Muscle mass predicts outcomes following liver transplantation

Abstract

For patients with end-stage liver disease, commonly used indices of nutritional status (ie, body weight and body mass index) are often inflated because of fluid overload (ie, ascites and peripheral edema), and this results in an underdiagnosis of malnutrition. Because muscle is the largest protein reservoir in the body, an estimate of the muscle mass may be a more reliable and valid estimate of nutritional status. Therefore, we used pretransplant computed tomography data for 338 liver transplantation (LT) candidates to identify muscle and fat mass on the basis of a specific abdominal transverse section commonly used in body composition analyses, and we investigated the contribution of this measure to specific post-LT outcomes. We found that the majority of our patients (68%) could be defined as cachectic. For men, muscle mass predicted many important posttransplant outcomes, including intensive care unit (ICU) stay, total length of stay (LOS), and days of intubation. Muscle mass was a significant predictor of survival and also predicted disposition to home versus another facility. For women, muscle mass predicted ICU stay, total LOS, and days of intubation, but the effect was modest. Muscle mass did not predict survival or disposition for women. In conclusion, because pretransplant muscle mass is associated with many important postoperative outcomes, we discuss these findings in the context of possible pretransplant interventions for either improving or sustaining muscle mass before surgery.

Figure 1

Examples of Body Composition Analysis at L3-4 Transverse Section Legend for Sliceomatic screen images: red is subcutaneous fat, blue is visceral fat and green is muscle. Speckling in the muscle may represent fatty infiltration First Image. 55 yo male ALD, BMI 20, total fat 294, MELD 20, muscle/height 43 (cachetic), LOS 58 days Middle Image. 66 yo male HBV/HCC, BMI 34, total fat 806 MELD 9, muscle/height 56.7 (not cachetic), LOS 26 then to skilled nursing facility, Last Image. 60 yo female with NASH, BMI 30, muscle/height 27.5 (cachetic), total fat 360, MELD 24, died during hospitalization at 21 days

Figure 2

Venn diagram of BMI Classes and Percent Cachetic