Effect of age on response to and tolerability of highly active antiretroviral therapy: a case-control study

Purpose of the study

Patients who develop HIV infection in their older years represent a special issue for health care providers. We sought to determine the characteristics of HIV infection in older individuals, including co-morbid conditions, response and tolerability to highly active antiretroviral therapy (HAART), and to compare these aspects with those diagnosed among younger subjects.

Methods

All outpatients medical records of HIV-infected patients, newly diagnosed between 1 Jan. 2000 and 30 April 2008 at the Infectious Diseases Clinic of Perugia University Hospital, were reviewed. All patients were selected, and divided in two groups, according to age (<50 years>). Demographic data, HIV risk behaviours, stage of HIV disease (including CD4 cell count, HIV viral load), use of HAART, co-morbid conditions and tolerability of therapy were collected. When available, 6- and 12-month data on CD4 cell count, HIV-RNA undetectability, side-effects and modification of treatments were collected as well. Data were analysed with t-test for continuous variables and chi-square for categorical variables; logistic regression was used for multivariate analysis.

Summary of results

During the study period 328 consecutive adult patients had been diagnosed as HIV positive; 51 were older than 50 years. Compared to younger patients, older patients were more frequently male (p = 0.015) and Italian (p < 0.001); drug addiction was less frequent among older patients, although this result was marginally significant (p = 0.054). Older patients had significantly more co-morbidities (diabetes, hypertension, dyslipidemia) (p < 0.001). We did not find significant differences for HIV-RNA undetectability and for CD4 cell count at 6 and 12 months. However, older patients had more side-effects (p = 0.001) and changed treatment more frequently (p < 0.001).

Conclusion

The main problem with older patients is treatment tolerability, which causes a more frequent change of antiretroviral drugs. However, viro-immunological results do not differ between the two age groups. Clinical trials admitting older HIV patients are needed.