OP009 RELATIVE VALIDITY OF PREDICTIVE EQUATIONS FOR RESTING ENERGY EXPENDITURE IN FRAIL ELDERLY ITALIAN PATIENTS IN HOME ENTERAL NUTRITION

Abstract

Rationale: The mechanisms behind postoperative insulin resistance and impaired glucose utilization are not fully understood. In this study we aimed to specifically evaluate the transcription profile of genes in the insulin and adipokine signaling pathways in different fat depots, subcutaneous and omental adipose tissue, following surgical injury. Methods: Twelve non-diabetic patients (7 females, 65 [46 72] years, body mass index 24.8 [16.5 29.8] kg/m2) undergoing major abdominal surgery were included. Relative expression of 21 target genes was analysed in both subcutaneous and omental adipose tissue sampled at the beginning and at the end of operation and the mRNA levels at the two time points were compared. Results: Following surgery, both subcutaneous and omental adipose tissue mRNA levels of genes involved in the interleukin 6 (interleukin 6: >20-fold; signal transducer and activator of transcription 3: >1.5-fold; suppressor of cytokine signaling 3: >50-fold) and nicotinamide phosphoribosyltransferase (>4-fold) pathways were increased, whereas mRNA levels of insulin receptor substrate 1 (>1.5fold) and adiponectin (1.1 and 2.0-fold) were reduced (p < 0.05). Tumor necrosis factor pathway genes were differently regulated between subcutaneous and omental adipose tissue, and glucose transporter 4 mRNA levels were decreased (1.8-fold, p = 0.012) only in omental adipose tissue. Conclusion: The transcriptional output of pivotal inflammatory and insulin signaling pathway genes is altered after surgery and this pattern differs between different fat depots. This could be of importance for the metabolic aberrations associated to postsurgical complications, such as insulin resistance and hyperglycemia.