The effect of type 1 diabetes mellitus on the gender difference in coronary artery calcification

Women Have Greater Endothelin-B Receptor Function and Lower Mitochondrial Capacity Compared to Men With Type 1 Diabetes

CONTEXT

Type 1 diabetes (T1D) negatively affects both the endothelin system and muscle oxidative capacity. The endothelin pathway is a critical regulator of microcirculatory function and may exhibit sexual dichotomy by which healthy premenopausal women have greater endothelin-B receptor (ETBR) function compared to men. Moreover, T1D may differentially alter muscle oxidative capacity in men and women; however, whether ETBR function is impaired in women compared to men with T1D and its relationship with muscle oxidative capacity has yet to be explored.

OBJECTIVE

The purpose of this investigation was to determine if ETBR-mediated dilation is impaired in women compared to men with T1D and if this is related to their skeletal muscle oxidative capacity.

METHODS

Men (n = 9; glycated hemoglobin A1c [HbA1c] = 7.8 ± 1.0%) and women (N = 10 women; HbA1c = 8.4 ± 1.3%) with uncomplicated T1D were recruited for this investigation. Near-infrared spectroscopy (NIRS) and intradermal microdialysis (750 nM BQ-123 + ET-1 [10-20-10-8 mol/L]) were used to evaluate skeletal muscle oxidative capacity and assess ETBR-mediated vasodilation, respectively.

RESULTS

Skeletal muscle oxidative capacity was significantly lower (P = .031) in women compared with men with T1D. However, ETBR-mediated dilation induced a significantly greater (P = .012) vasodilatory response in women compared to men with T1D, and the area under the curve was negatively associated with skeletal muscle oxidative capacity (r = -.620; P = .042).

CONCLUSION

Compared to men with uncomplicated T1D, muscle oxidative capacity was lower and ETBR-mediated vasodilation was higher in women with uncomplicated T1D. ETBR-induced vasodilatory capacity was inversely related to skeletal muscle oxidative capacity, suggesting there may be compensatory mechanisms occurring to preserve microvascular blood flow in women with T1D.

Smoking and diabetes: sex and gender aspects and their impact on vascular diseases

Smoking and diabetes mellitus (DM) have been identified as two major cardiovascular risk factors for many years. In the field of cardiovascular diseases, considering sex differences, or gender differences, or both has become an essential element in moving toward equitable and quality healthcare. We reviewed the impact of sex or gender on the link between smoking and DM. The risk of type 2 DM (T2DM) due to smoking has been established in both sexes at the same level. As is the case in the general population, the prevalence of smoking in those with DM is higher in men than in women, although the decrease in smoking observed in recent years is more pronounced in men than in women. Regarding chronic DM complications, smoking is an independent risk factor for all-cause mortality, as well as macrovascular and microvascular complications, in both sexes. Nevertheless, in T2DM, the burden of smoking appears to be greater in women than in men for coronary heart disease morbidity, women having a 50% higher risk of fatal coronary event. Women are more dependent to nicotine, cumulate psychosocial barriers to quitting smoking, and are more likely to gain weight, which might make it more difficult for them to quit smoking. Smoking cessation advice and treatments should take into account gender differences to improve the success and long-term maintenance of abstinence in people with and without DM. This might include interventions that address emotions and stress in women or designed to reach specific populations of men.

Uncovering Cardiac Involvement in Childhood Diabetes: Is it Time to Move Toward Speckle Tracking Echocardiography in Childhood Diabetes Management?

Context:

One of the most common endocrine disorders in children is diabetes which is the leading cause of premature cardiovascular disease in adulthood.

Aims:

This study is aimed to investigate the extend of cardiac involvement in diabetic children by speckle tracking echocardiography (STE) in comparison to two-dimensional (2D) echocardiography and routine laboratory data.

Settings and Design:

A cross-sectional study conducted on patients under 18 years of age who deal with type one diabetes mellitus for more than 5 years.

Subjects and Methods:

To compare the STE results, we included the STE data of 25 normal age-matched children. All patients underwent laboratory analysis for lipid profile, blood sugar, and 2D echocardiography plus STE.

Statistical Analysis Used:

Two-sample independent t-test, Chi-square test, logistic regression test, Spearman's rank correlation coefficient, and the Pearson correlation coefficient.

Results:

From March 2018 to 2019, we included 53 patients, mean age 15.8 ± 0.39 years and 52.8% female, and 25 nondiabetic control in this study. STE revealed global longitudinal strain (LS) −18.4 versus − 24.2 for patient (44 valid cases) versus control group, respectively, with significant statistical difference. Diabetic patients had lower LS in all segments compared to the control group.

Conclusions:

STE has very high sensitivity to detect cardiac involvement far earlier than 2D echocardiography. None of the routine biomarkers or demographic features can predict cardiac involvement based on segmental abnormalities of STE. Active investigation to clear the remote impact of STE abnormalities and its practical role in childhood diabetes management is highly recommended.

Cardiovascular Risk Management in Type 1 Diabetes

PURPOSE OF REVIEW

Type 1 diabetes mellitus (T1DM) is associated with increased mortality, with premature cardiovascular disease (CVD) a major factor. To date, research has identified multiple risk factors for this excess CVD liability. However, gaps remain in our understanding of the underlying mechanisms.

RECENT FINDINGS

T1DM is generally diagnosed at a young age. Since cardiovascular complications often only manifest at a later stage of life, there is generally less focus in earlier years on reducing CVD risk for affected individuals. This is an area that requires improvement as risk factors might be managed from earlier age to reduce later development of CVD. In this review, we discuss the evidence for cardiovascular risk factors, risk prediction models, candidate surrogate measurements and CVD risk management.

Cardiovascular Magnetic Resonance as Pathophysiologic Tool in Diabetes Mellitus

Diabetes mellitus can independently contribute to cardiovascular disease and represents a severe risk factor for premature development of cardiovascular disease. A three-fold higher mortality than the general population has been observed in type 1 diabetes mellitus whereas a two- to four-fold increased probability to develop cardiovascular disease has been observed in type 2 diabetes mellitus. Cardiovascular magnetic resonance, a non-radiative modality, is superior to all other modalities in detecting myocardial infarction. The main cardiovascular magnetic resonance sequences used include a) balanced steady-state free precession (bSSFP) for function evaluation; b) T2-W for oedema detection; c) T1 W for ischemia detection during adenosine stress; and d) late gadolinium enhanced T1-W images (LGE), evaluated 15 min after injection of paramagnetic contrast agent gadolinium, which permit the diagnosis of replacement fibrosis, which appears white in the middle of suppressed, nulled myocardium. Although LGE is the technique of choice for diagnosis of replacement fibrosis, it cannot assess diffuse myocardial fibrosis. The application of T1 mapping (native or pre contrast and post contrast) allows identification of diffuse myocardial fibrosis, which is not detectable my other means. Native T1 and Contrast-enhanced T1 mapping are involved in the extracellular volume fraction (ECV) calculation. Recently, 1H-cardiovascular magnetic resonance spectroscopy has been applied to calculate the amount of myocardial triglycerides, but at the moment it is not part of the routine assessment of diabetes mellitus. The multifaceted nature of cardiovascular magnetic resonance has the great potential of concurrent evaluation of function and myocardial ischemia/fibrosis in the same examination and represents an indispensable tool for accurate diagnosis of cardiovascular disease in diabetes mellitus.

Metabolic and Appetite Effects of Fructose and Glucose in Subjects with Type 1 Diabetes: A Randomized Crossover Clinical Trial

BACKGROUND

Fructose has been widely used for producing lower post-infusion glucose increase than other carbohydrates, but it seems that it promotes an increase in post-infusion triglycerides.

OBJECTIVE

The present study investigated the effects of fructose and glucose in metabolic variables and appetite sensations in patients with type 1 diabetes mellitus (T1DM).

METHODS

This is a single-blind, randomized, and crossover study (washout of 1-5 weeks), which evaluated 16 adult T1DM patients, accompanied at University Hospital. After eight hours of overnight fasting, there was an assessment of capillary blood glucose, anthropometric variables, appetite sensations, and laboratory tests (glycemia, lipemia, leptin and glucagon) were conducted. Subsequently, they received 200mL of solutions with water and 75g of crystal fructose or glucose. Appetite sensations and capillary blood glucose were evaluated in different post-infusion times. Blood was drawn after 180 minutes for the laboratory tests.

RESULTS

Blood glucose increased after the intake of both solutions, but glucose induced a higher elevation. None of them increased triglycerides or glucagon. Glucagon maintenance was similar among the solutions. Furthermore, both solutions reduced leptin and increased fullness, but only fructose increased the lack of interest in eating sweets.

CONCLUSION

Fructose induced a smaller increase in postprandial blood glucose than glucose, without changes in triglycerides and glucagon. In addition, leptin levels and appetite sensations were similar to glucose. Other studies are needed in order to confirm these findings, especially in the long term, so that their use becomes really reliable.

Undertreatment of cardiovascular risk factors in the type 1 diabetes exchange clinic network (United States) and the prospective diabetes follow-up (Germany/Austria) registries

AIM

To examine the control of cardiovascular risk factors in type 1 diabetes (T1D) registries from the United States and Germany/Austria.

MATERIALS AND METHODS

Data on individuals aged ≥12 years with T1D for ≥1 year, from the T1D Exchange Clinic Network (T1DX, United States) and the Prospective Diabetes Follow-up Registry (DPV, Germany/Austria) from 1 January 2016 to 31 March 2018 were analysed. Linear and logistic regression models adjusted for age groups, sex, duration of diabetes and minority status were used to compare clinical characteristics and achievement of diabetes management targets between registries.

RESULTS

The cohort consisted of 47 936 patients (T1DX, n = 19 442; DPV, n = 28 494). Achievement of HbA1c goals (<7.0%, ages 18-65 years; all others, <7.5%) was better in the DPV for those aged <65 years (all P < .001). However, more older adults (aged ≥65 years) in the T1DX achieved an HbA1c goal of <7.5% compared with DPV (70% vs. 50%, P < .001). The frequency of patients with overweight (53% vs. 51%, P < .001) and obesity (19% vs. 9%, P < .001) was higher in T1DX. The frequency of meeting blood pressure goals (84% vs. 66%, P < .001) and lipid goals (73% vs. 62%, P < .001) was higher in T1DX; this was observed across all age groups (all P < .001). Few young adults aged <26 years received antihypertensive and lipid-lowering medications, respectively, despite indications in both registries (T1DX: 5% and 3%, DPV: 3% and 1%).

CONCLUSION

A minority of patients with T1D achieve glycaemic targets and the majority are inadequately treated for hypertension and dyslipidaemia. This highlights the need for improved diabetes and cardiovascular risk management strategies in T1D.

High levels of endothelial and platelet microvesicles in patients with type 1 diabetes irrespective of microvascular complications

INTRODUCTION

Patients with type 1 diabetes have high risk of developing microvascular complications, and microangiopathy contributes to premature cardiovascular disease in this population. The role that microvesicles (MVs) may play in the development of microangiopathy in type 1 diabetes remains unclear.

MATERIALS AND METHODS

Plasma levels of endothelial MVs (EMVs) and platelet MVs (PMVs) in 130 patients with type 1 diabetes without microangiopathy, 106 patients with microangiopathy and 100 matched healthy controls were analyzed using flow cytometry. MV expression of procoagulant phosphatidylserine (PS) and proinflammatory high mobility group box-1 protein (HMGB1) was also assessed.

RESULTS

Patients with type 1 diabetes had markedly elevated levels of EMVs and PS+ EMVs as well as PMVs and PS+ PMVs compared to healthy controls (p < .001 for all). Furthermore, HMGB1+ EMVs and HMGB1+ PMVs were significantly increased in patients (p < .001 for all). After adjusting for potential confounders, there were no clear differences between patients with or without microvascular complications for any of the MV parameters.

CONCLUSION

Type 1 diabetes is a prothrombotic and proinflammatory disease state that, regardless of the presence of clinical microangiopathy, is associated with elevated levels of plasma MVs, in particular those of an endothelial origin. We have for the first time demonstrated that patients with type 1 diabetes have higher levels of HMGB1+ MVs. HMGB1 is an alarmin with potent proinflammatory effects that drive endothelial dysfunction, and it would therefore be of interest to further study the role of HMGB1+ MVs in the development of macrovascular complications in type 1 diabetes.

Type 1 Diabetes Accelerates Progression of Coronary Artery Calcium Over the Menopausal Transition: The CACTI Study

OBJECTIVE

Type 1 diabetes is associated with a higher risk of cardiovascular disease (CVD) in women. Although menopause increases risk of CVD, it is uncertain how menopause affects risk of CVD in women with type 1 diabetes. We examined whether risk of CVD changes differentially in women with and those without type 1 diabetes over the transition through menopause.

RESEARCH DESIGN AND METHODS

Premenopausal women with type 1 diabetes (n = 311) and premenopausal women without diabetes (n = 325) enrolled in the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study and attended up to four study visits over 18 years. Coronary artery calcium (CAC) volume was measured from computed tomography scans obtained at each visit. Longitudinal repeated-measures modeling estimated the effect of diabetes on CAC volume over time and the effect of menopause on the diabetes-CAC relationship.

RESULTS

CAC volume was higher at baseline and increased more over time in women with type 1 diabetes than in women without diabetes. A significant diabetes-by-menopause interaction was found (P < 0.0001): postmenopausal women with type 1 diabetes had significantly higher CAC volumes than premenopausal women (5.14 ± 0.30 vs. 2.91 ± 0.18 mm³), while there was no difference in women without diabetes (1.78 ± 0.26 vs. 1.78 ± 0.17 mm³). This interaction remained significant after adjusting for CVD risk factors.

CONCLUSIONS

Type 1 diabetes was associated with higher CAC volume and accelerated progression of CAC over time. Menopause increased CAC progression more in women with diabetes than in women without diabetes independent of age and other CVD risk factors known to worsen with menopause.

Female sex, high soluble CD163, and low HDL-cholesterol were associated with high galectin-3 binding protein in type 1 diabetes

Background

Galectin-3 binding protein (Gal3BP), sCD163, galectin-3, and depression have been linked to cardiovascular disease and mortality. In patients with type 1 diabetes, female sex has also been linked to cardiovascular disease and mortality. The aim was to explore whether female sex, sCD163, galectin-3, and depression were associated with Gal3BP in patients with type 1 diabetes. We adjusted for metabolic variables, creatinine, smoking, physical inactivity, and cardiovascular disease.

Methods

Cross-sectional design. Patients with type 1 diabetes (n = 285, women 44%, age18–59 years, diabetes duration 1–55 years) were consecutively recruited from one diabetes outpatient clinic. Blood samples, anthropometrics, and blood pressure were collected, supplemented with data from electronic medical records. High Gal3BP was defined as ≥3.3 mg/l (≥80th percentile). Depression was assessed by a self-report instrument. Linear and logistic regression models were elaborated for the associations and calibrated and validated for goodness of fit with the data variables.

Results

Median (q₁, q₃) Gal3BP was 2.3 (1.8, 3.1) mg/l. The prevalence of high Gal3BP for women was 30% and 14% for men (p = 0.001). Female sex (adjusted odds ratio (AOR) 3.0), sCD163 (per μg/l) (AOR 6.6), and total cholesterol (per mmol/l) (AOR 1.6) were positively associated with high Gal3BP, and HDL-cholesterol (per mmol/l) (AOR 0.2) was negatively associated with high Gal3BP.

Conclusions

High Gal3BP levels were associated with female sex, increasing sCD163 and total cholesterol levels, and decreasing HDL-cholesterol levels in patients with type 1 diabetes. The prevalence of high Gal3BP was more than twice as high in the women as in the men.

Glucose Management and the Sex Difference in Excess Cardiovascular Disease Risk in Long-Duration Type 1 Diabetes

PURPOSE OF REVIEW

The protection against CVD observed in women compared to men in the general population is essentially erased in type 1 diabetes. This review will discuss evidence regarding the role of glucose management on CVD risk by sex, with a particular focus on studies of long-duration type 1 diabetes of > 20 years.

RECENT FINDINGS

Across studies, women with type 1 diabetes have similar or worse glycemic control compared to men, despite higher rates of intensive insulin therapy. The association between HbA1c and CVD risk does not seem to differ by sex, but few studies have reported on sex-specific analyses. Beyond HbA1c, there is a lack of published data regarding the relationship between other aspects of glucose management and CVD risk by sex in type 1 diabetes. Glucose management factors do not seem to directly account for the increased CVD risk in women with type 1 diabetes, but may influence other risk factors that play a more direct role.

Low short-term and long-term cardiovascular and all-cause mortality in absence of coronary artery calcium: A 22-year follow-up observational study from large cohort

OBJECTIVES

We sought to evaluate the gender-specific predictive value of coronary artery calcium (CAC) score on all-cause mortality and cardiovascular disease (CVD) mortality in individuals with and without diabetes mellitus (DM).

BACKGROUND

CAC score is a robust predictor of CVD and all-cause mortality during long-term follow-up in large cohorts in adults with DM. However, less is known about its sex-specific impact on all-cause mortality in DM.

METHODS

We evaluated 25,563 asymptomatic participants with no known history of coronary artery disease (CAD) who underwent clinically indicated CAC. 1999 (7.8%) individuals had diabetes. CAC was characterized as an Agatston score of 0, 1-99, 100-300, and ≫300. We evaluated the association between CAC and all-cause mortality and CVD mortality.

RESULTS

Overall, 1345 individuals died (5.3%) from all causes during a mean follow-up of 14.7 ± 3.8 years. CAC score was 0 in 57.5% females and 34.4% of males without DM, while 36.6% females and 20.3% males with DM had CAC-0. The frequency of CAC ≫ 300 was 18% and 36% in females and males with DM, respectively. CAC score of zero was associated with low all-cause mortality event rate in females and males with diabetes (1.7 and 2.5 events per 1000 person-years, respectively). Cardiovascular mortality per 1000 person years was ≪1 in females and males with CAC score of 0 irrespective of their diabetes. Adjusted multivariable analysis, compared to CAC-0, HR for all-cause mortality associated with CAC 1-99, 100-299 and ≫300 were 1.74(95% CI 0.65, 4.63, P-0.20), 5.54(95% CI 2.16, 14.22, P ≪ 0.001) and 5.75(95% CI 2.30, 14.37, P ≪ 0.001) in females with DM respectively; in males with DM HR associated with CAC 1-99, 100-299 and ≫300 were 1.87(95% CI 0.95, 3.66, P-0.06), 2.15(95% CI 1.05, 4.38, P-0.035) and 2.60(95% CI 1.34, 5.0, P-0.004), respectively.

CONCLUSION

Presence of subclinical atherosclerosis varies among individuals with DM. The absence of CAC was associated with very low cardiovascular as well as all-cause mortality events in all subgroups during long term follow-up.

Cardiovascular Risk in Type 1 Diabetes Mellitus

Type 1 diabetes mellitus (T1DM) is associated with premature cardiovascular disease (CVD), but the underlying mechanisms remain poorly understood. The American Diabetes Association and the European Association for the Study of Diabetes recently updated their position statement on the management of type 2 diabetes mellitus (T2DM) to include additional focus on cardiovascular risk; improved management of risk factors in T1DM is also needed. There are important differences in the pathophysiology of CVD in T1DM and T2DM. Hyperglycaemia appears to have a more profound effect on cardiovascular risk in T1DM than T2DM, and other risk factors appear to cause a synergistic rather than additive effect, so achievement of treatment targets for all recognized risk factors is crucial to reducing cardiovascular risk. Here we discuss the evidence for addressing established cardiovascular risk factors, candidate biomarkers and surrogate measurements, and possible interventions.

Midnight salivary cortisol secretion and the use of antidepressants were associated with abdominal obesity in women with type 1 diabetes: a cross sectional study

BACKGROUND

Abdominal obesity is a risk factor for cardiovascular disease. The aim was to explore the influence of midnight salivary cortisol (MSC), antidepressants and sex on abdominal obesity in type 1 diabetes (T1D). We controlled for physical inactivity, smoking, depression and alexithymia.

METHODS

Cross sectional study of 190 T1D patients (86 women/104 men, 18-59 years, diabetes duration 1-55 years), consecutively recruited from one specialist diabetes outpatient clinic. Anthropometrics, blood pressure, saliva and blood samples were collected, supplemented with data from electronic medical records. Depression and alexithymia were assessed by self-report instruments. MSC (nmol/l) was categorised into 3 levels: high MSC: (≥ 6.7) (n = 64); intermediate MSC: ≥ 3.7- < 6.7) (n = 64); low MSC (< 3.7) (n = 62). Abdominal obesity was defined as waist circumference (meters) ≥ 0.88 for women and as ≥ 1.02 for men. Multiple logistic regression analyses (Backward: Wald) were performed. The Hosmer and Lemeshow test for goodness-of-fit and Nagelkerke R² were used to evaluate each multiple logistic regression analysis model.

RESULTS

The prevalence of abdominal obesity was three times higher in the women than in the men (24% versus 8%) (p = 0.002). Antidepressants were used by 10% of the women and by 4% of the men (p = 0.09). The prevalence of high MSC was 1.7 times higher in the women (43% versus 26%); the prevalence of both intermediate MSC (28% versus 38%) and low MSC (29% versus 36%) were lower in the women (p = 0.048). Significant associations with abdominal obesity were for all 190 patients: female sex (adjusted odds ratio (AOR) 3.4 (confidence interval (CI) 1.4-8.2)) and the use of antidepressants (AOR 4.3 (CI 1.2-14.8)); for the 86 women: high MSC (AOR 18.4 (CI 1.9-181)) and use of antidepressants (AOR 12.2 (CI 2.0-73.6)); and for the 104 men: alexithymia (AOR 5.2 (CI 1.1-24.9)).

CONCLUSIONS

Clear sex differences were demonstrated with a distinct higher prevalence of abdominal obesity, as well as a distinct higher prevalence of high midnight salivary cortisol in the women with type 1 diabetes. High midnight salivary cortisol secretion and the use of antidepressants were independent risk factors for abdominal obesity in the women.

Gender differences in diabetes self-care in adults with type 1 diabetes: Findings from the T1D Exchange clinic registry

AIMS

To evaluate gender differences in diabetes self-care components including glycemic, blood pressure and lipid control, utilization of diabetes technologies and acute diabetes complications in adults with type 1 diabetes.

METHODS

A total of 9,481 participants >18 years were included in the analysis, 53% were female. Variables of interest included glycemic control measured by HbA1c, systolic/diastolic blood pressures, presence of dyslipidemia, insulin delivery modality, and rates of acute complications.

RESULTS

Glycemic control was similar in women and men (mean HbA1c in both groups: 8.1% ± 1.6% (64 ± 16 mmol/mol), (p = 0.54). More women used insulin pump therapy (66% vs. 59%, p < 0.001) but use of sensor technology was similar (p < = 0.42). Women had higher rates of diabetic ketoacidosis (DKA) (5% vs. 3%, p < 0.001) and eating disorders (1.7% vs. 0.1%, p < 0.001). Severe hypoglycemia rates were not different between men and women (p = 0.42). Smoking (6% vs 4%, p < 0.001), systolic (125 ± 14.2 vs. 121 ± 14.4, p < 0.001) and diastolic blood pressure (73.3 ± 9.5 vs. 72.2 ± 9.3, p < 0.001) and rate of dyslipidemia (28% vs. 23%, p < 0.001) were higher in men.

CONCLUSION

While glycemic control in type 1 diabetes was similar regardless of gender, rates of DKA and eating disorders were higher in women while rates of smoking, hypertension and dyslipidemia were higher in men.

Mortality risk remains higher in individuals with type 1 diabetes: A population-based cohort study (the Ayrshire diabetes follow-up cohort [ADOC])

AIMS

Type 1 diabetes is associated with an increased risk of cardiovascular disease and all-cause mortality. Numerous studies have demonstrated that outcomes for diabetes are improved by intensive glycaemic control, blood pressure control, and treatment of dyslipidaemia in addition to cessation of smoking. The aim of this study was to compare mortalities in individuals with type 1 diabetes with that in non-diabetic individuals, and to investigate the effects of age, gender, glycaemic control, socio-economic status, hypertension, ischaemic heart disease (IHD), smoking status, body mass index (BMI) and dyslipidaemia.

METHODS

A population-based analysis in Ayrshire and Arran, Scotland included 253 304 non-diabetic individuals and 1324 individuals with type 1 diabetes who were tracked from 2009 to 2014.

RESULTS

Patients with type 1 diabetes had higher mortality rates than non-diabetic individuals (HR, 3.20; P < .01), with relative mortality in female individuals with type 1 diabetes being higher than that in males (OR, 2.38 vs 1.52; P < .01). Increasing age (HR, 2.37), smoking (HR, 1.85), IHD (HR, 1.62) and hypertension (HR, 1.21) (all P < .01) increased mortality risk. A hypertensive female with type 1 diabetes and IHD who smoked had an HR of 11.6 compared with a non-smoking, normotensive non-diabetic female without IHD. For a hypertensive male with type 1 diabetes and IHD who smoked, HR was 6.96. BMI > 30 kg/m² was associated with reduced mortality risk in both non-diabetic (HR, 0.61) and diabetic subjects (HR, 0.40).

CONCLUSIONS

This study confirmed that the risk of mortality in individuals with type 1 diabetes remains elevated. Further studies are required to understand how gender affects the disparity in mortality and why obesity appears to be protective.

Abdominal obesity in type 1 diabetes associated with gender, cardiovascular risk factors and complications, and difficulties achieving treatment targets: a cross sectional study at a secondary care diabetes clinic

Background

Abdominal obesity is linked to cardiovascular diseases in type 1 diabetes (T1D). The primary aim was to explore associations between abdominal obesity and cardiovascular complications, metabolic and inflammatory factors. The secondary aim was to explore whether achieved recommended treatment targets differed between the obese and non-obese participants.

Methods

Cross sectional study of 284 T1D patients (age 18-59 years, men 56%), consecutively recruited from one secondary care specialist diabetes clinic in Sweden. Anthropometrics, blood pressure, serum-lipids and high-sensitivity C-reactive protein (hs-CRP) were collected and supplemented with data from the patients' medical records and from the Swedish National Diabetes Registry. Abdominal obesity was defined as waist circumference men/women (meters): ≥1.02/≥0.88. Hs-CRP was divided into low-, moderate-, and high-risk groups for future cardiovascular events (< 1, 1 to 3, and > 3 to ≤8.9 mg/l). Treatment targets were blood pressure ≤ 130/≤ 80, total cholesterol ≤4.5 mmol/l, LDL: ≤ 2.5 mmol/l, and HbA1c: ≤5 2 mmol/mol (≤ 6.9%). Different explanatory linear, logistic and ordinal regression models were elaborated for the associations, and calibrated and validated for goodness of fit with the data variables.

Results

The prevalence of abdominal obesity was 49/284 (17%), men/women: 8%/29% (P < 0.001). Women (adjusted odds ratio (AOR) 6.5), cardiovascular complications (AOR 5.7), HbA1c > 70 mmol/mol (> 8.6%) (AOR 2.7), systolic blood pressure (per mm Hg) (AOR 1.05), and triglycerides (per mmol/l) (AOR 1.7), were associated with abdominal obesity. Sub analyses (n = 171), showed that abdominal obesity (AOR 5.3) and triglycerides (per mmol/l) (AOR 2.8) were associated with increasing risk levels of hs-CRP. Treatment targets were obtained for fewer patients with abdominal obesity for HbA1c (8% vs 21%, P = 0.044) and systolic blood pressure (51% vs 68%, P = 0.033). No patients with abdominal obesity reached all treatment targets compared to 8% in patients without abdominal obesity.

Conclusions

Significant associations between abdominal obesity and gender, cardiovascular disease, and the cardiovascular risk factors low-grade inflammation, systolic blood pressure, high HbA1c, and triglycerides, were found in 284 T1D patients. Fewer patients with abdominal obesity reached the treatment targets for HbA1c and systolic blood pressure compared to the non-obese.

Sex-specific differences in insulin resistance in type 1 diabetes: The CACTI cohort

OBJECTIVE

To test the hypothesis that multitissue deficits in insulin sensitivity are greater among women than men with type 1 diabetes compared to respective controls.

RESEARCH DESIGN AND METHODS

Three-stage hyperinsulinemic-euglycemic clamps (4, 8, 40 mU/m²/min) were performed on 41 people with type 1 diabetes and 47 adults without diabetes (mean ± SD age 46 ± 8). Infusions of [1-¹³C]palmitate, [1,1,2,3,3-²H₂]glycerol, and [6,6-²H₂]glucose isotope tracers were used to determine free fatty acid (FFA), glycerol, and glucose kinetics in 52 of these participants (25 M and 27 W).

RESULTS

There was no difference in age or BMI by type 1 diabetes status in either sex. Free fatty acid rate of appearance (FFA Ra) was higher in both sexes with type 1 diabetes compared to those without diabetes during stages 1 and 2. The same was seen with glycerol for stages 1 and 2. During stage 3 glucose rate of disappearance (Rd) was lower in those with type 1 diabetes among both sexes. All had sex by type 1 diabetes interactions with greater deficits in insulin sensitivity in women. While there was no sex by diabetes interaction in regards to glucose rate of appearance (Ra), those with type 1 diabetes had a higher glucose Ra than those without diabetes.

CONCLUSIONS

We found that type 1 diabetes affected adipose and skeletal muscle insulin sensitivity to a greater extent in women than in men, perhaps contributing to the greater relative increase in cardiovascular risk in women with type 1 diabetes.

Coronary artery calcium may stabilize following islet cell transplantation in patients with type 1 diabetes

Islet cell transplantation can functionally cure type 1 diabetes and also improve carotid intima-media thickness. This study provides a preliminary description of changes in coronary artery calcium following islet transplantation, and associated factors. Coronary artery calcium was measured in 14 patients with type 1 diabetes (11 had measures both pre- and post-transplant [mean 2.3 years]) in the University of Illinois at Chicago's clinical trial. Multivariable mixed-effects linear regression of repeated measures was used to quantify calcium change and determine if this change was longitudinally associated with risk/protective factors. Thirteen of the patients were female, with mean baseline age, diabetes duration, and BMI of 47.6 and 28.7 years, and 23.1, respectively. Over half (57%) had detectable coronary artery calcium pre-transplant. Minimal change (0.39 mm³ /y, P = .02) occurred in coronary artery calcium levels pre- to post-transplant. No patient met criteria for calcium progression. Coronary artery calcium was positively associated with total and small VLDL particles (P ≤ .02), statin dose (P = .02), and urine albumin-to-creatinine ratio (P = .04) and negatively associated with free fatty acids (P = .03), total HDL (P = .03), large HDL particles (P = .005), and tacrolimus dose (P = .02). Islet transplant may stabilize coronary artery calcium, with optimal management of lipids and kidney function remaining key therapeutic targets. [NCT00679041].

Sex-gender-related therapeutic approaches for cardiovascular complications associated with diabetes

Diabetes is a chronic disease associated with micro- and macrovascular complications and is a well-established risk factor for cardiovascular disease. Cardiovascular complications associated with diabetes are among the most important causes of death in diabetic patients. Interestingly, several sex-gender differences have been reported to significantly impact in the pathophysiology of diabetes. In particular, sex-gender differences have been reported to affect diabetes epidemiology, risk factors, as well as cardiovascular complications associated with diabetes. This suggests that different therapeutic approaches are needed for managing diabetes-associated cardiovascular complications in men and women. In this review, we will discuss about the sex-gender differences that are known to impact on diabetes, mainly focusing on the cardiovascular complications associated with the disease. We will then discuss the therapeutic approaches for managing diabetes-associated cardiovascular complications and how differences in sex-gender can influence the existing therapeutic approaches.

A Contemporary Estimate of Total Mortality and Cardiovascular Disease Risk in Young Adults With Type 1 Diabetes: The Pittsburgh Epidemiology of Diabetes Complications Study

OBJECTIVE

The degree to which mortality and cardiovascular disease (CVD) incidence remains elevated in young U.S. adults with type 1 diabetes (T1DM) is unclear. We determined contemporary rates for adults <45 years old with long-standing, childhood-onset T1DM from the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study.

RESEARCH DESIGN AND METHODS

Members of the EDC Study cohort <45 years old during the 1996-2012 follow-up period (n = 502) were studied. Mortality and CVD rates were calculated for those aged 30-39 and 40-44 years. Data from the background Allegheny County, Pennsylvania, population were used to calculate age- and sex-matched standardized mortality (SMR) and incidence rate ratios (IRR).

RESULTS

In both age groups, the SMR for total mortality was ∼5 (95% CIs: 30-39-year-olds, 2.8, 7.2; 40-44-year-olds, 3.4, 7.8). CVD mortality SMRs ranged from 19 (95% CI 11, 32) to 33 (95% CI 17, 59). Hospitalized CVD IRR was ∼8 (95% CIs: 30-39-year-olds, 2.5, 18.9; 40-44-year-olds, 4.5, 12.8); revascularization procedures account for much of the increased risk. For all outcomes, the relative risk was larger in women. Participants aged 30-39 years had 6.3% (95% CI 3.8, 9.8) absolute 10-year CVD risk, approaching the American College of Cardiology/American Heart Association-recommended cut point of 7.5% for initiation of statin therapy in older adults.

CONCLUSIONS

Total and CVD mortality and hospitalized CVD are all significantly increased in this contemporary U.S. cohort of young adults with long-standing T1DM. These findings support more aggressive risk factor management in T1DM, especially among women.

Lipoprotein subfraction cholesterol distribution is more atherogenic in insulin resistant adolescents with type 1 diabetes

AIMS/HYPOTHESIS

Adolescents with type 1 diabetes (T1D) often have a less atherogenic-appearing fasting lipid profile than controls, despite increased rates of cardiovascular disease (CVD) as adults. We previously reported an atherogenic lipoprotein subfraction cholesterol distribution associated with insulin resistance (IR) in T1D adults. We sought to determine if T1D youth have more atherogenic profile than controls via a cross-sectional study.

METHODS

Following 3 days of controlled diet and restricted exercise, fasting plasma samples were drawn from 28 T1D youth [50% female, age 15.3 ± 2 yr, body mass index (BMI) 48%ile; diabetes duration 73 ± 52 months, hemoglobin A1c (HbA1c) 8.3 ± 1.4%] and 17 non-diabetic controls (47% female, age: 15.0 ± 2 yr, BMI 49%ile) prior to a hyperinsulinemic euglycemic clamp. Lipoproteins were fractionated by fast protein liquid chromatography (FPLC) and lipoprotein cholesterol distribution determined. Outcome measures were IR assessed by glucose infusion rate (GIR) and FPLC lipoprotein subfraction cholesterol distribution.

RESULTS

T1D youth were more IR (GIR 9.1 ± 3.6 vs. 14.7 ± 3.9 mg/kg/min, p < 0.0001) and had more cholesterol distributed as small dense low density lipoprotein-cholesterol (LDL-C) and less as large buoyant high density lipoprotein-cholesterol (HDL-C) than controls (p < 0.05), despite no differences in the fasting lipid panel. T1D girls lacked the typical female less-atherogenic profile, whereas control girls tended to have a shift toward less dense LDL-C and HDL-C vs. control boys. Among T1D, IR but not HbA1c was associated with a more atherogenic lipoprotein profile.

CONCLUSIONS/INTERPRETATIONS

Normal weight T1D youth, especially females, had more atherogenic LDL-C and HDL-C distributions which correlated with lower insulin sensitivity. IR may contribute to the increased CVD burden in T1D.

Influences of gender on cardiovascular disease risk factors in adolescents with and without type 1 diabetes

Background

Women with type 1 diabetes (T1D) have a four-fold increased risk for cardiovascular disease (CVD) compared to non-diabetic (non-DM) women, as opposed to double the risk in T1D men compared to non-DM men. It is unclear how early in life CVD risk differences begin in T1D females. Therefore, our objective was to compare CVD risk factors in adolescents with and without T1D to determine the effects of gender on CVD risk factors.

Methods

The study included 300 subjects with T1D (age 15.4±2.1 years, 50 % male, 80 % non-Hispanic White (NHW), glycated hemoglobin (A1c) 8.9±1.6 %, diabetes duration 8.8±3.0 years, BMI Z-score 0.62±0.77) and 100non-DM controls (age 15.4±2.1 years, 47 % male, 69 % NHW, BMI Z-score 0.29±1.04). CVD risk factors were compared by diabetes status and gender. Multivariate linear regression analyses were used to determine if relationships between diabetes status and CVD risk factors differed by gender independent of differences in A1c and BMI.

Results

Differences in CVD risk factors between T1D subjects and non-DM controls were more pronounced in girls. Compared to boys with T1D and non-DM girls, T1D girls had higher A1c (9.0 % vs. 8.6 % and 5.1 %, respectively), BMI Z-score (0.70 vs. 0.47 and 0.27), LDL-c (95 vs. 82 and 81 mg/dL), total cholesterol (171 vs. 153 and 150 mg/dL), DBP (68 vs. 67 and 63 mmHg), and hs-CRP (1.15 vs. 0.57 and 0.54 mg/dL) after adjusting for Tanner stage, smoking status, and race/ethnicity (p <0.05 for all). In T1D girls, differences in lipids, DBP, and hs-CRP persisted even after adjusting for centered A1c and BMI Z-score.

Testing interactions between gender and T1D with CVD risk factors indicated that differences were greater between girls with T1D and non-DM compared to differences between boys with T1D and non-DM. Overall, observed increases in CVD risk factors in T1D girls remained after further adjustment for centered A1c or BMI Z-score.

Conclusions

Interventions targeting CVD risk factors in addition to lowering HbA1c and maintaining healthy BMI are needed for youth with T1D. The increased CVD risk factors seen in adolescent girls with T1D in particular argues for earlier intervention to prevent later increased risk of CVD in women with T1D.

Transcriptome Profiles Using Next-Generation Sequencing Reveal Liver Changes in the Early Stage of Diabetes in Tree Shrew (Tupaia belangeri chinensis)

Determining the liver changes during the early stages of diabetes is critical to understand the nature of the disease and development of novel treatments for it. Advances in the use of animal models and next-generation sequencing technologies offer a powerful tool in connection between liver changes and the diabetes. Here, we created a tree shrew diabetes model akin to type 1 diabetes by using streptozotocin to induce hyperglycemia and hyperlipidemia. Using RNA-seq, we compiled liver transcriptome profiles to determine the differentially expressed genes and to explore the role of hyperglycemia in liver changes. Our results, respectively, identified 14,060 and 14,335 genes in healthy tree shrews and those with diabetes, with 70 genes differentially expressed between the two groups. Gene orthology and KEGG annotation revealed that several of the main biological processes of these genes were related to translational processes, steroid metabolic processes, oxidative stress, inflammation, and hypertension, all of which are highly associated with diabetes and its complications. These results collectively suggest that STZ induces hyperglycemia in tree shrew and that hyperglycemia induced oxidative stress led to high expression of aldose reductase, inflammation, and even cell death in liver tissues during the early stage of diabetes.

Associations between intensive diabetes therapy and NMR-determined lipoprotein subclass profiles in type 1 diabetes

Our objective is to define differences in circulating lipoprotein subclasses between intensive versus conventional management of type 1 diabetes during the randomization phase of the Diabetes Control and Complications Trial (DCCT). NMR-determined lipoprotein subclass profiles (NMR-LSPs), which estimate molar subclass concentrations and mean particle diameters, were determined in 1,294 DCCT subjects after a median of 5 years (interquartile range: 4-6 years) of randomization to intensive or conventional diabetes management. In cross-sectional analyses, we compared standard lipids and NMR-LSPs between treatment groups. Standard total, LDL, and HDL cholesterol levels were similar between randomization groups, while triglyceride levels were lower in the intensively treated group. NMR-LSPs showed that intensive therapy was associated with larger LDL diameter (20.7 vs. 20.6 nm, P = 0.01) and lower levels of small LDL (median: 465 vs. 552 nmol/l, P = 0.007), total IDL/LDL (mean: 1,000 vs. 1,053 nmol/l, P = 0.01), and small HDL (mean: 17.3 vs. 18.6 μmol/l, P < 0.0001), the latter accounting for reduced total HDL (mean: 33.8 vs. 34.8 μmol/l, P = 0.01). In conclusion, intensive diabetes therapy was associated with potentially favorable changes in LDL and HDL subclasses in sera. Further research will determine whether these changes contribute to the beneficial effects of intensive diabetes management on vascular complications.

MENSTRUAL AND REPRODUCTIVE FUNCTION IN WOMEN WITH TYPE 1 DIABETES

OBJECTIVE

Menstrual irregularities, reproductive abnormalities, and androgen excess are reported to be more prevalent in women with type 1 diabetes (T1D). The objective of this study was to investigate the prevalence of menstrual irregularities, reproductive abnormalities, and androgen excess among women with T1D and their age-matched controls.

METHODS

A survey requesting information regarding menstrual and reproductive histories was administered to all participants. Results were stratified according to age (18 to 40, 40 to 50, and >50 years).

RESULTS

There were no significant differences between women with and without diabetes in age at menarche, cycle length, or androgen excess in any group. Women who self-reported difficulty with glycemic control were more likely to report irregular menses than controls (P = .04). Among women who reported ever being pregnant, there were fewer pregnancies (P = .02) and live births (P = .002) in women with T1D. Women with T1D reported a lower frequency of oral contraceptive use (P = .003), despite being less likely to smoke (P = .016).

CONCLUSION

Menstrual and reproductive abnormalities were not observed more frequently in women with T1D in this study. Subtle but measurable differences in menstrual and reproductive function were confined to the subgroup of women who perceived poor control of their diabetes. Additional prospective studies of T1D and menstrual and reproductive function would be useful.

Risk of all-cause mortality and vascular events in women versus men with type 1 diabetes: a systematic review and meta-analysis

BACKGROUND

Studies have suggested sex differences in the mortality rate associated with type 1 diabetes. We did a meta-analysis to provide reliable estimates of any sex differences in the effect of type 1 diabetes on risk of all-cause mortality and cause-specific outcomes.

METHODS

We systematically searched PubMed for studies published between Jan 1, 1966, and Nov 26, 2014. Selected studies reported sex-specific estimates of the standardised mortality ratio (SMR) or hazard ratios associated with type 1 diabetes, either for all-cause mortality or cause-specific outcomes. We used random effects meta-analyses with inverse variance weighting to obtain sex-specific SMRs and their pooled ratio (women to men) for all-cause mortality, for mortality from cardiovascular disease, renal disease, cancer, the combined outcome of accident and suicide, and from incident coronary heart disease and stroke associated with type 1 diabetes.

FINDINGS

Data from 26 studies including 214 114 individuals and 15 273 events were included. The pooled women-to-men ratio of the SMR for all-cause mortality was 1·37 (95% CI 1·21-1·56), for incident stroke 1·37 (1·03-1·81), for fatal renal disease 1·44 (1·02-2·05), and for fatal cardiovascular diseases 1·86 (1·62-2·15). For incident coronary heart disease the sex difference was more extreme; the pooled women-to-men ratio of the SMR was 2·54 (95% CI 1·80-3·60). No evidence suggested a sex difference for mortality associated with type 1 diabetes from cancer, or accident and suicide.

INTERPRETATION

Women with type 1 diabetes have a roughly 40% greater excess risk of all-cause mortality, and twice the excess risk of fatal and nonfatal vascular events, compared with men with type 1 diabetes.

FUNDING

None.

[Cardiovascular disease in patients with type 1 and type 2 diabetes in Spain]

BACKGROUND AND OBJECTIVE

To describe the prevalence of cardiovascular disease (CVD) in type 1 diabetes (T1DM) and to compare it with that observed in type 2 diabetes (T2DM) and normal population in Spain.

PATIENTS AND METHODS

Cross-sectional study (18-70 years-old). Information on CVD was available from a nurse-administered questionnaire (Di@bet.es Study, NORMAL=3,430, T2DM=312) and from a physician reporting form (T1DM=1,382). Differences in the crude and adjusted prevalence of coronary heart (CHD), cerebrovascular (CNSD), peripheral vascular (PVD) and overall CV (CVD) disease were investigated between T1DM vs. NORMAL, and T1DM vs. T2DM groups.

RESULTS

We found differences in age, body mass index, proportion of women, dyslipemia and antihypertensive medication between T1DM vs. NORMAL and T1DM vs. T2DM (all P<.001). Smoking prevalence was not different between T1DM vs. T2DM and it was lower in T1DM compared to NORMAL (P<.0001). The percentage of CHD, CNSD, PVD, and overall CVD in T1DM vs. NORMAL was 3.0 vs. 2.5 (P=.31), 0.70 vs. 1.10 (P=.22), 2.61 vs. 0.20 (P<.0001), and 5.1 vs. 3.44 (P<.01), respectively. The prevalence in T2DM (vs. T1DM) was 11.3 (P<.0001), 3.5 (P<.0001), 4.2 (P=.13), and 17% (P<.0001), respectively. Multiple logistic regression adjusted models showed a higher prevalence of CHD (odds ratio [OR] 2.27, 95% confidence interval [95% CI] 1.41-3.67), PVD (OR 15.35, 95% CI 5.61-42.04), and overall CVD (OR 2.32, 95% CI 1.55-3.46), but not for CNSD (OR 0.49, 95% CI 0.19-1.27) in T1DM compared to NORMAL. No differences were found between T1DM and T2DM.

CONCLUSIONS

We found a higher prevalence of CVD in a Mediterranean population of T1DM individuals compared with non-diabetic subjects. This prevalence was similar to that observed in T2DM.

Low prevalence of subclinical atherosclerosis in asymptomatic patients with type 1 diabetes in a European Mediterranean population

OBJECTIVE

To evaluate the presence of early carotid and coronary atherosclerosis in asymptomatic patients with type 1 diabetes with no history of ischemic heart disease.

RESEARCH DESIGN AND METHODS

One hundred and fifty patients with type 1 diabetes (58% males; 38.6 ± 8.1 years, 20.4 ± 8.1 years of evolution; HbA1c 8.1 ± 2.3%; 52% nonsmokers; 26% retinopathy; 9% microalbuminuria) and 50 nondiabetic control subjects age and sex matched were studied. Carotid ultrasonography to determine common carotid artery intima-media thickness (c-IMT) and the presence of atheroma plaques and cardiac computed tomography for calcium analysis and quantification (coronary artery calcium score [CACS]) were performed.

RESULTS

Most patients with type 1 diabetes and control subjects displayed a CACS of 0 (82 vs. 92%). Patients with type 1 diabetes with CACS ≥1 were older and had higher HbA1c (44.5 ± 5.1 vs. 36.7 ± 8.1 years [P < 0.001] and 8.5 ± 1.1 vs. 7.8 ± 1.0% [P < 0.003], respectively) and longer evolution of diabetes (25.4 ± 9.2 vs. 19.3 ± 7.4 years, P < 0.005) and mean c-IMT (0.67 ± 0.18 vs. 0.53 ± 0.11 mm, P < 0.001) compared with patients with CACS of 0. Smoking (P < 0.02), nephropathy (P < 0.05), retinopathy (P < 0.05), and male sex (P < 0.03) were significantly and positively associated with CACS ≥1. Mean c-IMT was significantly higher in patients with type 1 diabetes (0.55 ± 0.14 vs. 0.48 ± 0.14 mm, P < 0.01), and 11% of them presented atheroma plaques (8% of control subjects). Multivariant logistic regression analysis showed that c-IMT was related to CACS (β = 6.87, P < 0.001).

CONCLUSIONS

A small percentage of patients with type 1 diabetes showed data suggestive of subclinical atherosclerosis. Universal screening of coronary disease in this population is not justified. Carotid ultrasonography may be useful for screening in the subset of patients with cardiovascular risk factors and long disease evolution.

Plasma levels of advanced glycation endproducts are associated with type 1 diabetes and coronary artery calcification

Background

Advanced glycation endproducts (AGEs) may play a role in the development of coronary artery calcification (CAC) in type 1 diabetes (T1DM). We studied plasma AGEs in association with T1DM and CAC, and whether or not the latter association could be explained by low-grade inflammation (LGI) or endothelial dysfunction (ED).

Methods

We studied 165 individuals with and 169 without T1DM. CAC was quantified in a CAC score based on CT-scanning. Plasma levels of protein-bound pentosidine, N^ϵ-(carboxymethyl)lysine (CML) and N^ϵ-(carboxyethyl)lysine (CEL) were measured with HPLC/UPLC with fluorescence detection or tandem-mass spectrometry. Tetrahydropyrimidine (THP) was measured with ELISA, as were HsCRP, and sVCAM-1 and vWF, as markers for LGI and ED, respectively. Associations were analyzed with ANCOVA and adjusted for age, sex, BMI, waist-to-hip ratio, smoking, blood pressure, lipid profile, eGFR and T1DM.

Results

Individuals with T1DM had higher plasma levels of pentosidine, CML and THP compared with controls; means (95% CI) were 0.69 (0.65-0.73) vs. 0.51 (0.48-0.54) nmol/mmol LYS, p < 0.001; 105 (102–107) vs. 93 (90–95) nmol/mmol LYS, p < 0.001; and 126 (118–134) vs. 113 (106–120) U/mL, p = 0.03, respectively. Levels of pentosidine were higher in individuals with T1DM with a moderate to high compared with a low CAC score, means (95% CI) were 0.81 (0.70-0.93) vs. 0.67 (0.63-0.71) nmol/mmol LYS, p = 0.03, respectively. This difference was not attenuated by adjustment for LGI or ED.

Conclusions

We found a positive association between pentosidine and CAC in T1DM. These results may indicate that AGEs are possibly involved in the development of CAC in individuals with T1DM.

Impaired renal function further increases odds of 6-year coronary artery calcification progression in adults with type 1 diabetes: the CACTI study

OBJECTIVE

To determine whether baseline estimated glomerular filtration rate (eGFR) and albumin-to-creatinine ratio (ACR) independently predict coronary artery calcification (CAC) progression, and to determine how eGFR changes over 6 years in adults with type 1 diabetes compared with nondiabetic adults.

RESEARCH DESIGN AND METHODS

The Coronary Artery Calcification in Type 1 Diabetes study participants (n = 1,066) with complete data for eGFR assessment at baseline and 6 years were included. Three Chronic Kidney Disease Epidemiology Collaboration equations (serum creatinine, cystatin C, and both) were used to estimate eGFR. The association of baseline ACR and eGFR with CAC progression was analyzed using multiple logistic regression.

RESULTS

Increasing categorical baseline ACR (<10, 10-30, and >30 µg/mg) predicted CAC progression in participants with type 1 diabetes (odds ratio [OR], 2.15; 95% CI, 1.50-3.09; 7.19 [3.90-13.26]; and 18.09 [8.48-38.62]), respectively, compared with nondiabetic subjects. Baseline eGFR <60 mL/min/1.73 m(2) also predicted CAC progression (OR, 5-7, compared with nondiabetic participants). ORs for CAC progression were higher in women than in men when using the cystatin C-based Chronic Kidney Disease Epidemiology Collaboration equations. Participants with type 1 diabetes had greater eGFR decreases over 6 years than nondiabetic participants using cystatin C-based equations.

CONCLUSIONS

Although increasing ACR or decreasing eGFR predicts CAC progression, coronary atherosclerosis progresses faster in people with type 1 diabetes even in the absence of diabetic kidney disease. These findings emphasize the interaction between kidney disease and cardiovascular disease in type 1 diabetes and highlight the public health importance of lowering cardiorenal risk in people with type 1 diabetes.

The methylglyoxal-derived AGE tetrahydropyrimidine is increased in plasma of individuals with type 1 diabetes mellitus and in atherosclerotic lesions and is associated with sVCAM-1

AIMS/HYPOTHESIS

Methylglyoxal (MGO) is a major precursor for advanced glycation end-products (AGEs), which are thought to play a role in vascular complications in diabetes. Known MGO-arginine-derived AGEs are 5-hydro-5-methylimidazolone (MG-H1), argpyrimidine and tetrahydropyrimidine (THP). We studied THP in relation to type 1 diabetes, endothelial dysfunction, low-grade inflammation, vascular complications and atherosclerosis.

METHODS

We raised and characterised a monoclonal antibody against MGO-derived THP. We measured plasma THP with a competitive ELISA in two cohort studies: study A (198 individuals with type 1 diabetes and 197 controls); study B (individuals with type 1 diabetes, 175 with normoalbuminuria and 198 with macroalbuminuria [>300 mg/24 h]). We measured plasma markers of endothelial dysfunction and low-grade inflammation, and evaluated the presence of THP and N (ε)-(carboxymethyl)lysine (CML) in atherosclerotic arteries.

RESULTS

THP was higher in individuals with type 1 diabetes than in those without (median [interquartile range] 115.5 U/μl [102.4-133.2] and 109.8 U/μl [91.8-122.3], respectively; p = 0.03). THP was associated with plasma soluble vascular cell adhesion molecule 1 in both study A (standardised β = 0.48 [95% CI 0.38, 0.58]; p < 0.001) and study B (standardised β = 0.31 [95% CI 0.23, 0.40]; p < 0.001), and with secreted phospholipase A2 (standardised β = 0.26 [95% CI 0.17, 0.36]; p < 0.001) in study B. We found no association of THP with micro- or macro-vascular complications. Both THP and CML were detected in atherosclerotic arteries.

CONCLUSIONS/INTERPRETATION

Our results suggest that MGO-derived THP may reflect endothelial dysfunction among individuals with and without type 1 diabetes, and therefore may potentially play a role in the development of atherosclerosis and vascular disease.

Vascular calcification in diabetes: mechanisms and implications

Cardiovascular disease (CVD) remains the leading cause of death among adults with diabetes, and CVD prevention remains a major challenge. Coronary artery calcium (CAC) score measured by electron beam tomography (EBT) or multi-slice detector computed tomography correlates closely with plaque burden and coronary angiography, and predicts coronary events independently of other risk factors. Further, progression of CAC over several years has been shown to predict increased mortality. Coronary calcification is an active process strongly associated with atherosclerotic plaque evolution and is an accepted surrogate endpoint in studies of patients with diabetes older than 30. In this review, recent findings regarding the mechanisms and implications of vascular calcification in diabetes will be discussed.

Is the risk and nature of CVD the same in type 1 and type 2 diabetes?

The incidence of both type 1 and type 2 diabetes is increasing globally, most likely explained by environmental changes, such as changing exposures to foods, viruses, and toxins, and by increasing obesity. While cardiovascular disease (CVD) mortality has been declining recently, this global epidemic of diabetes threatens to stall this trend. CVD is the leading cause of death in both type 1 and type 2 diabetes, with at least a two- to fourfold increased risk in patients with diabetes. In this review, the risk factors for CVD are discussed in the context of type 1 and type 2 diabetes. While traditional risk factors such as dyslipidemia, hypertension, and obesity are greater in type 2 patients than in type 1 diabetes, they explain only about half of the increased CVD risk. The role for diabetes-specific risk factors, including hyperglycemia and kidney complications, is discussed in the context of new study findings.

Relationship between insulin resistance and coronary artery calcium in young men and women

Background

The gender disparity in cardiovascular disease (CVD) risk is greatest between young men and women. However, the causes of that are not fully understood. The objective of this study was to evaluate the relationship between insulin resistance and the presence of coronary artery calcium (CAC) to identify risk factors that may predispose young men and women to CVD.

Methodology/Principal Findings

Insulin resistance and CVD risk factors were examined in 8682 Korean men and 1829 women aged 30–45 years old. Insulin resistance was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR), and CAC was measured using computed tomography. Women were less likely to be insulin resistant (upper quartile of HOMA-IR, 18% vs. 27%, p<0.001) and had a lower prevalence of CAC (1.6% vs. 6.4%, p<0.001). Even when equally insulin resistant men and women were compared, women continued to have lower prevalence of CAC (3.1% vs. 7.2%, p = 0.004) and a more favorable CVD risk profile. Finally, after adjustment for traditional CVD risk factors, insulin resistance remained an independent predictor of CAC only in men (p = 0.03).

Conclusions/Significance

Young women have a lower risk for CVD and a lower CAC prevalence compared with men. This favorable CVD risk profile in women appears to occur regardless of insulin sensitivity. Unlike men, insulin resistance was not a predictor of CAC in women in this cohort. Therefore, insulin resistance has less impact on CVD risk and CAC in young women compared with men, and insulin resistance alone does not explain the gender disparity in CVD risk that is observed at an early age.

Can augmentation index substitute aortic pulse wave velocity in the assessment of central arterial stiffness in type 1 diabetes?

The aim of this study was to test whether the augmentation index adjusted for heart rate (AIx@HR75) can be used as a substitute for aortic pulse wave velocity (aPWV) in the measurement of arterial stiffness (AS) in type 1 diabetes. Sixty-eight patients with type 1 diabetes and 68 age- and sex-matched controls were evaluated. AS was assessed by aPWV and AIx@HR75 using applanation tonometry. Subjects with type 1 diabetes had higher aPWV compared to controls, but no differences were found between groups regarding AIx@HR75 [men: 10.75 % (2.63-20.75) vs. 8.25 % (4.00-11.38); p = 0.462. Women: 20.75 % (5.00-30.16) vs. 14.50 % (11.38-22.16); p = 0.418]. In univariate analyses, aPWV correlated positively with AIx@HR75 in both groups (type 1: r = 0.340, p = 0.005; healthy subjects: r = 0.451, p < 0.001). However, AIx@HR75 was not associated with aPWV after adjustment for cardiovascular risk factors in multivariate models (type 1: p = 0.342; healthy subjects: p = 0.976). Our findings suggest that AIx@HR75 should not be used as a substitute for aPWV for measuring AS in type 1 diabetes.

Gender-specific care of diabetes

Diabetic men have benefited in the last 30 years from a significant improvement in total and cardiovascular mortality, whereas diabetic women have had no improvement at all. Moreover, recent research focused on the role of sex hormones in glucose homeostasis, and might account for different pathophysiologic mechanisms in the development of diabetes-related complications. Thus, care of diabetic women is a challenge that requires particular attention. The available data regarding gender-specific care of diabetes mellitus are uneven, rich in some domains but very poor in others. The large prospective trials performed in the last 20 years have assumed that the natural history of diabetes mellitus in men and women, as well as the efficiency of glucose-lowering therapies and management of hyperglycemic-related complications, could be attributable without distinction to men and women. We propose in this paper to analyze the published medical literature according to the specific management of diabetes mellitus in women, and to try to distinguish some particular features. We found important distinctions between diabetic men and women regarding the patterns of abnormalities of glucose regulation, epidemiology, development of diabetes-related complications, ischemic heart disease, morbidity and mortality, impact of cardiovascular risk factors, development of the metabolic syndrome, depression and osteoporosis, as well as the impact of lifestyle modifications or primary and secondary preventions on cardiovascular risk factors, and finally medical therapeutics. Moreover, special considerations were given to some particular aspects of the medical life in diabetic women, such as the features of gestational diabetes mellitus and the management of pregnancy in pregestational diabetic women, use of contraception, hormone-replacement therapy and polycystic ovary syndrome.

Sex differences in cardiovascular disease risk in adolescents with type 1 diabetes

BACKGROUND

Cardiovascular disease is seen at a younger age and at a higher prevalence in patients with type 1 diabetes than in the general population. It is well described that women with type 1 diabetes have a higher relative risk of cardiovascular disease than men with type 1 diabetes, unlike that seen in the general population. The pathophysiology behind this is unknown.

OBJECTIVE

We performed a cross-sectional study to examine sex differences in cardiovascular disease risk factors in adolescents with type 1 diabetes between ages 13 and 20 years, compared with children of a similar age without type 1 diabetes.

METHODS

All patients underwent a dual energy x-ray absorptiometry scan to measure body composition and a pulse wave test measure of arterial elasticity. Fasting serum lipid levels, apolipoprotein B, and apolipoprotein C-III levels were measured in each patient. Twenty-nine children with type 1 diabetes (10 girls, 19 boys) and 37 healthy children (18 girls, 19 boys) participated.

RESULTS

Although no sex differences for body mass index (P = 0.91) and glycosylated hemoglobin (P = 0.69) were seen, girls with type 1 diabetes had a significantly higher percent trunk fat compared with boys (P = 0.004). No sex differences were found (P > 0.05) for percent trunk fat in adolescents without diabetes. There was no sex difference among any other cardiovascular risk factors in either children with or without diabetes.

CONCLUSIONS

Female adolescents with type 1 diabetes have more centrally distributed fat, which may contribute to their relatively higher cardiovascular disease risk. Attenuation of the central distribution of fat through exercise and dietary modifications may help ameliorate their subsequent cardiovascular disease burden.

Cardiovascular disease risk in young people with type 1 diabetes

Cardiovascular disease (CVD) is the most frequent cause of death in people with type 1 diabetes (T1D), despite modern advances in glycemic control and CVD risk factor modification. CVD risk identification is essential in this high-risk population, yet remains poorly understood. This review discusses the risk factors for CVD in young people with T1D, including hyperglycemia, traditional CVD risk factors (dyslipidemia, smoking, physical activity, hypertension), as well as novel risk factors such as insulin resistance, inflammation, and hypoglycemia. We present evidence that adverse changes in cardiovascular function, arterial compliance, and atherosclerosis are present even during adolescence in people with T1D, highlighting the need for earlier intervention. The methods for investigating cardiovascular risk are discussed and reviewed. Finally, we discuss the observational studies and clinical trials which have thus far attempted to elucidate the best targets for early intervention in order to reduce the burden of CVD in people with T1D.

Risk of cardiovascular disease and total mortality in adults with type 1 diabetes: Scottish registry linkage study

BACKGROUND

Randomized controlled trials have shown the importance of tight glucose control in type 1 diabetes (T1DM), but few recent studies have evaluated the risk of cardiovascular disease (CVD) and all-cause mortality among adults with T1DM. We evaluated these risks in adults with T1DM compared with the non-diabetic population in a nationwide study from Scotland and examined control of CVD risk factors in those with T1DM.

METHODS AND FINDINGS

The Scottish Care Information-Diabetes Collaboration database was used to identify all people registered with T1DM and aged ≥20 years in 2005-2007 and to provide risk factor data. Major CVD events and deaths were obtained from the national hospital admissions database and death register. The age-adjusted incidence rate ratio (IRR) for CVD and mortality in T1DM (n = 21,789) versus the non-diabetic population (3.96 million) was estimated using Poisson regression. The age-adjusted IRR for first CVD event associated with T1DM versus the non-diabetic population was higher in women (3.0: 95% CI 2.4-3.8, p<0.001) than men (2.3: 2.0-2.7, p<0.001) while the IRR for all-cause mortality associated with T1DM was comparable at 2.6 (2.2-3.0, p<0.001) in men and 2.7 (2.2-3.4, p<0.001) in women. Between 2005-2007, among individuals with T1DM, 34 of 123 deaths among 10,173 who were <40 years and 37 of 907 deaths among 12,739 who were ≥40 years had an underlying cause of death of coma or diabetic ketoacidosis. Among individuals 60-69 years, approximately three extra deaths per 100 per year occurred among men with T1DM (28.51/1,000 person years at risk), and two per 100 per year for women (17.99/1,000 person years at risk). 28% of those with T1DM were current smokers, 13% achieved target HbA(1c) of <7% and 37% had very poor (≥9%) glycaemic control. Among those aged ≥40, 37% had blood pressures above even conservative targets (≥140/90 mmHg) and 39% of those ≥40 years were not on a statin. Although many of these risk factors were comparable to those previously reported in other developed countries, CVD and mortality rates may not be generalizable to other countries. Limitations included lack of information on the specific insulin therapy used.

CONCLUSIONS

Although the relative risks for CVD and total mortality associated with T1DM in this population have declined relative to earlier studies, T1DM continues to be associated with higher CVD and death rates than the non-diabetic population. Risk factor management should be improved to further reduce risk but better treatment approaches for achieving good glycaemic control are badly needed. Please see later in the article for the Editors' Summary.

Macrovascular angiopathy in children and adolescents with type 1 diabetes

Diabetes represents one of the most common diseases globally. Worryingly, the worldwide incidence of type 1 diabetes (T1D) is rising by 3% per year. Despite the rapid increase in diabetes incidence, recent advances in diabetes treatment have been successful in decreasing morbidity and mortality from diabetes-related retinopathy, nephropathy, and neuropathy. In contrast, there is clear evidence for the lack of improvement in mortality for cardiovascular diseases (CVDs). This emphasizes the importance of focusing childhood diabetes care strategies for the prevention of CVD in adulthood. Furthermore, although most work on diabetes and macrovascular disease relates to type 2 diabetes, it has been shown that the age-adjusted relative risk of CVD in T1D far exceeds that in type 2 diabetes. As T1D appears predominantly during childhood, those with T1D are at greater risk for coronary events early in life and require lifelong medical attention. Because of the important health effects of CVDs in children and adolescents with T1D, patients, family members, and care providers should understand the interaction of T1D and cardiovascular risk. In addition, optimal cardiac care for the patient with diabetes should focus on aggressive management of traditional cardiovascular risk factors to optimize those well-recognized as well as new specific risk factors which are becoming available. Therefore, a complete characterization of the molecular mechanisms involved in the development and progression of macrovascular angiopathy is needed. Furthermore, as vascular abnormalities begin as early as in childhood, potentially modifiable risk factors should be identified at an early stage of vascular disease development.