Background:  Sex and age differences in HIV RNA and CD4 counts have been described in cross-sectional studies of ART-naïve individuals, but have not been explored in relationship to response to initial HAART. In this study we compared immunologic and virologic response to HAART in naïve pre- and postmenopausal women to age-stratified men.

Methods:  Utilizing 2 observational clinical cohorts (Johns Hopkins University and University of North Carolina), we identified all individuals entering HIV care from January 1, 1998 through January 1, 2004, and included all women and men ³ 50 years of age. We randomly selected 3:1 sex-matched controls < 50 years old. Subjects were included if they were ART-naïve, initiated HAART during follow-up, and had CD4 counts and HIV RNA levels available at baseline and 6 months after initiation. All analyses were intention to treat; multivariable logistic regression was used to model 6-month outcomes:  increased CD4 proportion > 25% (CD4 6-month/CD4 BL), and HIV RNA <400 copies/mL.

Results:  Of 63 cases (29% women) and 183 controls (28% women) HAART included a protease inhibitor (PI) in 122 (50%), non-nucleoside reverse transcriptase inhibitor (NNRTI) in 127 (52%) and triple nucleoside in 15 (6%). Pre-HAART CD4 were highest in women ³ 50 (median cells/mm³:  women ³ 50, 212, men ³ 50, 108, men < 50, 88, and women < 50, 43; p = 0.07), while HIV RNA were comparable (median log₁₀ copies/mL: Women ³ 50, 4.9, men ³ 50, 5.2, men < 50, 5.1, women < 50, 5.0; p = 0.61). At 6 months, no differences in achieving > 25% proportional increase in CD4 count were observed:  women ³ 50, 61%, men ³ 50, 71%, men < 50, 76%, women < 50, 77% (p = 0.54), and persisted after adjusting for baseline CD4, HIV RNA, type of HAART, and site:  OR (95% CI) for women ³ 50, men ³ 50 and women < 50 each compared with men < 50 were:  1.1 (0.3 to 4.0), 1.1 (0.4 to 2.6), and 1.3 (0.5 to 3.1), respectively. Similar results were observed among patients with 6-month HIV RNA < 400 copies/mL. At 6 months, slight non-significant differences were observed between groups in achieving HIV RNA < 400 copies/mL:  women ³ 50, 78%, men ³ 50, 73%, men < 50, 66%, women < 50, 67% (p = 0.68); including in multivariable adjusted analyses:  OR (95% CI) for women ³ 50, men ³ 50, and women < 50 each compared with M < 50 were:  1.8 (0.5 to 6.4), 1.8 (0.8 to 3.9), 1.2 (0.6 to 2.5), respectively.

Conclusions:  This is the first analysis of response in older women. These women appear to present to care with a higher CD4 cell count despite similar HIV RNA. Initial evaluations suggests that overall treatment responses in older women and men are similar and virologic responses may be superior to men < 50 years of age.

Keywords: Menopause; Women ; Elderly