Department of Orthopaedic Surgery, China-Japan Friendship Hospital, Beijing, 100029, China.
People's Hospital of Xinjiang Uygur Autonomous Region Bainiaohu Hospital (The Second Affiliated Hospital of Xi'an Jiaotong University Xinjiang Hospital), Urumqi, 830022, China.
BMC Geriatr. 2024 Nov 28;24(1):977. doi: 10.1186/s12877-024-05556-3.
Sarcopenia and knee osteoarthritis (KOA) are two common musculoskeletal disorders, often coexisting in aged population and potentially influencing each other. However, the underlying relationship between two conditions remains unclear and controversial. To fill this knowledge gap, we aimed to investigate the longitudinal association among the older Chinese population.
Data were attracted from 2 waves of the China Health and Retirement Longitudinal Study (CHARLS), and 6212 individuals aged ≥ 60 years were included. Sarcopenia status was defined by the Asian Working Group for Sarcopenia 2019 criteria. Multivariate logistic regression and generalized estimation equation models were applied to estimate the impact of sarcopenia on KOA. A prognostic nomogram was developed through train-test cross-validation.
At baseline in CHARLS 2015, the prevalence of symptomatic KOA was 12.7% (792/6212) in total population, 9% (270/2996) in no-sarcopenia group, 17.5% (286/1638) in possible sarcopenia group, and 15.0% (236/1578) in sarcopenia group. Over a 3-year follow-up, 4980 respondents were included, with incident KOA cases identified as 56 (2.2%), 38 (3.0%), and 43 (3.6%) in no-sarcopenia, possible sarcopenia, and sarcopenia groups, respectively. Sarcopenia was significantly associated with increased new-onset KOA compared to no-sarcopenia peers in the fully adjusted model (OR: 1.91, 95% CI: 1.15-3.18), whereas this association was non-significant for possible sarcopenia. In females, low muscle mass alone significantly increased the incident risk of KOA (OR: 2.58, 95% CI: 1.05-6.49). The final prognostic model and nomogram, including sarcopenia status, age, gender, body mass index, self-reported health status, comorbidities, history of falls and physical activity, had a considerable discrimination (AUC = 0.744, C-index = 0.660). The calibration curve indicated significant agreement between predicted and actual observations. Decision curve analysis revealed net benefits for clinical intervention at a probability threshold of 1-17%.
Sarcopenia was associated with a higher incident risk of symptomatic KOA, wherein low muscle mass may play an important role. The inferior prognosis of sarcopenia in KOA needs more attention in clinical practice.
肌少症和膝骨关节炎（KOA）是两种常见的肌肉骨骼疾病，常同时存在于老年人群中，并可能相互影响。然而，这两种疾病之间的潜在关系尚不清楚，存在争议。为了填补这一知识空白，我们旨在调查中国老年人群中两者之间的纵向关联。
数据来源于中国健康与养老追踪调查（CHARLS）的 2 个波次，共纳入 6212 名年龄≥60 岁的个体。肌少症状态根据亚洲肌少症工作组 2019 标准定义。采用多变量逻辑回归和广义估计方程模型来估计肌少症对 KOA 的影响。通过训练-测试交叉验证开发预后列线图。
在 CHARLS 2015 的基线调查中，总人群中症状性 KOA 的患病率为 12.7%（792/6212），无肌少症组为 9%（270/2996），可能肌少症组为 17.5%（286/1638），肌少症组为 15.0%（236/1578）。在 3 年的随访期间，共纳入 4980 名应答者，无肌少症、可能肌少症和肌少症组新发生 KOA 的病例分别为 56 例（2.2%）、38 例（3.0%）和 43 例（3.6%）。在完全调整后的模型中，与无肌少症同龄人相比，肌少症与新发 KOA 显著相关（OR：1.91，95%CI：1.15-3.18），而对于可能的肌少症，这种关联无统计学意义。在女性中，单纯的低肌肉量显著增加 KOA 的发病风险（OR：2.58，95%CI：1.05-6.49）。最终的预后模型和列线图，包括肌少症状态、年龄、性别、体重指数、自我报告的健康状况、合并症、跌倒史和体力活动，具有相当的判别能力（AUC=0.744，C 指数=0.660）。校准曲线表明，预测值与实际观察值之间存在显著一致性。决策曲线分析显示，在概率阈值为 1-17%时，临床干预具有净获益。
肌少症与症状性 KOA 的发生风险较高相关，其中低肌肉量可能发挥重要作用。在 KOA 中，肌少症的不良预后需要在临床实践中引起更多关注。
