A buildup of subcutaneous adipose tissue (SAT) of the upper trunk—fat below the skin in the chest and back (“buffalo hump”)—is associated with insulin resistance in HIV-positive patients, a new study in the Journal of Acquired Immune Deficiency Syndromes reports. Other studies have linked visceral adipose tissue (VAT) increases—enlarged fat deposits deep within the body—with insulin resistance, but the new research is the first to report an association between upper trunk SAT and the pre-diabetes insulin abnormality.

Among the HIV-infected subjects with the highest amount of upper trunk fat, 57 percent showed insulin resistance. Among the HIV-negative control group with upper trunk fat, 61 percent were insulin resistant. "Strikingly, there was very little difference between HIV infected people and controls” in terms of upper trunk SAT buildup says Carl Grunfeld, MD, PhD of the University of California, San Francisco, and a lead author other study. “If you have fat up top, it's bad for you."

In insulin resistance, cells in the body become increasingly resistant to the action of insulin, a hormone that regulates blood sugar (glucose) levels. The result is chronically high blood glucose, which can have many serious effects on health.