| Characteristics | Carotid    ultrasound  normal N=93 | Carotid    ultrasound abnormal N=82 | p-value | 
      
        | N | (%) | N | (%) | 
      
        | Age at the carotid ultrasound    date (years) |  |  |  |  |  | 
      
        | ≤45 | 38 | (75) | 13 | (25) | <0.001 | 
      
        | 46-55 | 36 | (51) | 34 | (49) |  | 
      
        | ≥56 | 19 | (35) | 35 | (65) |  | 
      
        | Age at the carotid ultrasound    date (years) | 47 | (42-53) | 54 | (49-59) | <0.001 | 
      
        | Age at antiretroviral therapy    initiation date | 43 | (36-47) | 47 | (40-52) | 0.005 | 
      
        | Adherence in the first year of    antiretroviral therapy |  |  |  |  |  | 
      
        | <95% | 9 | (31) | 20 | (69) | 0.007 | 
      
        | ≥95% | 81 | (59) | 57 | (41) |  | 
      
        | Year of first antiretroviral    therapy |  |  |  |  |  | 
      
        | 1996-1999 | 21 | (36) | 37 | (64) | 0.005 | 
      
        | 2000-2005 | 36 | (65) | 19 | (35) |  | 
      
        | After 2006 | 36 | (58) | 26 | (42) |  | 
      
        | History of injection drug use |  |  |  |  |  | 
      
        | No | 82 | (57) | 63 | (43) | 0.046 | 
      
        | Yes | 5 | (26) | 14 | (74) |  | 
      
        | Unknown | 6 | (55) | 5 | (45) |  | 
      
        | First antiretroviral therapy    regimen |  |  |  |  |  | 
      
        | NNRTI | 23 | (55) | 19 | (45) | 0.005 | 
      
        | PI Single | 11 | (39) | 17 | (61) |  | 
      
        | Boosted PI | 48 | (67) | 24 | (33) |  | 
      
        | Other | 11 | (33) | 22 | (67) |  | 
      
        | Any AIDS defining illnesses    prior to ultrasound date |  |  |  |  |  | 
      
        | No | 69 | (53) | 60 | (47) | 0.878 | 
      
        | Yes | 24 | (52) | 22 | (48) |  | 
      
        | Years on antiretroviral therapy    before carotid ultrasound date | 5 | (2-7) | 7 | (3-12) | 0.008 | 
      
        | Duration (years) of NNRTI    exposure prior to ultrasound date | 1.30 | (0.21-2.94) | 2.27 | (1.12-5.22) | 0.034 | 
      
        | Duration (years) of PI exposure    prior to ultrasound date | 3.62 | (1.96-5.18) | 4.09 | (1.43-5.73) | 0.582 | 
      
        | Nadir CD4 cell count (prior to    ultrasound date) (cells/mm3) | 140 | (40-250) | 140 | (50-190) | 0.795 | 
      
        | CD4 value nearest to time of    ultrasound (cells/mm3) | 500 | (410-620) | 480 | (380-600) | 0.268 | 
      
        | Peak plasma viral load (prior to    ultrasound date) (copies/mL) | 100010 | (73900-100010) | 100010 | (76378-100010) | 0.987 | 
      
        | Plasma viral load nearest to    time of ultrasound (copies/mL) | 499 | (499-499) | 499 | (499-499) | 0.337 | 
    
    Note: For continuous variables, we presented the median and the 25