other calculations thrown in for fun). The greater the weight, the higher the BMI for a given height. The problem is, people can add weight as fat, or they can add weight as muscle. Somebody who exercises a lot may be strong, healthy… and have a BMI that qualifies as overweight.

If that’s the case, then that would explain why the “overweight” group fights off disease and injury so well. Which is good news if you’re fit, but not so good news if you’re flabby.

Mar
01
2005

Life expectancy in the US hit a new high on Monday. The Centers for Disease Control and Prevention (CDC) announced that the average American now lives 77.6 years. This is the highest figure ever recorded.

The mortality rate for the two biggest killers—cancer and heart disease—both fell. On average, women still live longer than men, though the gaps is shrinking. And, for reasons that are not explained, people in Hawaii live the longest. Must be all the surfing.