Baseline lipid levels rather than the presence of reported body shape changes determine the degree of improvement in lipid levels after switching to atazanavir.

Purpose: To study factors influencing lipid changes after switching to atazanavir (ATV) and the effectiveness of ATV in maintaining virus suppression. Methods: Retrospective cohort study in patients with viral suppression, comparing patients switching to ATV with those continuing combination antiretroviral therapy (cART). Outcome measures were 48-week total (TC), high-density (HDL) and low-density lipoprotein (LDL) cholesterol, and triglycerides (TG) changes, stratified for dyslipidemia and lipodystrophy and virological failure (time to first of two consecutive detectable HIV RNA). Results: 225 patients switched to ATV (193 [85.8%] RTV boosted), and 3120 continued cART. In patients with baseline TC >6.2 mmol/L, those switching had greater mean (95% CI) TC decreases compared to those continuing cART (-1.26 [-1.63 to -0.89] and -0.54 [-0.64 to -0.44] mmol/L, p=.002). Likewise greater TG changes were observed in patients with high (>2.3 mmol/L) baseline TG (-1.44 [-2.05 to -0.83] and -0.54 [-0.70 to -0.38] mmol/L, p=.002). Effects were seen irrespective of presence of lipodystrophy. Patients switching to ATV had virological failure more often (17/224 [7.8%]) than those continuing cART (73/3100 [2.4%], p<.0001). Conclusions: Patients with virological suppression, including those with lipodystrophy, may benefit from switching to ATV with lipid profile improvement, especially if baseline lipid levels are high. This should be balanced against a possible higher virological failure risk.