根据CT确定肝移植患者肌肉减少症发生率

　　住院患者广泛存在肌肉减少现象，使用CT第三腰椎平面肌肉面积评估肌肉减少症已经得到广泛认可，故美国拉什大学应用该方法调查了肝移植术患者肌肉减少情况。

　　该研究入组2010年1月～2015年8月接受肝移植术且手术30天内行腹部CT检查的患者共53例。

　　结果发现，其中38例（72%）的患者出现肌肉减少症，肌肉减少症组BMI中位数相比非肌肉减少症组显著降低（P=0.02），两组之间肝移植相关并发症发生率无统计学差异。

　　因此，肌肉减少症高发病率可能是因为入组标准要求患者必须进行CT检查而造成的偏倚。

JPEN J Parenter Enteral Nutr. 2017;41(2):296-297.

Prevalence of computed tomography defined myopenia among liver transplant patients.

Kaleigh N. Brown; Anne Coltman; Benjamin Bienia; Diane Sowa; Sarah Peterson.

Rush University Medical Center, Chicago, Illinois, USA.

PURPOSE: Myopenia, or decreased muscle mass, is a clinically significant condition that affects a wide range of hospitalized patients. Identification of myopenia is often difficult due to the limited accuracy of physical assessment. The use of computed tomography (CT) scans to identify myopenia has been widely accepted as a new gold standard. The purpose of this study was to describe the prevalence of CT-defined myopenia among patients receiving liver transplant and to examine the association between decreased muscle mass and complications at 6 months posttransplant.

METHODS: Patients receiving a liver transplant between January 2010 and August 2015 with a diagnostic abdominal CT scan at the third lumbar region within 30 days of transplant were included. Cross-sectional skeletal muscle mass (cm²) at L3 was measured using Slice-O-Matic; pixels between −29 to +150 Hounsfield units were categorized as muscle. Skeletal muscle index (SMI) was calculated by dividing cross-sectional skeletal muscle mass (cm²) by height (m²). The following patients were categorized as myopenic: men with body mass index (BMI) <25 kg/m² and SMI ≤43 cm²/m², men with BMI ≥25 and SMI <53 cm²/m², and women with SMI <41 cm²/m². Transplant complications, including graft function, infectious complications, and mortality, were tracked for 6 months posttransplant.

RESULTS: A total of 53 patients met inclusion criteria; within this sample, 72% (n = 38) were myopenic. However, low overall median SMI was observed in both myopenic (38.7 [33, 46]) and nonmyopenic patients (52.0 [44, 60]). There was a trend toward males having a higher prevalence of myopenia compared with females (64% vs 36%, P = .18). Compared with nonmyopenic patients, those with myopenia had a significantly lower median BMI (29.9 kg/m² [25, 38] vs 26.0 kg/m² [24, 28], P = .02), although the majority of patients in both groups were categorized as overweight or obese. No statistically significant association in transplant complications was observed between myopenic and nonmyopenic subjects; however, the lack of association may be related to high overall prevalence of low muscle mass.

CONCLUSIONS: Identification of myopenia is an important component of nutrition assessment. CT-defined myopenia may be a useful prognostic tool in certain populations. Because only patients requiring a CT scan were included in this sample, patients may inherently have higher rates of myopenia and associated complications. Replication of this methodology, including a larger sample of liver failure patients, may allow for elucidation of the role of myopenia in posttransplant morbidity and mortality.

DOI: 10.1177/0148607116686023