Aortic distensibility in type 1 diabetes

Associations of aortic stiffness and intra-aortic flow parameters with epicardial adipose tissue in patients with type-2 diabetes

Background

It has been shown that increased aortic stiffness is related to type-2 diabetes (T2D) which is considered as a risk factor for cardiovascular disease. Among other risk factors is epicardial adipose tissue (EAT) which is increased in T2D and is a relevant biomarker of metabolic severity and adverse outcome.

Purpose

To assess aortic flow parameters in T2D patients as compared to healthy individuals and to evaluate their associations with EAT accumulation as an index of cardiometabolic severity in T2D patients.

Materials and methods

Thirty-six T2D patients as well as 29 healthy controls matched by age and sex were included in this study. Participants had cardiac and aortic MRI exams at 1.5 T. Imaging sequences included cine SSFP for left ventricle (LV) function and EAT assessment and aortic cine and phase-contrast imaging for strain and flow parameters quantification.

Results

In this study, we found LV phenotype to be characterized by concentric remodeling with decreased stroke volume index despite global LV mass within a normal range. EAT was increased in T2D patients compared to controls (p<0.0001). Moreover, EAT, a biomarker of metabolic severity, was negatively correlated to ascending aortic (AA) distensibility (p=0.048) and positively to the normalized backward flow volume (p=0.001). These relationships remained significant after further adjustment for age, sex and central mean blood pressure. In a multivariate model, presence/absence of T2D and AA normalized backward flow (BF) to forward flow (FF) volumes ratio are both significant and independent correlates of EAT.

Conclusion

In our study, aortic stiffness as depicted by an increased backward flow volume and decreased distensibility seems to be related to EAT volume in T2D patients. This observation should be confirmed in the future on a larger population while considering additional biomarkers specific to inflammation and using a longitudinal prospective study design.

Determinants of arterial elastic function in middle-aged and elderly people: A population-based cross-sectional study from a low-income population in China

Background

Arterial stiffness is closely associated with the occurrence of many cardiovascular and cerebrovascular diseases. However, the risk factors and mechanisms related to arterial stiffness development have only been partially elucidated. We aimed to describe arterial elastic function and its influencing factors in middle-aged and elderly people in rural China.

Methods

This was a cross-sectional study conducted among residents, aged ≥45 years, of Tianjin, China, between April and July 2015. Data regarding participant demographics, medical history, lifestyle, and physical examination results were collected and assessed the association with arterial elastic function using linear regression.

Results

Of the 3,519 participants, 1,457 were male (41.4%). Brachial artery distensibility (BAD) decreased by 0.5%/mmHg with every 10-year increment in age. The mean BAD value was 0.864%/mmHg lower in women than in men. With each unit increase in mean arterial pressure, the BAD decreased by 0.042%/mmHg. In patients with hypertension or diabetes, the BAD decreased by 0.726 and 0.183%/mmHg, respectively, compared with those without hypertension or diabetes. For each unit increase in triglyceride (TG) level, the mean BAD increased by 0.043%/mmHg. With each increase in body mass index (BMI) category, the BAD increased by 0.113%/mmHg. Brachial artery compliance (BAC) decreased by 0.007 ml/mmHg with each 10-year increase in age, and brachial artery resistance (BAR) increased by 30.237 dyn s-1 cm-5. The mean BAC in women was 0.036 ml/mmHg lower and the mean BAR was 155.231 dyn s-1 cm-5 higher in women than in men. In individuals with hypertension, the mean BAC decreased by 0.009 ml/mmHg and the mean BAR increased by 26.169 dyn s-1 cm-5. With each increase in BMI category, the mean BAC increased by 0.005 ml/mmHg and the mean BAR decreased by 31.345 dyn s-1 cm-5. For each unit increase in TG level, the mean BAC increased by 0.001 ml/mmHg.

Conclusion

These findings indicate that age, sex, mean arterial pressure, BMI, diabetes, hypertension, and TG level are independently associated with the components of peripheral arterial elasticity. Understanding the factors influencing arterial stiffness is important for developing interventions to minimize arterial aging and cardiovascular and cerebrovascular diseases caused by arterial aging.

Time-varying parameters of glycemic control and glycation in relation to arterial stiffness in patients with type 1 diabetes

BACKGROUND

A substantial proportion of type 1 diabetes (T1D) patients free from known cardiovascular disease (CVD) show premature arterial stiffening, with age, blood pressure, and HbA1c-as gold standard of glycemic control-as main predictors. However, the relationship of arterial stiffness with other time-varying parameters of glycemic control and glycation has been far less explored. This study investigated the relationship of arterial stiffness with several short- and long-term parameters of glycemic control and glycation in patients with T1D, such as advanced glycation end-products (AGEs) and continuous glucose monitoring (CGM)-derived parameters.

METHODS

Cross-sectional study at a tertiary care centre including 54 patients with T1D free from known CVD. Arterial stiffness was assessed with carotid-femoral pulse wave velocity (cf-PWV). Current level and 10-year history of HbA1c were evaluated, and skin AGEs, urinary AGEs, and serum soluble AGE-receptor (sRAGE) concentrations. CGM for 7 days was used to determine time in range, time in hyper- and hypoglycemia, and glycemic variability.

RESULTS

Cf-PWV was associated with current HbA1c (r_s = + 0.28), mean 10-years HbA1c (r_s = + 0.36), skin AGEs (r_s = + 0.40) and the skin AGEs-to-sRAGE ratio (r_s = + 0.40), but not with urinary AGE or serum sRAGE concentrations; and not with any of the CGM-parameters. Multiple linear regression for cf-PWV showed that the model with the best fit included age, T1D duration, 24-h mean arterial pressure and mean 10-years HbA1c (adjusted R² = 0.645, p < 0.001).

CONCLUSIONS

Longer-term glycemic exposure as reflected by current and mean 10-years HbA1c is a key predictor of arterial stiffness in patients with T1D, while no relationship was found with any of the short-term CGM parameters. Our findings stress the importance of early and sustained good glycemic control to prevent premature CVD in patients with T1D and suggest that HbA1c should continue to be used in the risk assessment for diabetic complications. The role of skin glycation, as a biomarker for vascular aging, in the risk assessment for CVD is an interesting avenue for further research.

Cardiovascular disease in patients with type 1 diabetes: Early evaluation, risk factors and possible relation with cardiac autoimmunity

Cardiovascular disease now is the leading cause of mortality among patients with type 1 diabetes (T1D). The risk of death from cardiovascular events in subjects with T1D is 2-10 times higher than the general population, depending on blood glucose control. Although complications of cardiovascular disease occur in middle and old age, pathological processes begin in childhood. Some methods used to evaluate subclinical cardiovascular disease, such as carotid intima-media thickness and pulse wave velocity, can detect early cardiovascular abnormalities in adolescence. The effect of risk factors including hypertension, dyslipidemia and diabetic nephropathy on cardiovascular disease has been well studied. According to the current clinical practice recommendations from the American Diabetes Association, cardiovascular risk factors should be systematically assessed at least annually and treated as recommended. And yet, the effects of intensive insulin therapy on cardiovascular risk, as well as the mechanisms of cardiac autoimmunity require further studying. This review concentrates on the cardiovascular risk in type 1 diabetes in order to provide a comprehensive outlook of its epidemiology, early assessment, risk factors and possible relations with cardiac autoimmunity, aiming to propose promising therapeutic strategies.

Insulin protects against type 1 diabetes mellitus-induced aortopathy associated with the inhibition of biomarkers of vascular injury in rats

BACKGROUND

We sought to investigate the protective effect of insulin against type 1 diabetes mellitus (T1DM)-induced aortic injury (aortopathy) associated with the inhibition of biomarkers of vascular injury.

MATERIAL AND METHODS

T1DM was induced in rats by streptozotocin (STZ) (65 mg/kg), and the protection group started insulin treatment 2 days post diabetic induction and continued until being sacrificed at week 8.

RESULTS

Aortopathy was developed in the diabetic rats as demonstrated by profound alterations to the aorta ultrastructure, which was substantially protected by insulin. In addition, insulin significantly inhibited diabetes-induced dyslipidaemia, soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1), oxidative stress, and inflammation. However, blood levels of these biomarkers in the insulin-treated group were still significant (p < .05) compared with the control group, whereas insulin treatment returned blood glucose and triglyceride to control levels.

CONCLUSIONS

We demonstrate effective protection by insulin against T1DM-induced aortopathy in rats, which is associated with the inhibition of vascular injury biomarkers.

Reference ranges ("normal values") for cardiovascular magnetic resonance (CMR) in adults and children: 2020 update

Cardiovascular magnetic resonance (CMR) enables assessment and quantification of morphological and functional parameters of the heart, including chamber size and function, diameters of the aorta and pulmonary arteries, flow and myocardial relaxation times. Knowledge of reference ranges ("normal values") for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. Compared to the previous version of this review published in 2015, we present updated and expanded reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques. Further, databases and references for deep learning methods are included.

Suppression of type 2 diabetes mellitus-induced aortic ultrastructural alterations in rats by insulin: an association of vascular injury biomarkers

Diabetes represents a major public health problem and an estimated 70% of people with diabetes die of cardiovascular complications. The protective effect of insulin treatment against ultrastructural damage to the tunica intima and tunica media of the aorta induced by type 2 diabetes mellitus (T2DM) has not been investigated before using transmission electron microscopy (TEM). Therefore, we induced T2DM in rats using high fat diet and streptozotocin (50 mg/kg) and administered insulin daily by i.v injection for 8 weeks to the treatment group. Whereas, the T2DM control group were left untreated for the duration of the experiment. A comparison was also made between the effect of insulin on aortic tissue and the blood level of biomarkers of vascular injury, inflammation, and oxidative stress. T2DM induced profound ultrastructural damage to the aortic endothelium and vascular smooth muscle cells, which were substantially protected with insulin. Furthermore, insulin returned blood sugar to a control level and significantly (p < .05) inhibited diabetic up-regulation of endothelial and leukocyte intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion protein 1 (VCAM-1), endothelial cell adhesion molecules, P-selectin and E-selectin, tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), and malondialdehyde (MDA). Furthermore, insulin augmented the blood level of the anti-oxidant enzyme superoxide dismutase (SOD). We conclude that in a rat model of T2DM, insulin treatment substantially reduces aortic injury secondary to T2DM for a period of 8 weeks, possibly due to the inhibition of hyperglycemia, vascular activation, inflammation, and oxidative stress.

Clinical Research on the Aortic Elasticity in Patients with Type 1 Diabetes Mellitus Complicated with Hypertension

OBJECTIVE

To investigate the characteristics of aortic elasticity in type 1 diabetes mellitus (DM1) patients with hypertension using dual-source computed tomography (DSCT).

METHODS

Subjects were divided into four groups: 31 with hypertension (EH group), 28 with DM1 (DM1 group), 30 with hypertension and DM1 (DM1 + EH group), and 30 healthy volunteers (control group, CG). ECG-gated DSCT was used to measure the cross-sectional area of the aorta in diastole and systole and calculate the aortic elasticity (D). Analysis of variance and multiple linear regression were used for statistical analysis.

RESULTS

Compared with the CG, aortic elasticity (D) in the DM1 group patients was not significantly decreased. Compared with the EH group, the DM1 + EH group showed no significant change. The aortic elasticity (D) in the EH and DM1 + EH groups was significantly lower than that in the CG and DM1 group.

CONCLUSION

DM1 slightly affects the aortic elasticity of the descending aorta, whereas hypertension exerts the main effect.

Aortic stiffness is independently associated with interstitial myocardial fibrosis by native T1 and accelerated in the presence of chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) have considerable cardiovascular morbidity and mortality. Aortic stiffness is an independent predictor of cardiovascular risk and related to left ventricular remodeling and heart failure. Myocardial fibrosis is the pathophysiological hallmark of the failing heart.

METHODS AND RESULTS

An observational study of consecutive CKD patients (n = 276) undergoing comprehensive clinical cardiovascular magnetic resonance imaging. The relationship between aortic stiffness, myocardial fibrosis, left ventricular remodeling and the severity of chronic kidney disease was examined. Compared to age-gender matched controls with no known kidney disease (n = 242), CKD patients had considerably higher myocardial native T1 and central aortic PWV (p ≪ 0.001), as well as abnormal diastolic relaxation by E/e' (mean) by echocardiography (p ≪ 0.01). A third of all patients had LGE, with similar proportions for the presence and the (ischaemic and non-ischaemic) pattern between the groups. PWV was strongly associated with and age, NT-proBNP and native T1 in both groups, but not with LGE presence or type; the associations were amplified in severe CKD stages. In multivariate analyses, PWV was independently associated with native T1 in both groups (p ≪ 0.01) with near two-fold increase in adjusted R2 in the presence of CKD (native T1 (10 ms) R2, B(95%CI) CKD vs. non-CKD 0.28, 0.2(0.15-0.25) vs. 0.18, 0.1(0.06-0.15), p ≪ 0.01).

CONCLUSIONS

Aortic stiffness and interstitial myocardial fibrosis are interrelated; this association is accelerated in the presence of CKD, but independent of LGE. Our findings reiterate the significant contribution of CKD-related factors to the pathophysiology of cardiovascular remodeling.

Increased aortic stiffness index in patients with type 1 diabetes without cardiovascular disease compared to controls

PURPOSE

Increased arterial stiffness is an early sign of endothelial dysfunction. Nevertheless, measures of the elastic properties of the aortic root in patients with type 1 diabetes are still lacking. The aim of this study was to compare aortic root stiffness index in type 1 diabetes and healthy controls.

METHODS

Ninety-three patients with type 1 diabetes without cardiovascular diseases were recruited and compared to 33 healthy controls. Aortic root elastic properties were estimated by measuring the systolic and diastolic diameters on M-mode acquisition.

RESULTS

None of the subjects showed alterations of either systolic or diastolic echocardiographic parameters. Patients with type 1 diabetes had a very low prevalence of chronic complications and their metabolic control was good. Significantly increased aortic stiffness index was found in type 1 diabetes compared to controls, and the same different pattern was found in men and women. The presence of type 1 diabetes and increased pulse pressure was significantly associated with aortic stiffness index in a multivariate linear analysis.

CONCLUSION

This study strongly suggests that patients with type 1 diabetes develop aortic root stiffness in the absence of cardiovascular diseases. This alteration may be part of a more generalized arterial dysfunction in type 1 diabetes.

Subclinical vascular disease in patients with diabetes is associated with insulin resistance

Patients with diabetes experience increased cardiovascular risk that is not fully explained by deficient glycemic control or traditional cardiovascular risk factors such as smoking and hypercholesterolemia. Asymptomatic patients with diabetes show structural and functional vascular damage that includes impaired vasodilation, arterial stiffness, increased intima-media thickness and calcification of the arterial wall. Subclinical vascular injury associated with diabetes predicts subsequent manifestations of cardiovascular disease, such as ischemic heart disease, peripheral artery disease and stroke. Noninvasive detection of subclinical vascular disease is commonly used to estimate cardiovascular risk associated to diabetes. Longitudinal studies in normotensive subjects show that arterial stiffness at baseline is associated with a greater risk for future hypertension independently of established risk factors. In patients with type 2 diabetes, vascular disease begins to develop during the latent phase of insulin resistance, long before the clinical diagnosis of diabetes. In contrast, patients with type 1 diabetes do not manifest vascular injury when they are first diagnosed due to insulin deficiency, as they lack the preceding period of insulin resistance. These findings suggest that insulin resistance plays an important role in the development of early vascular disease associated with diabetes. Cross-sectional and prospective studies confirm that insulin resistance is associated with subclinical vascular injury in patients with diabetes, independently of standard cardiovascular risk factors. Asymptomatic vascular disease associated with diabetes begins to occur early in life having been documented in children and adolescents. Insulin resistance should be considered a therapeutic target in order to prevent the vascular complications associated with diabetes.

The early detection of atherosclerosis in type 1 diabetes: why, how and what to do about it

The major cause of morbidity and often premature mortality in people with type I diabetes (T1D) is cardiovascular disease owing to accelerated atherosclerosis. We review publications relating to the rationale behind, and clinical tests for, detecting and treating early atherosclerosis in people with T1D. Currently available tools for atherosclerosis assessment include risk equations using vascular risk factors, arterial intima-media thickness, the ankle-brachial index, coronary artery calcification and angiography, and for more advanced lesions, intravascular ultrasound and optical coherence tomography. Evolving research tools include risk equations incorporating novel clinical, biochemical and molecular tests; vascular MRI and molecular imaging. As yet there is little information available to quantify early atherosclerosis. With better means to control the vascular risk factors, such as hypertension, dyslipidaemia and glycaemic control, and emerging therapies to control novel risk factors, further epidemiologic and clinical trials are merited to facilitate the translation into clinical practice of robust means to detect, monitor and treat early atherosclerosis in those with T1D.

Normal values for cardiovascular magnetic resonance in adults and children

Morphological and functional parameters such as chamber size and function, aortic diameters and distensibility, flow and T1 and T2* relaxation time can be assessed and quantified by cardiovascular magnetic resonance (CMR). Knowledge of normal values for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. In this review, we present normal reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques and sequences.

Magnetic resonance imaging measures of decreased aortic strain and distensibility are proportionate to insulin resistance in adolescents with type 1 diabetes mellitus

OBJECTIVES

To determine whether children with type 1 diabetes mellitus (T1DM) have evidence of increased aortic stiffness or early atherosclerosis as measured by magnetic resonance imaging (MRI).

BACKGROUND

T1DM increases risk for cardiovascular disease in adults but whether this process starts in childhood is unknown.

SUBJECTS

A total of 54 T1DM patients (15.4 ± 2.6 yr) and 30 age-matched controls (14.8 ± 2.7 yr) participated.

METHODS

MRI was performed to assess aortic arch pulse wave velocity (PWV), strain, and distensibility of the ascending and descending thoracic aorta and measures of atherosclerosis.

RESULTS

Groups were well-matched for age, pulse pressure, and gender. Low-density lipoprotein-cholesterol (LDL-C) was higher in T1DM (119.3 ± 50 vs. 76.1 ± 13.5 mg/dL, p < 0.0001). There was a trend toward decreased strain and distensibility in T1DM vs. controls in the ascending (distensibility: T1DM 62.2 ± 19.9 kPa⁻¹ × 10⁻³, control 71.6 ± 26.4 kPa⁻¹ × 10⁻³, p = 0.08) and descending aorta (strain: T1DM 25.8 ± 6.2% vs. control 28.3 ± 6.8%, p = 0.09). There was no difference in arch PWV. Advancing age and male gender was negatively associated with aortic stiffness. Hemoglobin A1c (HbA1c) was inversely related to descending aorta strain and distensibility (p < 0.05). Children with diabetes in the lowest two tertiles of insulin sensitivity demonstrated thoracic descending aortas with significantly lower strain (p = 0.027) and distensibility (p = 0.039) and increased measures of wall irregularity (p = 0.005). There were no differences in measurements of atherosclerosis between the two groups.

CONCLUSIONS

Adolescents with T1DM, especially those with lower insulin sensitivity, demonstrated a trend toward stiffer, less compliant thoracic aortas, which was inversely associated with diabetes control. These data suggest large vessel aortopathy starts early in T1DM.

Site-specific association between distal aortic pulse wave velocity and peripheral arterial stenosis severity: a prospective cardiovascular magnetic resonance study

BACKGROUND

Vascular disease expression in one location may not be representative for disease severity in other vascular territories, however, strong correlation between disease expression and severity within the same vascular segment may be expected. Therefore, we hypothesized that aortic stiffening is more strongly associated with disease expression in a vascular territory directly linked to that aortic segment rather than in a more remote segment. We prospectively compared the association between aortic wall stiffness, expressed by pulse wave velocity (PWV), sampled in the distal aorta, with the severity of peripheral arterial occlusive disease (PAOD) as compared to atherosclerotic markers sampled in remote vascular territories such as PWV in the proximal aorta and the normalized wall index (NWI), representing the vessel wall thickness, of the left common carotid artery.

METHODS

Forty-two patients (23 men; mean age 64±10 years) underwent velocity-encoded cardiovascular magnetic resonance (CMR) in the proximal and distal aorta, whole-body contrast-enhanced MR angiography (CE-MRA) and carotid vessel wall imaging with black-blood CMR in the work-up for PAOD. Strength of associations between aortic stiffness, carotid NWI and peripheral vascular stenosis grade were assessed and evaluated with multiple linear regression.

RESULTS

Stenosis severity correlated well with PWV in the distal aorta (Pearson rP=0.64, p<0.001, Spearman rS=0.65, p<0.001) but to a lesser extent with PWV in the proximal aorta (rP=0.48, p=0.002, rS=0.22, p=0.18). Carotid NWI was not associated with peripheral stenosis severity (rP=0.17, p=0.28, rS=0.14, p=0.37) nor with PWV in the proximal aorta (rP=0.22, p=0.17) nor in the distal aorta (rP=0.21, p=0.18). Correlation between stenosis severity and distal aortic PWV remained statistically significant after correction for age and gender.

CONCLUSIONS

Distal aortic wall stiffness is more directly related to peripheral arterial stenosis severity than markers from more remote vascular territories such as proximal aortic wall stiffness or carotid arterial wall thickness. Site-specific evaluation of vascular disease may be required for full vascular risk estimation.

Clinical Use of Cardiac Magnetic Resonance in Systemic Heart Disease

A systemic disease is one that affects a number of organs and tissues, or the body as a whole. Systemic diseases include endocrine, metabolic, nutritional, multisystem (rheumatic) and HIV disease. Cardiovascular involvement is a common and underestimated problem in systemic diseases, and may present with disease associated cardiac involvement at diagnosis or later in the course of the systemic disease. The cardiac involvement in these diseases is usually silent or oligo-symptomatic and includes different pathophysiological mechanisms such as, myocardial inflammation, infarction, diffuse, subendocardial vasculitis, valvular disease and different patterns of fibrosis. Furthermore, acuity of heart involvement may be underestimated due to non-specific cardiac signs, and finally, most of patients are female and unable to exercise, due to arthritis or muscular discomfort/weakness or may have limited acoustic window, due to increased breast size. Cardiovascular magnetic resonance (CMR), due to its ability to reliably assess cardiac anatomy, function, inflammation, stress perfusion-fibrosis, aortic distensibility, and iron and fat deposition, constitutes an excellent tool for early diagnosis of heart involvement, risk stratification, treatment evaluation and long-term follow-up of patients with cardiac disease due to systemic diseases.

Kidney disease and related findings in the diabetes control and complications trial/epidemiology of diabetes interventions and complications study

OBJECTIVE Kidney disease manifests clinically as elevated albumin excretion rate (AER), impaired glomerular filtration rate (GFR), or both, and is a cause of substantial morbidity and mortality in type 1 diabetes (T1D). The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study tested whether intensive diabetes therapy (INT) aimed at lowering glucose concentrations as close as safely possible to the normal range reduces the risks of kidney disease and other diabetes complications. RESEARCH DESIGN AND METHODS In the DCCT, 1,441 participants with T1D were randomly assigned to INT or conventional diabetes therapy (CON) for a mean duration of 6.5 years. Subsequently, participants have been followed for 18 years in the ongoing observational EDIC. Standardized longitudinal measurements of AER, estimated GFR, and blood pressure were made throughout the DCCT/EDIC. RESULTS During the DCCT, INT reduced the risks of incident microalbuminuria (AER ≥40 mg/24 h) and macroalbuminuria (AER ≥300 mg/24 h) by 39% (95% CI 21-52%) and 54% (29-74%), respectively. During EDIC years 1-8, participants previously assigned to DCCT INT continued to experience lower rates of incident microalbuminuria and macroalbuminuria, with risk reductions of 59% (39-73%) and 84% (67-92%), respectively. Beneficial effects of INT on the development of impaired GFR (sustained estimated GFR <60 mL/min/1.73 m(2)) and hypertension became evident during combined DCCT/EDIC follow-up, with risk reductions of 50% (18-69%) and 20% (6-21%), respectively, compared with CON. CONCLUSIONS In the DCCT/EDIC, INT resulted in clinically important, durable reductions in the risks of microalbuminuria, macroalbuminuria, impaired GFR, and hypertension.

Update on cardiovascular outcomes at 30 years of the diabetes control and complications trial/epidemiology of diabetes interventions and complications study

OBJECTIVE To describe the beneficial long-term effects of an average of 6.5 years of intensive diabetes therapy (INT) in type 1 diabetes on measures of atherosclerosis, cardiac structure and function, and clinical cardiovascular events observed in the Diabetes Control and Complications Trial (DCCT) and the Epidemiology of Diabetes Interventions and Complications (EDIC) study. RESEARCH DESIGN AND METHODS The DCCT was a randomized clinical trial of 1,441 participants assigned to receive INT or conventional therapy (CON). It was conducted between 1983-1993 with an average follow-up of 6.5 years. EDIC (1994-present) is an observational follow-up of the DCCT cohort. Cardiovascular events have been recorded throughout. During EDIC common carotid intima-media thickness (IMT) was measured with ultrasound, coronary artery calcification with computed tomography, and cardiac structure and function with cardiac magnetic resonance imaging. RESULTS DCCT INT and lower levels of HbA1c during DCCT/EDIC were associated with thinner carotid IMT, less coronary calcification, and a lower incidence of clinical cardiovascular events including myocardial infarction, stroke, and cardiac death. While there were no significant differences in cardiac structure and function between the former INT and CON groups, they were significantly associated with higher HbA1c during DCCT/EDIC. CONCLUSIONS DCCT INT and the attendant 6.5 years of lower HbA1c had long-term salutary effects on the development and progression of atherosclerosis and cardiovascular disease during the subsequent follow-up during EDIC.

Type 1 diabetes and cardiovascular disease

The presence of cardiovascular disease (CVD) in Type 1 diabetes largely impairs life expectancy. Hyperglycemia leading to an increase in oxidative stress is considered to be the key pathophysiological factor of both micro- and macrovascular complications. In Type 1 diabetes, the presence of coronary calcifications is also related to coronary artery disease. Cardiac autonomic neuropathy, which significantly impairs myocardial function and blood flow, also enhances cardiac abnormalities. Also hypoglycemic episodes are considered to adversely influence cardiac performance. Intensive insulin therapy has been demonstrated to reduce the occurrence and progression of both micro- and macrovascular complications. This has been evidenced by the Diabetes Control and Complications Trial (DCCT) / Epidemiology of Diabetes Interventions and Complications (EDIC) study. The concept of a metabolic memory emerged based on the results of the study, which established that intensified insulin therapy is the standard of treatment of Type 1 diabetes. Future therapies may also include glucagon-like peptide (GLP)-based treatment therapies. Pilot studies with GLP-1-analogues have been shown to reduce insulin requirements.