The relationship between nutritional indexes and disease activitiy in ankylosing spondylitis patients

İntroduction: Ankylosing spondylitis (AS) is a chronic inflammatory disease with spinal, sacroiliac joint and peripheral joint involvement and is classified among seronegative sponyloarthropathies. It can be an important cause of disability in the later stages of the disease and cause serious functional limitation. Therefore, identification and control of inflammation is important in the follow-up of the disease. The risk of malnutrition can be seen in AS patients due to comorbidities, ongoing chronic inflammation and multiple drug use. In this study, we aimed to determine the relationship between the nutritional status of AS patients, which we evaluated with Prognostic Nutritional Index (PNI), Nutritional Risk Index (NRI) and Controlling Nutritional Status Index (CONUT) with disease activity. Material and methods: 100 patients who were diagnosed with Ankylosing spondylitis according to the Modified New York and Assessment of Spondylo Arthritis International Society (ASAS) criteria and followed-up by the, Physical Medicine and Rehabilitation outclinic between December 2020 and June 2021 were included in this study. As the control group, 90 volunteer healty hospital personel were included. Gender, age, body mass index, smoking, educational status, and marital status of the patients and control groups included in the study were recorded. Disease duration, drug use, HLAB-27 positivity, history of uveitis, peripheral arthritis and enthesitis were also recorded in the patient group. Bath Ankylosing Sponylitis Disease Activity Index (BASDAI) and Ankylosing Sponylitis Disease Activity Score- CRP (ASDAS-CRP) scores were used to assess disease activity, Bath Ankylosing Spondylitis Functional Index (BASFI) was used for functional assessment, and Bath Ankylosing Spondylitis Metrology Index (BASMI) was used for spinal mobility assessment. In the nutritional evaluation of the patients PNI, NRI and CONUT scores obtained by calculating the relevant parameters from the hemogram and biochemistry results were used. Results: A total of 190 people, including 100 patients with Ankylosing spondylitis (42 female, 58 men) and 90 healty volunteers controls (47 female, 43 men) were included in the study. The mean age of the patients group was 44 (range:17-71); countrol group was found to be 48,5 (range:19-70). The groups were similar in terms of age, BMI, gender, smoking, maritial status and educational status. The PNI values were statistically significantly lower in AS patients compared to the control group (p=0.004). When we grouped AS patients as active or inactive by BASDI score (24 active, 76 inactive) however, no statistically significant difference was observed in terms of PNI (p=0.327). When we grouped AS patients as high-very high and low-intermediate according to the ASDAS-CRP score (60 high-very high, 40 low-moderate), no statistically significant difference was found in terms of PNI in among groups. The NRI values were found statistically significant different in AS patients than control group (p=0.049). When we grouped AS patients from active to inactive (24 active, 76 inactive) by BASDAI score, no statistically significant difference was observed in terms of NRI (p=0.876). When we grouped AS patients as high-very high and low-intermediate according to the ASDAS-CRP scores (60 high-very high, 40 low-intermediate), no statistically significant difference was found in terms of NRI values (p=0.332). The CONUT values were found to be lower in AS patients compared to the control group, but this difference was not statistically significant (p=0.058). When we grouped AS patients from active to inactive (24 active, 76 inactive) by BASDAI score, no statistically significant difference was observed in terms of CONUT (p=0.621). Conclusion: The lower level of nutritional indexes in AS patients compared to the healthy control group suggests that nutritional indexes may have a role in inflammation. Key words: Ankylosing spondylitis, BASDAI, ASDAS-CRP, PNI, NRI, CONUT