Relationship between Triglyceride-Glucose Index and Disease Activity and Subclinical Atherosclerosis in Rheumatoid Arthritis

Abstract

Background: In rheumatoid arthritis (RA), insulin resistance (IR) is related to inflammatory markers, disease activity, and progression of atherosclerotic changes. Triglyceride-glucose (TyG) index is a relatively new indicator of IR. Aims: The present study aimed to investigate the relationship between TyG index, disease activity and subclinical atherosclerosis (SCA) in RA patients. Objective: The present study aimed to investigate the relation between TyG index, disease activity and subclinical atherosclerosis (SCA) in RA patients. Methods: The present case-control study included 100 RA patients and 50 age- and sex-matched healthy controls. All participants were subjected to careful history taking through clinical examination and standard laboratory assessment. The TyG index was calculated as TyG index = ln (Fasting triglyceride (mg/dL) × fasting glucose (mg/dL))/2. Carotid intima-media thickness (CIMT) measurement was done using B-mode ultrasound. Results: Patients had significantly higher TyG index as compared to controls. Patients with high disease activity had significantly higher frequency of extraarticular manifestations (39.6% versus 51.6%, p = 0.028), higher Larsen score (3.8 ± 1.3 versus 2.8 ± 1.2, p < 0.001), higher anti-cyclic citrullinated peptide (anti-CCP) levels (median (IQR): 243.1 (205.0-408.0) U/ml versus 99.0 (78.0-332.5), p < 0.001), higher TyG index (4.8 ± 0.22 versus 4.67 ± 0.24, p = 0.006), and higher CIMT (0.87 ± 0.22 versus 0.77 ± 0.17 mm, p = 0.018). Patients with SCA had higher BMI (34.6 ± 6.2 versus 30.5 ± 5.3 Kg/m2, p < 0.001), higher Larsen score (3.7 ± 1.4 versus 3.1 ± 1.3, p = 0.028) and higher TyG index (4.89 ± 0.23 versus 4.64 ± 0.19, p < 0.001). Binary logistic regression analysis identified patients’ age (OR (95% CI): 0.94 (0.89-0.99), p = 0.018), Larsen score (OR (95% CI): 1.93 (1.32-2.82), p = <0.001), anti-CCP (OR (95%): 1.04 (1.02-1.07), p = 0.032), and TyG index (OR (95% CI): 22.67 (2.14-240.4), p = 0.01) as significant predictors of high disease activity in multivariate analysis. Conclusion: IR estimated by the TyG index is related to disease activity and SCA in RA patients.