サルコペニアは肝硬変患者の死亡率と関連する

サルコペニアは肝硬変患者の死亡率と関連するという論文を紹介します。

Aldo J. Montano-Loza, et al: Sarcopenia Is Associated with Mortality in Patients with Cirrhosis. Clinical Gastroenterology and Hepatology doi:10.1016/j.cgh.2011.08.028

対象は肝移植の評価をされた肝硬変患者112人です。サルコペニアはL3レベルでの腹部CTの筋肉量から評価しています。サルコペニアは45人（40％）に認めました。

多変量解析では、Child-Pugh分類、model for end-stage liver disease (MELD) （終末期肝疾患モデル）の得点、サルコペニアの3項目のみが、死亡率と有意に関連していました。また、サルコペニアとChild-Pugh分類、MELDの間には有意な相関を認めませんでした。

これより肝疾患では肝機能とは別にサルコペニアを評価しておくことが重要といえます。慢性肝不全では、慢性の心不全、腎不全、呼吸不全と同様に悪液質を認めますので、悪液質の結果、サルコペニアを認める方も少なくありません。

今回、Child-Pugh分類ではBの方が最も多かったですが、それでも4割にサルコペニアを認めます。これがChild-Pugh分類でCの方や肝細胞がんを伴う肝硬変であれば、4割以上の方がサルコペニアだと推測されます。すべての肝硬変、慢性肝不全患者でサルコペニアの評価が大切です。

Abstract
Background; Aims Sarcopenia, defined as a low level of muscle mass levels, occurs in patients with cirrhosis. We assessed its incidence among cirrhotic patients undergoing evaluation for liver transplantation, to investigate associations between sarcopenia and mortality and prognosis.

Methods We studied 112 patients with cirrhosis (78 male, mean age 54±1 years) who were consecutively evaluated for liver transplantation and had a computed tomography scan at the level of the 3rd lumbar (L3) vertebrae, to determine the L3 skeletal muscle index (L3 SMI); sarcopenia was defined using previously published, sex-specific cutoffs.

Results Of patients studied, 45 had sarcopenia (40%). Univariate Cox analysis associated mortality with ascites (hazard ratio [HR],2.12; P=.04), encephalopathy (HR,1.99; P=.04), level of bilirubin (HR,1.007; P<.01), international normalized ratio (HR,7.69; P<.001), level of creatinine (HR,1.01; P=.005), level of albumin (HR,.94; P=.008), serum level of sodium (HR,.89; P<.001), model for end-stage liver disease (MELD) score (HR,1.14; P<.01), Child-Pugh score (HR, 2.84; P<.001), and sarcopenia (HR,2.18; P=.006). By multivariate Cox analysis, only Child-Pugh (HR,1.85; P=0.04) and MELD scores (HR 1.08; P=0.001), and sarcopenia (HR,2.21; P=0.008), were independently associated with mortality. The median survival time for sarcopenic patients was 19±6 months, compared with 34±11 months among non-sarcopenic patients (P=.005). There was a low level of correlation between L3 SMI and MELD (r,-.07; P=.5) and Child-Pugh scores (r,-.14; P=.1).

Conclusions Sarcopenia is associated with mortality in patients with cirrhosis; it does not correlate with the degree of liver dysfunction, evaluated using conventional scoring systems. Scoring systems should include evaluation of sarcopenia to better assess mortality among patients with cirrhosis.

Keywords: INR; wasting; prognostic factor; complications