Nov. 17 (Bloomberg) -- Inflammation triggered by the most commonly used AIDS drugs may help explain why some HIV sufferers are more likely to develop diabetes and heart disease, doctors in Australia said.

Gilead Sciences Inc.’s Truvada and other medicines known as nucleoside reverse transcriptase inhibitors prompt fat cells to release inflammatory molecules which may lead to the metabolic complications, said Katherine Samaras, head of the diabetes and obesity clinical research group at Sydney’s Garvan Institute.

The finding adds to evidence first described by Garvan researchers a decade ago that virus-suppressing therapy increases the risk of a harmful redistribution of body fat, which can cause cardiovascular disease and other chronic conditions. The research, published last week in the journal Obesity, will also help scientists improve treatments for HIV, a virus infecting more than 33 million people worldwide.

“People being treated for HIV tend to lose fat on their arms, legs, face and buttocks and gain it around their abdomen,” Samaras said in an e-mailed statement today. “This redistribution of fat is termed ‘lipodystrophy’ and those patients with the condition have a cardiac and metabolic risk profile worse than being very obese.”

She said the inflammatory response was linked predominantly to treatment with nucleoside reverse transcriptase inhibitors, a class of medicines first used more than two decades ago. It’s difficult to identify side effects caused by specific medications because patients routinely take a cocktail of pills to prevent the virus from developing resistance, Samaras said.

Obese Group

Samaras and colleagues at Sydney’s St. Vincent’s Hospital and the Royal Perth Hospital in Western Australia compared the body composition and metabolic responses of 20 HIV-positive men on antiretroviral therapy with 26 obese men suffering insulin resistance, a precursor to diabetes, who didn’t have human immunodeficiency virus.

“What is novel in this paper is how much more inflammation there is with treated HIV infection, and that there is more inflammation that circulates in the blood stream than what we see in very overweight people,” Samaras said in an interview.

The waist circumference of most HIV sufferers will expand as a result of treatment, though may register below “overweight” parameters, she said. Even those individuals are more prone to having insulin resistance, high cholesterol and other risk factors for diabetes and cardiovascular disease.

“For us, it was a surprise because these people are usually quite healthy in their body size, they’re not obese,” Samaras said.

HIV, or human immunodeficiency virus, causes AIDS, which weakens the body’s ability to protect itself from infections, parasites and a variety of cancers. People catch the disease from infected blood or semen.

To contact the reporter on this story: Jason Gale in Singapore at j.gale@bloomberg.net

Last Updated: November 17, 2008 03:09 EST