Disease Activity Score in 28 Joints Using GGT Permits a Dual Evaluation of Joint Activity and Cardiovascular Risk.

Objective: To identify the factors potentially associated with serum gamma-glutamyltransferase (GGT) elevation in patients with rheumatoid arthritis (RA).

Methods: This is a cross-sectional monocentric study including RA patients over a 12-month period. Data on liver function, RA disease activity, and hepatotoxic and cardiovascular (CV) risk factors were systematically collected. To provide a simple tool to evaluate both joint disease activity and CV risk factors, we constructed the Disease Activity Score in 28 joints (DAS28)-GGT composite index by replacing erythrocyte sedimentation rate (ESR) with GGT.

Results: Among the 129 included patients, 32 (25%) had isolated GGT increase. GGT correlated with age, C-reactive protein (CRP) levels, and body weight and were significantly increased in patients with alcohol intake, type 2 diabetes mellitus, hypertension, dyslipidemia, and metabolic syndrome. GGT levels also gradually increased with the number of CV risk factors and correlated with the Framingham CV risk score. The composite index DAS28-GGT remained a reliable marker of RA disease activity and accurately detected patients with CV risk factors. Conversely to the DAS28 and the DAS28-CRP, the DAS28-GGT steadily increased according to the number of CV risk factors and had an increased diagnostic value compared to the DAS28 and DAS28-CRP for the presence of at least 2 CV risk factors and a Framingham CV risk score greater than 10%.

Conclusion: GGT may be considered as a marker of systemic inflammation and CV risk in patients with RA. Based on these findings, we herein propose an original index, the DAS28-GGT, which is able to evaluate both joint disease activity and CV risk. This index will deserve further validation in prospective cohorts.