P375. Sarcopaenia in inflammatory bowel disease (IBD), a prominent finding in males with normal BMI: What are we missing?
R. Bryant1, C. Schultz2, R. Grafton1, J. Hughes1, C. Goess1, M. Schoeman1, D. Bartholomeusz1, J. Andrews1, 1Royal Adelaide Hospital, Department of Gastroenterology and Hepatology, Adelaide, Australia, 2Royal Adelaide Hospital, Department of Nuclear Medicine, Adelaide, Australia
Body composition is poorly studied amongst adult IBD patients, yet may be an important determinant in quality of life. Lean tissue deficits are associated with poor muscle performance and morbidity. Sarcopaenia refers to decreased muscle mass and performance. Recognition of sarcopaenia may be limited with standard clinical assessment. We therefore assessed body composition in an adult IBD cohort to assess the potential prevalence of this problem.
Cross-sectional data were prospectively gathered on consecutive 18–50 year old premenopausal IBD patients. Whole body composition analysis, height and weight were assessed at the time of dual energy X-ray absorptiometry (DXA) (GE – Lunar Prodigy). These data were then used to calculate: body mass index (BMI, weight/height2, kg/m2), fat mass index (FMI, fat mass/height2, kg/m2), appendicular skeletal muscle index (ASMI, appendicular lean mass/height2, kg/m2) and lean mass index (LMI, lean mass/height2, kg/m2). National Health and Nutrition Examination Survey DXA population reference values were used for FMI, LMI and ASMI , and established normative data for grip strength comparisons . Z scores were calculated using standard deviation (SD) values from age specific normative data. Sarcopaenia was defined as 1SD deviation below the normal range for both ASMI and grip strength. Single sample, 2-tailed t tests were used.
71 IBD patients, 41 (58%) males, 54 (76%) Crohn's Disease, 15 (21%) ulcerative colitis, and 2 (3%) IBD unspecified, mean age of 34.3, median 32.8 (range 19–50) years had an overall mean BMI of 27.1 (median 25.3), males 26.5 (median 25), females 28 (median 24.4). FMI amongst the cohort was normal. LMI was found to be low amongst both males and females (p < 0.001 both). However, only males were found to have reduced ASMI (p < 0.001, females p = 0.08) and grip strength (p < 0.001, females p = 0.4). Sarcopaenia by our combined anatomical/functional definition was evident in 12 (29.3%) males and 2 (6%) females (Figure 1).
Despite normal BMI, both males and females with IBD were found to have low muscle mass. Males are particularly affected, with loss of appendicular muscle and decreased grip strength constituting sarcopaenia in nearly one third. The causes and consequences of this striking finding warrant further evaluation.
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2. Mathiowetz V, Kashman N, Volland G, Weber K, Dowe M, Rogers S., (1985), Grip and pinch strength: normative data for adults, Archives of Physical Medicine and Rehabilitation, 69–72, 66(2), 2012–09–12.