The predictive role of parathyroid hormone for non-alcoholic fatty liver disease based on invasive and non-invasive findings in candidates of bariatric surgery

Abstract

Non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH) and hepatic fibrosis are the most detrimental hepatic abnormalities associated with increased body weight with devastating clinical outcomes. Therefore, there is a substantial necessity for efficient management strategies, including significant weight reduction. Bariatric surgery has been used as a therapeutic approach in a selected obese patient with NAFLD/NASH and other cardiometabolic comorbidities. The study is focused on the predictive role of PTH with the indices of hepatic steatosis/NAFLD and NASH based on liver biopsy, elastography, and sonography in morbidly obese patients. Ninety patients with BMI between 35 and 40 kg/m2 with more than two comorbidities who referred to Imam Reza outpatient clinic from December 2016 to September 2017 were recruited and underwent initial assessments, including demographic profiles, psychological assessment, anthropometric measurements, hepatic biopsy, and basic laboratory tests. Liver stiffness was evaluated using two-dimensional shear wave elastography (2D-SWE) at least two weeks before liver biopsy. The histological analysis of the liver was performed using biopsy samples which obtained from left hepatic lobe during bariatric surgery under direct surgeon observation using a 16-gauge Tru-cut needle. The study was approved by the ethical committee (IR.MUMS.fm.REC.1396.312). The level of PTH was significantly high in patients with positive histology for hepatic fibrosis, steatosis, and NASH/NAFLD compared to patients with negative histology (p = 0.005, p = 0.009, and p = 0.013, respectively). Also, patients with liver fibrosis confirmed by elastography had significantly higher serum PTH concentration than patients without fibrosis (p = 0.011). PTH was also positively correlated with hepatic fibrosis, NASH, and steatosis (p = 0.007, p = 0.012, p = 0.023, respectively). High levels of PTH was significantly associated with histological indices of (hepatic fibrosis, steatosis, NAFLD and NASH) and elasticity indices. Therefore, it is imperative to assess for high levels of PTH in the morbidly obese population pre-and post-bariatric surgery. However, for a more robust and comprehensive assessment, a randomized controlled trial is needed. The study was conducted in accordance with the practice guidance in the diagnosis and management of NAFLD from the American association for the study of liver disease (AASLD) 2018. Evidence obtained from well-designed cohort or case-control analytic studies.