P536 Is there any association between fat body mass and bone mineral density in patients with Inflammatory Bowel Disease?
Ratajczak, A.E.(1)*;Michalak, M.(2);Szymczak-Tomczak, A.(1);Rychter, A.M.(1);Zawada, A.(1);Skoracka, K.(1);Dobrowolska, A.(1);Krela-Kaźmierczak, I.(1);
(1)Poznan University of Medical Sciences, Department of Gastroenterology- Dietetics and Internal Diseases, Poznan, Poland;(2)Poznan University of Medical Sciences, Department of Computer Science and Statistics, Poznan, Poland;
Background
Low bone mineral density (BMD) in inflammatory bowel disease (IBD) is multifactorial and includes nutritional status. The study aimed to look for the association between fat body mass and fat-free mass and BMD of the lumbar spine (L1-L4), femoral neck and total body.
Methods
The study subjects included 95 patients with Crohn’s disease (CD), 68 with ulcerative colitis (UC) and 40 healthy adults (control group - CG) in age of 18-50 years old, recruited at the Department of Gastroenterology, Dietetics and Internal Medicine, Poznan University of Medical Sciences between 2020-2021. The summary of the methods is presented in Figure 1..png)
DXA- Dual-energy X-ray absorptiometry
Results
A lowered fat mass percentage occurred in about 8% of CD, 13% of UC and 3% of CG. Additionally, an increased percentage of fat mass occurred above 50% of CD, 40% of UC and about 60% of CG. It is interesting because the median, lower and upper quartile for BMI (body mass index) was normal for CD [21.70 (19.20; 24.40] and UC [20.30 (18.45; 24.05)]. Fat body mass and fat mass percentage were significantly lower among UC compared with the CG and CD in women but not men. Additionally, healthy women presented higher fat-free mass than CD and UC women. We did not find the same differences for men. In CD women, but not men, with a high body fat percentage, we find a higher BMD and T-score of L1-L4-but than the standard body fat percentage. Fat body mass correlated positively with BMD and T-score of L1-L4 and total body in men with UC but not in men with CD and women with UC. However, we find a positive correlation between fat body mass and BMD and T-score of L1-L4, femoral neck and total body. Among CG, positive correlations occurred between the fat body mass and BMD of L1-L4, BMD of total body and T-score of total body, but only in men. Fat-free mass correlated positively with BMD and T-score of L1-L4 and total body and BMD, T-score and Z-score of the femoral neck in CD women but not UC women. In men, correlations occurred between the fat-free mass and BMD and T-score of L1-L4, femoral neck and total body in CD. Among UC, fat-free mass correlated with BMD, T-score, and Z-score of L1-L4, femoral neck and total body. We did not find a correlation in CG. CRP (C-reactive protein) correlated negatively with fat body mass only in men with CD and negatively in healthy women.
Conclusion
A higher fat mass percentage is common among IBD patients and healthy adults despite normal BMI. Probably, fat body mass and fat-free mass are predictors of nutritional status and the course of the disease, therefore correlated positively with BMD, T-score and Z-score. On the other hand, a high-fat mass percentage with a normal BMI indicates metabolic obesity with normal weight.