Study: Obesity Not Enough To Predict Cardiovascular Risks

Obesity alone may not be a good predictor of cardiovascular risk and death, according to a new survey.

In a study of almost 18,000 men and women, researchers found that body shape -- whether fat was distributed on the abdomen or on the thighs and hips -- was a better predictor.

The study, conducted by University of Texas Southwestern researcher Edward Harry Livingston, was presented Tuesday at Experimental Biology 2004 as part of the American Physiological Society's scientific sessions.

The researchers found that cardiovascular deaths in women rose as obesity increased, but leveled off before the average weight hit 200 pounds. However, death rates for men continued to climb as weight went up.

Studies have shown that obesity contributes to diabetes and hypertension, which in turn are linked to cardiovascular diseases -- but a connection between obesity and death were not clear. As a result, the researchers observed body shapes and sizes to determine relationships between obesity, cardiovascular mortality and individual heart risk factors, including cholesterol, triglycerides, blood sugar and blood pressure.

They found that death from cardiovascular disease increased steadily for women once they passed a body mass index of 25 until they reached a BMI of 30. To put that into context, a 5-foot-6-inch woman with a BMI of 25 weighs about 160 pounds, while a woman with a BMI of 30 weighs about 185 pounds.

Based on obesity alone, a woman with a BMI of 50 was no more likely to die than those with a BMI of 35.

For men, death from cardiovascular death continued to climb as their BMI climbed. Only blood pressure, both diastolic and systolic, increased in anything resembling a similar pattern, researchers said.

Irrespective of weight, the worst combination of cardiovascular risk was found in people with large waists and narrow thighs. Seriously obese individuals without this body type had a better cardiovascular risk profile than people with this body type who weighed less.

Researchers cautioned that the findings don't mean that obese people don't have cardiovascular risks. They said that they hope the research reinforces the importance of body shape.

Some very obese individuals appear to have the ability to store fat in their lower bodies without causing the increase in cholesterol that occurs in those who store fat in their abdomen, allowing them to become massively obese without raising cardiovascular risks, they said.