Ectopic lipids and organ function : Current Opinion in Lipidology (original) (raw)

Nutrition and metabolism: Edited by Paul Nestel and Ronald P Mensink

Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research; Department of Medicine/Metabolic Diseases, Heinrich Heine University Düsseldorf, Düsseldorf, Germany

Correspondence to Michael Roden, MD, Head, Institute for Clinical Diabetology, Director, German Diabetes Center, Chair, Department of Internal Medicine/Metabolic Diseases, Heinrich Heine University, Auf'm Hennekamp 65, D-400225 Düsseldorf, Germany E-mail: [email protected]

Abstract

Purpose of review

To summarize recent studies that shed more light on possible mechanisms by which ectopic lipid storage affects organ function.

Recent findings

Although ectopic lipids have been considered as biomarkers of lipotoxicity, adaptation of metabolic fluxes and of mitochondrial function seem to be more important than actual cellular fat contents in liver and muscle. Diabetic and obese humans have elevated myocardial lipid contents, which are associated with mitochondrial and contractile dysfunction and could even precede the development of heart failure. Although pancreatic fat content is negatively associated with insulin secretion, β-cell triglycerides are not easily accessible to measurement in humans rendering their role for β-cell function unclear. New approaches to quantify energy metabolism in various organs could help to identify novel biomarkers of organ function in humans.

Summary

Dietary intake of high-caloric high-fat diets and sedentary lifestyle lead to increased storage of triglycerides not only in adipose tissue but also ectopically in other tissues. Intracellular lipid contents in skeletal muscle and liver have been related to insulin resistance and inflammatory processes. Myocardial fat is increased in heart failure, whereas pancreatic fat could relate to insulin secretion.