台灣類風濕性關節炎患者使用類固醇對於骨質疏鬆及脆性骨折的影響：台灣骨質疏鬆篩檢計畫之次分析

The Impact of Glucocorticoids on Prevalent Osteoporosis or Fragility Fracture in Taiwanese Patients with Rheumatoid Arthritis: A Sub-Study of Taiwan OsteoPorosis Survey

目的：探討類風濕性關節炎（RA）患者使用類固醇（GC）後對於骨質疏鬆症和脆弱性骨折的影響。
方法：2008年至2011年間，台灣骨質疏鬆症學會進行全國性骨密度篩檢計畫，參與民眾於檢測前完成FRAX問卷。自述罹患RA且使用GC大於3個月者（RA-GCs）作為研究組，年齡及性別匹配之罹患RA者但沒有使用GC大於3個月（RA-non GCs）者為對照組，針對兩組間骨密度、骨質疏鬆比例、既往骨折發生率、FRAX骨折風險及超過個人化介入閾值比例進行比較。
結果：共18,992位民眾參加篩檢，其中872位民眾自述罹患RA，RA-GCs民眾為469位，RA-non GCs為403位。在年齡和性別（1:1）匹配後，分別各349名民眾進入研究組（RA-GCs，A組）和對照組（RA-non GCs，B組）。與B組的參與者相比，A組的腰椎、全髖骨、股骨頸處的骨密度顯著較低，骨質疏鬆症比例更高，但既往骨折發生率反而較低。A組10年骨折風險（主要骨鬆性骨折或髖部骨折）及超過介入閾值的概率亦顯著高於B組。
結論：本研究顯示與RA沒使用類固醇大於3個月者相比，RA且使用類固醇大於3個月者的骨密較低，10年骨折機率較高，既往骨折發生率反而較低，這表明類固醇的使用雖然會導致骨質減少，但透過改善關節功能和日常活動可能可以預防RA相關的有症狀的骨折，但長期的骨折的風險仍然較高，但這也仍需要進一步研究。

Objective: This study aimed to explore the impact of glucocorticoid (GC) use on rheumatoid arthritis (RA)-related osteoporosis and fracture.
Method: This was a cross-sectional cohort sub-study of a nationwide osteoporosis screening program conducted in Taiwan from 2008 to 2011. Patients with RA who received GCs (RA-GCs) for 3 months were recruited as the study group. Patients with RA who were not on GCs (RA-non GCs) were recruited as controls. Osteoporosis was defined as a T-score at the femoral neck (FN) of≤-2.5 compared with that of young adult Caucasian females.
Results: A total of 872 patients with RA, including RA-GCs (n=469) and RA-non GCs (n=403) were recruited. After age and sex matching (1:1), 349 participants each were included in the study group (RAGCs, Group A) and the control group (RA-non-GCs, Group B). Compared with Group B, Group A had a significantly lower bone mineral density (BMD) at L1–4, the hip (total), and the FN and a significantly higher rate of osteoporosis but a lower rate of self-reported previous fracture. The 10-year probability of major or hip fractures was significantly higher in Group A than in Group B.
Conclusion: Our study showed that RA-GCs had lower BMD and a higher 10-year probability of fracture but had a lower rate of a previous fracture than those had by RA-non GCs.
This suggests that GCs use by patients with RA may induce systemic bone loss. Our findings of GCs use and fracture history requires further investigation.