Wysham Katherine D, Shoback Dolores M, Andrews James S, Katz Patricia P
Puget Sound Health Care System, Department of Veterans Affairs, Seattle, WA, USA.
Department of Medicine, Division of Rheumatology, University of Washington, Seattle, WA, USA.
Bone Rep. 2020 May 22;12:100284. doi: 10.1016/j.bonr.2020.100284. eCollection 2020 Jun.
Frailty in the general population is associated with poor health outcomes including low bone mass and osteoporotic fracture. The relationship between frailty and low bone mineral density (BMD) in rheumatoid arthritis (RA) is unknown. This study examined associations between frailty and BMD in RA, controlling for established osteoporosis risk factors.
We performed a cross-sectional analysis of a longitudinal RA cohort (n = 138; 117 female, 21 male). Participants fulfilled ACR RA classification criteria. Frailty was evaluated using the Fried Index, categorizing each participant as robust, pre-frail or frail. To identify independent predictors of BMD, we performed a multivariable linear regression analysis. Because risk factors for low BMD differ between sexes, we performed additional sex-stratified multivariable analyses.
Mean age and disease duration were 58.0 ± 10.8 and 19 ± 10.9 years, respectively. The majority of participants were categorized as pre-frail (70%) or frail (10%). Females had higher rates of frailty than males. In the whole cohort, both pre-frail and frail had independent negative associations with BMD (β = -0.074 and -0.092 respectively, p < 0.05). In sex-stratified analyses, frailty did not have a significant association with BMD in females, but had a strong independent negative association in males (β = -0.247, p = 0.001).
Frailty was associated with BMD in patients with RA. Females had higher rates of frailty than males, yet frailty was independently associated with BMD in males but not in females. Frailty appears to be an important factor associated with low BMD; sex may influence this relationship in RA.
普通人群中的衰弱与包括低骨量和骨质疏松性骨折在内的不良健康结局相关。类风湿关节炎（RA）患者中衰弱与低骨密度（BMD）之间的关系尚不清楚。本研究在控制已确定的骨质疏松风险因素的情况下，探讨RA患者中衰弱与BMD之间的关联。
我们对一个纵向RA队列（n = 138；117名女性，21名男性）进行了横断面分析。参与者符合美国风湿病学会（ACR）RA分类标准。使用Fried指数评估衰弱情况，将每位参与者分类为健康、衰弱前期或衰弱。为了确定BMD的独立预测因素，我们进行了多变量线性回归分析。由于低BMD的风险因素在性别之间存在差异，我们进行了额外的按性别分层的多变量分析。
平均年龄和病程分别为58.0±10.8岁和19±10.9年。大多数参与者被分类为衰弱前期（70%）或衰弱（10%）。女性的衰弱率高于男性。在整个队列中，衰弱前期和衰弱均与BMD存在独立的负相关（β分别为-0.074和-0.092，p<0.05）。在按性别分层的分析中，衰弱与女性的BMD无显著关联，但在男性中存在强烈的独立负相关（β = -0.247，p = 0.001）。
RA患者中衰弱与BMD相关。女性的衰弱率高于男性，但衰弱仅在男性中与BMD独立相关，在女性中则不然。衰弱似乎是与低BMD相关的一个重要因素；性别可能会影响RA中的这种关系。
