双能X线吸收法估算四肢骨骼肌质量以诊断肝硬化患者的肌肉减少症
由于肝硬化患者往往伴有腹水，传统的骨骼肌质量评估工具适用性低。
为此，巴西圣保罗大学、里贝朗普雷图医学院、佩洛塔斯天主教大学、圣保罗心脏医院、美国彭宁顿生物医学研究中心使用双能X线吸收仪估算骨骼肌指数（DXA-ASMI）及非惯用手握力（ND-HGS）方法，试图证明这些方法可以避免腹水影响，对于诊断肝硬化腹水患者肌肉减少症具有良好的适用性。
结果发现，腹水穿刺前后DXA-ASMI无统计学差异，表明该指标不受腹水影响。肝硬化患者DXA-ASMI及ND-HGS值均显著低于健康对照（P＜0.001），且DXA-ASMI，尤其是联合ND-HGS时，可以有效确定骨骼肌质量低及死亡风险，对于肌肉减少症具有良好的诊断价值。
JPEN J Parenter Enteral Nutr. 2017;41(2):269.
Diagnosing sarcopenia in patients with cirrhosis by dual-energy x-ray absorptiometry estimates of appendicular skeletal muscle mass.
Giliane Belarmino; Maria Cristina Gonzalez; Priscila Sala; Raquel S. Torrinhas; Wellington Andraus; Luiz Augusto Carneiro D'Albuquerque; Rosa Maria R. Pereira; Valéria F. Caparbo; Eduardo Ferrioli; Karina Pfrimer; Lucas Damiani; Steven B. Heymsfield; Dan L. Waitzberg.
University of Sao Paulo, Sao Paulo, Brazil; Catholic University of Pelotas, Pelotas, Brazil; Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA; University of Sao Paulo Medical School, Sao Paulo, Brazil; Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil; Research Institute, Heart Hospital, Sao Paulo, Brazil.
PURPOSE: In cirrhosis, ascites limits skeletal muscle (SM) mass assessment using available tools. We propose that sarcopenia diagnosis in cirrhosis can be improved by using dual-energy x-ray absorptiometry to calculate the appendicular skeletal muscle index (DXA-ASMI), as it bypasses the abdominal compartment. We evaluated whether the DXA-ASMI is influenced by ascites and can be applied to diagnose sarcopenia with prognostic value for mortality, alone or in combination with nondominant handgrip strength (ND-HGS).
METHODS: DXA-ASMI and ND-HGS values were obtained and mortality recorded in 144 male cirrhotic patients. DXA-ASMI was calculated preparacentesis and postparacentesis in 20 patients with ascites and compared with data from 20 matched volunteers. The capacity of DXA-ASMI and DXA-ASMI + ND-HGS to predict mortality was tested in Cox proportional hazards models adjusted for lower limb edema, liver transplantation, Child-Pugh and Model for End-Stage Liver Disease scores, and age. Survival probabilities were obtained for sarcopenia diagnosed by the European Working Group on Sarcopenia in Older People (EWGSOP) cutoff for DXA-ASMI and ND-HGS values and a cutoff calculated from DXA-ASMI + ND-HGS tertiles in this study; these were compared using Kaplan-Meier analysis.
RESULTS: DXA-ASMIs did not differ preparacentesis and postparacentesis. DXA-ASMI and ND-HGS values were lower in cirrhotic patients than in volunteers (P < .001). Mortality prediction was influenced by DXA-ASMI (hazard ratio [HR] = 0.41, P = .019) and DXA-ASMI + ND-HGS (HR = 1.02, P = .040; Pinteraction = 0.017). All sarcopenia diagnosed using the EWGSOP cutoff was also diagnosed with the specific cutoff; both predicted mortality (53% and 72%, respectively), but the latter was more sensitive for greater mortality risk identification (P = .011).
CONCLUSIONS: In patients with cirrhosis, DXA-ASMI estimates are not influenced by ascites and can identify low SM mass for diagnosing sarcopenia with prognostic value for mortality, mainly when combined with ND-HGS.
FINANCIAL SUPPORT: This work was supported by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), project no. 2011/13243-3, DD 2012/15677-3.
DOI: 10.1177/0148607116686023