Different durations of arthritis and hip fracture risk among middle-aged and older adults evidence from CHARLS...

Objectives. Hip fracture is a major cause of disability and death among older adults. Arthritis is a common chronic condition that may influence fracture risk through changes in bone health, mobility limitation, and falls. However, the association between arthritis duration and hip fracture risk in the Chinese population remains unclear.

Data were obtained from 9433 participants aged > 45 years in the China Health and Retirement Longitudinal Study (CHARLS). Individuals with prior hip fractures or missing key information on arthritis status or covariates were excluded. Participants were categorized by self-reported arthritis duration into four groups: none, ≤ 3 years, 4-6 years, and > 6 years. Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for hip fracture risk across duration groups, adjusted for demographic characteristics, lifestyle factors, and comorbid conditions. Trend tests, Kaplan-Meier analyses, and subgroup and sensitivity analyses were performed to assess the robustness of the results.

During nine years of follow-up, 372 hip fractures were recorded. Participants with arthritis had a higher risk of hip fracture than those without arthritis (HR 1.59, 95% CI 1.24-2.05). By arthritis duration, the hazard ratios were 1.59 (95% CI 1.11-2.28) for ≤ 3 years, 1.83 (95% CI 1.20-2.78) for 4-6 years, and 1.53 (95% CI 1.15-2.04) for > 6 years, with a significant trend across duration categories (P for trend < 0.01). Subgroup and sensitivity analyses showed consistent results.

Self-reported arthritis was associated with an increased risk of hip fracture among Chinese adults aged > 45 years. The association varied across arthritis duration categories, with a relatively higher estimate observed in the 4-6-year group. Further studies are needed to clarify whether this pattern reflects differences in arthritis subtype, disease severity, treatment, or other unmeasured factors. Key Points • In this nationally representative cohort of Chinese adults aged >45 years, self-reported arthritis was associated with a higher risk of hip fracture. • The association varied across arthritis duration categories, with a relatively higher estimate observed in the 4-6-year group. • Further studies are needed to clarify the factors underlying this duration-specific pattern.