類風濕性關節炎患者之脆性骨折的風險因子──單一醫學中心的配對病例對照研究

Risk Factors Analysis of Fragility Fractures in Rheumatoid Arthritis: A Single-center, Matched Case-control Study

目的：探討風濕性關節炎（RA）患者脆性骨折的危險因子。
方法：本登錄研究在高雄長庚紀念醫院進行，時間從2014年9月1日到2020年12月16日收納類風濕性關節炎患者，並記錄了臨床特徵、檢驗數據、脆性骨折病史和骨折風險評估工具（FRAX®）中的風險因子。參與者被分為有骨折組（A組）和沒有骨折組（B組）。然後將A組參與者按照年齡和性別與B組進行1:2匹配分為F組和N組。
結果：本研究共納入682名患者，匹配後F組有147名參與者而N組有294名參與者。單變相分析顯示較高的HAQ評分、較長的病程、使用類固醇、較高的副甲狀腺激素、較低的身高、股骨頸處骨密度（BMD）降低、髖部BMD降低、較低的丙胺酸轉胺（ALT）和鹼性磷酸酶（ALK-P）與風濕性關節炎患者的脆性骨折有關。多變項分析顯示髖部BMD降低（OR 10.44，95% CI 1.20-90.61）和較高的iPTH（OR 1.02，95% CI 1.00-1.03）是風濕性關節炎患者脆性骨折的獨立危險因子。
結論：經年齡和性別配對後，髖部BMD降低和較高的iPTH是RA患者脆性骨折的獨立危險因子。因此我們建議對類風濕性關節炎患者進行iPTH和BMD的測量，以評估骨折風險並預防未來的潛在脆性骨折。

Purpose: To explore the risk factors associated with fragility fractures in patients with rheumatoid arthritis (RA)
Methods: This study was conducted using the RA registry at Kaohsiung Chang Gung Memorial Hospital, one medical center in southern Taiwan for RA-related osteoporosis/fracture, between September 1, 2014, and December 16, 2020. The study recorded the demographics, clinical characteristics, history of previous fragility fractures, and risk factors assessed by the Fracture Risk Assessment Tool (FRAX®). The participants were categorized into two groups: those with a history of previous fractures (group A) and those without (group B). Additionally, participants were further divided into two subgroups, group F and group N, based on 1:2 matching of their age and gender with both group A and group B.
Results: The study enrolled a total of 682 participants. After matching, 147 and 294 participants were allocated to groups F and N. The uni-variate analysis revealed that several factors were associated with fragility fracture in RA patients, including higher Health Assessment Questionnaire score (HAQ-DI), longer disease duration, use of glucocorticoids (GCs), higher intact parathyroid hormone level (iPTH), lower body height, lower bone mineral density (BMD) at the femoral neck (FN) and at the hip, lower alanine aminotransferase (ALT) level, and lower alkaline phosphatase level (Alk-P). Furthermore, the multi-variate analysis showed that lower BMD at the hip (OR, 10.44 (1.20-90.61), p = 0.033) and higher iPTH level (OR, 1.02 (1.00-1.03), P=0.028) were independent risk factors for fragility fracture in RA patients.
Conclusions: Lower hip BMD and higher iPTH level were identified as independent risk factors for fragility fracture in patients with RA after age and gender been matched.