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

Abstract

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. The present study aimed to investigate the relationship between TyG index, disease activity and subclinical atherosclerosis (SCA) in RA patients. 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. 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. IR estimated by the TyG index is related to disease activity and SCA in RA patients.