Changes in serum concentrations and tissue expression of fibroblast growth factor-21 during and after elective major cardiac surgery
Jana Drapalova1, Tomas Kotulak2, Petr Kopecky1, Milos Mraz1, Hynek Riha2, Jan Blaha1, Petr Kramar2, Ivan Netuka2, Jan Maly2, Jaromir Kremen1, Eva Kotrlikova1, Stepan Svacina1 & Martin Haluzik1
Introduction: Fibroblast growth factor-21 (FGF-21) is a novel regulator of glucose and lipid metabolism and insulin sensitivity. Possible role of FGF-21 in the development of insulin resistance in critically ill patients has not been studied yet.
Objective: To study the changes in FGF21 production and adipose tissue and skeletal muscle FGF-21 mRNA gene expression in cardiac surgery patients.
Methods: Sixteen patients (16 men, aged 66±1.8 years, BMI 29.2±0.79 kg/m2) undergoing elective aorto-coronary by-pass were included into the study. Serum FGF-21 levels along with selected biochemical, hormonal and cytokine parameters were measured by commercial ELISA and RIA kits at several timepoints before, during, at the end and up to 3 days after the operation. FGF-21 mRNA expression was assessed from epicardial and subcutaneous adipose tissue and intercostal muscle taken at the beginning and end of the surgery. The study was approved by the Ethical Committee of Thomayer University Hospital in Prague.
Results: Serum concentrations of FGF-21 significantly increased along with the increase in glycemia, insulinemia, hsCRP, interleukin-6, interleukin-8, MCP-1 and TNF-α levels during and for up to 24 h after the operation and returned to nearly baseline levels at 96 h after the procedure. Baseline FGF-21 mRNA expression in skeletal muscle was more than 350-times higher than in adipose tissue and did not change significantly during the operation. FGF21 mRNA gene expression in epicardial adipose tissue significantly increased over the operation period, while no change was found in subcutaneous fat.
Conclusions: Circulating FGF-21 levels and its mRNA gene expression in epicardial fat were significantly stimulated by major cardiac surgery. This increase may play a role in the regulation of peri- and postoperative insulin sensitivity in these patients. Skeletal muscle may constitute another important source of FGF-21.
Supported by MZOVFN2005 and MSM0021620814.