IIB-Sant Pau and Department of Endocrinology/Medicine, Hospital Sant Pau, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBER-ER, Unidad 747), ISCIII, Barcelona, Spain.
Departamento de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain.
Clin Endocrinol (Oxf). 2021 Nov;95(5):735-743. doi: 10.1111/cen.14568. Epub 2021 Aug 6.
Cushing's syndrome (CS) is associated with skeletal muscle structural and functional impairment which may persist long-term despite surgical removal of the source of cortisol excess. Prevalence of sarcopenia and its impact on Health-Related-Quality of Life (HRQoL) in 'cured' CS is not known. There is a need to identify easy biomarkers to help the clinicians recognise patients at elevated risk of suffering sustained muscle function.
We studied 36 women with CS in remission, and 36 controls matched for age, body mass index, menopausal status, and level of physical activity. We analysed the skeletal muscle mass using dual-energy X-ray absorptiometry, muscle fat fraction using two-point Dixon magnetic resonance imaging and muscle performance and strength using the following tests: hand grip strength, gait speed, timed up and go and 30-s chair stand. We assessed HRQoL with the following questionnaires: SarQoL, CushingQoL, SF-36. We calculated the sarcopenia index (SI; serum creatinine/serum cystatin C × 100).
Prevalence of sarcopenia, according to the European Working Group on Sarcopenia in Older People (EWGSOP), was greater in CS as compared with controls (19% vs. 3%; p < .05). Patients with sarcopenia had a lower SarQoL score than those without sarcopenia (61 ± 17 vs. 75 ± 14; p < .05), and scored worse on the items pain, easy bruising and worries on physical appearance (p < .05 for all comparisons) of the CushingQoL questionnaire. Patients with sarcopenia had poorer physical functioning on SF-36 than those without sarcopenia (60 ± 23 vs. 85 ± 15; p < .01). SI was lower in patients with sarcopenia than those without (71 ± 3 vs. 77 ± 2; p = .032), and was associated with intramuscular fatty infiltration, worse performance on the 30-s chair stand test, slower gait speed, and worse muscle weakness-related HRQoL, as measured using the SarQoL questionnaire (p < .05). The optimised cut-off value for the SI ratio to diagnose sarcopenia was 72, which yielded a sensitivity of 73% and a specificity of 90%.
Sarcopenia is common in patients with CS in long-term remission, and associated with impaired quality of life. The SI is a potential biomarker allowing clinicians to identify patients at high risk of muscle dysfunction.
库欣综合征（CS）与骨骼肌结构和功能障碍有关，尽管皮质醇过多的来源已通过手术切除，但这种障碍可能会长期存在。在“治愈”的 CS 患者中，肌少症的患病率及其对健康相关生活质量（HRQoL）的影响尚不清楚。需要确定简单的生物标志物来帮助临床医生识别有持续肌肉功能受损风险的患者。
我们研究了 36 名缓解期 CS 女性患者和 36 名年龄、体重指数、绝经状态和身体活动水平相匹配的对照组。我们使用双能 X 射线吸收法分析骨骼肌质量，使用两点 Dixon 磁共振成像分析肌肉脂肪分数，使用以下测试分析肌肉性能和力量：握力、步态速度、计时起立行走和 30 秒坐立。我们使用以下问卷评估 HRQoL：SarQoL、CushingQoL、SF-36。我们计算了肌少症指数（SI；血清肌酐/血清胱抑素 C×100）。
根据欧洲老年人肌少症工作组（EWGSOP）的标准，CS 患者的肌少症患病率高于对照组（19% vs. 3%；p<0.05）。患有肌少症的患者 SarQoL 评分低于无肌少症的患者（61±17 与 75±14；p<0.05），在 CushingQoL 问卷的疼痛、容易瘀伤和对身体外观的担忧等项目上的评分也较差（所有比较均为 p<0.05）。与无肌少症的患者相比，患有肌少症的患者在 SF-36 上的身体机能更差（60±23 与 85±15；p<0.01）。肌少症患者的 SI 低于无肌少症的患者（71±3 与 77±2；p=0.032），且与肌内脂肪浸润、30 秒坐立试验表现更差、步态速度更慢以及 SarQoL 问卷测量的肌肉无力相关 HRQoL 更差相关（p<0.05）。SI 比值的最佳截断值为 72，可诊断肌少症，其灵敏度为 73%，特异性为 90%。
长期缓解期 CS 患者肌少症很常见，且与生活质量受损有关。SI 可能是一种潜在的生物标志物，可帮助临床医生识别有肌肉功能障碍高风险的患者。
