Echocardiographic parameters according to insulin dose in young patients affected by type 1 diabetes.

Insulin dose has been found to associate to several cardiometabolic risk factors in type 1 diabetes. Changes over time in body weight and composition may partly explain this association. However, no data are available on the relationship between insulin dose and echocardiographic parameters of both systolic and diastolic function in type 1 diabetes. Therefore, the aim of the present study was to examine systolic and diastolic echocardiographic parameters in relation to insulin dose in young patients with type 1 diabetes. The study was carried out on 93 consecutive outpatients with type 1 diabetes with a mean age of 32.8 ± 9.8 years. All patients were examined with a transthoracic echocardiography. Clinical and laboratory data were collected. The median value of daily insulin dose was used to categorized patients in two groups: high and low insulin dose group. Patients belonging to the high insulin dose group showed higher levels of cardiometabolic risk factors such as BMI, triglycerides and TG/HDL cholesterol ratio. Indexes of both systolic and diastolic function were similar in both groups except isovolumetric relaxation time (IVRT), that was significantly prolonged in patients of the high insulin group (94.4 ± 15.0 vs 86.7 ± 13.1 ms, p = 0.008). In the multivariate regression analysis, insulin dose was positively and significantly associated with IVRT. In this study we report an association between insulin dose and impaired active diastolic myocardial relaxation. Future studies are needed to further explore this observation.

Left ventricular chamber dilation and filling pressure may help to categorise patients with type 2 diabetes.

BACKGROUND: Type 2 diabetes may alter cardiac structure and function. Many patients with type 2 diabetes have diastolic dysfunction with preserved ejection fraction (EF). Recently, this latter measure was criticised. Thus, this research looked at the impact of left ventricular end-diastolic volume and E/e' ratio variations in patients with type 2 diabetes and preserved EF with the aim to recognise different clinical phenotypes. METHODS: In this cross-sectional study, we evaluated 176 men affected by type 2 diabetes with transthoracic echocardiography. All subjects have preserved EF (>50%). Patients were stratified into four groups based on the median value of both left ventricular end-diastolic volume and E/e' ratio, and the clinical variables were registered. The independent predictors associated with the groups were analysed by a multinomial logistic regression model. RESULTS: Diabetes duration, age, estimated glomerular filtration rate and antihypertensive treatments were significantly different among the groups as were EF, left atrial volume index (LAVI), E/A, septum thickness and s' mean wave. Multinomial regression analysis showed that the groups significantly differed for age, diabetes duration, EF, LAVI, septum thickness and s' mean wave. The main result of this study was that patients with higher left ventricular volume and higher E/e' ratio (group 2) showed the worse clinical profile. CONCLUSIONS: Our study might suggest that variations of left ventricular end-diastolic volume along with E/e' ratio variations, even in the normal range, may allow to recognise phenotypes of patients with type 2 diabetes with worse clinical characteristics. This finding should be tested in prospective studies to assess the predictive roles of these phenotypes.

Association between subclinical left ventricular systolic dysfunction and glycemic control in asymptomatic type 2 diabetic patients with preserved left ventricular function.

BACKGROUND: Type 2 diabetes is strongly associated with the occurrence of cardiovascular diseases, especially heart failure. Some studies have suggested that subclinical systolic dysfunction as assessed by tissue Doppler imaging (TDI) is already present in uncomplicated diabetic patients with normal left ventricular ejection fraction (LVEF). Considering the importance of this aspect, the aim of this cross-sectional study was to examine the relationship between glycated hemoglobin and mean s' wave velocity (a reliable measure of early LV systolic dysfunction) in a cohort of type 2 diabetic outpatients with preserved LVEF and without ischemic heart disease. METHODS: Forty-four male patients with newly diagnosed and 172 male patients with established type 2 diabetes were recruited for this cross-sectional study. All patients were evaluated with a transthoracic echocardiographic Doppler. The statistical analysis was conducted by a linear multivariate regression analysis, including several potential confounders. RESULTS: The mean values of mean s' wave velocity were lower in patients with a worse glycemic control and progressively decreased across the quartiles of glycated hemoglobin. The multivariate linear regression analysis showed that mean s' wave velocity was inversely and independently associated with glycated hemoglobin (standardized beta coefficient -0.178; p = 0.043) after adjustment for age, duration of diabetes, body mass index, pulse pressure, estimated glomerular filtration rate, microvascular complication status, and indexed cardiac mass. CONCLUSIONS: These results suggest that s' wave velocity, as evaluated by TDI echocardiography, was an early marker of systolic dysfunction in type 2 diabetic patients with preserved LVEF and without prior ischemic heart disease. Moreover, early systolic dysfunction was independently associated with poor glycemic control in these patients. Future studies are needed to elucidate the pathogenic role of chronic hyperglycemia in the development of early LV systolic dysfunction.