Incidence and risk factors of prolonged QTc interval in type 1 diabetes: the EURODIAB Prospective Complications Study.

OBJECTIVE: Corrected QT (QTc) prolongation is predictive of cardiovascular mortality in both the general and diabetic populations. As part of the EURODIAB Prospective Complication Study, we have assessed the 7-year incidence and risk factors of prolonged QTc in people with type 1 diabetes. RESEARCH DESIGN AND METHODS: A total of 1,415 type 1 diabetic subjects, who had normal QTc at baseline, were reanalyzed after the 7-year follow-up period. QTc >0.44 s was considered abnormally prolonged. RESULTS: Cumulative incidence of prolonged QTc was 18.7%, which is twofold higher in women than in men (24.5 vs. 13.9%, P < 0.0001). At the baseline examination, incident cases were older and less physically active than nonincident cases, had higher mean values of systolic blood pressure and HDL cholesterol, and had higher frequencies of hypertension, coronary heart disease, and distal symmetrical polyneuropathy. In multivariate logistic regression analyses, female sex and higher values of A1C and systolic blood pressure were associated with the risk of prolonged QTc, whereas physical activity and BMI within the range of 21.5-23.2 kg/m2 were protective factors. In women, association with modifiable factors, particularly BMI, was stronger than in men. CONCLUSIONS: In type 1 diabetic subjects from the EURODIAB cohort, female sex, A1C, and systolic blood pressure are predictive of prolonged QTc, whereas physical activity and BMI within the range of 21.5-23.2 kg/m2 play a protective role. These findings are clinically relevant, as they may help to identify subjects at higher risk for prolonged QTc, as well as provide potential targets for risk-lowering strategies.

Does carvedilol impair insulin sensitivity in heart failure patients without diabetes?

BACKGROUND: An increased risk for impaired glucose tolerance or diabetes was shown in patients on beta-blockers, whereas alpha1 blockers seem to have favorable effects on glycemic profile. In this study, the metabolic effect of carvedilol in nondiabetic patients with chronic heart failure (CHF) was evaluated. METHODS AND RESULTS: Twenty-eight nondiabetic CHF patients were enrolled. Before being started on carvedilol and on the highest tolerated dose, each patient underwent an oral glucose tolerance test and fasting insulin, glycohemoglobin, lipid concentrations were measured and insulin sensitivity indices (HOMA, ISI-gly, and ISI-composite) were calculated. An impaired glucose tolerance was found (2-hour glycemia 144 +/- 42 mg/dL), with a fasting glycemia at upper limits of normal (108 +/- 13 mg/dL) and no significant differences between basal and carvedilol treatment measurements. Fasting insulinemia significantly decreased during carvedilol treatment (13.6 +/- 7.3 versus 9.8 +/- 5.1 muU/mL; P = .022), with a reduction of the HOMA index (3.75 +/- 1.95 versus 2.73 +/- 1.47; P = 034) and an increase of the ISI-gly index (0.85 +/- 0.22 versus 1.03 +/- 0.31; P = .025). The lipoprotein profile did not significantly change. CONCLUSION: Carvedilol might have some positive metabolic effects on increasing insulin sensitivity that would make it suitable for diabetic patients that have a worse prognosis than non diabetic patients with CHF.

Autonomic neuropathy and QT interval in hemodialysed patients.

BACKGROUND: QT interval prolongation increases the risk of ventricular arrhythmias and sudden death in diabetic autonomic neuropathy and ischemic heart disease. In end-stage renal disease (ESRD), the effects of hemodialysis on QT interval are diverse and the influence of autonomic neuropathy has yet to be clearly defined. METHODS: Sixty-nine ERSD patients (age 64 +/- 14) were studied. Prior to the dialysis session, patients underwent four standard autonomic cardiovascular tests; before and after the dialysis session, a 12-lead ECG was recorded. Corrected QT intervals (QTc) were measured and QT dispersion (QTd) was calculated. Twelve subjects (age 59 +/- 6) with normal renal function served as control group. RESULTS: Compared to controls, ESRD patients showed a longer QTc (434 +/- 26 vs 414 +/- 28 ms; p = 0.016) and a similar QTd (35 +/- 13 vs 37 +/- 14 ms; p = 0.54).QTc was > 440 ms in 33.3% of the patients. No difference in the prevalence or score of autonomic neuropathy was observed between the subgroups with and without a prolonged QTc. After the hemodialysis session, QTc increased in 56% and decreased in 43% of the patients, and QTd increased in 45 % and decreased in 55% of the patients. QTc and QTd changes were not related to the presence of autonomic neuropathy. CONCLUSIONS: A large variability in QTc and QTd response was observed after hemodialysis. Autonomic neuropathy did not contribute to QTc and QTd length, nor to QTc and QTd change after dialysis.

Fine-needle aspiration biopsy of the thyroid: comparison between thyroid palpation and ultrasonography.

OBJECTIVE: To describe our experience with fine-needle aspiration biopsy (FNAB) of the thyroid and compare our results with direct palpation versus ultrasound scanning (USS) in an area of endemic goiter in Italy. METHODS: We considered all patients submitted to ultrasound-guided FNAB of thyroid nodules during a 10-month period at our outpatient clinic and analyzed the following: (1) clinical data (number of nodules and identification of the nodule for FNAB); (2) USS data (number of nodules and identification of the nodule for FNAB on the basis of hypoechoic pattern + blurred perinodal halo + microcalcifications or intranodal color Doppler signal indicative of blood flow); (3) cytologic specimens, categorized as suspicious, malignant, negative, or nondiagnostic; and (4) histologic final report of the cytologically positive nodules. RESULTS: The study group consisted of 348 female and 72 male patients who underwent FNAB of the thyroid at our institution. Among the 140 patients with no palpable thyroid nodules, USS showed that 106 had a single nodule and 34 had multinodular goiters. Among the 182 patients with a single palpable thyroid nodule, USS revealed that 138 had a single nodule, 42 had a multinodular goiter, and 2 had lobe enlargement without detectable nodules. All 98 patients with multinodular palpable goiter had a similar pattern on USS. Of the 420 cytologic specimens, 46(11.0%) were positive for thyroid cancer, 313 (74.5%)were negative, and 61 (14.5%) were nondiagnostic. Histologic malignant growth was confirmed in 27 cytologically positive nodules. Of these histologically malignant nodules, 12 (45%) were nonpalpable, 9 (33%) were single palpable nodules, and 6 (22%) were from a nodule with a suspicious ultrasound pattern within a multinodular goiter. CONCLUSION: Manually guided FNAB is not feasible in nonpalpable nodules and not accurate in a multinodular goiter. Both situations are clinical challenges, and USS should be performed for accurate FNAB under these circumstances. Because 52% of histologically malignant nodules in our study were found only with the aid of ultrasound-guided FNAB, this procedure should be used where multinodular goiter is endemic. Our overall rate of nondiagnostic specimens was comparable to that reported in the literature.

Prevalence of Q-T interval dispersion in type 1 diabetes and its relation with cardiac ischemia : the EURODIAB IDDM Complications Study Group.

OBJECTIVE: The interlead variation in duration of the Q-T interval on the surface electrocardiogram (Q-T interval dispersion [QTd]) has been shown to predict mortality in type 2 diabetic patients. We evaluated the prevalence of QTd prolongation in the EURODIAB population and its relation to corrected Q-T interval (QTc), sex, age, duration of diabetes, blood glucose control, and complications. RESEARCH DESIGN AND METHODS; A total of 3,042 type 1 diabetic patients were studied. QTc was calculated according to the Bazett's formula; QTc > 0.44 s was considered abnormally prolonged. QTd was calculated using the difference between the maximum and the minimum QTc in any thoracic lead. QTd >0.080 s was considered abnormally prolonged. RESULTS: The prevalence of an increased QTd was 7%. A significant relation was observed between QTd prolongation and diastolic blood pressure (P < 0.05). A higher prevalence of QTd prolongation was observed in patients with ischemic heart disease (P = 0.004), whereas no relationship was observed with retinopathy, albumin excretion rate, or measures of somatic and autonomic neuropathy. QTc and QTd were significantly related (P = 0.001); however, a proportion of patients with normal QTd showed a prolonged QTc (>0.44 s). CONCLUSIONS: In patients with type 1 diabetes, QTd is associated with ischemic heart disease and diastolic blood pressure but not neuropathy. Although QTd is statistically related to duration of QTc, increased QTd and increased QTc identify different patients, and their predictive value deserves prospective evaluation.