Endocrine Abstracts

Background and aim: Hyperglycemia is an important pathogenetic factor, which causes abnormalities at the cardiac myocyte level, leading to structural and functional abnormalities and diabetic cardiomyopathy (DCM). It has been proposed that DCM could also occur as a consequence of other metabolic alterations. Adiponectin concentration is negatively associated with obesity, insulin resistance (IR), oxidative stress and endothelial dysfunction. It can be considered as a predictive biomarker of IR and cardiovascular risk. Treatment of diabetic patients with conventional sulfonylurea such as glibenclamide has been reported to be associated with adverse cardiovascular effects and a higher incidence of cardiovascular death. The aim of this study was to assess the effect of glibenclamide on adiponectine level and its impact on left ventricular function in type 2 diabetic patients.

Methods: This single-blind, prospective, randomized controlled study consists of 32 weeks screening period and a 24-weeks treatment period with glibenclamide. From the 167 patients screened, most of whom were treated for hypertension or with metformin, 40 type 2 diabetic patients, were divided in two groups (glimepiride vs glibenclamide) with a body mass index (BMI) >25 treated with glibenclamide for more than 3 months before screening were included in the study. Anthropometric, biochemical and echocardiographic measurements were performed before and at the end of treatment.

Results: In the glibenclamide group significant differences were observed in HbA1C which was decreased from 8.8%±1.4 to 8.3%±1.1% (P<0.001), and in the other hand adiponectin was significanty decreased (from 34.3±22.6 to 20.3±11.3 ng/ml, P=0.011). From echocardiographic measurements early diastolic (e’) and systolic (s’) myocardial wall velocity of the septum (from 6.7±1.4 cm/s to 5.6±1.5 cm/s, P=0.04, and from 7.0±1.2 cm/s to 6.1±1.2 cm/s, P=0.03, respectively); as well as right e’ and s’ (from 11.7±2.7 cm/s to 7.9±3.8 cm/s, P=0.01, and from 12.5±4.3 cm/s to 8.4±3.2 cm/s, P=0.01, respectively) were decreased from baseline to the 24 weeks treatment. While DcT time was significantly increased in the group of Glibenclamide, which can explain worsening of diastolic dysfunction in diabetic patients treated with this drug.

Conclusions: The decreased adiponectine level after the treatment with glibenclamide is strongly associated with deterioration LV diastolic and systolic function, in type 2 diabetic patients. This finding highlights the need of further investigations of the impact of metabolic disorders on cardiac function in diabetic patients, beyond hyperglicemia.