Use of temporal muscle thickness measured by ultrasonography in the assessment of nutritional status in patients with inflammatory bowel disease

Introduction and Aim: Malnutrition is common during the course of inflammatory bowel disease (IBD). Malnutrition can cause local and systemic complications, decrease in quality of life, increase in psychological comorbidities and mortality risk in IBD. For all these reasons, IBD patients who are at high risk for malnutrition should be monitored for the development of malnutrition during their follow-up, regardless of disease activation. Anthropometric measurements, biochemical evaluations, body composition analyzes and malnutrition assessment scales are used in the evaluation of malnutrition in IBD patients. None of these are specific to IBD, nor are they sufficient for early diagnosis of malnutrition. There are recent studies that show that a decrease in temporal muscle mass measurement may be a strong predictor of malnutrition and mortality. In our study, we used temporal muscle thickness (TMT) measured by ultrasonography as a new parameter in the evaluation of nutritional status and detection of malnutrition in patients followed up with the diagnosis of IBD. We aimed to confirm the validity and reliability of TMT alone to determine nutritional status and to investigate whether it is significantly associated with nutritional status. Materials and Methods: Within the scope of the study, 184 people, 92 of whom were diagnosed with IBD, 62 patients with Ulcerative Colitis, 30 patients with Crohn's Disease, and 92 healthy controls, were included in the study. Our research is a single-center, cross- sectional study. Demographic data (gender, age, place of residence, smoking habits, chronic diseases) and laboratory parameters (white blood cell, hemoglobin, neutrophil, lymphocyte, platelet, total protein, albumin, erythrocyte sedimentation rate, C-reactive protein, iron, iron binding capacity, ferritin, vitamin B12, folate and vitamin D) of the patients were obtained retrospectively by examining the files of the patients from the routine outpatient examinations and examinations performed during the hospitalization. No extra routine tests were requested. Anthropometric measurements (body weight, body mass index, triceps skinfold thickness, temporal muscle thickness) were calculated. Femoral and vertebral bone densitometry (DEXA) measurements were performed once in all patients. The malnutrition risk of the patients was evaluated using the MUST (Malnutrition Universal Screening Tool) score. Malnutrition risk classification was made according to MUST scoring and compared with patients' anthropometric measurements and TMT values. Results: Within the scope of the study, a total of 184 individuals, including 62 UC (median age: 50 years) diagnosed, 30 CD (median age: 36.5 years) diagnosed and 62 healthy controls (median age: 47.5 years), were examined. In our study, malnutrition risk groups were determined by using the MUST scoring system in IBD patients. While the malnutrition risk was low in 41 (66.1%) of 62 patients with UC, it was found to be moderate in 9 (14.1%) and high in 12 (19.4%). Malnutrition risk was low in 14 (46.7%) of 30 patients with CD, moderate in 3 (10.0%) and high in 13 (43.3%). Low and medium malnutrition risk groups were combined and compared with high risk groups. Accordingly, 19.4% (n=12) of patients with UC had a high risk of malnutrition, while 43.3% (n=13) of patients with CD had a high risk of malnutrition. A statistically significant difference was found between patients with UC and CD in terms of malnutrition risk (p=0.015). A statistically significant difference was found between the low-intermediate malnutrition risk group and the high malnutrition risk group in terms of body mass index (BMI) for both UC and CD (respectively; p=0.004, p=0.001). In our study, the presence of one or more of the symptoms of IBD (nausea-vomiting, abdominal pain, diarrhea, bloody stools, weight loss) was found to be associated with a high risk of malnutrition in both diseases (for UC and CD, respectively; p=0.013; p=0.003). In our study, in which we determined disease activation using Partial Mayo Scoring Index for UC and CDAI (Chron's Disease Activity Index) activation score for CD, a statistically significant difference was found between disease activation and malnutrition risk for both disease groups (for UC and CD, respectively; p<0.001; p<0.001). When we examined the laboratory parameters in malnutrition risk groups, lower hemoglobin and xvii serum iron levels, higher ESR and CRP were found in the group with UC and high malnutrition risk, and these results were statistically significant (respectively; p=0.015; p<0.001; p=0.001; p=0.001). A statistically significant difference was found between white blood cell, neutrophil, lymphocyte, NLR, ESR, CRP, total protein and albumin levels in the group with high malnutrition risk for those with Crohn's Disease (respectively; p=0.025; p=0.003; p=0.012; p<0.001; p=0.048; p=0.003; p=0.008; p=0.001). Although right and left TMT were measured lower in groups with high malnutrition risk in both UC and CD, no statistically significant difference was found between risk groups. This result shows that although the TMT value measured by ultrasonography in IBD does not correlate with the currently used malnutrition score, it is statistically significantly decreased compared to the control group, but it is not diagnostic in predicting patients with high malnutrition risk. Conclusion: It has been shown that the temporal muscle thickness value measured by ultrasonography is not a predictor of malnutrition in inflammatory bowel disease. Keywords: Crohn's disease, inflammatory bowel disease, malnutrition, temporal muscle thickness, ulcerative colitis