RESUMEN
OBJECTIVE: To explore the effects of thyroid hormone on islet ß cell function among type 2 diabetics with normal thyroid function. METHODS: A total of 266 type 2 diabetics with normal thyroid function were recruited. Their clinical, biochemical parameters and thyroid related hormones were measured. And acute insulin response (AIR) was examined by arginine stimulating test. RESULTS: The serum levels of triiodothyronine (T3) ((1.49 ± 0.03), (1.59 ± 0.03), (1.70 ± 0.04) µmol/L) and free triiodothyronine (FT3) ((4.01 ± 0.08), (4.37 ± 0.09), (4.44 ± 0.07) pmol/L) were significantly different among tertile groups of AIR (both P < 0.01) while those of thyroxine (T4), free thyroxine (FT4) and thyroid stimulating hormone (TSH) showed no significant differences among tertile groups of AIR (all P > 0.05). A significant positive correlation existed between lnAIR and T3, FT3 (r = 0.303, 0.302, both P < 0.01). T4 and FT4 were not correlated with lnAIR (both P>0.05). AIR was significantly different among tertile groups of T3 ((2.38 ± 0. 12), (2.64 ± 0.12) and (3.03 ± 0.10) mU/L) and FT3 ((2.34 ± 0.11), (2.69 ± 0.13), (2.99 ± 0.10) mU/L, P < 0.01). AIR were not significantly different among tertile groups of T4, FT4 and TSH (all P > 0.05). Multivariate linear regression demonstrated that T3 and FT3 level were independently associated with AIR (ß = 0.686, 95% CI 0.289-0.884, P = 0.001, ß = 0.296, 95% CI 0.125-0.467, P = 0.01). CONCLUSIONS: Significant positive associations exist between serum T3, FT3 and AIR in type 2 diabetics with normal thyroid function. Serum T3 and FT3 may be the independent risk factors of predicting islet beta cell function in type 2 diabetics with normal thyroid function. However, it remains to be determined whether or not normal physiological concentrations of T3 and FT3 are protective factors for islet ß cell functions among type 2 diabetics.
Asunto(s)
Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/fisiopatología , Islotes Pancreáticos/metabolismo , Tiroxina/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Pruebas de Función de la Tiroides , Tirotropina/sangre , Triyodotironina/sangreRESUMEN
OBJECTIVE: The aim of this study was to investigate the efficiency and safety of ibutilide for cardioversion of persistent atrial fibrillation (AF) during radiofrequency ablation. METHODS: Eighteen patients (16 males) with persistent atrial fibrillation were enrolled in this study. All patients underwent circumferential pulmonary vein ablation guided by a Carto three-dimensional mapping system. In addition, linear ablation at the top of the left atrium and the isthmus of mitral valves and complex fractionated atrial electrogram (CAFE) ablation were performed. All patients were still in either atrial fibrillation or atrial flutter after ablation, the patients were treated with 1 mg intravenous ibutilide injection within 10 minutes after unsuccessful ablation. Intravenous injection was stopped in case of sinus rhythm (SR) restoration or occurrence of severe adverse reactions such as ventricular tachycardia. Cardioversion rate within 30 min and adverse reactions within 4 h were observed. Patients were divided into either conversion group or non-conversion group according to whether AF was converted to sinus rhythm within 30 minutes after injection. RESULTS: Eleven patients (61.11%) converted to SR after ibutilide injection. There were no significant differences in gender, age, body mass index, left atrium and left ventricular function between conversion group and non-conversion groups. The average conversion time was (13.80 ± 7.64) min, left atrium scar area ratio was significantly larger in non-conversion group (12.40 ± 11.03)% than in conversion group (5.12 ± 3.83)%, P < 0.05. Ibutilide significantly prolonged the average wavelength of the AF wave (171.8 ± 29.5) ms vs. (242.0 ± 40.0) ms at baseline, P < 0.01. The QT interval at 30 min after ibutilide injection (0.39 ± 0.21) s was significantly longer than before injection (0.51 ± 0.08) s, P < 0.05. There was no serious arrhythmias or other adverse reactions post ibutilide injection. CONCLUSIONS: Ibutilide is highly effective and safe agent for cardioversion in patients underwent unsuccessful ablation. Left atrium scar area ratio is an important determinant for the conversion rate in this cohort.