Nonalcoholic Fatty Liver Disease in Lean/Nonobese and Obese Individuals: A Comprehensive Review on Prevalence, Pathogenesis, Clinical Outcomes, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with an estimated prevalence of 25% globally. NAFLD is closely associated with metabolic syndrome, which are both becoming increasingly more common with increasing rates of insulin resistance, dyslipidemia, and hypertension. Although NAFLD is strongly associated with obesity, lean or nonobese NAFLD is a relatively new phenotype and occurs in patients without increased waist circumference and with or without visceral fat. Currently, there is limited literature comparing and illustrating the differences between lean/nonobese and obese NAFLD patients with regard to risk factors, pathophysiology, and clinical outcomes. In this review, we aim to define and further delineate different phenotypes of NAFLD and present a comprehensive review on the prevalence, incidence, risk factors, genetic predisposition, and pathophysiology. Furthermore, we discuss and compare the clinical outcomes, such as insulin resistance, dyslipidemia, hypertension, coronary artery disease, mortality, and progression to nonalcoholic steatohepatitis, among lean/nonobese and obese NAFLD patients. Finally, we summarize the most up to date current management of NAFLD, including lifestyle interventions, pharmacologic therapies, and surgical options.

Detection of Barrett's Esophagus Prior to Development of Esophageal and Esophagogastric Junction Adenocarcinoma

BACKGROUND

Guidelines differ on the definition of Barrett's esophagus (BE). We aimed to estimate the detection rate of esophagogastroduodenoscopy (EGD) with biopsy for BE, using longitudinal outcome of adenocarcinoma of the esophagus or esophagogastric junction (EAC, EGJAC) as the gold standard.

METHODS

We performed retrospective analyses of US Veterans with EAC/EGJAC between 2017 and 2021 who had an EGD prior to cancer diagnosis. We reviewed a random sample of 200 cases of EAC and 100 cases of EGJAC to tabulate the detection rate of EGD with biopsy, stratified by Siewert classification (S1 or S2).

RESULTS

After manual review, there were 136 S1 and 108 S2 cases. Among patients with endoscopic suspicion of BE who had biopsies, 96.8% of S1 and 97.9% of S2 had intestinal metaplasia (IM). BE defined as ≥1cm with IM had a detection rate of 66.2% for S1 and 39.8% for S2. When restricted to EGDs with appropriate biopsies, the detection rate of ≥1cm with IM improved to 70.3% in S1 and 41.4% in S2. 73% of S1 cases and 90% of S2 cases without BE diagnosed were due to lack of endoscopic suspicion for BE. BE or a visible lesion was present in 70% of photographs from EGDs not suspected of having BE by the original endoscopist.

CONCLUSIONS

IM appears required for development of EAC and likely EGJAC. EGD with biopsy had only modest rate for detecting a precursor state for subsequent adenocarcinoma and was lower for S2 compared to S1. Variability in endoscopic suspicion, including segments <1cm are potential areas for improvement in detection of BE by EGD.