Relationship Between a Frailty-Related Phenotype and Progressive Deterioration of the Immune System in HIV-Infected Men

CONTEXT: Immunological similarities have been noted between HIV-infected individuals and older HIV-negative adults. Immunologic alterations with aging have been noted in frailty in older adults, a clinical syndrome of high risk for mortality and other adverse outcomes. Using a frailty-related phenotype (FRP), we investigated in the Multicenter AIDS Cohort Study whether progressive deterioration of the immune system among HIV-positive individuals independently predicts onset of FRP. METHODS: FRP was evaluated semiannually in 1046 HIV-infected men from 1994 to 2005. CD4 T-cell count and plasma viral load were evaluated as predictors of FRP by logistic regression (generalized estimating equations), adjusting for age, ethnicity, educational level, AIDS status, and treatment era [pre-highly active antiretroviral therapy (HAART) (1994-1995) and HAART (1996-1999 and 2000-2005)]. RESULTS: Adjusted prevalences of FRP remained low for CD4 T-cell counts >400 cells per cubic millimeter and increased exponentially and significantly for lower counts. Results were unaffected by treatment era. After 1996, CD4 T-cell count, but not plasma viral load, was independently associated with FRP. CONCLUSIONS: CD4 T-cell count predicted the development of a FRP among HIV-infected men, independent of HAART use. This suggests that compromise of the immune system in HIV-infected individuals contributes to the systemic physiologic dysfunction of frailty.