Sarcopenia in Inflammatory Bowel Disease: A Narrative Overview

Abstract

Malnutrition is a common condition encountered in patients with inflammatory bowel disease (IBD) and is often associated with sarcopenia (the reduction of muscle mass and strength) which is an ever-growing consideration in chronic diseases. Recent data suggest the prevalence of sarcopenia is 52% and 37% in Crohn's disease and ulcerative colitis, respectively, however it is challenging to fully appreciate the prevalence of sarcopenia in IBD. Sarcopenia is an important consideration in the management of IBD, including the impact on quality of life, prognostication, and treatment such as surgical interventions, biologics and immunomodulators. There is evolving research in many chronic inflammatory states, such as chronic liver disease and rheumatoid arthritis, whereby interventions have begun to be developed to counteract sarcopenia. The purpose of this review is to evaluate the current literature regarding the impact of sarcopenia in the management of IBD, from mechanistic drivers through to assessment and management.

Keywords: exercise; inflammatory bowel disease; muscle mass; nutrition; sarcopenia.

Figure 1

Multi-factorial causes of malnutrition and their contribution to sarcopenia. Solid arrows reflect negative contributors to malnutrition whereas dashed lined represents intervention and preventative strategies. Inflammatory bowel disease (IBD), multidisciplinary team (MDT).

Figure 2

The possible impact of inflammatory bowel disease (IBD) on molecular pathways of muscle protein synthesis and muscle protein breakdown. Red arrows/lines demonstrate negative changes that occur in IBD. The green numbered squares demonstrate possible sites of intervention such that (1) protein supplementation, (2) anti-tumour necrosis factor alpha (TNFα) agents (3) omega 3 polyunsaturated fatty acids (n-3 PUFAs), (4) exercise programmes and (5) surgical intervention. Insulin growth factor-1 (IGF-1), peroxisome proliferator-activated receptor gamma (PPAR-γ), phosphoinositide 3-kinase (PI3K), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), protein kinase B (Akt), mammalian target of rapamycin complex 1 (mTORC1), muscle atrophy box (MAFbx) and muscle ring finger-1 (MuRF-1).