Fgf21 impairs adipocyte insulin sensitivity in mice fed a low-carbohydrate, high-fat ketogenic diet

PLoS One. 2013 Jul 9;8(7):e69330. doi: 10.1371/journal.pone.0069330. Print 2013.


Background: A low-carbohydrate, high-fat ketogenic diet (KD) induces hepatic ketogenesis and is believed to affect energy metabolism in mice. As hepatic Fgf21 expression was markedly induced in mice fed KD, we examined the effects of KD feeding on metabolism and the roles of Fgf21 in metabolism in mice fed KD using Fgf21 knockout mice.

Methodology/principal findings: We examined C57BL/6 mice fed KD for 6 or 14 days. Blood β-hydroxybutyrate levels were greatly increased at 6 days, indicating that hepatic ketogenesis was induced effectively by KD feeding for 6 days. KD feeding for 6 and 14 days impaired glucose tolerance and insulin sensitivity, although it did not affect body weight, blood NEFA, and triglyceride levels. Hepatic Fgf21 expression and blood Fgf21 levels were markedly increased in mice fed KD for 6 days. Blood β-hydroxybutyrate levels in the knockout mice fed KD for 6 days were comparable to those in wild-type mice fed KD, indicating that Fgf21 is not required for ketogenesis. However, the impaired glucose tolerance and insulin sensitivity caused by KD feeding were improved in the knockout mice. Insulin-stimulated Akt phosphorylation was significantly decreased in the white adipose tissue in wild-type mice fed KD compared with those fed normal chow, but not in the muscle and liver. Its phosphorylation in the white adipose tissue was significantly increased in the knockout mice fed KD compared with wild-type mice fed KD. In contrast, hepatic gluconeogenic gene expression in Fgf21 knockout mice fed KD was comparable to those in the wild-type mice fed KD.

Conclusions/significance: The present findings indicate that KD feeding impairs insulin sensitivity in mice due to insulin resistance in white adipose tissue. In addition, our findings indicate that Fgf21 induced to express by KD is a negative regulator of adipocyte insulin sensitivity in adaptation to a low-carbohydrate malnutritional state.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Hydroxybutyric Acid / blood
  • Adipocytes / metabolism*
  • Animals
  • Blood Glucose
  • Body Weight
  • Diet, Carbohydrate-Restricted*
  • Diet, High-Fat*
  • Fibroblast Growth Factors / blood
  • Fibroblast Growth Factors / genetics*
  • Fibroblast Growth Factors / metabolism
  • Glucagon
  • Gluconeogenesis / genetics
  • Glucose Intolerance
  • Insulin / blood
  • Insulin Resistance / genetics*
  • Ketone Bodies / biosynthesis
  • Liver / metabolism
  • Male
  • Mice
  • Mice, Knockout
  • Phenotype
  • Phosphorylation
  • Proto-Oncogene Proteins c-akt / metabolism


  • Blood Glucose
  • Insulin
  • Ketone Bodies
  • fibroblast growth factor 21
  • Fibroblast Growth Factors
  • Glucagon
  • Proto-Oncogene Proteins c-akt
  • 3-Hydroxybutyric Acid

Grant support

This work was supported by a Grant-in-aid for Scientific Research from the Ministry of Education, Science, Culture and Sports of Japan and the Takeda Science Foundation, Japan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.