Abstract Background Body Mass Index (BMI) is regularly used in clinical practice to determine “health” of patients. However, BMI only factors total mass and height and does not account for muscle mass, prosthetics, or pregnancy. Additionally, BMI is extremely limiting in its accuracy as women and minorities were not accurately represented when BMI was established. In conditions such as Inflammatory Bowel Disease (IBD), it is expected that those with very high or very low BMIs will have a higher chance of more severe disease activity, more hospitalisations, and more of a need for rescue therapy through steroids or surgery. This study aims to observe correlations between body composition in healthy controls and IBD patients measured through air displacement plethysmography (ADP) in the BOD POD and the benefits and advantages over traditional measurements, like BMI, in regular clinical use. Methods Patients were recruited from a tertiary referral centre IBD Clinic. Healthy Controls (HCs) were recruited on a voluntary basis with no inflammatory conditions. All participants had their body composition measured in the BOD POD. Results 47.1% (n = 8/17) of HCs, 55.0% (n = 11/20) Active Disease Patients, and 50.0% (n = 10/20) of Inactive Disease Patients had a BMI 25. Body Fat Percentage (BF%) varied significantly from BMI scores in which only 25% (n = 2/8) of HCs and 50% (n = 5/10) of Inactive Disease Patients with a BMI 25 had an above average BF%. Active Disease Patients displayed less discrepancy in which 73% (n = 8/11) of those with BMI 25 had an above average BF%. The higher percentage of above average BF% in the Active Cohort could be explained by the disease activity, steroid treatments, and/or initial medication effects as the Inactive cohort has a much lower percent of above average BF% and is closer to that of the HCs. 52% (n = 15/29) of all participants with BMI 25 had their body composition mis-represented when BMI only was used. Conclusion BMI does not accurately reflect body composition in IBD patients, nor in Healthy Controls. A more accurate representation is shown in BF% and would be more reflective of a person’s actual health. Those with IBD tend to be more likely to have an above average BF% but are less likely when they are in disease remission. References: 1. M. E. Valencia and R. C. Villegas-Valle (2012). Body Fat Measurement by Air Displacement Plethysmography: Theory, Practice, Procedures, and Applications. Handbook of Anthropometry. New York, United States of America, Springer: 397–413. 2. S. He, et al. (2023). “Association between body fat composition and disease duration, clinical activity, and intravenous corticosteroid-induced response in inflammatory bowel disease.” Lipids in Health and Disease 22. 3. R. Pray and S. Riskin (2023). “The History and Faults of the Body Mass Index and Where to Look Next: A Literature Review.” Cureus 15(11): e48230. 4. COSMED. “BOD POD GS-X.” Retrieved September, 2024, from https://www.cosmed.com/en/products/body-composition/bod-pod-gs-x. Conflict of interest: Girod, Parker: No conflict of interest Coe, Carolann: No conflict of interest Fennessy, Anne: No conflict of interest Hickey, Yvonne: No conflict of interest Sheridan, Juliette: No conflict of interest Cullen, Garret: No conflict of interest Mulcahy, Hugh: No conflict of interest Taylor, Cormac: No conflict of interest Doherty, Glen: Research or Education Grants (last 36 months): Abbvie, Pfizer, Janssen, Takeda, Tillotts, Celltrion, Abbott, Dr Falk, Amgen Speaker/Meeting Honoraria (Last 36 months): Abbvie, Dr Falk, Galapagos/Alfa Sigma, GSK
Girod et al. (Thu,) studied this question.