Micro- and macrovascular function in patients suffering from primary adrenal insufficiency: a cross-sectional case-control study.

BACKGROUND: Despite adequate glucocorticoid (GC) and mineralocorticoid (MC) replacement therapy, patients suffering from primary adrenal insufficiency (AI) have an increased mortality, mainly due to cardiovascular diseases. Only little knowledge exists on the contribution of MC substitution to the cardiovascular risk. Therefore, this study investigates the impact of plasma renin concentration on parameters of micro- and macrovascular function. METHODS: 26 patients with primary AI [female = 18, age: 51 (28; 78) years; BMI: 24 (18; 40) kg/m2; disease duration: 18 (5; 36) years] were included in this cross-sectional analysis. Intima media thickness (IMT) and pulse wave velocity (PWV) were investigated to assess macrovascular remodeling and arterial stiffness. Microvascular function was estimated by post-occlusive reactive hyperemia using laser Doppler fluxmetry. Baseline perfusion, biological zero, peak perfusion, time to peak and recovery time were recorded. Patients were grouped according to their median plasma renin concentration of previous visits (Reninhigh vs Reninlow) and were compared to a group of healthy women [age: 44 (43; 46) years; BMI: 24.2 (21.8; 27.5)]. RESULTS: PWV was significantly higher in AI patients compared to controls [9.9 (5; 18.5) vs 7.3 (6.8; 7.7) m/s; p < .01], whereas no differences in microvascular function could be found. In Reninlow time to peak perfusion was significantly longer [6.0 (3; 15) vs 3.5 (1.5; 11) s; p < .05], whereas no differences in IMT and PWV were observed between Reninhigh and Reninlow. No impact of GC dose was observed. CONCLUSIONS: Microvascular function is not impaired in patients with primary AI under adequate replacement therapy, although higher renin concentrations are associated with subclinical improvements. No relation between RAAS activity and macrovascular function is observed, while arterial stiffness might be increased in primary AI.

Speckle-Tracking-Based Evaluation of Vascular Strain at Different Sites of the Arterial Tree in Healthy Adults.

Purpose: Vascular ultrasound (US) allows the analysis of vascular strain by speckle-tracking. This study sought to assess the extent to which vas cular strain varies between different segments of the arterial tree. Furthermore, this study aimed to investigate the reproducibility of vascular strain determination as well as of the components that contribute to the variance of vascular strain measurements in different vascular beds. Materials and Methods: Speckle-tracking was used to determine the vascular strain of the abdominal aorta (AA), the common carotid artery (CCA), the common femoral (CFA) and the popliteal artery (PA) of healthy adults. Intra- and interday reproducibility and the components of variance of vascular strain of the respective arteries were determined. Results: A total of 589 US clips obtained in 10 healthy adults (7 males, 28.3 ±â€Š3.2 years) were analyzable. Vascular strain was 7.2 ±â€Š3.0 % in the AA, 5.7 ±â€Š2.1 % in the CCA, 2.1 ±â€Š1.1 % in the CFA and 1.9 ±â€Š1.1 % in the PA. The intraday coefficients of variation of vascular strain were 6.2 % (AA), 3.9 % (CCA), 3.3 % (CFA) and 6.1 % (PA), and the interday coefficients of variation were 5.9 % (AA), 8.4 % (CCA), 10 % (CFA) and 4.6 % (PA). The variance of vascular strain mainly depended on the investigated vessel and subject. Individual DUS clips, the day of examination and the (right/left) body side (in paired arteries) had no impact on the variance of vascular strain. Conclusion: Vascular strain substantially varies between different sites of the arterial tree. Speckle-tracking by DUS allows the reliable determination of vascular strain at different arterial sites.

Microvascular autoregulation in children and adolescents with type 1 diabetes mellitus.

AIMS/HYPOTHESIS: Deterioration of microvascular function may have an early onset in individuals with type 1 diabetes mellitus. We hypothesised that microvascular autoregulation is impaired in children with type 1 diabetes and can be detected non-invasively by postocclusive reactive hyperaemia (PORH). METHODS: Microvascular autoregulation was assessed in 58 children with type 1 diabetes and 58 age- and sex-matched healthy controls by PORH using laser Doppler fluxmetry. Baseline perfusion, biological zero (defined as a 'no flow' laser Doppler signal during suprasystolic occlusion), peak perfusion following occlusion, time to peak and recovery time (time until baseline perfusion is resumed) were recorded and compared between the groups. RESULTS: Peak perfusion was higher in children with type 1 diabetes than in healthy controls (1.7 ± 0.93 AU [arbitrary units] vs 1.29 ± 0.46 AU; p = 0.004), and biological zero was lower in children with type 1 diabetes vs controls (0.14 ± 0.04 AU vs 0.19 ± 0.04 AU; p < 0.0001). No differences were seen between the groups in baseline perfusion, time to peak during PORH and recovery time following PORH. CONCLUSIONS/INTERPRETATION: PORH reveals impaired microvascular autoregulation in children with type 1 diabetes. The higher peak perfusion might reflect a decline in the vasoconstrictive ability of arteriolar smooth muscle cells upstream of capillary beds in children with type 1 diabetes.

Impact of international guidelines on the management of cardiovascular risk factors in diabetic patients with peripheral arterial disease.

AIM: Recent data on the management of cardiovascular risk factors in high risk patients showed that dyslipidemia is still treated in an inadequate way, especially in diabetic patients. We wanted to analyze the impact of the recommendation of the Inter-Society Consensus for the management of PAD (TASC-II) on the actual situation. METHODS: In this retrospective cohort study we analyzed total-, HDL-, LDL-cholesterol, triglycerides and blood glucose using capillary blood in diabetic patients, admitted to our outpatient department. Besides the recording of a complete medical history and vascular risk factors, an ABI-measurement and a carotid Duplex ultrasonography were performed at presentation. RESULTS: We studied 111 diabetic patients (44 female and 67 male) with a mean age (+/-SD) of 70, 3 (+/-9, 9) years; a BMI of 28, 2 (+/-4, 2) and a mean waist circumference of 103 (+/-12, 2) cm. Metabolic syndrome according to the NCEP-ATP-III criteria (2001) was shown in 86% (N.=95). 41% (N.=45) had clinically manifest vascular disease in a second and 23% (N.=26) even in a third vascular territory. Total-cholesterol was 183+/-43 mg/dL; LDL-C 94 +/-30 mg/dL; HDL-cholesterol 44 +/-12 mg/dl and triglycerides 219+/-103 mg/dL. A total of 33% (N.=37) in this high risk cohort attained the LDL-C target levels according to the TASC-II guidelines. A total of 68% (N.=76) was on a HMG-CoA-reductase-inhibitor, 61% (N.=68) had platelet aggregation inhibitors. CONCLUSIONS: We found poor adherence to international guidelines for secondary prevention in diabetic patients with PAD in this outpatient setting.

Effect of a low-fat diet enriched either with rapeseed oil or sunflower oil on plasma lipoproteins in children and adolescents with familial hypercholesterolaemia. Results of a pilot study.

BACKGROUND/OBJECTIVES: There is convincing evidence that unsaturated fatty acids exert favourable effects on plasma cholesterol levels. However, it is not clear which type of oil has the most pronounced effect, especially not in paediatric patients. The aim was to compare two low-fat diet regimes enriched with either monounsaturated fatty acids by rapeseed oil (RO) or polyunsaturated fatty acids by sunflower oil (SO) in children affected with familial hypercholesterolaemia (FH). SUBJECTS/METHODS: Twenty-one children aged 6-18 years affected with FH were enrolled in this randomized and double-blind pilot trial. The subjects and their families were trained to adhere to a low-fat/low-cholesterol diet. All visible fats were to be replaced by either RO or SO (14-27 g/day) for 13 weeks. Dietary adherence was controlled by repeated 4-day dietary records; plasma lipids, lipoproteins and risk markers were assessed at baseline and post-intervention. Out of 21 subjects, 16 could be followed-up after 6 months. RESULTS: Both fat-modified diets resulted in significant reduction in total cholesterol concentrations of 9.4% (RO P<0.005 vs SO P<0.05) and low-density lipoprotein (LDL) cholesterol concentrations of 12.7% (P<0.005) for RO and 11.3% (P<0.05) for SO. The reduction of the LDL/high-density lipoprotein (HDL) cholesterol ratio (RO 9% vs SO 3.5%) and high-sensitivity C-reactive protein (RO 16.8% vs SO 1.7%) were not statistically significant, respectively. In most participating families, a change in eating habits could be observed. CONCLUSIONS: A fat-modified diet enriched with RO seems to have very similar effects on cholesterol levels as with SO. However, our study suggests that RO has possibly more favourable effects concerning cardiovascular risk profile. Both diets appear to be feasible and were well accepted among our subjects. Although these results are promising, larger trials will be required to validate our findings.

Cerebral microembolism during transcatheter closure of patent foramen ovale.

BACKGROUND: Although transcatheter closure of patent foramen ovale (PFO) and atrial septal defect (ASD) has become a commonly performed intervention, the incidence of cerebral embolism with or without neurological deficits during such procedures has not been studied. METHODS: We monitored the middle cerebral artery in two different depths (48 mm and 53 mm) by continuous transcranial Doppler ultrasound during transcatheter PFO closure in 35 consecutive patients (F/M 20/15, mean age 47 +/- 11 years) and during ASD closure in 8 patients (F/M 7/1, mean age 45 +/- 5 years). All automatically detected high intensity transient signals (HITS) were manually reviewed to eliminate artifacts. RESULTS: HITS were detected in 33 of 35 patients (96%) with a median rate of 8 (interquartile range 4-19, range 2-29) HITS. The highest rates were observed when the septum was crossed with the guide wire (median 2; IQR 0-12; range 0-25) and when the left atrial disc was deployed (median 2; IQR 1-4; range 0-13). Despite this high rate of cerebral microembolism no clinically apparent neurological or neuropsychological deficit was observed. CONCLUSIONS: Silent cerebral embolism frequently occurs during transcatheter PFO and ASD closure. The peak of HITS at the time of crossing the septum with the guide wire may support the hypothesis that cerebral emboli in patients with PFO may originate from the septum itself. This may represent an alternative mechanism to the generally assumed paradoxical embolism.

Neointimal proliferation within carotid stents is more pronounced in diabetic patients with initial poor glycaemic state.

AIMS/HYPOTHESIS: We studied the influence of initial hyperglycaemia on neointimal proliferation within carotid Wallstents. METHODS: A total of 112 patients were followed by duplex sonography after carotid stenting for 24 months. Patients were assigned to three groups: non-diabetic subjects (group A) and diabetic patients, who were assigned according to their baseline HbA(1)c values, to group B1(HbA(1)c6.5%). RESULTS: At baseline the groups did not differ with respect to other vascular risk factors and residual stenosis on angiograms. The maximal thickness of the layer between the stent and the perfused lumen was measured at the duplex follow-ups. At 3 months the typical ultrasonic structure of the neointima was clearly discernible. From this point on, group B2 differed significantly ( p<0.001) compared with B1 and A with respect to the maximal thickness of neointima and the time course of its ingrowth: group A vs B1 vs B2 was 0.51+/-0.39 vs 0.52+/-0.33 vs 0.56+/-0.35 at 3 months, 0.91+/-0.27 vs 0.90+/-0.38 vs 1.14+/-0.48 at 6 months, 1.02+/-0.24 vs 0.97+/-0.34 vs 1.21+/-0.44 at 12 months and 1.09+/-0.23 vs 1.10+/-0.31 vs 1.23+/-0.37 at 24 months. CONCLUSION/INTERPRETATION: Initial hyperglycaemia seems to be a predictor of more pronounced neointimal proliferation after carotid stenting independent of diabetes. As intimal hyperplasia is known to be responsible for stent restenosis, strict optimisation of the hyperglycaemic state should be aimed at before elective carotid artery stenting.