INS and rheumatoid arthritis: Thereafter, a study published by the same group showed that nondiabetic patients with RA exhibited a significant increase in the insulin sensitivity index (calculated through the equation proposed by Matsuda, which provides a reliable estimation of the whole-body insulin sensitivity), along with a significant, although modest, reduction in HbA1c values (−0.2%) and glucose and insulin area under the curves during the oral glucose tolerance test at 6 months after abatacept initiation [198].