Signals for Muscular Protein Turnover and Insulin Resistance in Critically Ill Patients: A Narrative Review

Sebastián P. Chapela; SIMANCAS RACINES, DANIEL ALEJANDRO; Martha Montalvan; Evelyn Frias-Toral; Alison Simancas-Racines; Giovanna Muscogiuri; Luigi Barrea; Gerardo Sarno; Pablo I. Martínez; María J. Reberendo; Natalia D. Llobera; Carlos A. Stella

doi:10.3390/nu15051071

Signals for Muscular Protein Turnover and Insulin Resistance in Critically Ill Patients: A Narrative Review

Journal

Nutrients

ISSN

2072-6643

Date Issued

2023-02-21

Author(s)

Sebastián P. Chapela

SIMANCAS RACINES, DANIEL ALEJANDRO

Facultad de Ciencias de la Salud Eugenio Espejo

Martha Montalvan

Evelyn Frias-Toral

Alison Simancas-Racines

Facultad de Ciencias de la Salud Eugenio Espejo

Giovanna Muscogiuri

Luigi Barrea

Gerardo Sarno

Pablo I. Martínez

María J. Reberendo

Natalia D. Llobera

Carlos A. Stella

DOI

10.3390/nu15051071

URL

https://cris.ute.edu.ec/handle/123456789/419

Abstract

Sarcopenia in critically ill patients is a highly prevalent comorbidity. It is associated with a higher mortality rate, length of mechanical ventilation, and probability of being sent to a nursing home after the Intensive Care Unit (ICU). Despite the number of calories and proteins delivered, there is a complex network of signals of hormones and cytokines that affect muscle metabolism and its protein synthesis and breakdown in critically ill and chronic patients. To date, it is known that a higher number of proteins decreases mortality, but the exact amount needs to be clarified. This complex network of signals affects protein synthesis and breakdown. Some hormones regulate metabolism, such as insulin, insulin growth factor glucocorticoids, and growth hormone, whose secretion is affected by feeding states and inflammation. In addition, cytokines are involved, such as TNF-alpha and HIF-1. These hormones and cytokines have common pathways that activate muscle breakdown effectors, such as the ubiquitin–proteasome system, calpain, and caspase-3. These effectors are responsible for protein breakdown in muscles. Many trials have been conducted with hormones with different results but not with nutritional outcomes. This review examines the effect of hormones and cytokines on muscles. Knowing all the signals and pathways that affect protein synthesis and breakdown can be considered for future therapeutics.