Systemic Immune‐Inflammation‐Based Biomarker and Fragility Fractures in People Living With HIV: A 10‐Year Follow‐Up Cohort Study in China

Fragility fractures are a significant concern among people living with HIV(PLWH) due to the combined effects of chronic inflammation, immune dysregulation, and antiretroviral therapy. Traditional biomarkers have limited predictive value for fragility fractures in this population. This study aims to evaluate the systemic immune inflammation-based scores as novel biomarkers for predicting fragility fractures in PLWH in China. We conducted a cohort study of PLWH in the orthopedic department of Beijing Ditan Hospital from January 2011 to September 2023. We monitored fragility fractures and collected data on demographics, clinical characteristics, and laboratory parameters. Multivariate Cox and logistic regression models were used to assess the predictive value of the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI) for fragility fractures. Restricted cubic splines (RCS) were employed to explore potential nonlinear relationships, and subgroup analyses were conducted to examine the stability of these associations. During a median follow-up of 5.5 years, our study included 1148 PLWH patients, and 204 patients (17.8%) experienced fragility fractures. After adjusting for all covariates, SII and SIRI were identified as independent risk factors for fragility fractures in PLWH, whereas NLR, PLR, and MLR were not. Patients with higher levels of SII and SIRI had a significantly increased risk of fragility fractures compared to those with lower levels (HR: 1.96, 95% CI: 1.24-3.10, p = 0.004; HR: 1.83, 95% CI: 1.16-2.88, p = 0.009). RCS analysis indicated a stable linear relationship between SIRI and fragility fractures. Furthermore, KM curves demonstrated that patients with higher SII and SIRI scores had a higher likelihood of experiencing fragility fractures. Our research shows that SII and SIRI are promising biomarkers for predicting fragility fractures in PLWH. Clinicians should consider incorporating SIRI into clinical practice to improve fracture risk stratification and guide preventive strategies for this vulnerable population.