Utility of Ultrasound, Transaminases, and Visual Inspection to Assess Nonalcoholic Fatty Liver Disease in Bariatric Surgery Patients

Abstract

Background Nonalcoholic fatty liver disease (NAFLD) is common in adults with extreme obesity and can impact long-term health and survival. Liver biopsy is the only accurate test for diagnosis and staging, but is invasive and costly. Non-invasive testing offers an attractive alternate, but the overall accuracy remains a significant issue. This study was conducted to determine the accuracy and clinical utility of preoperative ultrasound and liver transaminase levels, as well as intra-operative hepatic visual inspection, for assessing presence of NAFLD as confirmed by hepatic histology. Methods Data was collected prospectively from 580 morbidly obese adult patients who underwent Roux-en-Y gastric bypass surgery with intraoperative wedge biopsy between January 2004 and February 2009. Complete data for ultrasound, ALT and AST levels, and documented visual inspection was available for 513 patients. Results The prevalence of NAFLD was 69 % and that of NASH was 32 %. The individual non-invasive clinical assessments demonstrated low sensitivity, specificity, and accuracy for detecting the presence of steatosis, steatohepatitis, or fibrosis. The combination of normal or abnormal results for all tests improved predictive utility. Abnormal tests with all three assessments had a sensitivity of 95–98 % and a specificity of 28–48 % for major histologic findings in NAFLD/NASH. Normal tests with all three assessments had a sensitivity of 12–22 % and a specificity of 89–97 % for major histologic findings in NAFLD/NASH. Conclusions Although individual clinical tests for NAFLD have limited accuracy, the use of combined clinical tests may prove useful.

Angptl8 antisense oligonucleotide improves adipose lipid metabolism and prevents diet-induced NAFLD and hepatic insulin resistance in rodents

“…Liver tissue was preserved in formalin for histological analysis [35]. Adipose tissue was preserved in RNALater (Qiagen) and stored at −80°C [36].…”

Circulating microRNAs in nonalcoholic fatty liver disease

“…However, significant differences in BMI, blood glucose, triglyceride levels, total cholesterol, and ALT were present between the NAFLD and control groups; thus, additional studies will be necessary to demonstrate the robustness of miR-15b as a biomarker for human NAFLD. It is also worth noting that NAFLD patients were likely skewed toward severe disease given the criteria for persistently elevated aminotransferase levels, which we have found do not occur in most obese patients with biopsy-proven NAFLD 3, 24 .…”

Accuracy of imaging methods for steatohepatitis diagnosis in non‐alcoholic fatty liver disease patients: A systematic review

“…Heterogeneous histopathological definitions of NASH were used . The accepted definition of NASH as the contemporary presence of steatosis, lobular inflammation and ballooning independently of fibrosis was generally followed, but in six studies fibrosis was included in the definition of NASH or classified with NASH . Even among studies which referred to the most used classification by the Clinical Research Network, cases defined as borderline or with NAFLD Activity Score 3‐4 were either classified with simple steatosis or with NASH.…”

“…US non‐elastographic techniques (Table ) include several parameters and scores that took into consideration features related to the severity of steatosis, spleen diameter or visceral adiposity, all evaluated in one single study, resulting in AUROCs ranging from 0.76 of US‐fatty liver indicator (US‐FLI) for NAS ≥ 2 to 0.92 of splenic diameter. With a cut‐off of 4, US‐FLI presented 100% sensitivity and 46% specificity for the diagnosis of severe NASH .…”