Introduction
Inflammatory bowel disease (IBD) is a chronic inflammatory condition
involving the gut primarily, encompasses two major groups of idiopathic
disorders:
Crohn’s disease (CD) and
ulcerative
colitis (UC) 1 .
Extraintestinal manifestations are also frequently observed and involve
the joints, eyes, hepatobiliary tract as well as skin2 . CD is characterized by transmural
inflammation of the intestine. Studies have shown that approximately
50% of the CD patients have ileocolitis and the incidence is 3.1–20.2
per 100 000. Furthermore, UC is more prevalent than CD with incidence of
9-20 per 100 000 3 . It starts in the rectum and
usually extends proximally through part or the entire colon in a
continuous manner4 . Currently,
there is a general agreement that IBD is a result of an interaction of
genetic, gut microbiota, intestinal mucosal immune response factors and
surrounding environment 5 , and causes
suffering, mortality and economic loss every year6 .
Immunopathogenesis of IBD induces an inflammatory response involving
both the innate immune cells and the adaptive immune cells7 . In particular, T-helper 1 and T-helper 2
responses are thought to drive the pathogenesis of CD and UC,
respectively 8 .
Furthermore, adipose tissues can secrete adipokines that play major
roles in metabolism, immunity, and inflammation. Meanwhile, resistin is
one of the adipokine, mainly produced by macrophages and detectable in
human serum. It is a cysteine-rich peptide with different biological
effects and initially proposed to regulate obesity, glucose metabolism
and insulin sensitivity 9 . Some researchers
reported that human resistin may also play a major role in regulating
inflammation 10 . Resistin expression has been
identified in the non-adipocyte stromal vascular parts of white adipose
tissue 11 ,
moreover, IBD is typically characterized by malnutrition, body
composition changes and mesenteric white adipose tissue hypertrophy12 . And previous
studies have investigated the serum levels of resistin in IBD patients
and healthy controls13-22 . However,
the results are inconsistent. In light of these inconsistent findings,
we made a meta-analysis of published studies that studied serum levels
of resistin in patients with CD and UC compared with healthy controls.