A prospective study of coronary heart disease in relation to fasting insulin, glucose, and diabetes. The Atherosclerosis Risk in Communities (ARIC) Study

Association of long-term insulin variability before the onset of diabetes with cardiovascular outcomes in later life: Findings from the coronary artery risk development in young adults (CARDIA) study

Background

The important effects of variability of some physiological/biological characteristics (such as LDL cholesterol, blood pressure) on cardiovascular outcomes have been elucidated, while the role of insulin variability is undefined.

Objectives

To investigate the associations of long-term fasting insulin variability during young adulthood before the onset of diabetes with subsequent cardiovascular outcomes in middle age.

Methods

We included 3,983 CARDIA (Coronary Artery Risk Development Study in Young Adults) participants aged 18 to 30 years with at least three fasting insulin measurements. Intra-individual fasting insulin variability was defined by the average real variability (ARV) of insulin and standard deviation (SD) of insulin during 30-year follow-up. The presence and the degree of coronary artery calcification (CAC) were assessed by computed tomography at year 25. Incident cardiovascular disease (CVD) and all-cause mortality were adjudicated.

Results

After multivariable adjustment, comparing high versus low tertile of insulin ARV, the hazard of CVD increased by 65 % (HR, 1.65; 95 % CI, 1.13-2.39) and all-cause mortality by 97 % (HR, 1.97; 95 % CI, 1.38-2.82). Higher tertile of insulin ARV was associated with significantly worse degree of CAC (β =0.1; 95 % CI, 0.03-0.18) but not with the presence of CAC (P = 0.197). Similar results were also observed in insulin SD.

Conclusion

High long-term insulin variability in young adulthood before the onset of diabetes was associated with an increased risk of CVD and all-cause mortality in later life, independent of average FG, HOMA-IR and other established cardiovascular risk factors. Long-term insulin variability was associated with the degree but not the presence of CAC.

Weight Gain, Weight Loss, and Type 2 Diabetes Risk: Evidence From the Atherosclerosis Risk in Communities (ARIC) Study

INTRODUCTION

While type 2 diabetes (T2DM) has become a major health issue in the North American and Caribbean region, the effects of weight change on incident T2DM, conditional on either initial or attained weight, are poorly addressed. Therefore, we aimed to assess the impact of 3-year weight change on incident T2DM over 6 years among US individuals.

METHODS

A total of 8377 participants aged 45-64 years (4601 women), free of T2DM or cancer at baseline from the Atherosclerosis Risk in Communities (ARIC) study were included. Weight measurements were taken at baseline (visit 1, 1987-89) and approximately 3 years later (visit 2, 1990-92). Participants were categorised based on their weight change ratio into ≥ 5% weight loss, stable (±5%), and ≥ 5% weight gain. Cox proportional hazards models, adjusting for known diabetes risk factors, were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident T2DM, with stable weight (±5%) as the reference category.

RESULTS

During a median follow-up period of 6 years, participants were classified into three categories: 361 persons remained stable (±5%), 47 with ≥ 5% loss, and 135 with ≥ 5% gain. In multivariable analysis, after adjustment with initial weight, ≥ 5% weight gain and loss were significantly associated with higher [HR (95% CI): 1.68 (1.36-2.06), p-value < 0.0001] and lower [0.73 (0.53-1.00), p-value = 0.05] risks of incident T2DM, respectively. When adjusted for attained weight, weight gain ≥ 5% remained a significant risk factor for T2DM [1.51 (1.21-1.88)]; however, weight loss ≥ 5% lost statistical significance [0.84 (0.60-1.17), p-value = 0.31].

CONCLUSIONS

We found a robust association between weight gain and incident T2DM; however, the beneficial impact of weight loss was significantly attenuated after considering the attained weight.

[Coronarography and etiologies of heart failure with impaired left ventricular ejection fraction in Senegal]

INTRODUCTION

Heart failure is a major public health problem because of the number and duration of hospitalizations. Patients with heart failure may have mixed etiologies that are not mutually exclusive, and etiologies vary between high-income and developing countries. The aim of our work was to study the contribution of coronary angiography in the etiological investigation of heart failure with impaired LVEF in the cardiology department of HPD.

METHODOLOGY

This was a descriptive and analytical cross-sectional study with retrospective data collection on 103 patients hospitalized in the cardiology department of DAKAR's Hospital Principal presenting with heart failure with impaired LVEF and who underwent coronary angiography from January 2019 to December 2022.

RESULTS

Our study included 103 patients with a clear male predominance 79.6% and a sex ratio of 3.7. Their mean age was 64±13.5 years. Diabetes was prevalent at 24.3% (p=0.033). All patients had impaired segmental and/or global left ventricular kinetics. Mean ejection fraction was 28.1±6.8. The right radial route was predominantly used 83.7% of the time, and there were no procedural incidents or accidents. Diabetes was significantly associated with coronary involvement (p=0.033). Coronary angiography was normal in 37.8% of patients and showed tri-truncular lesions in 19.4% of patients and bi-truncular lesions in 17.4%. We found 91 significant lesion and 67 non-significant lesion. A total of 41 patients had ischemic heart disease, equivalent to 39.8%.

CONCLUSION

Our study shows that ischemic heart disease plays an important role in the etiology of heart failure with impaired LVEF, and that coronary angiography should be performed routinely.

Data-driven Cluster Analysis Reveals Increased Risk for Severe Insulin-deficient Diabetes in Black/African Americans

CONTEXT

Diabetes is a heterogenic disease and distinct clusters have emerged, but the implications for diverse populations have remained understudied.

OBJECTIVE

Apply cluster analysis to a diverse diabetes cohort in the US Deep South.

DESIGN

Retrospective hierarchical cluster analysis of electronic health records from 89 875 patients diagnosed with diabetes between January 1, 2010, and December 31, 2019, at the Kirklin Clinic of the University of Alabama at Birmingham, an ambulatory referral center.

PATIENTS

Adult patients with International Classification of Diseases diabetes codes were selected based on available data for 6 established clustering parameters (glutamic acid decarboxylase autoantibody; hemoglobin A1c; body mass index; diagnosis age; HOMA2-B; HOMA2-IR); ∼42% were Black/African American.

MAIN OUTCOME MEASURE(S)

Diabetes subtypes and their associated characteristics in a diverse adult population based on clustering analysis. We hypothesized that racial background would affect the distribution of subtypes. Outcome and hypothesis were formulated prior to data collection.

RESULTS

Diabetes cluster distribution was significantly different in Black/African Americans compared to Whites (P < .001). Black/African Americans were more likely to have severe insulin-deficient diabetes (OR, 1.83; 95% CI, 1.36-2.45; P < .001), associated with more serious metabolic perturbations and a higher risk for complications (OR, 1.42; 95% CI, 1.06-1.90; P = .020). Surprisingly, Black/African Americans specifically had more severe impairment of β-cell function (homoeostatic model assessment 2 estimates of β-cell function, C-peptide) (P < .001) but not being more obese or insulin resistant.

CONCLUSION

Racial background greatly influences diabetes cluster distribution and Black/African Americans are more frequently and more severely affected by severe insulin-deficient diabetes. This may further help explain the disparity in outcomes and have implications for treatment choice.

Causes of Excess Mortality in Diabetes Patients Without Coronary Artery Disease: A Cohort Study Revealing Endocrinologic Contributions

Background

Diabetes mellitus (DM) patients without coronary artery disease (CAD) have a higher all-cause mortality rate than patients with neither DM nor CAD. We examined cause-specific death of DM patients with and without CAD.

Methods

We conducted a cohort study of all patients who underwent CAG in Western Denmark between 2003 and 2016. Using Danish health registries, patients were followed for a maximum of 10 years and stratified according to their DM and CAD status. Outcomes included all-cause-, cancer-, circulatory-, and endocrinologic death. Ten-year cumulative risks were computed as well as adjusted and unadjusted hazard ratios (aHR and HR).

Results

A total of 132,432 patients (28,524 deaths, median follow-up of 6.2 years) were included. Compared to patients with neither DM nor CAD, DM patients without CAD had a higher 10-year risk of all-cause death (27.9% versus 19.7%, aHR 1.43 [95% CI 1.35-1.52]), cancer death (7.2% versus 5.4%, aHR 1.29 [95% CI 1.15-1.46]), circulatory death (9.1% versus 6.9%, aHR 1.35 [95% CI 1.22-1.49]), and endocrinologic death (3.9% versus 0.3%, aHR 14.02 [95% CI 10.95-17.95]). Among endocrinologic deaths, 87% were due to classical complications of DM, such as diabetic nephropathy and ketoacidosis, in DM patients without CAD.

Conclusion

Diabetes patients without CAD exhibit a higher risk of all-cause mortality, driven primarily by elevated rates of cancer, circulatory, and endocrinologic deaths, particularly related to diabetic microvascular complications.

Differential Ophthalmological Profile in Patients with Coronary Artery Disease Coexisting with Type 2 Diabetes Mellitus: Elevated Tear Cytokine Concentrations

Background/Objectives: Coronary artery disease (CAD) and type-2 diabetes mellitus (T2DM) are characterized by chronic low-grade inflammation. However, measuring cytokines typically involves invasive blood sampling, which can be problematic for CAD patients. This study aimed to assess ophthalmological parameters and tear cytokines in patients with CAD, comparing those with comorbid T2DM to those without to understand their inflammatory profiles. Methods: One hundred subjects with suspected chronic or acute CAD were initially included in this single-center cross-sectional study after clinical stabilization. Seventy-two patients with confirmed CAD were divided into two groups: 32 patients with T2DM and 40 patients without T2DM. A total of 144 eyes were examined, and tear fluid samples were collected to determine cytokine concentrations. Ophthalmological parameters and tear concentrations of cytokines were analyzed, controlling for age, sex, and other cardiovascular risk factors. Results: Patients with CAD and T2DM exhibited decreased ophthalmological parameters and increased cytokine concentrations in comparison to those without T2DM. Significant inverse correlations between ophthalmological parameters and cytokine concentrations were observed. Following adjustment, a full logistic regression model for distinguishing patients with CAD and comorbid T2DM included macular cube volume, mean macular thickness, interleukin (IL)-4, IL-5, IL-6, IL-8, IL-9, IL-13, granulocyte colony-stimulating factor (G-CSF), CCL3, CCL4, and CCL11/eotaxin-1, demonstrating excellent discriminatory power (Area Under the Curve = 0.95, 95% Confidence Interval = 0.91-0.99; p < 0.001). Subsequently, IL-5 (Odds Ratio = 1.68, 95% CI = 1.26-2.24; p < 0.001), G-CSF (OR = 1.06, 95% CI = 1.02-1.11; p < 0.01), and CCL11/eotaxin-1 (OR = 1.56, 95% CI = 1.19-2.05; p = 0.001) emerged as the most distinguishing variables in a reduced model (AUC = 0.89, 95% CI = 0.84-0.95; p < 0.001). Conclusions: Differences in ophthalmological variables, mainly in cytokine concentrations, suggest distinct pathophysiological mechanisms in patients with CAD based on the presence of T2DM. These findings demonstrate that the inflammatory profile can be readily detected through tear sample cytokines, proving valuable for establishing more accurate prognoses and monitoring in cardiometabolic disorders.

The proteasome activator REGγ promotes diabetic endothelial impairment by inhibiting HMGA2-GLUT1 pathway

Diabetic vascular endothelial impairment is one of the main causes of death in patients with diabetes lacking adequately defined mechanisms or effective treatments. REGγ, the 11S proteasome activator known to promote the degradation of cellular proteins in a ubiquitin- and ATP-independent manner, emerges as a new regulator in the cardiovascular system. Here, we found that REGγ was upregulated in streptozocin (STZ)-induced diabetic mouse aortic endothelium in vivo and high glucose (HG)-treated vascular endothelial cells (ECs) in vitro. REGγ deficiency ameliorated endothelial impairment in STZ-induced diabetic mice by protecting against a decline in cellular glucose uptake and associated vascular ECs dysfunction by suppressing high mobility group AT-hook 2 (HMGA2) decay. Mechanically, REGγ interacted with and degraded the transcription factor HMGA2 directly, leading to decreased HMGA2 transcriptional activity, subsequently lowered expression of glucose transporter type 1 (GLUT1), and reduced cellular glucose uptake, vascular endothelial dysfunction, and impaired diabetic endothelium. Ablation of endogenous GLUT1 or HMGA2 or overexpressing exogenous HMGA2 in vascular ECs significantly blocked or reestablished the REGγ-dependent action on cellular glucose uptake and vascular endothelial functions of HG stimulation in vitro. Furthermore, exogenously introducing HMGA2 improved diabetic mice endothelial impairment features caused by REGγ in vivo, thereby substantiating a REGγ-HMGA2-GLUT1 pathway in diabetic endothelial impairment. Our findings indicate that modulating REGγ-proteasome activity may be a potential therapeutic approach for diabetic disorders with endothelial impairment.

Diabetes Mellitus and Heart Failure

Diabetes mellitus (DM) is a major risk factor for new-onset heart failure (HF) and vice versa. The pathogenesis of new-onset HF in DM is complex and has been largely attributed to the toxic cardiovascular effects of hyperglycemia and relevant metabolic abnormalities (diabetic cardiomyopathy) as well as the frequently coexisting morbidities such as hypertension (HTN), coronary artery disease (CAD), and diabetic nephropathy. In patients with type 1 DM (T1DM), HF develops in the setting of a dysregulated immune response, whereas in most patients with type 2 DM (T2DM), against a background of overweight/obesity. HF prevention in DM is feasible with rigorous treatment of cardiovascular risk factors and selective antidiabetic agents. Conversely, development of new-onset T2DM in HF (cardiogenic DM) is common and has been attributed to an increase in the resistance to insulin, especially in the skeletal muscle, liver, and adipose tissue as well as in diminished insulin secretory response to hyperglycemia by pancreatic β-cells. Cardiogenic DM further deteriorates cardiac dysfunction and adversely affects outcome in HF. Novel lifesaving medications employed in HF management such as sacubitril/valsartan and sodium glucose cotransporter 2 inhibitors (SGLT-2i) have a favorable metabolic profile and lower the incidence of cardiogenic diabetes. Whether mitigation of cardiogenic DM should be a treatment target in HF deserves further investigation.

Association of the Prognosis of Ankle-brachial Index Improvement One Year Following Endovascular Therapy in Patients with Peripheral Artery Disease: Data from the I-PAD NAGANO Registry

Objective Despite reports on the effects of ankle-brachial index (ABI) improvement following endovascular therapy (EVT) on the limb prognosis, studies evaluating cardiovascular events are limited. We investigated whether or not ABI improvement 1 year following EVT was associated with cardiovascular events. Methods The I-PAD NAGANO registry is an observational multicenter cohort study that enrolled 337 patients with peripheral artery disease (PAD) who underwent EVT between August 2015 and July 2016. From this cohort, we identified 232 patients whose ABI data 1 year following EVT were available, after excluding patients with critical limb ischemia. We divided the patients into two groups according to the degree of ABI improvement 1 year following EVT (ΔABI) - the ΔABI <0.15 group and the ΔABI ≥0.15 group - and compared the outcomes. The primary endpoint was major adverse cardiovascular events (MACEs), including all - cause death, myocardial infarction (MI), and stroke. The secondary endpoints were major adverse limb events (MALEs), defined as a composite of target lesion revascularization and major amputation, all - cause death, MI, and stroke. The median follow-up period was 3.3 years. Results The incidence of MACEs was significantly higher in the ΔABI <0.15 group than in the ΔABI ≥0.15 group (ΔABI <0.15 vs. ΔABI ≥0.15, 25.8% vs. 11.9%, log-rank p=0.036), as was the incidence of stroke (14.1% vs. 2.2%, log-rank p=0.016). A Cox regression analysis revealed that ΔABI ≥0.15 was significantly associated with fewer MACEs (hazard ratio 0.38, 95% confidence interval 0.17-0.83, p=0.016). Conclusion An increase in ABI ≥0.15 at 1 year following EVT was a predictor of reduced MACEs.

Statin but not Aspirin Treatment is Associated with Reduced Cardiovascular Risk in Patients with Diabetes without Obstructive Coronary Artery Disease

AIMS

Patients with diabetes and no obstructive coronary artery disease (CAD) as assessed by coronary angiography (CAG) are frequently treated with aspirin and statins. We examined the effectiveness of aspirin and statin treatment on cardiovascular and bleeding incidence in patients with diabetes and absent obstructive CAD.

METHODS AND RESULTS

The study included patients with diabetes and absent obstructive CAD as assessed by CAG from 2003 to 2016 in Western Denmark. We stratified patients by aspirin and statin treatment within 6 months after CAG in two separate analyses. Outcomes were MACE (major adverse cardiovascular events, a composite of myocardial infarction, ischaemic stroke, and death) and bleeding (aspirin only). To account for confounding, we used propensity score-based weights to estimate the inverse probability of treatment-weighted hazard ratios (HRIPTW). We included 4,124 patients with diabetes but without CAD as assessed by CAG, among whom 2,474 (60%) received aspirin and 2,916 (71%) received statin treatment within 6 months following CAG. Median follow-up was 4.9 years. Aspirin did not reduce 10-year MACE (21.3% vs 21.8%, HRIPTW 1.01, 95% confidence interval (CI) 0.82-1.25), all-cause death (HRIPTW 0.96, 95% CI 0.74-1.23), or bleeding (HRIPTW 0.95, 95% CI 0.73-1.23), compared to those not receiving aspirin treatment. Statin treatment reduced MACE (25% vs. 37%, HRIPTW 0.58, 95% CI 0.48-0.70) compared to those not receiving statin treatment.

CONCLUSION

Among patients with diabetes and no obstructive CAD, aspirin neither reduced MACE nor increased bleeding. In contrast, statin treatment was associated with a major reduction in risk of MACE.

Ten-year cardiovascular risk in diabetes patients without obstructive coronary artery disease: a retrospective Western Denmark cohort study

BACKGROUND

Diabetes patients without obstructive coronary artery disease as assessed by coronary angiography have a low risk of myocardial infarction, but their myocardial infarction risk may still be higher than the general population. We examined the 10-year risks of myocardial infarction, ischemic stroke, and death in diabetes patients without obstructive coronary artery disease according to coronary angiography, compared to risks in a matched general population cohort.

METHODS

We included all diabetes patients without obstructive coronary artery disease examined by coronary angiography from 2003 to 2016 in Western Denmark. Patients were matched by age and sex with a cohort from the Western Denmark general population without a previous myocardial infarction or coronary revascularization. Outcomes were myocardial infarction, ischemic stroke, and death. Ten-year cumulative incidences were computed. Adjusted hazard ratios (HR) then were computed using stratified Cox regression with the general population as reference.

RESULTS

We identified 5734 diabetes patients without obstructive coronary artery disease and 28,670 matched individuals from the general population. Median follow-up was 7 years. Diabetes patients without obstructive coronary artery disease had an almost similar 10-year risk of myocardial infarction (3.2% vs 2.9%, adjusted HR 0.93, 95% CI 0.72-1.20) compared to the general population, but had an increased risk of ischemic stroke (5.2% vs 2.2%, adjusted HR 1.87, 95% CI 1.47-2.38) and death (29.6% vs 17.8%, adjusted HR 1.24, 95% CI 1.13-1.36).

CONCLUSIONS

Patients with diabetes and no obstructive coronary artery disease have a 10-year risk of myocardial infarction that is similar to that found in the general population. However, they still remain at increased risk of ischemic stroke and death.

The relationship between coronary artery severity and insulin resistance in patients with impaired glucose tolerance and metabolic syndrome

Background

The relation between metabolic syndrome (MS) and coronary artery disease (CAD) is multifactorial, and the well-known risk factors can explain only about 25% of the disease as the relation between insulin resistance (IR) on top of MS and severity of CAD still a subject of debate with conflicting data. Also, IR and glucose intolerance are included in the definition of metabolic syndrome only by some associations. So, the aim of this research was to analyze the the relation between CAD severity (measured by the modified Gensini score) and the different components of the metabolic syndrome including insulin resistance and glucose intolerance.

Results

Out of 70 patients enrolled, 71.4% represented impaired glucose tolerance group (IGT group; n = 50) and 28.6% represented normal glucose tolerance group (NGT group; n = 20). The following variables were significantly greater among the IGT group including BMI (30.19 ± 2.27 vs 23.62 ± 2.92; P < 0.001), waist circumference (105.09 ± 8.02 vs 92.89 ± 19.92; P < 0.001), frequency of hypertension (80% vs 50%; P = 0.012), 2 h post prandial glucose (164 ± 30 vs 110 ± 20; P < 0. 04), fasting insulin (9.2 ± 1.2 vs 5.1 ± 4.3; P = 0.003), HOMA-IR (3.03 ± 0.12% vs 1.9 ± 0.12, P < 0.001), serum uric acid (4.8 ± 1.3 vs 5.8 ± 2.6; P = 0.03), mean modified Gensini score (22.3 ± 9.2 vs 15.4 ± 6.8; P < 0.001), while the mean serum HDL was significantly higher among the NGT group (40.8 ± 10.1 vs 50.6 ± 10.2; P < 0.001). There was a positive correlation between HOMA–IR; hs-CRP; MS-related variables (including waist circumflex; BMI; serum uric acid; HDL; TG);and the modified Gensini score (for HOMA, r = 0.63; P < 0.001). Several predictors for high scores of modified Gensini were noted in multiple regression analysis; however, out of those several predictors, HOMA-IR was the strongest one (OR = 4.0, 95% CI = (2.04-7.08).

Conclusion

IR is an independent risk factor for CAD severity in patients with IGT and MS. In patients with IR; those with aggressive CAD (or with a positive family history of premature CAD), IGT should be managed aggressively even before any evidence of frank diabetes. IR workup should be recommended among the other standard workup for those patients, if documented, interventions targeted against IR should be considered among the other standard management.

The IDF Definition Is Better Suited for Screening Metabolic Syndrome and Estimating Risks of Diabetes in Asian American Adults: Evidence from NHANES 2011-2016

OBJECTIVE

extensive effort has been made to better define metabolic syndrome (MetS). Whether current definitions accurately diagnose MetS and predict risk of cardiovascular disease (CVD) or diabetes in diverse ethnic groups remains largely unknown. The objective of this study was to compare the prevalence of MetS and risk of CVD and diabetes among Asian American adults using two MetS definitions, one proposed by the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III) and one by the International Diabetes Federation (IDF).

METHODS

we obtained a nationally representative sample of 2121 Asian American adults in the noninstitutionalized civilian population of the United States from the National Health and Nutrition Examination Survey (2011-2016). We computed age-adjusted, gender-specific MetS prevalence and each MetS component using ATP III and IDF definitions.

RESULTS

based on the IDF definition, MetS prevalence was 39.26% among Asian American men and 39.66% among Asian American women included in the study sample. Based on the ATP III definition, MetS prevalence in our sample was 39.38% among men and 36.11% among women. We found good concordance between the IDF and the ATP III definitions in identifying MetS in Asian American adults. Those with MetS defined only by the IDF definition had significantly higher body mass index (BMI) and waist circumference than those with MetS defined only by the ATP III definition. The IDF definition also better predicted elevated fasting insulin.

CONCLUSIONS

the IDF definition is more pertinent than the ATP III definition for screening and estimating risk of CVD and diabetes in Asian American adults. Future studies should examine differences in MetS prevalence across Asian ethnic groups to facilitate the development of culturally tailored strategies improve MetS prevention and detection in Asian Americans.

Sex differences in cardiovascular risk factors before and after the development of type 2 diabetes and risk for incident cardiovascular disease

AIMS

To assess sex differences in cardiovascular (CVD) risk factor changes before and after the development of type 2 diabetes, and, the association between incident diabetes with incident CVD in mid-life.

METHODS

We included 4893 Coronary Artery Risk Development in Young Adults Study participants, age 18-30 years at enrollment (1985-86). We ascertained incident diabetes and assessed sex differences in annual change in body mass index, blood pressure, and lipids before and after the ascertainment of diabetes using piecewise linear regression. We examined sex differences in the association between incident diabetes with incident CVD over 31 years of median follow-up.

RESULTS

Progression in most CVD risk factors did not differ by sex before diabetes. Women had better CVD profiles at the time of diabetes compared to men, and after diabetes, women had worse annual changes in blood pressure and lipids. Incident diabetes was associated with a higher hazard for incident CVD (Hazard Ratio [HR]: 1.45, 95% confidence limits: 1.07, 1.96) and we did not observe effect modification by sex (p for interaction = 0.8).

CONCLUSIONS

CVD risk factors worsened more rapidly after the development of type 2 diabetes for women than men. However, diabetes was not a stronger risk factor for incident CVD for women than men.

Genetics Insights in the Relationship Between Type 2 Diabetes and Coronary Heart Disease

Diabetes mellitus is a major risk factor for coronary heart disease (CHD). The major form of diabetes mellitus is type 2 diabetes mellitus (T2D), which is thus largely responsible for the CHD association in the general population. Recent years have seen major advances in the genetics of T2D, principally through ever-increasing large-scale genome-wide association studies. This article addresses the question of whether this expanding knowledge of the genomics of T2D provides insight into the etiologic relationship between T2D and CHD. We will investigate this relationship by reviewing the evidence for shared genetic loci between T2D and CHD; by examining the formal testing of this interaction (Mendelian randomization studies assessing whether T2D is causal for CHD); and then turn to the implications of this genetic relationship for therapies for CHD, for therapies for T2D, and for therapies that affect both. In conclusion, the growing knowledge of the genetic relationship between T2D and CHD is beginning to provide the promise for improved prevention and treatment of both disorders.

Association of insulin resistance, from mid-life to late-life, with aortic stiffness in late-life: the Atherosclerosis Risk in Communities Study

Background

Insulin resistance may contribute to aortic stiffening that leads to end-organ damage. We examined the cross-sectional association and prospective association of insulin resistance and aortic stiffness in older adults without diabetes.

Methods

We analyzed 2571 men and women at Visit 5 (in 2011–2013), and 2350 men and women at repeat examinations from baseline at Visit 1 (in 1987–1989) to Visit 5 (in 2011–2013). Linear regression was used to estimate the difference in aortic stiffness per standard unit of HOMA-IR, TG/HDL-C, and TyG at Visit 5. Linear mixed effects were used to assess if high, as opposed to non-high, aortic stiffness (> 75th percentile) was preceded by a faster annual rate of change in log-HOMA-IR, log-TG/HDL-C, and log-TyG from Visit 1 to Visit 5.

Results

The mean age of participants was 75 years, 37% (n = 957) were men, and 17% (n = 433) were African American. At Visit 5, higher HOMA-IR, higher TG/HDL-C, and higher TyG were associated with higher aortic stiffness (16 cm/s per SD (95% CI 6, 27), 29 cm/s per SD (95% CI 18, 40), and 32 cm/s per SD (95% CI 22, 42), respectively). From Visit 1 to Visit 5, high aortic stiffness, compared to non-high aortic stiffness, was not preceded by a faster annual rate of change in log-HOMA-IR from baseline to 9 years (0.030 (95% CI 0.024, 0.035) vs. 0.025 (95% CI 0.021, 0.028); p = 0.15) or 9 years onward (0.011 (95% CI 0.007, 0.015) vs. 0.011 (95% CI 0.009, 0.013); p = 0.31); in log-TG/HDL-C from baseline to 9 years (0.019 (95% CI 0.015, 0.024) vs. 0.024 (95% CI 0.022, 0.026); p = 0.06) or 9 years onward (− 0.007 (95% CI − 0.010, − 0.005) vs. − 0.009 (95% CI − 0.010, − 0.007); p = 0.08); or in log-TyG from baseline to 9 years (0.002 (95% CI 0.002, 0.003) vs. 0.003 (95% CI 0.003, 0.003); p = 0.03) or 9 years onward (0 (95% CI 0, 0) vs. 0 (95% CI 0, 0); p = 0.08).

Conclusions

Among older adults without diabetes, insulin resistance was associated with aortic stiffness, but the putative role of insulin resistance in aortic stiffness over the life course requires further study.

Associations of a metabolic syndrome severity score with coronary heart disease and diabetes in fasting vs. non-fasting individuals

BACKGROUND AND AIMS

Many traditional assessments of risk for coronary heart disease (CHD) and diabetes require laboratory studies performed after an 8-h fast. We assessed whether metabolic-syndrome (MetS) severity would remain linked to future CHD and diabetes even when assessed from non-fasting samples.

METHODS AND RESULTS

Participants in the Atherosclerosis Risk in Communities study were assessed at 4 visits and followed for 20-years of adjudicated CHD outcomes. We used Cox proportional-hazard models (for 20-year CHD outcomes) and logistic regression (for 9-year diabetes outcomes) to compare incident disease risk associated with a race/ethnicity-specific MetS-severity Z-score (MetS-Z) calculated in participants who were fasting (≥8 h) or non-fasting. All analyses were adjusted for sex, race, education, income and smoking. MetS Z-scores were overall similar between participants who were always fasting vs. those non-fasting at Visits 1-3 (all values -0.1 to 0.4), while MetS-Z for participants who were non-fasting at Visit-4 were higher at each visit. Baseline MetS-Z was linked to future CHD when calculated from both fasting and non-fasting measurements, with hazard ratio (HR) for fasting MetS-Z 1.53 (95% confidence interval [CI] 1.42, 1.66) and for non-fasting 1.28 (CI 1.08, 1.51). MetS-Z at Visit-1 also remained linked to future diabetes when measured from non-fasting samples, with odds ratio for fasting MetS-Z 3.10 (CI 2.88, 3.35) and for non-fasting 1.92 (CI 1.05, 3.51).

CONCLUSIONS

MetS-Z remained linked to future CHD and diabetes when assessed from non-fasting samples. A score such as this may allow for identification of at-risk individuals and serve as a motivation toward interventions to reduce risk.

Prevalence of diabetes mellitus as well as cardiac and other main comorbidities in a representative sample of the adult Greek population in comparison with the general population

BACKGROUND

Diabetes mellitus (DM) is the most common metabolic disorder that increases the risk of cardiovascular disease by two to four times compared with the general population. There are limited data on the prevalence of heart diseases in subjects with DM in Greece. In this study, we examined the prevalence of self-reported DM as well as cardiac and other main comorbidities in a representative sample of the adult Greek population.

METHODS

The target study population included 30,843 participants stratified by gender, age, and district, and this was a representative sample of the adult Greek population in 2010. A structured questionnaire was built to report the prevalence of self-reported DM and the main comorbidities in participants with and without DM. Collection of data was performed through telephone interviews.

RESULTS

The prevalence of self-reported DM was 6.6%. The prevalence of the main comorbidities in participants with DM vs. those without DM was as follows: heart diseases 24.0% vs. 8.9%, p<0.001; lung diseases 11.3% vs. 5.3%, p<0.001; kidney diseases 3.4% vs. 1.2%, p=0.001; liver diseases 1.4% vs. 0.7%, p=0.001; benign blood diseases 1.6% vs. 0.9%, p=0.005; and solid organ and/or blood malignancies 2.9% vs. 1.5%, p<0.001.

CONCLUSIONS

The prevalence of self-reported DM in a representative sample of the adult Greek population in 2010 was 6.6%. The prevalence of heart diseases in subjects with DM was 2.7-fold higher than the prevalence in those without DM. Diseases of the lung, kidney, liver, and blood as well as malignancies were significantly more common among participants with DM.

Long-term outcomes after percutaneous coronary intervention relative to bypass surgery in diabetic patients with multivessel coronary artery disease according to clinical presentation

BACKGROUND

For diabetic patients with multivessel coronary artery disease (MVD), limited data exist on the long-term outcomes of percutaneous coronary intervention (PCI) versus coronary artery bypass graft (CABG) according to clinical presentation [stable coronary artery disease (SCAD) or non-ST-elevation acute coronary syndrome (NSTE-ACS)].

PATIENTS AND METHODS

From a Korean multicenter registry, we analyzed 1135 diabetic patients with MVD treated with PCI (n = 660) or CABG (n = 475). After propensity score matching, 8-year major adverse cardiovascular and cerebrovascular events [MACCE; composite of all-cause death, myocardial infarction (MI), or stroke] were compared between PCI and CABG according to clinical presentation.

RESULTS

After matching, MACCE was not different between PCI and CABG for SCAD patients [15.6 vs. 17.2%, hazard ratio (HR)  = 0.94, 95% confidence interval (CI)  = 0.55-1.63, P = 0.837], whereas it was higher in PCI than in CABG for NSTE-ACS patients (31.1 vs. 22.4%, HR = 1.63, 95% CI = 1.03-2.59, P = 0.036), mainly driven by the higher MI occurrence (HR = 2.18, 95% CI = 1.04-4.59, P = 0.035). A significant interaction between revascularization strategy and clinical presentation was observed for MACCE (P-interaction = 0.022). However, when PCI was further classified according to revascularization completeness, the treatment gap between PCI and CABG with respect to MI in NSTE-ACS patients was improved by complete-revascularization PCI.

CONCLUSION

Among diabetic patients with MVD, the long-term outcomes of PCI versus CABG differed according to clinical presentation. CABG may be more beneficial for NSTE-ACS patients with MVD in reducing MACCE and MI, whereas PCI was as effective as CABG for SCAD patients with MVD. Therefore, clinical presentation must be considered when choosing revascularization strategies in these patients.

Assessing Baseline and Temporal Changes in Cardiometabolic Risk Using Metabolic Syndrome Severity and Common Risk Scores

Background Type 2 diabetes mellitus (T2 DM ) is considered a cardiovascular disease ( CVD ) risk equivalent, thereby linking assessment of cardiometabolic risk with that of CVD risk over time. Our goal was to determine how commonly used CVD risk scores and metabolic syndrome (MetS) severity performed in predicting T2 DM with and without ultimate CVD . Methods and Results We assessed data from 8273 participants of the ARIC (Atherosclerosis Risk in Communities) Study, using the pooled cohort atherosclerotic CVD risk score, the Framingham Risk Score, and a MetS severity Z score to assess their association with future risk for CVD alone, T2 DM alone, or both over 20 years of follow-up. Baseline levels of all scores were significantly associated with isolated incident T2 DM (odds ratios [ OR s] for each 1- SD increase: atherosclerotic CVD =1.7, Framingham risk score=1.7, MetS Z score=5.1). All 3 baseline scores were also significantly associated with isolated incident CVD (atherosclerotic CVD OR =2.4, Framingham risk score OR =2.3, MetS Z-score OR =1.8), with the 2 CVD scores remaining significant independent of MetS severity. MetS severity was strongly associated with future T2 DM leading to CVD (MetS Z-score OR =7.0, atherosclerotic CVD OR =3.9, Framingham risk score OR =3.5). Furthermore, changes in MetS severity were independently associated with future T2 DM - CVD progression. Conclusions CVD risk scores are associated with risk for future isolated T2 DM in addition to isolated CVD . However, MetS severity (both baseline and changes over time) was more strongly associated with T2 DM , including T2 DM ultimately leading to CVD . Following MetS severity within patients over time may identify those at greatest risk of combined cardiometabolic disease.

Diabetic Cardiomyopathy: Impact of Biological Sex on Disease Development and Molecular Signatures

Diabetic cardiomyopathy refers to a unique set of heart-specific pathological variables induced by hyperglycemia and insulin resistance. Given that cardiovascular disease (CVD) is the leading cause of death in the world, and type 2 diabetes incidence continues to rise, understanding the complex interplay between these two morbidities and developing novel therapeutic strategies is vital. Two hallmark characteristics specific to diabetic cardiomyopathy are diastolic dysfunction and cardiac structural mal-adaptations, arising from cardiac cellular responses to the complex toxicity induced by hyperglycemia with or without hyperinsulinemia. While type 2 diabetes is more prevalent in men compared to women, cardiovascular risk is higher in diabetic women than in diabetic men, suggesting that diabetic women take a steeper path to cardiomyopathy and heart failure. Accumulating evidence from randomized clinical trials indicate that although pre-menopausal women have lower risk of CVDs, compared to age-matched men, this advantage is lost in diabetic pre-menopausal women, which suggests estrogen availability does not protect from increased cardiovascular risk. Notably, few human studies have assessed molecular and cellular mechanisms regarding similarities and differences in the progression of diabetic cardiomyopathy in men versus women. Additionally, most pre-clinical rodent studies fail to include female animals, leaving a void in available data to truly understand the impact of biological sex differences in diabetes-induced dysfunction of cardiovascular cells. Elegant reviews in the past have discussed in detail the roles of estrogen-mediated signaling in cardiovascular protection, sex differences associated with telomerase activity in the heart, and cardiac responses to exercise. In this review, we focus on the emerging cellular and molecular markers that define sex differences in diabetic cardiomyopathy based on the recent clinical and pre-clinical evidence. We also discuss miR-208a, MED13, and AT2R, which may provide new therapeutic targets with hopes to develop novel treatment paradigms to treat diabetic cardiomyopathy uniquely between men and women.

Metabolic syndrome severity is significantly associated with future coronary heart disease in Type 2 diabetes

Background

The severity of the metabolic syndrome (MetS) is significantly associated with future coronary heart disease (CHD) among individuals without baseline Type 2 diabetes. However, the validity of assessing MetS severity among individuals with diabetes is unknown.

Objective

To assess for differences in MetS severity by timing of Type 2 diabetes diagnosis and to assess for associations between MetS severity and future CHD among individuals with diabetes.

Methods

We analyzed data from participants of the Atherosclerosis Risk in Communities study, including 1419 with- and 7241 without diabetes, followed during 4 visits and adjudicated CHD diagnoses over a 20-year period. We used Cox-regression techniques to assess hazard ratios (HR) of CHD based on a sex- and race/ethnicity-specific MetS-severity Z-score (standard MetS score) and a similar MetS-severity score formulated without incorporating glucose as a component of MetS (no-glucose MetS score).

Results

For both the standard- and no-glucose MetS-severity scores, scores were highest in the baseline-diabetes group, lowest in the never-diabetes group and intermediate in the incident-diabetes groups. Among participants with diabetes, increasing MetS-severity score at baseline was associated with incident CHD, using both the standard MetS score (HR 1.29, 95% confidence interval [CI] 1.21, 1.39) and the no-glucose score (HR 1.42, CI 1.24, 1.62) (both p < 0.001). For the baseline-diabetes group, this relationship remained significant when Visit 2 Hemoglobin-A_1c was included in the model, both for the standard MetS score (HR 1.21, CI 1.09, 1.34; p < 0.001) and the no-glucose score (HR 1.25, CI 1.04, 1.51; p = 0.02).

Conclusions

MetS severity appears to provide an estimate of metabolic disarray in the setting of diabetes and is predictive of future CHD events beyond HbA1c. Identifying MetS severity among individuals with diabetes may help in identifying those at higher risk, who could then receive further preventative treatment.

Electronic supplementary material

The online version of this article (10.1186/s12933-017-0647-y) contains supplementary material, which is available to authorized users.

Assessing the added predictive ability of a metabolic syndrome severity score in predicting incident cardiovascular disease and type 2 diabetes: the Atherosclerosis Risk in Communities Study and Jackson Heart Study

BACKGROUND

The severity of the metabolic syndrome (MetS) predicts future coronary heart disease (CHD) and diabetes independent of the individual MetS components. Our aim was to evaluate whether MetS severity conferred additional discrimination to existing scoring systems for cardiovascular disease (CVD) and diabetes risk.

METHODS

We assessed Cox proportional hazard models of CHD- and diabetes risk among 13,141 participants of the Atherosclerosis Risk in Communities Study and the Jackson Heart Study, using the Framingham Risk Calculator, the American Heart Association's Atherosclerotic CVD calculator, the American Diabetes Association diabetes risk score and an additional diabetes risk score derived from ARIC data. We then added a MetS-severity Z-score to these models and assessed for added risk discrimination by assessing Akaike information criterion, c-statistic, integrated discrimination improvement (IDI) and continuous net reclassification improvement (NRI).

RESULTS

The MetS severity score appears to add to the predictive ability of individual CHD and diabetes risk scores. Using the IDI, MetS improved risk prediction for diabetes but not CHD risk. In all 4 scoring systems, MetS severity had a significant non-event NRI, improving the ability to exclude individuals without events. Assessing interactions between risk scores and MetS severity revealed that MetS severity was more highly associated with disease risk among those in the lowest quintiles of risk score, suggesting that MetS was particularly able to identify risk among individuals judged to be of low risk by existing algorithms.

CONCLUSIONS

Mets severity improved prediction of diabetes more so than CHD. Incorporation of multiple risk predictors into electronic health records may help in better identifying those at high disease risk, who can then be placed earlier on preventative therapy.

Incidence, Predictors, and Clinical Outcomes of New-Onset Diabetes Mellitus after Percutaneous Coronary Intervention with Drug-Eluting Stent

We investigated the incidence, predictors, and long-term clinical outcomes of new-onset diabetes mellitus (DM) after percutaneous coronary intervention (PCI) with drug-eluting stent (DES). A total of 6,048 patients treated with DES were retrospectively reviewed and divided into three groups: 1) known DM (n = 2,365; fasting glucose > 126 mg/dL, glycated hemoglobin > 6.5%, already receiving DM treatment, or previous history of DM at the time of PCI); 2) non-DM (n = 3,247; no history of DM, no laboratory findings suggestive of DM at PCI, and no occurrence of DM during follow-up); and 3) new-onset DM (n = 436; non-DM features at PCI and occurrence of DM during follow-up). Among 3,683 non-DM patients, 436 (11.8%) patients were diagnosed with new-onset DM at 3.4 ± 1.9 years after PCI. Independent predictors for new-onset DM were high-intensity statin therapy, high body mass index (BMI), and high level of fasting glucose and triglycerides. The 8-year cumulative rate of major adverse cardiac events (a composite of cardiovascular death, myocardial infarction, stent thrombosis, or any revascularization) in the new-onset DM group was 19.5%, which was similar to 20.5% in the non-DM group (P = 0.467), but lower than 25.0% in the known DM group (P = 0.003). In conclusion, the incidence of new-onset DM after PCI with DES was not low. High-intensity statin therapy, high BMI, and high level of fasting glucose and triglycerides were independent predictors for new-onset DM. Long-term clinical outcomes of patients with new-onset DM after PCI were similar to those of patients without DM.

Sex difference in the effect of the fasting serum glucose level on the risk of coronary heart disease

OBJECTIVE

Diabetic women have a greater relative risk of coronary heart disease than diabetic men. However, the sex difference in the effect of fasting serum glucose levels below the diabetic range on the risk of coronary heart disease is unclear. We investigated whether the association between nondiabetic blood glucose levels and the incident risk of coronary heart disease is different between men and women.

METHODS

The fasting serum glucose levels and other cardiovascular risk factors at baseline were measured in 159,702 subjects (100,144 men and 59,558 women). Primary outcomes were hospital admission and death due to coronary heart disease during the 11-year follow-up.

RESULTS

The risk for coronary heart disease in women significantly increased with impaired fasting glucose levels (≥110mg/dL) compared to normal glucose levels (<100mg/dL), whereas the risk for coronary heart disease in men was significantly increased at a diabetic glucose range (≥126mg/dL). Women had a higher hazard ratio of coronary heart disease associated with the fasting serum glucose level than men (p for interaction with sex=0.021).

CONCLUSIONS

The stronger effect of the fasting serum glucose levels on the risk of coronary heart disease in women than in men was significant from a prediabetic range (≥110mg/dL).

Body-composition changes in the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE)-2 study: a 2-y randomized controlled trial of calorie restriction in nonobese humans

Background: Calorie restriction (CR) retards aging and increases longevity in many animal models. However, it is unclear whether CR can be implemented in humans without adverse effects on body composition.Objective: We evaluated the effect of a 2-y CR regimen on body composition including the influence of sex and body mass index (BMI; in kg/m²) among participants enrolled in CALERIE-2 (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy), a multicenter, randomized controlled trial.Design: Participants were 218 nonobese (BMI: 21.9-28.0) adults aged 21-51 y who were randomly assigned to 25% CR (CR, n = 143) or ad libitum control (AL, n = 75) in a 2:1 ratio. Measures at baseline and 12 and 24 mo included body weight, waist circumference, fat mass (FM), fat-free mass (FFM), and appendicular mass by dual-energy X-ray absorptiometry; activity-related energy expenditure (AREE) by doubly labeled water; and dietary protein intake by self-report. Values are expressed as means ± SDs.Results: The CR group achieved 11.9% ± 0.7% CR over 2-y and had significant decreases in weight (-7.6 ± 0.3 compared with 0.4 ± 0.5 kg), waist circumference (-6.2 ± 0.4 compared with 0.9 ± 0.5 cm), FM (-5.4 ± 0.3 compared with 0.5 ± 0.4 kg), and FFM (-2.0 ± 0.2 compared with -0.0 ± 0.2 kg) at 24 mo relative to the AL group (all between-group P < 0.001). Moreover, FFM as a percentage of body weight at 24 mo was higher, and percentage of FM was lower in the CR group than in the AL. AREE, but not protein intake, predicted preservation of FFM during CR (P < 0.01). Men in the CR group lost significantly more trunk fat (P = 0.03) and FFM expressed as a percentage of weight loss (P < 0.001) than women in the CR group.Conclusions: Two years of CR had broadly favorable effects on both whole-body and regional adiposity that could facilitate health span in humans. The decrements in FFM were commensurate with the reduced body mass; although men in the CR group lost more FFM than the women did, the percentage of FFM in the men in the CR group was higher than at baseline. CALERIE was registered at clinicaltrials.gov as NCT00427193.

Sex Differences in the Association Between Insulin Resistance and Incident Coronary Heart Disease and Stroke Among Blacks Without Diabetes Mellitus: The Jackson Heart Study

Background

Studies exploring the association between insulin resistance (IR) and cardiovascular disease in blacks have not been conclusive, especially for coronary heart disease (CHD). The McAuley index and homeostasis model assessment of IR (HOMA‐IR) perform differently in predicting cardiovascular disease. We investigated this association in the Jackson Heart Study, a large longitudinal cohort of blacks.

Methods and Results

IR was estimated for 3565 participants without diabetes mellitus and cardiovascular disease at baseline using the McAuley index and HOMA‐IR, and their associations with incident CHD and stroke (composite outcome) were compared. A lower McAuley index and higher HOMA‐IR are indicative of IR. Cox regression analysis was used to estimate adjusted hazard ratios for incident CHD and/or stroke. There were 158 events (89 CHD‐only, 58 stroke‐only, and 11 CHD/stroke) over a median follow‐up of 8.4 years. After adjustment for demographic factors, the risk of the composite outcome decreased with each SD increase in the McAuley index (hazard ratio 0.80; 95% CI: 0.67–0.96), with no attenuation after further accounting for CHD and stroke risk factors. When considered individually, McAuley index and HOMA‐IR were associated with CHD (hazard ratio 0.71, 95% CI: 0.55–0.92 and hazard ratio 1.33, 95% CI: 1.03–1.72, respectively), but not stroke risk. The logHOMA‐IR and CHD association was present in men, but not in women (P_interaction=0.01).

Conclusions

Both HOMA‐IR and the McAuley index demonstrate strong associations with CHD but not stroke risk in blacks. The logHOMA‐IR and CHD association was present in men, but not in women.

Insulin resistance, haemostatic factors and cardiovascular risk

Increased insulin resistance, which is present in the majority of type 2 diabetics patients, is associated with other metabolic and pro-coagulant cardiovascular risk factors and may account for the accelerated atherosclerosis and increased thrombotic potential observed in these patients. In individuals with normoglycaemia or impaired glucose tolerance (IGT), hyperinsulinaemia (a marker of insulin resistance) is associated with a similar clustering of risk factors and is predictive of cardiovascular events. The origins of insulin resistance are not well understood but data from families, twins and extended pedigrees suggest significant genetic and environmental contributions. The clustering of atherogenic traits begins in childhood, carries through to adult life and may result from the multiple effects of individual genes (pleiotropy) and environmental influences. Important environmental determinants of insulin resistance may occur before birth and, in conjunction with subsequent diet and exercise habits which result in obesity, lead to increased insulin resistance and cardiovascular risk. Therefore, primary prevention should centre around lifestyle changes which increase insulin sensitivity, maintain normoglycaemia and ameliorate atherothrombotic risk factor clustering.

Heart Rate Variability and Incident Stroke: The Atherosclerosis Risk in Communities Study

BACKGROUND AND PURPOSE

Low heart rate variability (HRV), a marker of cardiac autonomic dysfunction, has been associated with increased all-cause and cardiovascular mortality. We examined the association between reduced HRV and incident stroke in a community-based cohort.

METHODS

The Atherosclerosis Risk in Communities (ARIC) study measured HRV using 2-minute ECG readings in 12 550 middle-aged adults at baseline (1987-1989). HRV indices were calculated using the SD of RR intervals (SDNN), the mean of all normal RR intervals (meanNN), the root mean square of successive differences of successive RR intervals (RMSSD), low (LF) and high (HF) frequency power, and the LF/HF ratio. All HRV measures were categorized into quintiles. Incident stroke was adjudicated through 2011. Cox regression was used to estimate hazard ratios (HRs) with the lowest HRV quintile as the reference, with and without stratification by prevalent diabetes mellitus.

RESULTS

Over a median follow-up of 22 years, 816 (6.5%) participants experienced incident stroke. After covariate adjustment, there was no strong evidence of association between HRV and stroke risk. In stratified analyses, the lowest HRV quintile was associated with higher stroke risk compared with the highest quintile for SDNN (HR, 2.0, 95% confidence interval, 1.1-4.0), RMSSD (HR, 1.7; 95% confidence interval, 0.9-3.2), LF (HR, 1.5; 95% confidence interval, 0.8-3.0), and HF (HR, 1.7; 95% confidence interval, 0.9-3.0) only among people with diabetes mellitus.

CONCLUSIONS

Lower HRV was associated with higher risk of incident stroke among middle-aged adults with prevalent diabetes mellitus but not among people without diabetes mellitus.

Disordered haematopoiesis and athero-thrombosis

Atherosclerosis, the major underlying cause of cardiovascular disease, is characterized by a lipid-driven infiltration of inflammatory cells in large and medium arteries. Increased production and activation of monocytes, neutrophils, and platelets, driven by hypercholesterolaemia and defective high-density lipoproteins-mediated cholesterol efflux, tissue necrosis and cytokine production after myocardial infarction, or metabolic abnormalities associated with diabetes, contribute to atherogenesis and athero-thrombosis. This suggests that in addition to traditional approaches of low-density lipoproteins lowering and anti-platelet drugs, therapies directed at abnormal haematopoiesis, including anti-inflammatory agents, drugs that suppress myelopoiesis, and excessive platelet production, rHDL infusions and anti-obesity and anti-diabetic agents, may help to prevent athero-thrombosis.

Dietary Intake of Lutein and Diabetic Retinopathy in the Atherosclerosis Risk in Communities Study (ARIC)

PURPOSE

We tested the hypothesis that dietary intake of lutein is inversely associated with prevalence of diabetic retinopathy (DR) due to its antioxidant and anti-inflammatory properties and location within the retina.

METHODS

We used logistic regression to examine the association between prevalent DR and energy-adjusted lutein intake by quartile (Q) using data collected from 1430 Atherosclerosis Risk in Communities Study (ARIC) participants with diabetes (n = 994 white, n = 508 black). DR was assessed from 45° non-mydriatic retinal photographs of one randomly chosen eye taken at visit 3 (1993-1995). Dietary lutein intake was estimated using a 66-item food frequency questionnaire at visit 1 (1987-1989).

RESULTS

Median estimated daily lutein intake was 1370 µg/1000 kcals and prevalence of DR was ~21%. We found a crude association between lutein and DR (odds ratio, OR, 2.11, 95% confidence interval, CI, 1.45-3.09 for Q4, high intake, vs. Q1, low intake; p for trend <0.0001), which was attenuated after adjustment for ethnicity, duration of diabetes, glycosylated hemoglobin levels, field center and energy intake (OR 1.41, 95% CI 0.87-2.28; p for trend = 0.01). In analyses limited to persons with short diabetes duration (<6 years), the association no longer persisted (OR 0.94, 95% CI 0.31-2.16; p for trend =0.72) compared to the association in those with longer diabetes duration (≥6 years; OR 1.58, 95% CI 0.91-2.75; p for trend = 0.01).

CONCLUSION

Contrary to our hypothesis, we found that the odds of higher lutein intake were greater among those with DR than those without DR. However, after adjusting for confounders, intake of lutein was not associated with DR.

The severity of the metabolic syndrome increases over time within individuals, independent of baseline metabolic syndrome status and medication use: The Atherosclerosis Risk in Communities Study

BACKGROUND AND AIMS

The severity of the metabolic syndrome (MetS) is linked to future cardiovascular disease. However, it is unclear whether MetS severity increases among individuals followed over time.

METHODS

We assessed changes in a sex- and race/ethnicity-specific MetS severity Z-score over a 10-year period (visits 1-4) among 9291 participants of the Atherosclerosis Risk in Communities study cohort. We compared sex- and racial/ethnic subgroups for the rate of change in the MetS severity score and MetS prevalence as assessed using traditional ATP-III MetS criteria. We further examined effects of use of medications for hypertension, diabetes and dyslipidemia.

RESULTS

Over the 10 years of follow-up, MetS severity Z-scores increased in 76% of participants from an overall mean of 0.08 ± 0.77 at baseline to 0.48 ± 0.96 at visit 4 with the greatest progression in scores observed among African-American women. Baseline MetS severity scores predicted the time until ATP-III MetS diagnosis, with a model-predicted 77.5% of individuals with a visit 1 MetS severity score of 0.75 progressing to ATP-III MetS within 10 years. The rate of increase in MetS severity score was higher among those younger at baseline but was independent of baseline MetS status or the use of medications to treat blood pressure, lipids and diabetes.

CONCLUSION

The severity of metabolic derangements as measured using this MetS severity score increases over time within individuals and predicts diagnosis of ATP-III MetS. These data may have implications for tracking MetS related risk within individuals over time.

Genetic variants primarily associated with type 2 diabetes are related to coronary artery disease risk

BACKGROUND

The mechanisms underlying the association between diabetes and coronary artery disease (CAD) risk are unclear. We aimed to assess this association by studying genetic variants that have been shown to associate with type 2 diabetes (T2DM). If the association between diabetes and CAD is causal, we expected to observe an association of these variants with CAD as well.

METHODS AND RESULTS

We studied all genetic variants currently known to be associated with T2DM at a genome-wide significant level (p < 5*10(-8)) in CARDIoGRAM, a genome-wide data-set of CAD including 22,233 CAD cases and 64,762 controls. Out of the 44 published T2DM SNPs 10 were significantly associated with CAD in CARDIoGRAM (OR>1, p < 0.05), more than expected by chance (p = 5.0*10(-5)). Considering all 44 SNPs, the average CAD risk observed per individual T2DM risk allele was 1.0076 (95% confidence interval (CI), 0.9973-1.0180). Such average risk increase was significantly lower than the increase expected based on i) the published effects of the SNPs on T2DM risk and ii) the effect of T2DM on CAD risk as observed in the Framingham Heart Study, which suggested a risk of 1.067 per allele (p = 7.2*10(-10) vs. the observed effect). Studying two risk scores based on risk alleles of the diabetes SNPs, one score using individual level data in 9856 subjects, and the second score on average effects of reported beta-coefficients from the entire CARDIoGRAM data-set, we again observed a significant - yet smaller than expected - association with CAD.

CONCLUSIONS

Our data indicate that an association between type 2 diabetes related SNPs and CAD exists. However, the effects on CAD risk appear to be by far lower than what would be expected based on the effects of risk alleles on T2DM and the effect of T2DM on CAD in the epidemiological setting.

Carotid Intima Media Thickness, Atherosclerosis, and 5-Year Decline in Odor Identification: The Beaver Dam Offspring Study

BACKGROUND

The purpose of this study was to determine if subclinical markers of atherosclerosis are associated with a decline in olfactory function.

METHODS

The San Diego Odor Identification Test was administered to 2,302 participants (age 21-84 years) at the baseline (2005-2008) and 5-year follow-up (2010-2013) examinations of the Beaver Dam Offspring Study. A decline in odor identification was defined as a decrease in San Diego Odor Identification Test score of 2 or more (range 0-8) from Beaver Dam Offspring Study 1 to Beaver Dam Offspring Study 2. Carotid intima media thickness and plaque, blood pressure, pulse wave velocity, and body mass index were measured and other risk factor data were obtained by interview.

RESULTS

Overall 3.2% of participants had a decline in San Diego Odor Identification Test score at 5 years. In age- and sex-adjusted models, mean intima media thickness (odds ratio = 1.17, 95% CI = 1.01, 1.34, per 0.1 mm) and number of sites (range 0-6) with carotid artery plaque (odds ratio = 1.35, 95% CI = 1.11, 1.65, per site) at baseline were associated with an increased risk for decline. Plaque score (odds ratio = 1.24, 95% CI = 1.01, 1.53) remained a significant independent predictor of olfactory decline in a model that included age, sex, hypertension, body mass index, alcohol, and smoking.

CONCLUSIONS

Subclinical atherosclerosis was associated with an increased risk for olfactory decline indicating that atherosclerosis may be one of the risk factors for the decline in olfactory function seen with aging. Strategies to improve vascular health may also benefit olfactory health.

Insulin Sensitivity Following Exercise Interventions: Systematic Review and Meta-Analysis of Outcomes Among Healthy Adults

OBJECTIVE

Although exercise can improve insulin sensitivity, no adequate synthesis exists of exercise intervention studies with regard to their effect on insulin sensitivity. This comprehensive meta-analysis synthesized the insulin sensitivity outcomes of supervised exercise interventions.

METHOD

Extensive literature searching located published and unpublished intervention studies that measured insulin sensitivity outcomes. Eligible studies tested supervised exercise interventions among healthy adults. Primary study characteristics and results were coded. Random-effects meta-analyses of standardized mean differences included moderator analyses.

RESULTS

Data were synthesized across 2509 subjects (115 samples, 78 reports). The overall mean effect size for 2-group postintervention comparisons was 0.38 (95% confidence interval [CI] = 0.25-0.51, I (2) = 0%) and for 2-group pre-post comparisons was 0.43 (95% CI = 0.30-0.56, I (2) = 52%; higher mean insulin sensitivity for treatment than control subjects). The postintervention mean of 0.38 is consistent with treatment subjects ending studies with a mean fasting insulin of 6.8 mU/L if control participants' mean fasting insulin were 7.9 mU/L. Exploratory moderator analyses did not document different insulin sensitivity effect sizes across intervention characteristics or sample attributes.

CONCLUSION

This study documented that exercise is a valuable primary care and community health strategy for healthy adults to improve insulin sensitivity and lower the risk for diabetes conferred by insulin resistance.

Sex, sex steroids, and diabetic cardiomyopathy: making the case for experimental focus

More than three decades ago, the Framingham study revealed that cardiovascular risk is elevated for all diabetics and that this jeopardy is substantially accentuated for women in particular. Numerous studies have subsequently documented worsened cardiac outcomes for women. Given that estrogen and insulin exert major regulatory effects through common intracellular signaling pathways prominent in maintenance of cardiomyocyte function, a sex-hormone:diabetic-disease interaction is plausible. Underlying aspects of female cardiovascular pathophysiology that exaggerate cardiovascular diabetic risk may be identified, including increased vulnerability to coronary microvascular disease, age-dependent impairment of insulin-sensitivity, and differential susceptibility to hyperglycemia. Since Framingham, considerable progress has been made in the development of experimental models of diabetic disease states, including a diversity of genetic rodent models. Ample evidence indicates that animal models of both type 1 and 2 diabetes variably recapitulate aspects of diabetic cardiomyopathy including diastolic and systolic dysfunction, and cardiac structural pathology including fibrosis, loss of compliance, and in some instances ventricular hypertrophy. Perplexingly, little of this work has explored the relevance and mechanisms of sexual dimorphism in diabetic cardiomyopathy. Only a small number of experimental studies have addressed this question, yet the prospects for gaining important mechanistic insights from further experimental enquiry are considerable. The case for experimental interrogation of sex differences, and of sex steroid influences in the aetiology of diabetic cardiomyopathy, is particularly compelling-providing incentive for future investigation with ultimate therapeutic potential.

Inhibitory effect of atorvastatin on AGE-induced HCAEC apoptosis by upregulating HSF-1 protein

This study evaluates effect and mechanism of atorvastatin on human coronary artery endothelial cells (HCAEC) apoptosis. Results have shown that HCAEC apoptosis had increased with increasing concentration of AGEs. Atorvastatin may decrease HCAEC apoptosis, but the effect can be attenuated by PI3K inhibitor. Secretion of PI3K and P-Akt in HCAEC increased with increasing concentration of AGEs. Secretion of PI3K in HCAEC may be decreased by atorvastatin. The effect may be attenuated by PI3K inhibitor. HSF-1, HSP-70 mRNA expression level decreased with increasing concentration of AGEs. Atorvastatin may attenuate AGEs-induced HSF-1, HSP-70 mRNA expression in HCAEC, but the effect can be attenuated by PI3K inhibitor. It can be concluded that AGE can dose-dependently promote HCAEC apoptosis by the PI3K/AKT pathway. Atorvastatin may attenuate the effect possibly by upregulating HSF-1.

Estimated plasma stearoyl co-A desaturase-1 activity and risk of incident diabetes: the Atherosclerosis Risk in Communities (ARIC) study

OBJECTIVE

Evidence from pre-clinical studies suggests inhibition of stearoyl co-A desaturase-1 (SCD-1) activity improves insulin sensitivity. Translation of these findings to humans remains less defined. The purpose of this research was to evaluate the association between different measures of SCD-1 activity and incident diabetes in a large, prospective human study.

METHODS

In 2738 white participants (aged 45-64 yrs, 47% men) who were free of diabetes at baseline, SCD-1 activity was estimated at baseline by plasma fatty acid ratios in cholesterol esters (SCD16c=16:1n-7/16:0, SCD18c =18:1n-9/18:0) and in phospholipids (SCD16p=16:1n-7/16:0, SCD18p=18:1n-9/18:0). Incident diabetes was ascertained during 3 follow-up visits. Cox proportional hazards regression was used to determine the association between estimated SCD-1 activity and incident diabetes.

RESULTS

During follow-up (mean 8.0±SE 2.1 years), 207 (7.6%) participants developed diabetes. After adjusting for age and sex, higher SCD16c, higher SCD16p, and lower SCD18p were significantly associated with incident diabetes. After additional adjustment for education, parental history of diabetes, smoking, dietary intake (carbohydrate, fiber, saturated/monounsaturated/polyunsaturated fat), alcohol use, physical activity, body mass index (BMI), waist-hip ratio, blood pressure, and lipid composition - only SCD16c remained significantly associated with incident diabetes (Hazard Ratio=1.1 linearly across decreasing quintiles, 95% CI 1.01-1.30; p =0.03) which remained nominally associated after adjusting for insulin resistance (p=0.05).

CONCLUSIONS

In a large community-based prospective cohort study, the estimate of SCD-1 activity by SCD16c had the strongest association with incident diabetes. Refinement of SCD-1 measurement and replication of its association with incident diabetes in an independent cohort is recommended.

Association of weight status with mortality in adults with incident diabetes

CONTEXT

Type 2 diabetes in normal-weight adults (body mass index [BMI] <25) is a representation of the metabolically obese normal-weight phenotype with unknown mortality consequences.

OBJECTIVE

To test the association of weight status with mortality in adults with new-onset diabetes in order to minimize the influence of diabetes duration and voluntary weight loss on mortality.

DESIGN, SETTING, AND PARTICIPANTS

Pooled analysis of 5 longitudinal cohort studies: Atherosclerosis Risk in Communities study, 1990-2006; Cardiovascular Health Study, 1992-2008; Coronary Artery Risk Development in Young Adults, 1987-2011; Framingham Offspring Study, 1979-2007; and Multi-Ethnic Study of Atherosclerosis, 2002-2011. A total of 2625 participants with incident diabetes contributed 27,125 person-years of follow-up. Included were men and women (age >40 years) who developed incident diabetes based on fasting glucose 126 mg/dL or greater or newly initiated diabetes medication and who had concurrent measurements of BMI. Participants were classified as normal weight if their BMI was 18.5 to 24.99 or overweight/obese if BMI was 25 or greater.

MAIN OUTCOME MEASURES

Total, cardiovascular, and noncardiovascular mortality.

RESULTS

The proportion of adults who were normal weight at the time of incident diabetes ranged from 9% to 21% (overall 12%). During follow-up, 449 participants died: 178 from cardiovascular causes and 253 from noncardiovascular causes (18 were not classified). The rates of total, cardiovascular, and noncardiovascular mortality were higher in normal-weight participants (284.8, 99.8, and 198.1 per 10,000 person-years, respectively) than in overweight/obese participants (152.1, 67.8, and 87.9 per 10,000 person-years, respectively). After adjustment for demographic characteristics and blood pressure, lipid levels, waist circumference, and smoking status, hazard ratios comparing normal-weight participants with overweight/obese participants for total, cardiovascular, and noncardiovascular mortality were 2.08 (95% CI, 1.52-2.85), 1.52 (95% CI, 0.89-2.58), and 2.32 (95% CI, 1.55-3.48), respectively.

CONCLUSION

Adults who were normal weight at the time of incident diabetes had higher mortality than adults who are overweight or obese.

Shadow of diabetes over cardiovascular disease: comparative quantification of population-attributable all-cause and cardiovascular mortality

BACKGROUND

We contrasted impacts on all-cause and cardiovascular disease (CVD) mortality of diabetes vs. CVD.

METHODS

Among participants the Tehran lipid and glucose study aged ≥ 30 years (n = 9752), we selected those who participated in the follow-up study until 20 March 2009 (n = 8795). Complete data on covariate were available for 8, 469 participants, contributing to a 67935 person-year follow up. In the analysis of outcomes (all-cause and CVD mortality), diabetes and CVD were assessed using Cox proportional hazard regression model adjusting for established CVD risk factors. We used population attributable hazard fraction (PAHF) and rate advancement period (RAP) that expresses how much sooner a given mortality rate is reached among exposed than among unexposed individuals.

RESULTS

Ten percent of the participants self-reported to have pervious CVD, and diabetes was ascertained in 17% of participants at baseline examination. During a median follow-up of 9 years 386 participants died of which 184 were due to CVD. All-cause and CVD mortality rate (95% CIs) were 5.5 (5.0-6.1) and 2.6 (2.3-3.0) per 1000 person-year, respectively. The PAHF of all-cause mortality for diabetes 9.2 (7.3-11.1) was greater than the one for CVD 3.5 (1.1-5.5). RAP estimates for all-cause mortality associated with diabetes ranged from 7.4 to 8.6 years whereas the RAP estimates for all-cause mortality associated with CVD ranged from 3.1 to 4.3 years. The PAHF of CVD mortality for diabetes 9.4 (6.8-12.0) was greater than the one for CVD 4.5 (1.8-7.0). RAP estimates for CVD mortality associated with diabetes ranged from 8.2 to 9.8 years whereas the RAP estimates for CVD mortality associated with CVD ranged from 4.7 to 6.7 years.

CONCLUSIONS

We demonstrated that diabetes, which was shown to be keeping pace with prevalent CVD in terms of conferring excess risk of incident CVD, is currently causing more deaths in the population than does CVD.

Takeaway food consumption and cardio-metabolic risk factors in young adults

BACKGROUND/OBJECTIVES

Takeaway food consumption is positively associated with adiposity. Little is known about the associations with other cardio-metabolic risk factors. This study aimed to determine whether takeaway food consumption is associated with fasting glucose, insulin, lipids, homeostasis model assessment (HOMA) and blood pressure.

SUBJECTS/METHODS

A national sample of 1896, 26-36 year olds completed a questionnaire on socio-demographics, takeaway food consumption, physical activity and sedentary behaviour. Waist circumference and blood pressure were measured, and a fasting blood sample was taken. For this analysis, takeaway food consumption was dichotomised to once a week or less and twice a week or more. Linear regression was used to calculate differences in the adjusted mean values for fasting lipids, glucose, insulin, HOMA and blood pressure. Models were adjusted for age, employment status, leisure time physical activity and TV viewing.

RESULTS

Compared with women who ate takeaway once a week or less, women who ate takeaway twice a week or more had significantly higher adjusted mean fasting glucose (4.82 vs 4.88 mmol/l, respectively; P=0.045), higher HOMA scores (1.27 vs 1.40, respectively, P=0.034) and tended to have a higher mean fasting insulin (5.95 vs 6.45 mU/l, respectively, P=0.054). Similar associations were observed for men for fasting insulin and HOMA score, but the differences were not statistically significant. For both women and men adjustment for waist circumference attenuated the associations.

CONCLUSION

Consuming takeaway food at least twice a week was associated with cardio-metabolic risk factors in women but less so in men. The effect of takeaway food consumption was attenuated when adjusted for obesity.