AB0618 RELATIONSHIP OF BODY MASS INDEX AND FAT COMPOSITION USING DUAL-ENERGY X-RAY ABSORPTIOMETRY (DEXA) WITH DISEASE ACTIVITY AND PATIENT REPORTED OUTCOMES IN PATIENTS WITH RHEUMATOID ARTHRITIS (2024)

Abstract

Background: In patients with rheumatoid arthritis (RA), obesity has been linked to poorer response to disease-modifying medications, increased disease activity, and decreased achievement of remission (1, 2). Weight loss has been associated with increased chances of remission (1). As of now, there are limited studies in the Indian population to explore the relationship between fat distribution, disease activity, and Patient Reported Outcomes (PROs).

Objectives: To study the relationship between body mass index (BMI) and whole-body dual-energy x-ray absorptiometry (DEXA) parameters including fat-mass, lean mass, fat mass index, lean mass index and fat mass percentage with disease activity (DAS28) and PROs [Indian Health Assessment Questionnaire for disability, PROMIS fatigue score, Pittsburgh Sleep Quality Index, Patient Health Questionnaire 9 for depression and Rheumatoid Arthritis Impact of Disease (RAID) score].

Methods: In this cross-sectional study we recruited patients with RA at our rheumatology clinic from March 2022 to September 2023, in Jodhpur, India. Demographic, clinical, anthropometric, and treatment details of the patients were collected after informed written consent. Whole body DEXA was done using a DEXA scanner (Hologic Corp, model no - Horizon A S/N 303237M) (Image 1), and PROs were measured using relevant tools. Bivariate correlation analysis of BMI, fat mass, lean mass, fat mass index, lean mass index, and fat mass percentage with DAS28CRP and PROs was done. Binary logistic regression was done to see if BMI and fat distribution indices could predict disease activity and PROs.

Results: Of the 144 patients enrolled in the study, the mean age was 46.41±13.23 years and 75.4% were females. Mean BMI was 23.7±5.0 kg/m², 16.44% were overweight, 23.97% were pre-obese and 13.01% were obese. Whole-body DEXA was done for 102 patients. The median fat mass, lean mass, fat mass index, lean mass index, and fat percentage in the study population were 22.83±11.10 kg, 33.04±10.70 kg, 9.60±4.90 kg/m², 13.90±3.20 kg/m² and 39.80±9.60 % respectively. There was no significant correlation between BMI and DAS28 or PROs. A significant positive correlation was obtained between whole body fat mass and DAS-CRP (r = 0.198, p = 0.046) (Table 1), whole body fat percent and depression (PHQ9 depression score) (r = 0.187, p = 0.046), whole body fat mass and RAID composite score (r = 0.204, p = 0.04) and negative correlation was noted between lean mass and PROMIS Fatigue T score (r = -0.212, p = 0.033). None of the DEXA indices evaluated could reliably predict DAS28 and PROs using binary logistic regression models.

Conclusion: Obesity is prevalent in RA patients (13.01%). While BMI was not related to disease activity, whole body fat mass correlated with disease activity and RAID composite score. Lean mass was inversely related to fatigue. Our study highlights the relationship of body fat composition with disease activity and patient-reported outcomes suggesting that interventions aimed at optimizing fat distribution might have a role in achieving treatment targets and better patient-reported outcomes in RA.

Acknowledgements: NIL.

Disclosure of Interests: None declared.