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"Nearly 60 percent of those participants with the pattern B trait converted to a normal and healthier pattern A trait."

Game Changing Results
Weight Loss Can Reverse Effects of Genetic Predisposition to Heart Disease Risk

In a groundbreaking new study published in the July issue of Obesity, CHORI senior scientist Ronald Krauss, MD, CHORI scientist Patti Siri-Tarino, PhD, and their colleagues have shown that a specific low-density lipoprotein (LDL) profile, called pattern B trait, and the atherogenic lipoprotein phenotype (ALP) with which it is associated, can be reversed with weight loss.

The main objective of the study was to show that weight loss could reverse ALP and one of its characteristics, the pattern B trait, in a very large percentage of the study participants, which Dr. Krauss and his colleauges were in fact able to show - and then some.

The pattern B trait, an increase in levels of small, dense LDLs , along with the other elements of the ALP phenotype - increased triglycerides and reduced high density lipoproteins (HDL) - have all been associated with a significant increase in risk for heart disease.

"ALP also signifies the potential for developing high blood pressure, clotting abnormalities and inflammation, all of which can further magnify the risk of heart disease," says Dr. Krauss.

Reversing the ALP profile, however, would be likely to substantially reduce this increased heart disease risk. Previous studies conducted by Dr. Krauss and his colleagues had shown that weight loss due to calorie restriction had the potential to do just that, but many individuals remained at risk.

"We thought that this was perhaps because people needed to drop their weight to a level below what is commonly considered to be the threshold for being overweight, which is a body mass index of 25," explains Dr. Krauss. The body mass index, or BMI, is calculated as weight in kilograms divided by the square of height in centimeters. "We hoped that a reduction to that target could reverse the ALP and pattern B traits."

The randomized controlled clinical trial in which both healthy, pattern A men and pattern B men were randomized to either a regular diet or a weight-loss diet geared to achieve a BMI of 25 or less, provided the results Dr. Krauss was looking for.
"What this study shows is that sufficient weight loss - which can be achieved through limiting calories as well as exercise - could reverse the syndrome in the great majority of the population."
"Even though we know through previous studies that there are genetic factors that predispose people to ALP and pattern B, this means that only a minority, who would be considered genetically "hardwired" for heart disease, might require additional treatments."

The study revealed some important clues to understanding the bigger picture as well, however.

"Not everyone was able to achieve the desired BMI," explains Dr. Krauss. "Of course we see this a lot when we encourage weight loss, that it's not always easy to meet your target, and often hard to maintain. But what we found was that the individuals who had the greatest difficulty achieving the target BMI were those with the pattern B trait."
Along with additional, soon-to-be-published data by Dr. Krauss and his colleagues, this finding strongly suggests that there may be an underlying metabolic abnormality associated with pattern B that makes it more difficult to burn fat. According to Dr. Krauss, this would help explain both the pattern B trait itself, as well as why patients with the trait have a greater tendency toward being overweight and a harder time losing weight. While Dr. Krauss intends to investigate this phenomenon further, the results of the current study provide fresh hope for those facing increased heart disease risk.

"This study reinforces what we and others have been saying for many years: that achieving and maintaining a healthy body weight has an extraordinary number of beneficial affects," says Dr. Krauss. "Now we can add the reversal of ALP and pattern B to this long list of benefits that could substantially reduce the risk for heart disease and diabetes."

This study was funded by the National Dairy Council.

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Tuesday, May 17, 2011 8:19 AM

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