Abstract
To characterize the secondary failure of troglitazone, we retrospectively examined type 2 diabetic patients treated with troglitazone, whose HbA1c levels improved by≥1% within 6 months. Afterwards, HbA1c of 17 patients remained reliably controlled at≤0.5% fluctuation for 24 months (steady group) and that of 14 other patients increased by≥1%(deteriorated group). Fasting plasma insulin (IRI) and the homeostasis model assessment index (HOMA-R) declined significantly in troglitazone treatment of both groups but returned to pretreatment levels in the deteriorated group as glycemic control worsened. The deteriorated group had significantly lower pretreatment IRI and HOMA-R compared to the steady group. Multiple logistic regression analysis showed that significant predictors for deteriorating glycemic control were pretreatment HOMA-R and a body weight increase in the first 6 months. HOMA-R was a predictive factor in patients whose glycemic control deteriorated before 12 months and body weight increase was a factor in other patients with deterioration after 12 months. These results indicate that low insulin resistance may lead to early-onset secondary failure of troglitazone, while rapid body weight increase may lead to late-onset secondary failure.
