Factors associated with low skeletal muscle mass and sarcopenia in patients with inflammatory bowel disease: a systematic review and meta-analysis

Patients with inflammatory bowel disease (IBD) are at increased risk of low skeletal muscle mass and sarcopenia owing to chronic inflammation, impaired nutrient absorption, and metabolic disturbances. Identifying associated factors may facilitate early recognition and targeted intervention, but current evidence remains inconclusive. This study systematically synthesized evidence on factors associated with these conditions in patients with IBD. PubMed, Web of Science, Embase, and the Cochrane Library were searched from inception to March 18, 2026. Two reviewers independently extracted data and assessed study quality using the Newcastle–Ottawa Scale (NOS). Pooled multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using Stata 17.0. Heterogeneity was assessed using Cochran’s Q test and the I 2 statistic, and evidence certainty was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Thirteen cohort studies involving 5,559 patients with IBD were included. Based on study-specific definitions, 632 participants met the criteria for low skeletal muscle mass or sarcopenia. All studies had NOS scores of ≥ 8, although limitations in outcome definitions and confounder adjustment remained. Studies assessing muscle quantity alone were analyzed separately from those using multidimensional diagnostic criteria for sarcopenia. Low body mass index (BMI; OR = 4.70, 95% CI 2.13–10.38, low-certainty evidence) and a history of gastrointestinal surgery (OR = 2.07, 95% CI 1.30–3.27, low-certainty evidence) were associated with sarcopenia. Biologic use (OR = 2.33, 95% CI 1.32–4.12, low-certainty evidence), perianal disease (OR = 1.85, 95% CI 1.09–3.14, low-certainty evidence), and steroid use (OR = 1.77, 95% CI 1.02–3.07, very low-certainty evidence) were associated with low skeletal muscle mass. Low BMI and a history of gastrointestinal surgery were associated with sarcopenia, whereas biologic use, perianal disease, and steroid use were associated with low skeletal muscle mass in patients with IBD. These findings may help identify patients who require closer monitoring of muscle health. Treatment-related associations should be interpreted cautiously because they may reflect disease severity, disease duration, or confounding by indication. Further prospective studies using standardized muscle mass assessments and multidimensional diagnostic criteria for sarcopenia are needed. The review protocol was registered in PROSPERO (CRD420261374547)