Prospective Assessment of Glucocorticoid Toxicity in Rheumatology Practice: A Focus on the Glucocorticoid Toxicity Index

The glucocorticoid toxicity index (GTI) is developed to measure glucocorticoid (GC)-related morbidity over time. This study aimed to assess GC-toxicity in patients at a rheumatology outpatient clinic by using the GTI and to identify the factors that interfere with the GTI. This prospective study included patients with inflammatory arthritis (IA), connective tissue disease, and vasculitis who were newly prescribed GC-treatment (GC-naive) or have been still on GC-treatment for ≤2 years (GC-experienced). Patient demographics and disease characteristics, aggregate improvement score (GTI-AIS), cumulative worsening score (GTI-CWS), and cumulative GC-doses were recorded at baseline, 3rd month, and 6th month. Generalized estimating equations (GEE) were used to evaluate the GTI scores and associated factors including cumulative GC-doses. The study included 156 (48.7% GC-naive) patients with a mean age of 49.1 ± 17.1 years. More than half of the patients in both groups had a diagnosis of vasculitis. A higher cumulative GC-dose was found to be associated with higher GTI-scores in both groups (p< 0.001). In the GC-naive group, patients with vasculitis showed higher GTI-scores than IA patients (p< 0.001); there was also a significant increase in the GTI-CWS at the 6th month compared with the 3rd month. In the GC-experienced group, GTI-AIS and GTI-CWS were significantly different at 3rd and 6th month (p< 0.05). It was shown that GTI scores were associated with cumulative GC-doses and vasculitis patients in the GC-naive patients had higher GTI scores than inflammatory arthritis. The GTI allows individualized assessment and management of adverse effects experienced by patients as a result of GC treatment.