SATURDAY, Aug. 12, 2006 (HealthDay News) -- Older people with HIV/AIDS are more likely than younger people to take their antiretroviral medications consistently.
And it's a good thing they do, because HIV/AIDS patients over age 50 have more problems with elevated levels of cholesterol and blood sugar and have blood-cell and kidney abnormalities that should be closely monitored, experts reported.
In a series of studies, to be presented this weekend at the International AIDS Conference in Toronto, scientists monitored the therapy of more than 5,000 HIV/AIDS patients and found those in the oldest group -- over age 50 -- had the best compliance record in taking medication.
Michael J. Silverberg, a research scientist with the Kaiser Permanente Division of Research in Oakland, Calif., led a team that studied 5,079 patients who started highly active antiretroviral therapy (HAART) between 1995 and 2004. Of these, 997 were over age 50, 1834 were ages 40-49 and 2259 were ages 18-39.
Among patients over age 50, the researchers found that 38.8 percent achieved optimal adherence (taking 95 percent or more of their medications) and that 65.4 percent achieved good adherence (taking 75 percent or more of their medications). Among patients ages 40-49 and 18-39, optimal adherence was 33.4 and 30.2 percent, respectively, and good adherence was 61.2 and 59.1 percent, respectively. After three years of therapy, there were no group differences in HIV blood levels, rebound in HIV levels and changes in immune system T-cell levels.
Strict adherence to HAART is especially important for older patients. "When older patients start therapy, they have slower immune recovery compared to younger patients," Silverberg said. "Better adherence was the key factor that allowed older patients to catch up to younger patients after three years."
In a separate study of the same 5,079 patients, Silverberg and his colleagues found that the older patients had a significantly higher rate of cholesterol abnormalities during the first year of treatment (34 percent compared to 26.4 percent of patients ages 40-49 and 21 percent of patients ages 18-39). They also found higher rates of blood-sugar abnormalities (14.4 percent compared to 11.4 of patients ages 40-49 and 6 percent of patients ages 18-39) and higher rates of blood-cell and kidney abnormalities, but not of liver abnormalities.
"Evidence for a slower immunological rebound might be cause for worry among HIV-infected persons over the age of 50, but the higher adherence rates overcome this issue in the long run," said Dr. Sten H. Vermund, director of the Institute of Global Health at the Vanderbilt University School of Medicine in Nashville, Tenn. "However, increased drug side effects in older patients suggest the need to monitor carefully and consider treatment modifications to reduce toxicities, especially in older patients."
During the 1990s, the number of AIDS cases quintupled among people over age 50. "This is a fast-growing population," Silverberg said. "Because HIV therapies are life-long, we plan to continue monitoring our study subjects to identify the benefits and consequences of therapy, which is key to HIV research and the care of HIV patients."
In another Kaiser Permanente study, researchers assessed the effects of depression and use of selective serotonin reuptake inhibitors (SSRIs) on adherence rates and clinical outcomes in 3,431 HIV/AIDS patients. As expected, they found that depressed patients treated with SSRIs had a 5.3 percent higher adherence rate compared to patients with untreated depression.
But they were surprised to find that depressed patients on SSRIs had significantly poorer clinical outcomes. "That's probably because they were more severely depressed to begin with. They were so far behind the eight-ball that the effects of depression probably outweighed any benefits of the SSRIs," said Dr. Michael A. Horberg, director of HIV/AIDS policy at the Kaiser Permanente Health Plan in Oakland, Calif.
"The scientific term for that is called selection bias," explained Horberg, who called for further study to clarify the effects of depression treatment on HIV outcomes.
"The clinical implication of our study is that doctors who are treating HIV patients need to be very aggressive in screening for depression," Horberg said. "Even though we weren't able to find a clear benefit from SSRIs, we still believe that depressed patients should be started on SSRIs or, at the very least, put into active therapy programs and counseling."
"The use of selective serotonin reuptake inhibitors, one of the best approaches for pharmacotherapy of depression, proved disappointing, but the investigators observe correctly that their observational data were subject to selection bias," Vermund added. "The study's implication is that depression should be considered a co-factor of immense importance in the management of HIV treatment."
The U.S. government's Centers for Disease Control and Prevention has a series of articles on Living with HIV/AIDS