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

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.

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% 51.6%, p = 0.028), higher Larsen score (3.8 ± 1.3 2.8 ± 1.2, < 0.001), higher anti-cyclic citrullinated peptide (anti-CCP) levels (median (IQR): 243.1 (205.0-408.0) U/ml 99.0 (78.0-332.5), < 0.001), higher TyG index (4.8 ± 0.22 4.67 ± 0.24, = 0.006), and higher CIMT (0.87 ± 0.22 0.77 ± 0.17 mm, = 0.018). Patients with SCA had higher BMI (34.6 ± 6.2 30.5 ± 5.3 Kg/m, < 0.001), higher Larsen score (3.7 ± 1.4 3.1 ± 1.3, = 0.028) and higher TyG index (4.89 ± 0.23 4.64 ± 0.19, < 0.001). Binary logistic regression analysis identified patients' age (OR (95% CI): 0.94 (0.89-0.99), = 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), = 0.032), and TyG index (OR (95% CI): 22.67 (2.14-240.4), = 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.