Assessment of arterial damage in vascular Ehlers-Danlos syndrome: a retrospective multicentric cohort

Background

Vascular Ehlers-Danlos syndrome (vEDS) is a rare inherited connective tissue disorder due to pathogenic variants in the COL3A1 gene, leading to medium-size artery (MSA) dissection, aneurysm, and rupture with a poor prognosis. Conversely, aortic lesions are rarer and less investigated.

Purpose

To describe the association between the distribution of MSA and aortic lesions and the type of COL3A1 variants in a multicentric cohort of vEDS patients.

Methods

Analysis of the 330 vEDS adult patients from the French RaDiCO SEDVASC registry. At the time of the study, 87% were alive, 60.3% were index cases and 60.0% females. Median age at molecular diagnosis was 36 years (IQR 24.3–46.8). COL3A1 variants were identified using NGS and/or Sanger sequencing and classified according to their functional consequences: 80.6% dominant-negative (DN) and 19.4% leading to haplo-insufficiency (HI). Computed tomography angiography (CTA) was systematically performed during the initial work-up of patients. Carotid mechanics was also assessed by echotracking in a subgroup of 133 patients.

Results

Arterial lesion history was reported in 82.4% of the patients (N=272), with 227/272 patients (83.5%) having MSA lesions alone, 9 (3.3%) aortic lesions alone and 36 (13.2%) both. DN variant was associated with higher prevalence of arterial lesions than HI variant (P 0.044), especially on supra-aortic trunks and renal arteries (P 0.018 and P 0.0003 respectively). Importantly, the higher prevalence of aortic lesions observed in HI patients with arterial lesions versus DN patients (P 0.027) was not significantly different when adjusted for age (P 0.559). Carotid Young's modulus was lower in DN than HI patients (P 0.014), in association with the higher incidence of MSA lesions in this genotype group.

Conclusion

The prevalence of aortic lesions is not influenced by the COL3A1 genotype when adjusted for age. vEDS patients with DN variants have a higher frequency of MSA lesions especially in supra-aortic trunks which is associated with a lower carotid stiffness, suggesting a need for an optimal care for this subgroup of patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): French National Research Agency under the specific programme “Investments for the Future”, cohort grant-agreement ANR-l0-COHO-03-01

The Complexity of Dreams: a Multiscale Entropy Study on Cardiovascular Variability Series

Uncovering the physiological correlates of dreams is one of the most ambitious aim of multidisciplinary neuroscientific research. Here we investigated Autonomic Nervous System (ANS) dynamics associated with a dream recall, with a particular focus on the complexity assessment on cardiovascular control. We recorded electrocardiogram and arterial blood pressure signals from eight healthy subjects during rapid-eye-movement sleep before awakenings. Recordings were then split into two groups: the ones with a dream experience, and the ones without recall of dream experiences. The randomness of cardiovascular variability series was assessed through Sample Entropy metrics, which did not show any statistical difference between groups. On the other hand, a multiscale complexity analysis based on Distribution Entropy and Fuzzy Entropy revealed that a higher cardiovascular complexity is associated with a dreaming experience.

Diagnosis and treatment of hypertensive emergencies and urgencies among Italian emergency and intensive care departments. Results from an Italian survey: Progetto GEAR (Gestione dell'Emergenza e urgenza in ARea critica)

Hypertensive emergencies (HE) and urgencies (HU) are frequent causes of patients referral to Emergency Department (ED) and the approach may be different according to local clinical practice. Our aim was to explore awareness, management, treatment and counselling after discharge of HE and HU in Italy, by mean of an on-line survey. The young investigator research group of the Italian Society of Hypertension developed a 23-item questionnaire spread by e-mail invitation to the members of Italian Scientific societies in the field of Hypertension. 665 questionnaires were collected from EDs, Emergency and Urgency Medicine, Cardiology or Coronary Units, Internal Medicines, Intensive care, Stroke units. Symptoms considered suspicious of acute organ damage were: chest pain (89.0%), visual disturbances (89.8%), dyspnoea (82.7%), headache (82.1%), dizziness (52.0%), conjunctival haemorrhages (41.5%), tinnitus (38.2%) and epistaxis (34.4%). Exams more frequent prescribed were: electrocardiogram (97.2%), serum creatinine (91.4%), markers of cardiomyocyte necrosis (66.2%), echocardiography (65.1%). The use of intravenous or oral medications to treat HEs was 94.7% and 3.5%, while for HUs 24.4% and 70.8% respectively. Of note, a surprisingly high percentage of physicians (22 % overall, 24.5% in North Italy) used to prescribe sublingual nifedipine. After discharge, home blood pressure monitoring and general practitioner re-evaluation were more frequently suggested, while ambulatory blood pressure monitoring and hypertension specialist examination were less prescribed. The differences observed across the different macro-areas, regarded prescription of diagnostic test and drug administration. This survey depicts a complex situation of shades and lights in the real-life management of HE and HU in Italy.

Blood pressure phenotype reproducibility in CKD outpatients: a clinical practice report

Out-of-office blood pressure (BP) measurement is encouraged by recent hypertension guidelines for assessing BP phenotypes. These showed acceptable reproducibility in the short term, but few data exist about long-term reproducibility, particularly for chronic kidney disease (CKD) patients. We evaluated changes of the BP phenotypes at 6 and 12 months in 280 consecutive non-dialysis CKD outpatients (186 males, age 71 ± 12 years, eGFR 38 ± 13 ml/min/1.73), without any change in drug therapy. Elevated BP is defined as office BP > 140/90 and home BP > 135/85 mmHg for defining the following BP phenotypes: sustained uncontrolled hypertension (SUCH); white-coat uncontrolled hypertension (WUCH); masked uncontrolled hypertension (MUCH); and controlled hypertension (CH). At baseline, the prevalence of the phenotypes was SUCH 36.6%, CH 30.1%, WUCH 25.4% and MUCH 7.9%, and it was similar at 6 months and 12 months. On the other hand, individual phenotype reproducibility at 12 months was poor both overall (38.0%) and across the different phenotypes (SUCH 53.9%, WUCH 32.4% and CH 32.1%, MUCH 9.1%). Patients who were not maintaining the same phenotype (non-concordant) were not distinguished by age, sex, BMI, eGFR, presence of diabetes or cardiovascular disease, or pharmacological therapy. When reproducibility of BP phenotypes both at 6 months and at 12 months was assessed, it was very low (19.6%), particularly for MUCH (0%), CH (14%) and WUCH (15.5%), while it was 31% for SUCH. In a CKD cohort, the overall prevalence of the different BP phenotypes defined by office and home BP remains constant over time. However, only 38% of patients maintained the same phenotype at 12 months, suggesting a poor reproducibility over time for the BP phenotypes.

P2538Arterial stiffness and remodeling from large to small arteries in patients with spontaneous coronary artery dissection: evidence for a systemic subclinical involvement

Background and aim

Spontaneous coronary artery dissection (SCAD) is a major cause of acute coronary syndrome in women aged 50 years or less (22–43%). Its etiology is still unknown, though an association with systemic diseases such as fibromuscular dysplasia and collagenopathies has been found. This study is aimed at investigating the presence of subclinical structural and functional alterations in extracoronary districts in SCAD patients.

Methods

The design was a case-control study. Carotid, radial and digital arteries were scanned by standard or ultrahigh frequency ultrasound; clips were analyzed by automated image analysis software for diameter, intima-media thickness (IMT) and local distensibility. Applanation tonometry was used to obtain carotid-femoral pulse wave velocity, a measure of regional, aortic stiffness, and carotid pressure waveform.

Results

30 patients previously diagnosed with SCAD (27 women, age 51±10 years, 8 treated hypertensives, 4 smokers, mean BP 83±11mmHg, BMI 25±5kg/mq) and 30 controls, matched for age, sex and CV risk factors by propensity score, were enrolled. 18 SCAD patients underwent PTCA and 6 had a diagnosis of extracoronary fibromuscular dysplasia. In the left radial artery, wall thickness, cross-sectional area (2.96±1.07 vs 1.79±1.41mm2, p=0.008), and wall inhomogeneity were increased, especially in the outer layer, whereas diameter, wall/lumen ratio and distensibility were comparable to controls. In the left common carotid artery, an increased carotid stiffness was shown in SCAD (5.99±0.89 m/s vs 5.6±0.85, 0.03), while IMT tended to be increased bilaterally (0.63±0.12 vs 0.59±0.10mm, p=0.08). Aortic stiffness was similar in the two groups (7.0±1.9 vs 6.7±1.7m/s, p=0.60). Carotid (20.4±14.2 vs 11.9±15.0%, p=0.03), but not aortic augmentation index, was increased bilaterally.

Conclusions

SCAD patients showed a peculiar pattern of alterations in vascular remodeling and stiffness in extracoronary arterial segments such as the carotid and radial arteries, supporting the hypothesis that a systemic susceptibility is present even in the absence of systemic diseases.

P1553Differential association between vascular and chronological age with cardiovascular outcomes

Background/Introduction

Increased pulse wave velocity (PWV), is a reliable marker of early vascular aging (EVA). However, the identification of individuals whose arteries are abnormally healthy in comparison to their age and cardiovascular (CV) risk profile might be of interest, to discover novel pathways of cardioprotection and provide preventive strategies for successful vascular aging.

Purpose

1) to provide a novel calculation for vascular age and examine his determinants; 2) to test the hypothesis that individuals with the largest difference between chronological and vascular age (C-V age) show a lower rate of CV events than their counterparts, and may thus be defined as the supernormal vascular aging group (SUPERNOVA).

Methods

Vascular age was defined as predicted age based on classical CV risk factors and PWV. The best fitting model for vascular age was investigated in the multicenter, European, cross-sectional Reference Values for Arterial stiffness Collaboration Database (n=11406). Continuous variables were modelled as smoothing splines. Thereafter, the risk of fatal and non-fatal CV events associated with C-V age was examined in the longitudinal cohort of the Malmo Diet and Cancer Study (n=2663) using Cox proprotional hazard regression models. C-V age was examined as a continuous variable (natural splines) and as a 3 levels categorical variables based on the best grouping of the deciles of C-V age and corresponding to the EVA (<3.0 years), normal vascular aging (3.0 to 8.8 years) and SUPERNOVA (>8.8 years) respectively.

Results

In the Reference Values Cohort (age range 17–85 years, 52.4% men, 38.1% hypertensives, 3.9% diabetics, average PWV 7.8 m/s), the most significant predictor of vascular age (full model r2 0.598) was PWV. In the Malmo Diet and Cancer Study Cohort (age 61–89 years, 63.6% men, 64.0% hypertensives, 12.9% diabetics, PWV 11.5 m/s), during follow-up (6.6 years on average), 286 individuals developed a first cardiovascular event. In the Cox survival analysis, C-V age was significantly and inversely associated with CV events. Compare to normal vascular aging, participants with SUPERNOVA had lower risk for CV events [HR 0.51 (0.34–0.76)] whereas those with EVA had a higher risk [HR 2.71 (1.80–4.09)]. Instead, there was no significant association with all-cause mortality.

Conclusions

The use of PWV and CV risk factors may be useful to define early and supernormal vascular aging in particular, and to assess its clinical relevance towards the risk of cardiovascular disease and death.

Effects of carotid pressure waveforms on the results of wave separation, wave intensity and reservoir pressure analysis

OBJECTIVE

Recently great attention has been paid to innovative cardiovascular biomarkers obtained from wave separation (WS), wave intensity (WI) and reservoir-wave (RW) theories. All these approaches share a requirement for pressure information. The aim of this study was to evaluate differences in WS-, WI- and RW-derived parameters obtained achieving pressure waveforms in different ways.

APPROACH

Twenty-two individuals (49  ±  17 years, 59% males) were examined. Common carotid blood flow waveforms were obtained from pulsed-wave Doppler images. Carotid pressure waveforms were achieved in four different ways: (1) with applanation tonometry, used as a reference method; (2) linear scaling from an ultrasound (US)-derived diameter curve; (3) exponential scaling from a US-derived diameter curve; and (4) linear scaling from an accelerometric-derived diameter signal. For each case, the reflection magnitude (RM) and index (RI) were obtained from the WS. The amplitude of the first positive peak (W ₁), of the second positive peak (W ₂) and of the negative peak (W _b) were calculated from the WI, while the maximum of the reservoir (maxP_r) and the excess (maxP_ex) pressure were achieved from the RW.

MAIN RESULTS

According to the intra-class coefficient values, the agreement between the standard method and all the others was excellent for the RM (linear: 0.82; exponential: 0.83; accelerometric: 0.86), RI (linear: 0.84; exponential: 0.85; accelerometric: 0.87), maxP_r (linear: 0.97; exponential: 0.96; accelerometric: 0.97) and maxP_ex (linear: 0.85; exponential: 0.87; accelerometric: 0.89), while only a fair/good level was reached for W ₁ (linear: 0.67; exponential: 0.77; accelerometric: 0.52), W ₂ (linear: 0.52; exponential: 0.69; accelerometric: 0.83) and W _b (linear: 0.60; exponential: 0.44; accelerometric: 0.50).

SIGNIFICANCE

Measuring carotid pressure waveforms with different approaches does not influence the cardiovascular parameters obtained by WS and RW; those derived by WI are affected by the carotid pressure curve employed.

A priori dietary patterns and blood pressure in the EPIC Florence cohort: a cross-sectional study

PURPOSE

Several foods and nutrients have been independently associated with systolic (SBP) and diastolic (DBP) blood pressure values. This study aimed to evaluate the effects of combined dietary habits on SBP and DBP values in a large cohort of healthy adults, with a cross-sectional design. Adherence of participants to four a priori dietary patterns was considered: the Healthy Eating Index 2010 (HEI-2010); the Dietary Approaches to Stop Hypertension (DASH); the Greek Mediterranean Diet Score (MDS); and the Italian Mediterranean Index (IMI).

METHODS

Overall, 13,597 volunteers (35-64 years) were enrolled in 1993-1998 in the EPIC-Florence cohort. Information on dietary habits, anthropometry, smoking status, education, physical activity habits, previous diagnosis of hypertension and SBP and DBP measurements were collected at baseline. Multivariate regression models were performed on 10,163 individuals (7551 women) after excluding subjects with prevalent hypertension.

RESULTS

IMI, DASH and HEI-2010 were significantly and inversely associated with SBP and DBP values in the total population. The strongest association emerged between IMI and SBP (β - 1.80 excellent adherence vs low adherence, 95% CI - 2.99; - 0.61, p trend 0.001) and DBP (β - 1.12, 95% CI - 1.869; - 0.39, p trend 0.001) values. In sub-group analyses, an inverse association also emerged between IMI and SBP and DBP values among females and between DASH and DBP among males. MDS was not associated with SBP or DBP.

CONCLUSION

Overall, this study, carried out in a large cohort of healthy adults from Tuscany (Central Italy), showed inverse significant associations between specific a priori dietary patterns, identifying general models of health-conscious diet, and blood pressure values.

Endothelium and Oxidative Stress: The Pandora's Box of Cerebral (and Non-Only) Small Vessel Disease?

Common cerebral small vessel disease (cSVD) abnormalities are a common neuroradiological finding, especially in the elderly. They are associated with a wide clinical spectrum that leads to an increasing disability, impaired global function outcome and a reduced quality of life. A strong association is demonstrated with age and hypertension and other common vascular risk factors, including diabetes mellitus, dyslipoproteinemia, smoking, low vitamin B12 level, and hyperomocysteinemia. Although these epidemiological associations suggest a systemic involvement, etiopathogenetic mechanisms remain unclear. This review focuses on the potential role of endothelial dysfunction and oxidative stress in the pathogenic cascade leading to cSVD. We stressed on the central role of those pathways, and suggest the importance of quantifying the cerebral (and non-only) "endotheliopathic and oxidative load" and its clinical presentation that could lead to a better determination of vascular risk degree. In addition, understanding underlying pathogenic mechanisms could allow us to slow down the progression of vascular damage and, therefore, prevent the disability due to reiterated microvascular damage.

Physical activity and blood pressure in 10,000 Mediterranean adults: The EPIC-Florence cohort

BACKGROUND AND AIMS

The relevant role of physical activity (PA) in cardiovascular risk prevention is widely agreed. We aimed to evaluate, in a large Mediterranean population, the influence of PA on systolic (SBP) and diastolic blood pressure (DBP), taking into account individual characteristics and lifestyle habits.

METHODS AND RESULTS

In the Florence section of the European Prospective Investigation into Cancer and Nutrition 10,163 individuals, 35-64 years, without a previous diagnosis of hypertension were recruited. Information on occupational and leisure-time PA and blood pressure were collected at recruitment, together with data on lifestyle, dietary habits and anthropometry. Multivariate regression models were applied to evaluate the effect of total, occupational and leisure-time PA on SBP and DBP. Mean values of SBP and DBP in the study subjects were 124.4 (SD 15.6) and 79.7 mmHg (SD 9.4), respectively. Overall, a total PA index and an index including cycling, fitness and occupational PA (Cambridge index) were inversely associated with DBP (beta -0.87, p-value 0.02 actives vs inactives, p for trend 0.02 and beta -0.84, p value 0.003 actives vs inactives, p for trend 0.002, respectively), while SBP was associated only with the latter index (beta -1.14, p-value 0.01 actives vs inactives, p for trend 0.006). An inverse association emerged between manual/heavy manual occupation and DBP (p 0.02, ref sedentary/standing occupation) and between increasing cycling activity and SBP (p for trend 0.04).

CONCLUSIONS

In this large cohort of Mediterranean adults without a diagnosis of hypertension we confirm the role of overall PA in modulating SBP and DBP values. Cycling and manual occupations were associated with lower DBP values.

Advances in the non-invasive assessment of vascular dysfunction in metabolic syndrome and diabetes: Focus on endothelium, carotid mechanics and renal vessels

AIM

The present paper is a selective review on the methodology and clinical significance of techniques to assess specifically endothelial function, carotid mechanics and renal vascular function, particularly in the light of vascular dysfunction in metabolic syndrome and type 2 diabetes.

DATA SYNTHESIS

Endothelial dysfunction appears to be earlier detectable in the microcirculation of patients with altered glucose metabolism, while it attains significance in the macrocirculation at more advanced disease stages. Smooth muscle cell dysfunction is now increasingly recognized to play a role both in the development of endothelial dysfunction and abnormal arterial distensibility. Furthermore, impaired glucose metabolism affects carotid mechanics through medial calcification, structural changes in extracellular matrix due to advanced glycation and modification of the collagen/elastin material stiffness. The assessment of renal vascular function by dynamic ultrasound or magnetic resonance imaging has recently emerged as an appealing target for identifying subtle vascular alterations responsible for the development of diabetic nephropathy.

CONCLUSIONS

Vascular dysfunction represents a major mechanism for the development of cardiovascular disease in patients with abnormal glucose metabolism. Hence, the currently available non-invasive techniques to assess early structural and vascular abnormalities merit recommendation in this population, although their predictive value and sensitivity to monitor treatment-induced changes have not yet been established and are still under investigation.

Predictive value of dynamic renal resistive index (DRIN) for renal outcome in type 2 diabetes and essential hypertension: a prospective study

BACKGROUND

Hypertension (EH) and type 2 diabetes (T2DM) are major causes of chronic kidney disease (CKD) and identification of predictors of CKD onset is advisable. We aimed to assess whether dynamic renal resistive index (DRIN), as well as other markers of systemic vascular damage, are able to predict albuminuria onset and estimated glomerular filtration rate (eGFR) decline in patients with T2DM or EH.

METHODS

In this prospective observational cohort study, 27 T2DM and 43 EH patients, free of CKD at baseline, were followed-up for 4.1 ± 0.6 years. Resistive Index (RI), endothelium-dependent (FMD) and independent vasodilation in the brachial artery (after glyceryl trinitrate - GTN - 25 μg s.l.), carotid-femoral Pulse Wave Velocity (PWV), Augmentation Index (AIx), DRIN (%RI change after GTN 25 μg s.l.) were evaluated.

RESULTS

Patients developing microalbuminuria were older, more frequently T2DM, with higher UACR at baseline, and showed higher DRIN (-2.8 ± 6.7 vs -10.6 ± 6.4 %, p = 0.01) and PWV (9.9 ± 1.3 vs 7.9 ± 1.5 m/s, p = 0.004) at baseline. The best predictors of microalbuminuria onset were DRIN > -5.16 % in T2DM (sensitivity 0.83, specificity 0.80) and PWV > 8.6 m/s in EH (sensitivity 0.96, specificity 1.00). Individuals whose eGFR declined (n = 27) had higher eGFR at baseline, but similar vascular characteristics; however in EH showing eGFR decline, baseline DRIN and PWV were higher. PWV showed a steeper progression during follow-up in patients developing albuminuria (Visit-outcome interaction: p = 0.01), while DRIN was early compromised but no further impaired (Visit-outcome interaction: p = 0.04).

CONCLUSIONS

PWV and DRIN are able to predict microalbuminuria onset in newly diagnosed EH and T2DM. DRIN is early compromised in T2DM patients developing microalbuminuria.

Cardiovascular function in healthy Himalayan high-altitude dwellers

BACKGROUND

Residents of the Himalayan valleys uniquely adapted to their hypoxic environment in terms of pulmonary vasculature, but their systemic vascular function is still largely unexplored. The aim of the study was to investigate vascular function and structure in rural Sherpa population, permanently living at high altitude in Nepal (HA), in comparison with control Caucasian subjects (C) living at sea level.

METHODS AND RESULTS

95 HA and 64 C were enrolled. Cardiac ultrasound, flow-mediated dilation (FMD) of the brachial artery, carotid geometry and stiffness, and aortic pulse wave velocity (PWV) were performed. The same protocol was repeated in 11 HA with reduced FMD, after 1-h 100% O2 administration. HA presented lower FMD (5.18 ± 3.10 vs. 6.44  ±  2.91%, p = 0.02) and hyperemic velocity than C (0.61 ± 0.24 vs. 0.75 ± 0.28 m/s, p = 0.008), while systolic pulmonary pressure was higher (29.4 ± 5.5 vs. 23.6 ± 4.8 mmHg, p < 0.0001). In multiple regression analysis performed in HA, hyperemic velocity remained an independent predictor of FMD, after adjustment for baseline brachial artery diameter, room temperature and pulse pressure, explaining 8.7% of its variance. On the contrary, in C brachial artery diameter remained the only independent predictor of FMD, after adjustment for confounders. HA presented also lower carotid IMT than C (0.509 ± 0.121 vs. 0.576 ± 0.122 mm, p < 0.0001), higher diameter (6.98 ± 1.07 vs. 6.81 ± 0.85 mm, p = 0.004 adjusted for body surface area) and circumferential wall stress (67.6 ± 13.1 vs. 56.4 ± 16.0 kPa, p < 0.0001), while PWV was similar. O2 administration did not modify vascular variables.

CONCLUSIONS

HA exhibit reduced NO-mediated dilation in the brachial artery, which is associated to reduced hyperemic response, indicating microcirculatory dysfunction. A peculiar carotid phenotype, characterized by reduced IMT and enlarged diameter, was also found.

Poor sleep quality in systemic lupus erythematosus: does it depend on depressive symptoms?

Objectives

Sleep disturbances are frequently observed in rheumatic diseases including systemic lupus erythematosus (SLE). This study aimed at evaluating the prevalence of insomnia, poor sleep quality and their determinants in a cohort of SLE patients.

Methods

Eighty-one consecutive SLE female patients were evaluated in a cross-sectional study. The Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI), the Beck Depression Inventory (BDI) and the Self-rating Anxiety Scale (SAS) were administered. Patients with previous diagnosis of obstructive sleep apnea or restless legs syndrome were excluded. Fifty-three women with hypertension (without SLE) were enrolled as control group (H).

Results

In the SLE cohort poor sleep quality (65.4% vs 39.6%, p < 0.01) and difficulty in maintaining sleep and/or early morning awakening (65.4% vs 22.6%, p < 0.001), but not insomnia (33.3% vs 22.6%, p = ns), were more prevalent than in H. Depressive symptoms were present in 34.6% of SLE vs 13.2% H patients ( p < 0.001) while state anxiety was more common in H patients (H 35.8% vs SLE 17.3%, p < 0.005). SLE was associated with a 2.5-times higher probability of presenting poor sleep quality in comparison to H (OR 2.5 [CI 1.21–5.16]). After adjusting for confounders, both depressive symptoms (OR 4.4, [1.4–14.3]) and use of immunosuppressive drugs (OR 4.3 [CI 1.3–14.8]) were significantly associated with poor sleep quality in SLE patients. Furthermore, poor sleep quality was not associated either with disease duration or activity.

Conclusions

In a cohort of SLE women, insomnia and poor sleep quality, especially difficulties in maintaining sleep, were common. Depressive symptoms might be responsible for the higher prevalence of poor sleep quality in SLE.

Type 2 diabetes mellitus worsens arterial stiffness in hypertensive patients through endothelial dysfunction

AIMS/HYPOTHESIS

Endothelium-derived factors are thought to be physiological modulators of large artery stiffness. The aim of the study was to investigate whether endothelial function could be a determinant of arterial stiffness in essential hypertensive patients, in relation with the concomitant presence of type 2 diabetes mellitus.

METHODS

The study included 341 participants (84 hypertensive patients with and 175 without type 2 diabetes mellitus, 82 matched controls). Brachial artery endothelium-dependent flow-mediated dilation (FMD) was determined by high-resolution ultrasound and computerised edge detection system. Applanation tonometry was used to measure carotid-femoral pulse wave velocity (PWV).

RESULTS

Hypertensive patients with diabetes had higher PWV (10.1 ± 2.3 m/s vs 8.6 ± 1.4 m/s, p < 0.001) and lower FMD (3.51 ± 2.07 vs 5.16 ± 2.96%, p < 0.001) than non-diabetic hypertensive patients, who showed impaired vascular function when compared with healthy participants (7.9 ± 1.6 m/s and 6.68 ± 3.67%). FMD was significantly and negatively correlated to PWV only in hypertensive diabetic patients (r = -0.456, p < 0.001), but not in hypertensive normoglycaemic patients (r = -0.088, p = 0.248) or in healthy participants (r = 0.008, p = 0.946). Multivariate analysis demonstrated that, in the diabetic group, FMD remained an independent predictor of PWV after adjustment for confounders (r(2) = 0.083, p = 0.003). Subgroup analysis performed in non-diabetic hypertensive patients revealed that neither obesity nor the metabolic syndrome affected the relationship between FMD and PWV.

CONCLUSIONS/INTERPRETATION

Endothelial dysfunction is a determinant of aortic stiffness in hypertensive diabetic patients but not in hypertensive patients without diabetes. These results suggest that type 2 diabetes mellitus on top of hypertension might worsen arterial compliance by endothelium-related mechanisms.

Yellow fever vaccination in organ transplanted patients: is it safe? A multicenter study

BACKGROUND

Yellow fever (YF) may be very serious, with mortality reaching 50%. Live attenuated virus YF vaccine (YFV) is effective, but may present, although rare, life-threatening side effects and is contraindicated in immunocompromised patients. However, some transplant patients may inadvertently receive the vaccine.

METHODS

A questionnaire was sent to all associated doctors to the Brazilian Organ Transplantation Association through its website, calling for reports of organ transplanted patients who have been vaccinated against YF.

RESULTS

Twelve doctors reported 19 cases. None had important side effects. Only one had slight reaction at the site of YFV injection. Eleven patients were male. Organs received were 14 kidneys, 3 hearts, and 2 livers. Twelve patients received organs from deceased donors. Mean age at YFV was 45.6 ± 13.6 years old (range 11-69); creatinine: 1.46 ± 0.62 mg/dL (range 0.8-3.4); post-transplant time: 65 ± 83.9 months (range 3-340); and time from YFV at the time of survey: 45 ± 51 months (range 3-241). Immunosuppression varied widely with different drug combinations: azathioprine (7 patients), cyclosporine (8), deflazacort (1), mycophenolate (10), prednisone (11), sirolimus (3), and tacrolimus (4).

CONCLUSIONS

YFV showed no important side effects in this cohort of solid organ transplanted patients. However, owing to the small number of studied patients, it is not possible to extend these findings to the rest of the transplanted population, assuring safety. Therefore, these data are not strong enough to safely recommend YFV in organ transplanted recipients, as severe, even life-threatening side effects may occur.

Dynamic evaluation of renal resistive index in normoalbuminuric patients with newly diagnosed hypertension or type 2 diabetes

AIM/HYPOTHESIS

Renal resistive index is a useful measure for quantifying alterations in renal blood flow. In the present study we evaluated resistive index at baseline and after vasodilation induced by nitroglycerine in normoalbuminuric patients with type 2 diabetes or essential hypertension, relating the values to indices of systemic vascular dysfunction.

METHODS

Newly diagnosed treatment-naïve type 2 diabetic (n = 32) and hypertensive patients (n = 49) were compared with 27 age- and sex-matched healthy controls. Renal resistive index was obtained by duplex ultrasound at baseline and after 25 μg sublingual nitroglycerine. Endothelium-dependent (flow-mediated dilation) and -independent (response to nitroglycerine) vasodilation in the brachial artery was assessed by computerised edge detection system. Carotid-femoral pulse-wave velocity and augmentation index were assessed by applanation tonometry. Nitrotyrosine levels, an index of oxidative stress, were also measured.

RESULTS

Resistive index was higher in diabetic than in hypertensive patients and controls (p < 0.001), while changes in resistive index induced by nitroglycerine were lower in hypertensive patients compared with controls (p < 0.01), and were further reduced in type 2 diabetic patients. Hypertensive and diabetic patients showed significantly increased arterial stiffness, nitrotyrosine levels and reduced endothelial function than controls (p < 0.05). Changes in resistive index induced by nitroglycerine were independently related to serum glucose, reactive hyperaemia and aortic pulse-wave velocity in the overall population.

CONCLUSIONS/INTERPRETATION

These results support the dynamic evaluation of renal resistive index as an early detector of renal vascular alterations in the presence of type 2 diabetes and hypertension, even before the onset of microalbuminuria.

Reconstruction of an average cortical column in silico

The characterization of individual neurons by Golgi and Cajal has been the basis of neuroanatomy for a century. A new challenge is to anatomically describe, at cellular resolution, complete local circuits that can drive behavior. In this essay, we review the possibilities to obtain a model cortical column by using in vitro and in vivo pair recordings, followed by anatomical reconstructions of the projecting and target cells. These pairs establish connection modules that eventually may be useful to synthesize an average cortical column in silico. Together with data on sensory evoked neuronal activity measured in vivo, this will allow to model the anatomical and functional cellular basis of behavior based on more realistic assumptions than previously attempted.

Layer- and cell-type-specific suprathreshold stimulus representation in rat primary somatosensory cortex

Sensory stimuli are encoded differently across cortical layers and it is unknown how response characteristics relate to the morphological identity of responding cells. We therefore juxtasomally recorded action potential (AP) patterns from excitatory cells in layer (L) 2/3, L4, L5 and L6 of rat barrel cortex in response to a standard stimulus (e.g. repeated deflection of single whiskers in the caudal direction). Subsequent single-cell filling with biocytin allowed for post hoc identification of recorded cells. We report three major conclusions. First, sensory-evoked responses were layer- and cell-type-specific but always < 1 AP per stimulus, indicating low AP rates for the entire cortical column. Second, response latencies from L4, L5B and L6 were comparable and thus a whisker deflection is initially represented simultaneously in these layers. Finally, L5 thick-tufted cells dominated the cortical AP output following sensory stimulation, suggesting that these cells could direct sensory guided behaviours.

Immunosuppression in pancreas transplantation: mycophenolate mofetil versus sirolimus

The use of mycophenolate mofetil (MMF) in pancreas transplantation has increased graft survival and decreased the incidence of acute rejections episodes (ARE), regardless of the choice of calcineurin inhibitor. The combination of MMF with tacrolimus (TAC) is the most common protocol, it is considered the gold standard for new protocols. In the last few years, there have been reports of a small number of patients treated with sirolimus (RAPA), usually combined with TAC. Patient and pancreas survival rates as well as the incidence of ARE were similar to protocols with TAC and MMF. Twenty simultaneous pancreas and kidney (SPK) transplantations were performed using an immunosuppressive protocol of TAC, RAPA, and steroids (STE) after 2000. The incidence of ARE was 25%; all episodes responded to STE. Only 2 patients (10%) displayed hypercholesterolemia requiring treatment with statins. The use of RAPA as an alternative to MMF is promising, although presently one with limited experience. The combination of MMF and RAPA with or without a calcineurin inhibitor is an option to be evaluated in the future.

Pregnancy outcome after renal transplantation

AIMS

The aim of our study was to evaluate the frequency and the outcome of pregnancies in renal transplant recipients at our center.

METHODS

This study involved the retrospective analysis of 405 childbearing female renal recipients for presence of risk factors, the outcome of pregnancy, and maternal and fetal complications.

RESULTS

Fourty-four pregnancies occurred in 41 patients (10.8%). Mean age at transplantation was 23.6 +/- 6.3 years (range, 12-38 years). Only in 5 pregnancies were there no risk factors. In 13 (29.5%) pregnancies, the previous creatinine level was >1.5 mg/dL, in 16 (36.45%), proteinuria was >500 mg/24 hours; 29 (65.9%) were hypertensive; 14 (31.8%) had a time between transplantation and pregnancy less than 2 years (mean time, 35.5 +/- 30.9 months; range, 3-120 months). The outcomes were 27 (61.4%; 11 term and 16 premature delivery) successful pregnancies, 6 (13.6%) spontaneous abortions, 10 (22.7%) therapeutic abortions, and 1 (3.2%) fetal death. Pre-eclampsia occurred in 9 (20.4%) pregnancies and eclampsia in 1 (2.2%). The mean weight of the offspring was 2195 +/- 490 g (range, 1300- 2980 g). There were 2 cases of acute fetal distress and 1 oligodramnios. Median creatinine level was 1.0 (range, 0.4-3.0) mg/dL before conception and 1.2 (range, 0.7-9.0) mg/dL 6 month after pregnancy (P <.001). The long-term patient and graft survival rates were similar for pregnant versus nonpregnant recipients in the childbearing age.

CONCLUSION

Most pregnancies were successful, although the premature delivery rate was high (36.4%). Only 5 conceptions occurred in the absence of risk factors. Pregnancy did not impair the patient and graft survival during long-term follow-up.

Prognostic factors in Brazilian diabetic patients starting dialysis: a 3.6-year follow-up study

The objective of this study was to analyze the prognostic factors of a cohort of diabetic patients starting dialysis. This prospective, 3. 6-year population-based cohort study included 111 diabetic patients starting dialysis in all 18 dialysis centers of the metropolitan area of Porto Alegre, Brazil, between July 1995 and October 1996. The survival rate was analyzed by Kaplan-Meier curves and prognostic factors for death by Cox's proportional-hazards model. During the study period, 685 patients started dialysis; 182 (26.5%) had diabetes and 111 patients were included. Eighty-four percent of the 111 patients were classified as type 2 diabetes (random C-peptide>0. 6 ng/ml), and these patients presented more coronary artery disease (60% vs. 29%; P<0.02) than type 1 patients. In type 2 patients, later diagnosis of diabetes was associated with a shorter interval until beginning of dialysis (r=0.67; P=0.001). Diabetic nephropathy was the primary renal disease in 61% of all patients. Overall median survival (26 months) was similar for types 1 and 2 diabetic patients. Survival in the first, second, and third year was 69%, 51%, and 28%, respectively. Cardiovascular disease was the most common cause (63%) of death. According to Cox's proportional-hazards model, history of stroke (HR: 4.53, CI: 2.09-9.86, P<0.0001), amputations (HR: 3.2, CI: 1.61-6.35, P<0.0009), and coronary artery disease (HR: 1.67, CI: 0.95-2.96, P<0.076) at baseline were significantly associated with mortality. In conclusion, macrovascular complications were the main predictors of mortality in this cohort of diabetic patients starting dialysis. Intensive treatment of cardiovascular risk factors during dialysis might reduce the mortality rate of diabetic patients.

Dopamine and the mechanisms of cognition: Part I. A neural network model predicting dopamine effects on selective attention

BACKGROUND

Dopamine affects neural information processing, cognition, and behavior; however, the mechanisms through which these three levels of function are affected have remained unspecified. We present a parallel-distributed processing model of dopamine effects on neural ensembles that accounts for effects on human performance in a selective attention task.

METHODS

Task performance is stimulated using principles and mechanisms that capture salient aspects of information processing in neural ensembles. Dopamine effects are simulated as a change in gain of neural assemblies in the area of release.

RESULTS

The model leads to different predictions as a function of the hypothesized location of dopamine effects. Motor system effects are simulated as a change in gain over the response layer of the model. This induces speeding of reaction times but an impairment of accuracy. Cognitive attentional effects are simulated as a change in gain over the attention layer. This induces a speeding of reaction times and an improvement of accuracy, especially at very fast reaction times and when processing of the stimulus requires selective attention.

CONCLUSIONS

A computer simulation using widely accepted principles of processing in neural ensembles can account for reaction time distributions and time-accuracy curves in a selective attention task. The simulation can be used to generate predictions about the effects of dopamine agonists on performance. An empirical study evaluating these predictions is described in a companion paper.

Dopamine and the mechanisms of cognition: Part II. D-amphetamine effects in human subjects performing a selective attention task

BACKGROUND

A neural network computer model described in a companion paper predicted the effects of increased dopamine transmission on selective attention under two different hypotheses.

METHODS

To evaluate these predictions we conducted an empirical study in human subjects of D-amphetamine effects on performance of the Eriksen response competition task. Ten healthy volunteers were tested before and after placebo or D-amphetamine in a double-blind cross-over design.

RESULTS

D-amphetamine induced a speeding of reaction time overall and an improvement of accuracy at fast reaction times but only in the task condition requiring selective attention.

CONCLUSIONS

This pattern of results conforms to the prediction of the model under the hypothesis that D-amphetamine primarily affects dopamine transmission in cognitive rather than motor networks. This suggests that the principles embodied in parallel distributed processing models of task performance may be sufficient to predict and explain specific behavioral effects of some drug actions in the central nervous system.

Interpretation of pictorially presented social situations by learning disabled and normal children

The responses of learning disabled and normal children to a social inference task were compared. In individual interviews children were asked to interpret pictures of social situations. For some stimulus pictures children were asked to determine antecedents and predict consequences of the event. The LD children showed deficits in interpretation of the situation and determining consequences. No differences were found between groups in determining antecedents. Results are related to the cognitive and attentional deficits of LD children.