Since the emergence of new HIV therapies more than a decade ago, there has been a remarkable decrease in AIDS deaths. But physicians suspected these more potent medications led to unwanted side effects, such as unusual changes in body fat, elevations in cholesterol and triglycerides and other symptoms that characterize metabolic syndrome.
To help determine whether the benefits of the therapies outweigh the negative side effects, School of Medicine researchers compared the occurrence of metabolic syndrome in HIV-infected patients to non-infected people.
The researchers report in the journal Clinical Infectious Diseases that the incidence of metabolic syndrome among their HIV-infected population is about 26 percent, essentially the same as in age-matched people not infected with the virus. The type or duration of HIV therapy did not affect the rate of metabolic syndrome.
Metabolic syndrome is diagnosed when a patient has at least three of the following symptoms: abdominal obesity, high triglyceride levels, low HDL (good) cholesterol, elevated blood glucose and hypertension.
Since the mid-1990s, most HIV-infected patients have been treated with highly active antiretroviral therapy (HAART).
Using that therapy, there have been major reductions in morbidity and mortality from AIDS, but HAART and its major class of drugs — protease inhibitors — seem to be related to metabolic changes that increase the risk of cardiovascular disease.
“When HAART first became widespread in the mid- to late 1990s, clinicians began to notice really unusual things such as more deposition of fat around the mid-belly along with fat loss in the extremities, as well as extreme elevations in cholesterol or triglycerides,” said first author Kristin E. Mondy, M.D., assistant professor of medicine in the Division of Infectious Diseases.
“They were the sorts of changes you might otherwise see in obese people, and most HIV-infected patients were far from obese,” she added.
But as HAART medications have improved, the metabolic changes have become less pronounced. In addition, because physicians are aware of potential side effects such as elevated cholesterol and triglycerides, they watch for those problems and put many HIV-infected patients on cholesterol-lowering drugs along with HAART therapy.
Mondy said as HAART drugs have improved and physicians have found ways to stay on top of the side effects, HIV has become more of a chronic disease than the death sentence it once was. This study suggests that as HIV-infected patients live longer, they’ve begun to develop problems that probably are related neither to their disease nor to the therapy.
The researchers studied 471 patients from the University’s HIV Clinic and compared them to HIV-negative people from the National Health and Nutrition Examination Survey (NHANES).
Those included from the NHANES group were closely matched to HIV-infected subjects by age, sex, race and smoking status. The rate of metabolic syndrome in the HIV-infected group was 25.5 percent and in the NHANES group was 26.5 percent.
“Overall, the HIV-infected people tended to weigh less and to have lower HDL levels, higher triglycerides and lower glucose levels,” said the study’s senior investigator, Kevin E. Yarasheski, Ph.D., associate professor of medicine.
“But it didn’t seem that HIV therapy was influencing their risk for metabolic syndrome as much as the more traditional risk factors that everyone faces,” he added.
When Yarasheski, Mondy and their colleagues crunched the numbers, they found that HIV-infected patients with metabolic syndrome were more likely to be diabetic, to be older, white and have a high body-mass index. The type or duration of HIV therapy was not an independent risk factor.
Ironically, another important risk factor for metabolic syndrome was a high CD4 cell count. The CD4 count rises and falls as the patient’s immune system gets stronger and weaker. Higher CD4 counts mean a healthier patient.
“As CD4 counts went up, weight also seemed to climb,” Mondy said. “There’s that old saying about being fat and happy. When these people are healthy and doing well, many tend to gain some weight, and that can put them at risk.”
Mondy said it’s important to replicate these findings, but she said researchers in this study were able to look at significant numbers of African-American men and women.
Among HIV-infected African-American women, the rate of obesity was almost 45 percent. She said with rates that high, it’s time to start investigating the efficacy of exercise and other weight-loss methods in HIV-infected people.
“The mortality risk from HIV still outweighs all other risks,” Mondy said. “But as therapies have improved and people are living longer, clinicians have to be concerned about these other health problems.”