Objective:To investigate the occurrence of carotid artery abnormalities in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients and the related risk factors affecting the occurrence of carotid artery abnormalities.Methods:A total of 169 regular follow-up outpatients with HIV/AIDS from April 2003 to December 2019 in Peking Union Medical College Hospital, whose carotid artery ultrasound examination were performed from July 2015 to December 2019 were included. The patients were divided into young (≤44 years old), middle-aged and elderly (≥45 years old) according to their ages, and the physical examination data of the included patients were collected.The statistical methods were logistic regression analysis and single sample t test. Results:Among the 169 HIV/AIDS patients, 40(23.7%) had abnormal carotid artery and 129(76.3%) had no abnormal carotid artery. Middle-aged and elderly people (odds ratio ( OR)=3.85, 95%confidence interval (95% CI) 1.54-9.65, P<0.01), hypertension ( OR=6.24, 95% CI 1.95-20.00, P<0.01), hyperlipidemia ( OR=2.44, 95% CI 1.00-5.93, P<0.05), and elevated human leucocyte antigen (HLA)-DR + CD8 + /CD8 + ( OR=1.03, 95% CI 1.01-1.06, P<0.05) were the risk factors for carotid artery abnormality. The common carotid artery inner medium film thickness (IMT) of patients in HIV/AIDS group Ⅰ (20 to 30 years old), group Ⅱ (31 to 40 years old), group Ⅲ (41 to 50 years old) were (0.061 0±0.001 2), (0.062 9±0.001 4) and (0.065 6±0.002 6) cm, respectively, which were thicker than the control groups ((0.051±0.003), (0.056±0.004) and (0.063±0.002) cm, respectively). The differences were all statistically significant ( t=5.119, 4.775 and 1.739, respectively, all P<0.05). The common carotid artery IMT of patients in HIV/AIDS group A (30 to 44 years old) and group B (45 to 59 years old) were (0.062 6±0.001 1) and (0.072 3±0.003 4) cm, respectively, which were thicker than the control groups ((0.052±0.011) and (0.064±0.015) cm, respectively), the differences were both statistically significant ( t=9.520 and 3.012, respectively, both P<0.01). Conclusion:Younger HIV-positive people have a higher probability of abnormal carotid arteries and may be at greater risk of cardiovascular disease than HIV-negative people of the same age, suggesting that HIV-positive people, especially young people, should be examined early with ultrasound of the neck arteries to detect abnormalities and intervene as soon as possible.