Prevalence of graft steatosis after liver transplantation using controlled attenuation parameter measurements: a large cohort study

Abstract

Background: Liver steatosis is a cause of graft dysfunction after liver transplantation. The current study aims to determine the prevalence of steatosis in a large cohort of liver transplant recipients from a single center. Methods: Consecutive patients transplanted from 2003 to 2014 underwent liver stiffness (LS) and controlled attenuation parameter (CAP) measurements using transient elastography. Liver biochemistry and fasting lipid profile and glucose were taken. Results: A total of 554 patients underwent valid transient elastography, of which 396 (71.5%) were male, with a median age of 59 (range, 19-78) years, and median time to transient elastography of 77 months (range, 6-167) after transplantation. The majority (71.8%) was transplanted for hepatitis B related complications. The prevalence of no, mild, moderate, and severe steatosis was 49.1%, 6.3%, 25.8%, and 18.8% respectively. A higher CAP score was observed in males vs. females (229 vs 212 dB/m respectively, p=0.007) and in living vs. deceased donor transplant (229 vs 215 dB/m respectively, p=0.004). Steatosis, as diagnosed by CAP score of ≥222 dB/m, was observed in 282 (50.9%) patients, of which 35 (6.3%) had mild steatosis, 143 (25.8%) had moderate steatosis, and 104 (18.8%) had severe steatosis. Patients with steatosis had older age at transplant (53 vs. 51 years, p=0.005), older age at transient elastography (60 vs 57 years, p=0.001), and higher BMI (25.4 vs 23.2 kg/m2, p<0.001), ALT (24 vs 22 U/L, p=0.026), GGT (35 vs 28 U/L, p=0.041), platelets (181 vs 168, p=0.001), fasting glucose (5.8 vs 5.3, p=0.002), total cholesterol (4.3 vs 4.2, p=0.037), LDL-cholesterol (2.5 vs 2.2, p<0.001), triglyceride (1.3 vs 1.0, p<0.001). A lower HDL-cholesterol was observed in steatotic patients (1.2 vs 1.5, p<0.001). There was no significant difference in LS measurements between those with and without graft steatosis (4.9 vs 5.0 kPa, p=0.635). Hypertension, diabetes, and hyperlipidemia were present in 324 (58.5%), 190 (34.3%), and 124 (22.4%) patients respectively. A higher CAP score was observed in patients with hypertension (237 vs 204 dB/m, p<0.001), diabetes (233 vs 217 dB/m, p=0.008), and hyperlipidemia (239 vs 217 dB/m, p<0.001). The highest CAP scores was observed for those transplanted for alcoholic liver disease (254 dB/m) and cryptogenic cirrhosis (261 dB/m), with lowest scores seen in patients with biliary atresia (161 dB/m) and polycystic liver disease (188 dB/m)(p=0.019). Conclusion: Graft steatosis is common after liver transplantation, and is associated with higher baseline BMI, and higher rates of hypertension, diabetes, and hyperlipidemia. However, there is no significant increase in LS.