Prognostic nutritional index as an indicator for the development of bone fragility fracture in patients with rheumatoid arthritis.

Objectives: The validity of prognostic nutritional index (PNI) as an index of incident bone fragility fracture (inc-BFF) in rheumatoid arthritis (RA) patients was investigated.
Methods: RA patients whom continuously followed up for >3 years were picked up. Patients were classified in accordance with inc-BFF positivity (BFF+ and BFF-). Their clinical background including PNI was statistically examined for inc-BFF. The background factors were compared between the two groups. Patients were narrowed into subgroups according to the factor that showed a significant difference between the two groups, and they were statistically examined according to the PNI for the inc-BFF. The two groups were narrowed with propensity score matching and compared to the PNI.
Results: A total of 278 patients with 44 BFF+ and 234 BFF- were recruited. In the background factors, the presence of prevalent BFF and the simplified disease activity index remission rate had a significantly higher risk ratio. In a subgroup who comorbid lifestyle-related diseases, PNI had a significantly higher risk ratio for the inc-BFF. After the propensity score matching, the PNI showed no significant difference between the two groups.
Conclusions: PNI is available when patients with RA comorbid lifestyle-related diseases. PNI is not an independent key for the inc-BFF in RA patients.
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