title: Leptin in nonalcoholic fatty liver disease: a narrative review.
abstract: Leptin, the first described adipokine, interplays with hepatic metabolism. The aim of this review was to summarize available data on the association between leptin and nonalcoholic fatty liver disease (NAFLD). Leptin has a potential dual action on NAFLD experimental models, exerting a possible anti-steatotic, but also a proinflammatory and profibrogenic action. Observational clinical studies have shown higher or similar leptin levels between simple steatosis and nonalcoholic steatohepatitis (NASH) compared with controls. Interventional studies showed that circulating leptin diminishes together with body mass index after successful weight loss following lifestyle modifications or bariatric surgery. Studies providing evidence for the effect of other medications on leptin levels in NAFLD populations are limited and of low power. Data from small studies claim that recombinant leptin administration had a possibly beneficial effect on steatosis, but not fibrosis, in NAFLD patients with hypoleptinemia. Although the aforementioned dual leptin action has not yet been validated in humans, leptin administration in NAFLD patients with normoleptinemia or hyperleptinemia is discouraged. Further well-controlled studies in cautiously selected populations are needed to elucidate whether leptin has any prognostic and therapeutic role in NAFLD patients.
authors.affiliation: Second Medical Clinic, Department of Medicine, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece; Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. Electronic address: stergios@endo.gr.
authors.forename: Stergios A
authors.initials: SA
authors.lastname: Polyzos
authors.affiliation: Second Medical Clinic, Department of Medicine, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece.
authors.forename: Jannis
authors.initials: J
authors.lastname: Kountouras
authors.affiliation: Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: Christos S
authors.initials: CS
authors.lastname: Mantzoros
mesh_terms: D000818:Animals; D015992:Body Mass Index; D006801:Humans; D020738:Leptin / Q000378:metabolism*; D065626:Non-alcoholic Fatty Liver Disease / Q000378:metabolism* / Q000503:physiopathology*; D064887:Observational Studies as Topic; D015431:Weight Loss / Q000502:physiology
chemical_list: D020738:Leptin
keywords: Insulin resistance; Leptin; Leptin resistance; Nonalcoholic fatty liver disease; Nonalcoholic steatohepatitis