Visceral Fat More Dangerous

Hypertension has long been linked to obesity, but a new study shows that where that fat is matters.

A team of researchers at University of Texas Southwestern Medical Center in Dallas, TX conclude that when that fat is in the viscera—as opposed to accumulating under the skin—there is a strong chance patients will develop hypertension.

In an article published online Sept. 1 in the Journal of the American College of Cardiology http://content.onlinejacc.org/article.aspx?doi=10.1016/j.jacc.2014.05.057

lead author Alvin Chandra, MD and colleagues reported on 903 obese patients enrolled in a research project known as the Dallas Heart Study.

All had normal blood pressure when the study began. Using various scanning techniques, researchers measured patient’s fat and noted where it was located.

The three categories were visceral adipose tissue (VAT) in the internal abdomen, subcutaneous adipose tissue (SAT) under the skin, and lower body fat (LBF) in the lower extremities.

At follow-up 7 years later the team checked to see which patients had become hypertensive.

They found that the group with VAT was most likely to have developed high blood pressure. The exact mechanism remains unknown, the researchers said.

“There is growing evidence that VAT represents a pathological adipose tissue depot, which accumulates when subcutaneous depots are overwhelmed or not otherwise available for storage,” Chandra wrote.

VAT is associated with insulin resistance, and VAT secretes higher amounts of inflammatory cytokines and is linked to diabetes and heart disease, the authors noted.

Obese people with SAT and LBF appear less at risk, they found.

In an accompanying editorial http://content.onlinejacc.org/article.aspx?doi=10.1016/j.jacc.2014.07.005

Lawrence Krakoff of the Cardiovascular Institute at Mount Sinai Medical Center in New York, NY said the research raises intriguing questions about the causes of many diseases.

For example, he asked, “Could a compressing effect of perirenal fat alter renal function via salt retention” or other processes, he asked. Pending further research, Krakoff said the study shows another reason obese patients should lose weight.