Background/AimsHypothyroidism is reported to contribute to the development of nonalcoholic fatty liver disease (NAFLD). We compared the risk of the development of NAFLD among three groups with different thyroid hormonal statuses (control, subclinical hypothyroidism, and overt hypothyroidism) in a 4-year retrospective cohort of Korean subjects.MethodsApparently healthy Korean subjects without NAFLD and aged 20-65 years were recruited (n=18,544) at health checkups performed in 2008. Annual health checkups were applied to the cohort for 4 consecutive years until December 2012. Based on their initial serum-free thyroxine (fT4) and thyroid-stimulating hormone (TSH) levels, they were classified into control, subclinical hypothyroidism (TSH >4.2 mIU/L, normal fT4), and overt hypothyroidism (TSH >4.2 mIU/L, fT4 <0.97 ng/dL) groups. NAFLD was diagnosed on the basis of ultrasonography findings.ResultsNAFLD developed in 2,348 of the 18,544 subjects, representing an overall incidence of 12.7%: 12.8%, 11.0%, 12.7% in the control, subclinical hypothyroidism, and overt hypothyroidism groups, respectively. The incidence of NAFLD did not differ significantly with the baseline thyroid hormonal status, even after multivariate adjustment (subclinical hypothyroidism group: hazard ratio [HR]=0.965, 95% confidence interval [CI]=0.814-1.143, P=0.67; overt hypothyroidism group: HR=1.255, 95% CI=0.830-1.899, P=0.28).ConclusionsOur results suggest that the subclinical and overt types of hypothyroidism are not related to an increased incidence of NAFLD.

Nonalcoholic fatty liver disease (NAFLD) is an increasingly common cause of chronic liver disease worldwide and is becoming a major public health problem. NAFLD has been recognized as a hepatic manifestation of metabolic syndrome linked with insulin resistance. Growing evidence supports that NAFLD is associated with systemic diseases such as cardiovascular disease (CVD), chronic kidney disease (CKD), type 2 diabetes, obesity, and metabolic syndrome. The majority of deaths in patients with NAFLD come from cardiovascular disease. These findings are strongly attributed to nonalcoholic steatohepatitis (NASH) rather than simple steatosis. NAFLD should be considered not only a liver specific disease but also an early mediator of systemic disease. The underlying mechanisms and pathogenesis of NAFLD with regard to other medical disorders are not yet fully understood. Further investigation is needed for future therapeutic strategies for NAFLD. This review focuses on the relationship between NAFLD and various comorbid diseases and metabolic derangement.

Functional dyspepsia (FD) is a chronic upper gastrointestinal (GI) symptom complex that routine diagnostic work-up, such as endoscopy, blood laboratory analysis, or radiological examination, fails to identify a cause. It is highly prevalent in the World population, and its response to the various available therapeutic strategies is only modest because of the heterogenous nature of its pathogenesis. Therefore, FD represents a heavy medical burden for healthcare systems. We constituted a guideline development committee to review the existing guidelines on the management of functional dyspepsia. This committee drafted statements and conducted a systematic review and meta-analysis of various studies, guidelines, and randomized control trials. External review was also conducted by selected experts. These clinical practice guidelines for FD were developed based on evidence recently accumulated with the revised version of FD guidelines released in 2011 by the Korean Society of Neurogastroenterology and Motility. These guidelines apply to adults with chronic symptoms of FD and include the diagnostic role of endoscopy, Helicobacter pylori screening, and systematic review and meta-analyses of the various treatment options for FD (proton pump inhibitors, H. pylori eradication, and tricyclic antidepressants), especially according to the FD subtype. The purpose of these new guidelines is to aid the understanding, diagnosis, and treatment of FD, and the targets of the guidelines are clinicians, healthcare workers at the forefront of patient care, patients, and medical students. The guidelines will continue to be revised and updated periodically. (J Neurogastroenterol Motil 2020;26:29-50)

Tenofovir disoproxil fumarate (TDF) is a potent nucleotide analogue that is recommended as first-line therapy for patients with chronic hepatitis B. The results of a longitudinal study of TDF treatment demonstrated no development of resistance. We observed one treatment-naïve chronic hepatitis B (CHB) patient who developed TDF resistance after complete viral suppression during long-term TDF treatment. A 37-year-old HBeAg-positive man received TDF 300 mg/d for 43 mo. The hepatitis B virus (HBV) DNA titer was 8 log10 copies/mL at baseline and became undetectable at 16 mo after treatment. However, the HBV DNA titer rebounded to 7.5 log10 copies/mL at 43 mo after treatment. We performed full sequencing to find mutation sites associated with virologic breakthrough. The results showed 9 mutation sites, most of which had not been well-known as mutation sites. We changed the therapy from tenofovir to entecavir with a regimen of 0.5 mg once daily. After 4 mo, the HBV DNA titer decreased to 267 copies/mL, and the liver enzyme levels were normalized.