Introduction: Globally, the population of people living with HIV (PLWH) aged ≥50 years is rapidly growing, and these older PLWH face significant age-related comorbidity burdens. This study examined regional variations in comorbidity patterns among older PLWH in China to inform tailored interventions. Methods: A cross-sectional survey was conducted among PLWH ≥50 years receiving antiretroviral therapy (ART) in Chongqing and Jiamusi between April and September 2023. Data on demographics, HIV-related factors and 16 predefined comorbidities were collected. We estimated prevalence of comorbidity, identified its correlates using multivariate logistic regression, and explored disease clusters via association rule mining (Apriori algorithm) and network analysis. Results: Among 515 individuals, 74.95% were males and the median age was 60 (IQR:55-67) years. The overall comorbidity prevalence was 62.72%, with significant differences between Chongqing and Jiamusi (79.13% vs. 49.47%, P<0.001). Common conditions were dyslipidemia (19.22%), hypertension (19.03%), syphilis (14.17%) and cardio-cerebrovascular disease (11.07%). Chongqing had more metabolic comorbidities such as dyslipidemia (39.13%), while Jiamusi had more hypertension (20.00%) and syphilis (18.60%). Participants with advanced age, lower latest CD4 count, and higher healthcare burden showed significantly increased risk of comorbidity ( P<0.05). Association rule mining identified frequent pairs including ”hypertension + cardio-cerebrovascular diseases” and ”diabetes + dyslipidemia”. Network analysis highlighted hypertension as a central node linking metabolic (hypertension-dyslipidemia-diabetes) and infectious (eg. syphilis, hepatitis) clusters. Conclusion: Older PLWH in China have a high multimorbidity burden with distinct regional patterns. Chongqing’s older PLWH show metabolic comorbid profiles, whereas Jiamusi’s show cardio-cerebrovascular and sexually transmitted infection (STI) comorbidity patterns. Region-specific prevention like blood pressure control in northeast and metabolic risk reduction in the southwest as well as integrated care models is recommended to reduce multimorbidity risk and improve healthy aging in this population.

A thorough and precise comprehension understanding of the HIV epidemic is crucial for effective HIV prevention and control. We used Estimation and Projection Package (EPP)/Spectrum software to update the estimates of the overall HIV burden in China in 2018 from the obtained data from more than 1800 HIV sentinel surveillance sites, population-based seroprevalence surveys, and HIV screening of antenatal clinics and pre-marital medical check-ups across the country. In 2018, the total number of PLWH adults in China was estimated to be 1·23 million, corresponding to approximately 106.5/100,000. Over a half PLWH (58·6%) were infected through heterosexual contact, about one-third (30·2%) through male-to-male transmission, 9·0% through IDU, and 2·3% due to former plasma donation. In recent years, the number of new infections through blood donation has been eliminated, and the number of infections through injecting drug use has been kept low. Sexual contact became the predominant transmission route, while casual sexual contact became increasingly common. Overall, HIV mortality has been steadily increasing and has recently begun to decline during 2012-2018. The number of deaths from HIV/AIDS in 2018 was approximately 35 000 (95% UI: 30 000-41 000). The number of estimated PLWH in China has exceeded one million, due to the ongoing occurrence of new infections and longer survival rates. HIV transmission through blood products has been eradicated. Casual sex has become a significant mode of transmission. It is recommended to enhance the implementation of strategies and measures for sexual communication in the general population and to bolster multidisciplinary research.