Relationship between increased left atrial volume and microvascular complications in patients with type 2 diabetes

Association between Severity of Diabetic Retinopathy and Cardiac Function in Patients with Type 2 Diabetes

Background

The purpose of this research was to assess the relationship between the severity of diabetic retinopathy (DR) and indexes of left ventricle (LV) structure and function in type 2 diabetes mellitus (T2DM).

Methods

Retrospective analysis of 790 patients with T2DM and preserved LV ejection fraction. Retinopathy stages were classified as no DR, early nonproliferative DR, moderate to severe nonproliferative DR, or proliferative DR. The electrocardiogram was used to assess myocardial conduction function. Echocardiography was used to evaluate myocardial structure and function.

Results

Patients were divided into three groups based on the DR status: no DR group (NDR, n = 475), nonproliferative DR group (NPDR, n = 247), and proliferative DR group (PDR, n = 68). LV interventricular septal thickness (IVST) increased significantly with more severe retinopathy (NDR: 10.00 ± 1.09; NPDR: 10.42 ± 1.21; and PDR: 10.66 ± 1.58; P < 0.001). Multivariate logistic regression analysis showed that the significant correlation of IVST persisted between subjects with no retinopathy and proliferative DR (odds ratio = 1.35, P = 0.026). Indices of myocardial conduction function were assessed by electrocardiogram differences among groups of retinopathy (all P < 0.001). In multiple-adjusted linear regression analyses, the increasing degree of retinopathy was closely correlated with heart rate (β = 1.593, P = 0.027), PR interval (β = 4.666, P = 0.001), and QTc interval (β = 8.807, P = 0.005).

Conclusion

The proliferative DR was independently associated with worse cardiac structure and function by echocardiography. Furthermore, the severity of retinopathy significantly correlated with abnormalities of the electrocardiogram in patients with T2DM.

Diabetic microvascular complications are associated with left atrial structural alterations in asymptomatic type 2 diabetes patients: A cross-sectional study

AIMS

We used 4D-Auto LAQ to quantitatively evaluate the morphological and functional changes of left atrium in patients with asymptomatic type 2 diabetes mellitus (T2DM), and explored its correlations with diabetic microvascular complications (MICRO).

METHODS

This study included 319 patients with asymptomatic T2DM. According to the occurrence of MICRO, these patients were divided into 3 groups: patients with no complication, 1 complication, and 2-3 complications. 4D-Auto LAQ was used to evaluate left atrial volume (LAVImin, LAVImax, LAVIpre) and calculate the left atrial function (DEI, PEI, AEI) in different phases. Multiple linear regression was used to analyze the correlation between changes in left atrial volume and function and the number of MICROs in DM patients.

RESULTS

A total of 279 patients with asymptomatic T2DM were included in this study. (1) The ultrasound data of the three T2DM groups showed that there was no significant difference in left ventricular size and function among the three groups; (2) with the increase of MICRO number, the left atrial volume (LAVImin, LAVImax, LAVIpre) progressively increased, the left atrial storage function index (DEI) gradually decreased, and the differences were significant (P < 0.05). (3) Multiple linear regression analysis showed that: with the increase of MICRO number (no complication→1 complication→2-3 complications), the left atrial volume (LAVImin, LAVIpre) showed an increasing trend (both P < 0.05).

CONCLUSION

In asymptomatic T2DM patients, MICRO number showed a significant positive correlation with LAVImin and LAVIpre (P < 0.05). Therefore, the increase in left atrial volume can dynamically reflect the severity of microvascular lesions in patients with asymptomatic T2DM.

Burden of Microvascular Disease and Risk of Atrial Fibrillation in Adults with Type 2 Diabetes

BACKGROUND

Epidemiological data on the associations of microvascular disease with atrial fibrillation are scarce. We evaluated the associations of diabetes-related microvascular disease in multiple vascular beds and its burden with incident atrial fibrillation among adults with type 2 diabetes.

METHODS

A total of 7603 participants with type 2 diabetes and without atrial fibrillation were assessed for diabetic kidney disease, retinopathy, or neuropathy at baseline in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study. Incident atrial fibrillation events were adjudicated using follow-up electrocardiograms. Modified Poisson regression was used to generate risk ratios (RRs) and 95% confidence intervals (CIs) for atrial fibrillation.

RESULTS

Of the 7603 participants (mean age 62.5 years, 38.0% women, 63.4% white), 63.3% (n = 4816) had microvascular disease-defined as the presence of ≥1 of: diabetic kidney disease, retinopathy, or neuropathy at baseline. Over a median of 7 years, there were 137 atrial fibrillation events (1.8%). Participants with microvascular disease had a 1.9-fold higher risk of incident atrial fibrillation compared with those without microvascular disease (RR 1.88; 95% CI, 1.20-2.95). Compared with no microvascular disease, the RRs for atrial fibrillation were 1.62 (95% CI, 1.01-2.61) and 2.47 (95% CI, 1.46-4.16) for those with 1 and ≥2 microvascular territories affected, respectively. The RRs for atrial fibrillation by type of microvascular disease were 1.57 (95% CI, 1.09-2.26), 0.95 (95% CI, 0.53-1.70), and 1.67 (95% CI, 1.15-2.44) for neuropathy, retinopathy, and diabetic kidney disease, respectively.

CONCLUSIONS

In a large cohort of adults with type 2 diabetes, the presence of microvascular disease and its burden were independently associated with higher risk of incident atrial fibrillation.

Longer diabetes duration reduces myocardial blood flow in remote myocardium assessed by dynamic myocardial CT perfusion

AIMS

To investigate the relationship of type 2 diabetes duration and myocardial blood flow (MBF) assessed by myocardial CT perfusion.

MATERIALS AND METHODS

We prospectively included 140 patients with type 2 diabetes who underwent dynamic myocardial CT perfusion exam. MBF of the remote myocardium was calculated using the deconvolution technique and the Voronoi method. The relationships of MBF and diabetic duration, diabetic complications, conventional risk factors, coronary calcium, and coronary stenosis were assessed by logistic regression analysis.

RESULTS

A weak but significantly negative relationship was present between diabetes duration and MBF (R² = 0.05, p < 0.01). The average MBF of patients with a duration of >8 years was 13% lower than that of the remaining patients (1.11 ± 0.35 vs 1.28 ± 0.27 ml min^-1 g^-1, p < 0.01). Duration of one year was associated with a 6% increased risk for low MBF (<1.18 ml min^-1 g^-1) (odds ratio 1.06, 95% confidence interval 1.01-1.12, p < 0.05). Calcium score was also a significant factor for low MBF (odds ratio 1.08 (per 100 Agatston units), 95% confidence interval 1.01-1.17, p < 0.05).

CONCLUSION

Longer diabetes duration is associated with lower MBF independent of conventional cardiac risk factors or the presence of coronary stenosis.

Left ventricular systolic dysfunction predicts long-term major microvascular complication outcomes in type 1 diabetes. The Pittsburgh Epidemiology of Diabetes Complications (EDC) study of childhood onset diabetes

OBJECTIVES

We aimed to assess association between abnormal LVEF, in the absence of coronary artery disease (CAD), and 25-year incidence of major outcomes of diabetes (MOD) in a cardiology substudy of the Pittsburgh Epidemiology of Diabetes Complications cohort of childhood-onset type 1 diabetes.

METHODS

115 normotensive type 1 diabetes individuals without known CAD, underwent a baseline exercise radionuclide ventriculography. Abnormal LVEF was defined as a resting ejection fraction <50% or a failure to increase ejection fraction with exercise by >5% (men) or a fall in ejection fraction with exercise (women). Cox proportional hazards models were used to predict the composite endpoint of MOD (first instance of major CAD, stroke, end-stage renal disease, blindness, amputation or diabetes-related death).

RESULTS

Mean baseline age was 28 and diabetes duration 19 years. In a mean follow-up of 19 years, 50 MOD events were identified. Allowing for established risk factors at baseline, abnormal LVEF (n = 22) independently predicted MOD incidence (HR = 2.12, 95% CI: 1.12-4.00, p = 0.022) but not major CAD (HR = 1.33, 95% CI: 0.53-3.33, p = 0.539).

CONCLUSIONS

An abnormal LVEF may identify diabetic cardiomyopathy and predict long term risk of MOD (but not CAD alone) in type 1 diabetes individuals, consistent with it reflecting microvascular disease.

Cardiac Computed Tomography Angiographic Findings as Predictors of Late Heart Failure in an Asymptomatic Diabetic Cohort: An 8-Year Prospective Follow-Up Study

OBJECTIVES

Predictive models for heart failure (HF) in heterogeneous populations have had limited success. We examined cardiac computed tomography angiography (CTA) predictors of HF or cardiovascular death (HF-CVD) in a prospective study of asymptomatic diabetics undergoing baseline assessment by CTA.

METHODS

The subjects (n = 735, aged 55-74 years, 51.2% women) had no clinical history of cardiovascular disease at study entry. Coronary artery calcium (CAC) score, CTA-defined coronary atherosclerosis, cardiac chamber volumes, and clinical data were collected and late outcome events recorded over 8.4 ± 0.6 years (range 7.3-9.3).

RESULTS

HF-CVD occurred in 41 (5.6%) subjects, with HF occurring mostly (19/23, 82.6%) in subjects without preceding myocardial infarction. Baseline univariate clinical outcome predictors of HF-CVD included older age (p = 0.027), the duration of diabetes (p = 0.004), HbA1c (p < 0.0001), microvascular disease (retinopathy, microalbuminuria) (p < 0.0001), and systolic blood pressure (p = 0.035). Baseline univariate CTA predictors included CAC score (p = 0.004), coronary stenosis (p = 0.047), and a CTA-defined left/right atrial (LA/RA) volume ratio >1 (p < 0.0001). Independent predictors were an LA/RA volume ratio >1, microvascular disease, and systolic blood pressure (model C-statistic 0.792, 95% CI 0.758-0.824). Measures of the extent of coronary artery disease (CAD) were not independent predictors of HF-CVD.

CONCLUSIONS

In a low- to moderate-risk asymptomatic diabetic population, CTA LA enlargement (LA/RA volume ratio) but not the extent of CAD had independent prognostic value for HF-CVD in addition to the clinical variables.

Pancreatic Elastography From Acoustic Radiation Force Impulse Imaging for Evaluation of Diabetic Microangiopathy

OBJECTIVE

The purposes of this study were to compare pancreatic shear-wave velocity (SWV) in subjects with and those without diabetic microvascular complications and to investigate the feasibility of pancreatic SWV in evaluating diabetic microangiopathy.

SUBJECTS AND METHODS

SWV measurements were prospectively performed in 115 patients with diabetes mellitus and 115 healthy persons by use of acoustic radiation force impulse imaging. Patients with diabetes were divided into subgroups with and without microangiopathy. Pancreatic SWV was compared in three groups. Factors associated with increased SWV were studied.

RESULTS

Pancreatic SWV increased significantly in the subgroups with diabetes mellitus compared with the control group (p < 0.01). Especially, the SWV in the pancreatic body was significantly higher when microangiopathy was present (p < 0.01). In patients with diabetes, microangiopathy (standardized β = 0.208, p = 0.022), age (standardized β = 0.265, p = 0.004), and total cholesterol level (standardized β = 0.223, p = 0.011) were positively and markedly correlated with high SWV in the pancreatic body.

CONCLUSION

The increased SWV in the pancreatic body was significantly related to the presence of microangiopathy. It is feasible to use SWV in the pancreatic body to evaluate diabetic microangiopathy.

Early impairment in left ventricular longitudinal systolic function is associated with an increased risk of incident atrial fibrillation in patients with type 2 diabetes

AIMS

It is known that type 2 diabetic patients are at high risk of atrial fibrillation (AF). However, the early echocardiographic determinants of AF vulnerability in this patient population remain poorly known.

METHODS

We followed-up for 2years a sample of 180 consecutive outpatients with type 2 diabetes, who were free from AF and ischemic heart disease at baseline. All patients underwent a baseline echocardiographic-Doppler evaluation with tissue Doppler and 2-D strain analysis. Standard electrocardiograms were performed twice per year, and a diagnosis of incident AF was confirmed in affected patients by a single cardiologist.

RESULTS

Over the 2-year follow-up period, 14 (7.8%) patients developed incident AF. In univariate analyses, echocardiographic predictors of new-onset AF were greater indexed cardiac mass, larger indexed left atrial volume (LAVI), lower global longitudinal strain (LS_SYS), lower global diastolic strain rate during early phase of diastole (SR_E), lower global diastolic strain rate during late phase of diastole (SR_L), and higher E/SR_E ratio. Multivariate logistic regression analysis showed that lower LS_SYS remained the only significant predictor of new-onset AF (adjusted-odds ratio 1.63, 95%CI 1.17-2.27; p<0.005) after adjustment for age, sex, diabetes duration, indexed cardiac mass and LAVI. Results were unchanged even after adjustment for body mass index, hypertension and glycemic control.

CONCLUSIONS

This is the first prospective study to show that early LS_SYS impairment independently predicts the risk of new-onset AF in type 2 diabetic patients with preserved ejection fraction and without ischemic heart disease. Future larger prospective studies are needed to confirm these findings.

Evidence of left atrial remodeling and left ventricular diastolic dysfunction in type 2 diabetes mellitus with preserved systolic function

BACKGROUND AND AIMS

Prognosis of type 2 diabetes is associated with the occurrence of cardiovascular diseases. Left atrial (LA) size is a predictor of outcome in several diseases, including diabetes. Long duration of diabetes is an established risk factor of poor prognosis. No data are available on the relationship between LA size and duration of diabetes. The present study was aimed to investigate the relationship between LA volume index (LAVI) and the duration of diabetes to test the hypothesis that LA volume will increase as a function of diabetes duration.

METHODS AND RESULTS

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. About 28.2% of patients had increased LAVI. Indices of both diastolic and systolic function were significantly lower in patients with larger left atrium. The values of LAVI increased across classes of duration of diabetes. In multivariable analysis, longer duration was a predictor of LAVI ≥34 ml/m² (odds ratio 1.65, 95% CI 1.11-2.46, p = 0.014) after adjusting for age, hemoglobin A1c, hypertension, microvascular complication status, and relevant echocardiographic parameters of systolic and diastolic function.

CONCLUSIONS

These results indicate that duration of diabetes is strongly and positively associated with larger LAVI in type 2 diabetic men with preserved systolic function. Future studies are needed to better elucidate the biological mechanisms underlying linking type 2 diabetes with abnormally increased LAVI in subjects with type 2 diabetes.

Evaluation of the association between diabetic retinopathy and the incidence of atrial fibrillation: A nationwide population-based study

BACKGROUND

Atrial fibrillation (AF) is prevalent among type 2 diabetic patients. However, the association between diabetic retinopathy (DR) and AF is controversial.

METHODS

We included 40,500 patients with type 2 diabetes (≥40years, mean age 62±11years, 53% men) without AF from the Korean National Insurance Service-National Sample Cohort (2002-2007). Subjects were classified without DR (non-DR, n=30,178), with DR (DR, n=8920), and with proliferative DR (PDR, n=1402).

RESULTS

During a mean 5.9-year follow-up, 1261 (3.1%) patients were newly diagnosed as having AF (4.9, 6.0, and 8.3 per 1000 person-years in the non-DR, DR, and PDR groups, respectively). In multivariate Cox proportional hazard models, patients in the DR and PDR groups had a significantly higher risk of AF than those in the non-DR group (DR group: hazard ratio [HR] 1.14, 95% confidence interval [CI] 1.00-1.30; PDR group: HR 1.46, 95% CI 1.13-1.87); p for trend <0.001). The risk of AF increased in patients with DR and end-stage renal disease (ESRD) (HR 2.39, 95% CI 1.31-3.96, p<0.001) and in those with PDR and ESRD (HR 3.59, 95% CI 1.96-5.97, p<0.001) compared to those without DR and ESRD.

CONCLUSIONS

The presence and severity of DR was significantly associated with the incidence of AF. Also, the presence of ESRD had an impact on the incidence of AF in patients with DR.