Coronary calcification in long-term type 1 diabetic patients -- a study with multi slice spiral computed tomography

Atherosclerosis and Microvascular Complications: Results From the Canadian Study of Longevity in Type 1 Diabetes

OBJECTIVE

Type 1 diabetes carries a significant risk for cardiovascular mortality, but it is unclear how atherosclerosis associates with microvascular complications. We aimed to determine the relationships between atherosclerotic burden and neuropathy, retinopathy, and diabetic kidney disease (DKD) in adults with a ≥50-year history of type 1 diabetes.

RESEARCH DESIGN AND METHODS

Adults with type 1 diabetes (n = 69) underwent coronary artery calcification (CAC) volume scoring by wide-volume computerized tomography. Microvascular complications were graded as follows: neuropathy by clinical assessment, electrophysiology, vibration and cooling detection thresholds, heart rate variability, and corneal confocal microscopy; retinopathy by ultra-wide-field retinal imaging; and DKD by renal hemodynamic function measured by inulin and para-aminohippurate clearance at baseline and after intravenous infusion of angiotensin II. The cohort was dichotomized to high (≥300 Agatston units [AU]) or low (<300 AU) CAC and was stratified by diabetes status. A comparator group without diabetes (n = 73) matched for age and sex also underwent all study procedures except for retinal imaging.

RESULTS

CAC scores were higher in participants with type 1 diabetes (median Agatston score 1,000 [interquartile range = 222, 2,373] AU vs. 1 [0.75] AU in comparators, P < 0.001). In participants with type 1 diabetes, high CAC scores associated with markers of neuropathy and retinopathy, but not with DKD, or renal hemodynamic function at baseline or in response to angiotensin II.

CONCLUSIONS

The presence of high CAC in adults with longstanding type 1 diabetes was associated with large nerve fiber neuropathy and retinopathy but not with renal hemodynamic function, suggesting that neuropathy, retinopathy, and macrovascular calcification share common risk factors.

Genome-wide meta-analyses identifies novel taxane-induced peripheral neuropathy-associated loci

OBJECTIVE

Taxane containing chemotherapy extends survival for breast cancer patients. However, taxane-induced peripheral neuropathy (TIPN) cannot be predicted, prevented or effectively treated. Using genome-wide analyses, we sought to identify common risk variants for TIPN.

PATIENTS AND METHODS

Women with high-risk breast cancer enrolled in SWOG 0221 were genotyped using the Illumina 1M chip. Genome-wide analyses were performed in relation to ≥grade 3 Common Terminology Criteria for Adverse Events (CTCAE) neuropathy in European and African Americans. Data were meta-analyzed with GW associations of CTCAE ≥grade 3 versus <grade 3 in CALGB 40101 assuming a fixed effects model.

RESULTS

The percentage of ≥grade 3 TIPN in 1269 European Americans and 139 African Americans in S0221, was 11.6 and 22.3%, respectively. CALGB 40101 ≥grade 3 TOPN was 7.2%. The most significant association with ≥grade 3 TIPN was the G allele of rs1858826 in GNGT1 (Pmeta=1.1×10), which showed a decrease in risk of ≥grade 3 TIPN (odds ratio=0.29, 95% confidence interval: 0.18-0.46).

CONCLUSION

The genetic variants associated with ≥grade 3 TIPN are hypothesized to have biochemical functions and reside in and near genes involved in diabetes and diabetic neuropathy. This finding is consistent with results from CALGB 40101 pathway analyses. Larger homogeneous trials with similar dosing and criteria for defining neuropathy are needed to properly assess the relationship of genomics with the neuropathy spectrum.

Possible early detection of coronary artery calcium progression in type 1 diabetes: A case-control study of normoalbuminuric type 1 diabetes patients and matched controls

AIMS

Coronary artery calcium (CAC) is associated with cardiovascular (CV) disease and progression of CAC is an independent predictor of mortality. Type 1 diabetes is associated with increased CV risk, especially in persons with cardiovascular autonomic neuropathy (CAN). This study aimed to examine whether short-term progression of CAC is increased in persons with type 1 diabetes compared to matched controls and if CAN increases risk of CAC progression.

METHODS

Fifty-three normoalbuminuric persons with long-term type 1 diabetes (20 with CAN) were matched in a 1:2 ratio with 106 controls without diabetes according to age, sex and baseline CAC. All were examined twice with cardiac computed tomography scans. Progression of CAC was defined as a value ≥2.5 between the square root-transformed values of follow-up and baseline CAC volume scores.

RESULTS

The participants were examined median (interquartile range) of 25 (23-27) months (type 1 diabetes) and 29 (25-33) months (controls) apart. In multivariable logistic regression, participants with type 1 diabetes had an odds ratio of 3.3 (95% CI 1.3-8.2, p = 0.01) for CAC progression. CAN did not increase progression of CAC (p = 0.64).

CONCLUSIONS

Progression of CAC was increased in well-treated, normoalbuminuric persons with type 1 diabetes compared to matched controls without diabetes, suggesting that type 1 diabetes is a risk factor for short-term progression. This finding could explain some of the increased morbidity and mortality observed in persons with type 1 diabetes, but it does not specifically explain the increased CV risk in persons with CAN.

Coronary artery calcifications and diastolic dysfunction versus visceral fat area in type 1 diabetes: VISCERA study

AIMS

Type 1 diabetic patients (T1DM) experience a higher cardiovascular disease and mortality risk than controls. We investigated whether visceral adipose tissue (VAT) contributes to coronary artery calcifications (CAC) and cardiac dysfunction in T1DM.

METHODS

A cross-sectional study of 118 T1DM patients without a history of cardiovascular disease (men/women: 68/50, age 46±12years, HbA1c 7.6±0.9%, BMI 25.8±4.1kg/m²) was conducted. CAC and VAT were measured using a CT scan. CAC was scored using the Agatston method. Cardiac functional abnormalities were assessed by echocardiography.

RESULTS

CAC scored ≥10 in 42% of patients. Systolic function was normal in all, but diastolic dysfunction was present in 75%. Forty-six percent had VAT≥100cm². CAC score≥10 occurred more often in subjects with VAT≥100cm² (54% vs 31%; p=0.01). Age (OR=1.10; p<0.0001), diabetes duration (OR=1.10; p=0.008), gender (OR=4.28; p=0.016), LDL-cholesterol (OR=1.03; p=0.009) and metabolic syndrome (OR=5.79; p=0.005) were independently associated with a CACS≥10. Subjects with CACS≥10 were more prone to have diastolic dysfunction (84 vs 54%; p=0.03). Factors independently associated with diastolic dysfunction were age (OR=1.11; p=0.002), waist circumference (OR=1.10; p=0.016) and VAT (OR=0.99; p=0.035).

CONCLUSIONS

Excess VAT in T1DM, present in 46%, is associated with diastolic dysfunction and CAC, present in respectively 75% and 42% of patients. Timely detection might improve future cardiovascular risk.

Soluble TNFα-receptor 1 as a predictor of coronary calcifications in patients after long-term cure of Cushing's syndrome

PURPOSE

Increased cardiovascular (CV) risk persists in Cushing's syndrome (CS), despite remission of hypercortisolism. The aim of this study was to evaluate prevalence of coronary artery disease in CS patients and its correlation with classical CV risk factors and inflammatory markers.

METHODS

Cardiac multidetector computed tomography (MDCT) was performed in 41 patients (7 men, 31 of pituitary origin, 29 cured, mean age: 48.6 ± 13 years), using 64-slice Toshiba Aquilion systems. Coronary atherosclerotic plaques were detected and coronary calcifications quantified by the Agatston score (AS). Clinical and biochemical parameters were correlated with the AS to identify possible surrogate markers of coronary disease. Normal values for clinical and biochemical parameters were obtained from a gender- and age-matched normal reference population (n = 82).

RESULTS

CS patients with calcifications (AS > 0) (N = 13, 32%) had higher levels of sTNF-R1, homocysteine, triglycerides, blood pressure and body mass index than patients without calcifications (AS = 0) and those of normal reference population. Both groups of CS patients (AS > 0 and AS = 0) had elevated trunk fat mass and IL-6 compared to reference values. Patients with AS > 0 had less adiponectin and higher insulin, HOMA and fibrinogen than those found in normal reference population. sTNF-R1 correlated positively with AS and remained significant after adjusting for confounding factors. The same result was observed when we considered only cured CS patients.

CONCLUSION

In our cohort of CS patients sTNF-R1 was a predictor of coronary calcifications. Since MDCT is an expensive technique not readily available in daily clinical practice, increased sTNF-R1 could be a marker of CV risk even in cured CS.

Type 1 diabetes and cardiovascular disease

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

Coronary artery disease detected by multislice computed tomography in patients after long-term cure of Cushing's syndrome

OBJECTIVE

Increased cardiovascular risk persists in Cushing's syndrome (CS), despite remission of hypercortisolism. The aim of this study was to evaluate the prevalence of coronary artery disease in patients after long-term cure of CS.

METHODS

Cardiac multidetector computed tomography was performed in 29 cured CS patients (5 men, 21 of pituitary origin, 50 ± 13 y, mean time of "cure" 11 ± 6 y), using 64-slice Toshiba Aquilion systems (Toshiba Medical Systems, Otawara, Japan). Noncontrast acquisitions were performed to detect coronary calcifications and, after injection of an iodinated contrast agent, for coronary angiography. Calcium was quantified by the Agatston score. Cured patients were compared with 48 gender-matched and age-matched healthy controls.

RESULTS

Cured CS patients had more hypertension and smoked less than controls (P < .05). The prevalence of coronary calcifications (31% vs 21%) and noncalcified plaques (20% vs 7.8%) tended to be higher in cured CS patients than controls. When only women were analyzed (24 CS and 34 controls), more abnormal multidetector computed tomography results were found (42% vs 18%; P < .05). When patients and controls in the youngest tertile (<45 y) were compared, cured CS patients had significantly more noncalcified plaques than controls (30% vs 0%, P = .01); this difference persisted when hypopituitary or dyslipidemic CS patients were excluded.

CONCLUSION

Despite long-term biochemical "cure" of CS, patients exhibit more coronary artery disease, especially in women and in those aged <45 years, in comparison to healthy matched controls.

Cardiovascular autonomic neuropathy and subclinical cardiovascular disease in normoalbuminuric type 1 diabetic patients

Cardiovascular autonomic neuropathy (CAN) is associated with increased mortality in diabetes. Since CAN often develops in parallel with diabetic nephropathy as a confounder, we aimed to investigate the isolated impact of CAN on cardiovascular disease in normoalbuminuric patients. Fifty-six normoalbuminuric, type 1 diabetic patients were divided into 26 with (+) and 30 without (-) CAN according to tests of their autonomic nerve function. Coronary artery plaque burden and coronary artery calcium score (CACS) were evaluated using computed tomography. Left ventricular function was evaluated using echocardiography. Blood pressure and electrocardiography were recorded through 24 h to evaluate nocturnal drop in blood pressure (dipping) and pulse pressure. In patients +CAN compared with -CAN, the CACS was higher, and only patients +CAN had a CACS >400. A trend toward a higher prevalence of coronary plaques and flow-limiting stenosis in patients +CAN was nonsignificant. In patients +CAN, left ventricular function was decreased in both diastole and systole, nondipping was more prevalent, and pulse pressure was increased compared with -CAN. In multivariable analysis, CAN was independently associated with increased CACS, subclinical left ventricular dysfunction, and increased pulse pressure. In conclusion, CAN in normoalbuminuric type 1 diabetic patients is associated with distinct signs of subclinical cardiovascular disease.

Reduced heart rate variability predicts progression of coronary artery calcification in adults with type 1 diabetes and controls without diabetes

AIM

Reduced heart rate variability (HRV) is a manifestation of cardiac autonomic neuropathy, a known complication of type 1 diabetes (T1D). We evaluated whether HRV predicted coronary artery calcium (CAC) progression.

METHODS

Subjects between 19 and 56 years of age with T1D or those without diabetes from the Coronary Artery Calcification in Type 1 Diabetes study underwent supine deep breathing 12-lead electrocardiograms. The SD of consecutive RR intervals was used as a measure of HRV. CAC was measured at two visits 6.0 ± 0.5 years apart. Progression of CAC was defined as an increase in square root transformed CAC volume of ≥ 2.5 mm(3), excluding patients who had cardiovascular events during follow-up.

RESULTS

Reduced HRV was associated with older age, higher hemoglobin A1c, elevated albuminuria, CAC volume at baseline, and increased fibrinogen. Higher HRV at baseline was associated with lower likelihood CAC progression (odds ratio = 0.71, 95% confidence interval 0.56-0.90, P = 0.005), and the adjustment for known cardiovascular risk factors did not change this strong association, including adjustment for inflammatory markers.

CONCLUSIONS

Reduced HRV predicted progression of CAC in adults with and without T1D. This association further supports the participation of autonomic neuropathy in the atherosclerosis process.

Double-edged relationship between adiposity and coronary artery calcification in type 1 diabetes

Coronary artery disease (CAD), a leading cause of death in type 1 diabetes (T1D), often occurs two or more decades earlier in this population compared to the population without diabetes. Although CAD generally increases with adiposity, this association is unclear in T1D. In this study, we examined associations of adiposity with coronary artery calcium (CAC) in 315 individuals with T1D. Mean age and diabetes duration were 42 and 34 years, respectively, at study entry. CAC, visceral adiposity (VAT) and subcutaneous adiposity (SAT) were determined by electron beam tomography; and BMI and waist circumference (WC) were determined. The presence of CAC was positively associated with VAT, SAT and BMI in men (p<0.05) and with all four adiposity measures in women (p<0.05) after adjustment for age and other traditional cardiovascular risk factors. However, after adjustment, the degree of CAC was not associated with any of the four adiposity measures, with the exception of SAT in women. Women in the lowest tertile of SAT had more CAC than those in the second tertile (p<0.016). Adiposity was positively associated with the presence of CAC, but the relationship with its severity was either inverse or non-existent. This double-edged association emphasises the complex relationship between adiposity and cardiovascular risk in diabetes.

Impaired glucose tolerance, diabetes, and cardiovascular disease

OBJECTIVE

To analyze the association among impaired glucose tolerance (IGT), diabetes, and cardiovascular disease (CVD).

METHODS

We review current studies that have addressed the foregoing relationship and summarize the results of diagnostic and therapeutic interventions.

RESULTS

A major cause of the reduction in life expectancy in patients with diabetes is CVD and cardiovascular complications. Both prediabetes and diabetes predispose to cardiovascular alterations. IGT and even the upper normal values of nondiabetic glucose levels are associated with an increased cardiovascular risk. The risk of heart disease can be increased as early as 15 years before the diagnosis of diabetes. Patients with chronic or acute CVD and no previous diagnosis of diabetes frequently present with either IGT or diabetes. Thus, such patients should undergo screening for diabetes with an oral glucose tolerance test. In acute coronary syndromes, lowering of glucose levels to the near-normal range by administration of insulin is highly beneficial. Early, rigorous interventions to improve metabolic control will yield better cardiovascular outcomes in patients with dysglycemia.

CONCLUSION

Aggressive preventive and treatment strategies, which can include multiple interventions, are needed to minimize the potential effects of CVD in patients with diabetes or IGT.

The Links between Diabetes and Cardiovascular Disease

The aim of this study was to review current studies relevant to the link between impaired glucose tolerance (IGT), diabetes, and cardiovascular disease. Cardiovascular disease is a major cause of the reduction in life expectancy in patients with diabetes. Seventy-five percent of diabetic patients die prematurely of cardiovascular complications. Both prediabetes and diabetes highly pre-dispose to cardiovascular alterations. IGT and even the upper-normal of nondiabetic glucose values are associated with an increased cardiovascular risk. The risk of heart disease is increased up to 15 years prior diagnosis of diabetes. Patients with chronic or acute cardiovascular disease and no previous diagnosis of diabetes frequently present with either IGT or diabetes. Patients with cardiovascular disease and no previous diagnosis of diabetes need to be screened for diabetes with an oral glucose tolerance test. In acute coronary syndromes, lowering glucose levels to the near-normal range with insulin is highly beneficial. Early and rigorous improvement of metabolic control is highly supportive in improving the cardiovascular outcome in patients with dysglycemia. Preventive treatment strategies, which include multiple approaches, are required to overcome the burden of cardiovascular disease in diabetes and IGT.