Association between adherence to the mediterranean diet, physical activity, and sleep apnea-hypopnea syndrome (SAHS) in a middle-aged population with cardiovascular risk: Insights from the ILERVAS cohort

INTRODUCTION

Sleep Apnea-Hypopnea Syndrome (SAHS) is a common sleep disorder influenced by factors like age, gender, and obesity. The Mediterranean Diet (MedDiet) and physical activity have shown health benefits in lung diseases, but their effects on SAHS remain underexplored.

METHODS

In a cross-sectional analysis of 678 middle-aged individuals with low-to-moderate cardiovascular risk from the ILERVAS cohort, we assessed adherence to the MedDiet and physical activity levels using validated tools. Sleep parameters, SAHS severity, and excessive daytime sleepiness were evaluated through non-attended cardiorespiratory polygraphy and the Epworth Sleepiness Scale. Multinomial logistic regression models were employed to assess the relationship between MedDiet adherence, physical activity, and SAHS severity.

RESULTS

The prevalence of severe, moderate, and mild SAHS was 15.5%, 23.2% and 36.1%, respectively. We found no significant associations between adherence to the MedDiet, physical activity levels, and the presence or severity of SAHS. However, we noted a significant interaction between MedDiet and physical activity with minimum SpO2 values (p = 0.049). Notably, consuming more than one serving of red meat per day was independently associated with a higher risk of moderate SAHS [OR = 2.65 (1.29-5.44), p = 0.008].

CONCLUSION

Individually, MedDiet adherence and physical activity did not show independent correlations with SAHS. However, when considered together, a minimal but significant effect on minimum SpO2 was observed. Additionally, red meat consumption was associated with a moderate risk of SAHS. Further research is necessary to comprehend the intricate connections between lifestyle factors and sleep-breathing disorders, with a focus on personalized approaches for high-risk populations.

Predictors of poor health-related quality of life among people living with HIV aged ≥60 years in the PISCIS cohort: Findings from the Vive+ project

INTRODUCTION

Advancements in and accessibility to effective antiretroviral therapy has improved the life expectancy of people living with HIV, increasing the proportion of people living with HIV reaching older age (≥60 years), making this population's health-related quality of life (HRQoL) more relevant. Our aim was to identify the determinants of poor HRQoL in people living with HIV aged ≥60 years and compare them with those of their younger counterparts.

METHODS

We used data from the 'Vive+' study, a cross-sectional survey conducted between October 2019 and March 2020, nested within the PISCIS cohort of people living with HIV in Catalonia and the Balearic Islands, Spain. We used the 12-item short-form survey (SF-12), divided into a physical component summary (PCS) and a mental component summary (MCS), to evaluate HRQoL. We used the least absolute shrinkage and selection operator for variable selection and used multivariable regression models to identify predictors.

RESULTS

Of the 1060 people living with HIV (78.6% males) who participated in the study, 209 (19.7%) were aged ≥60 years. When comparing older people living with HIV (≥60 years) and their younger counterparts, older people exhibited a worse PCS (median 51.3 [interquartile range {IQR} 46.0-58.1] vs. 46.43 [IQR 42.5-52.7], p < 0.001) but a similar MCS (median 56.0 [IQR 49.34-64.7] vs. 57.0 [IQR 48.9-66.3], p = 0.476). In the multivariable analysis, cognitive function correlated with a PCS (β correlation factor [β] -0.18, p = 0.014), and depressive symptoms and satisfaction with social role correlated with an MCS (β 0.61 and β -0.97, respectively, p < 0.001) in people living with HIV aged ≥60 years.

CONCLUSION

Depressive symptoms, poor cognitive function, and lower satisfaction with social roles predict poorer HRQoL in older people living with HIV. These factors need to be considered when designing targeted interventions.

Effectiveness of smoking cessation interventions among pregnant women: An updated systematic review and meta-analysis

OBJECTIVE

To carry out a systematic review of systematic reviews with an update of the existing evidence relating to a broad range of smoking cessation interventions, including psycho-social, digital and pharmacologic interventions, for pregnant women.

DATA-SOURCES

Search was conducted in March 2022 in PubMed, EMBASE, and Cochrane in two stages: 1) a search of systematic reviews and meta-analyses, published from January 2012 through January 2022; 2) an update of those that fulfilled eligibility criteria reproducing the primary search strategy.

STUDY ELIGIBILITY CRITERIA

We selected randomized clinical trials (RCTs) that evaluated the effectiveness of pharmacological, digital, and psychosocial interventions in aged 18 years and over who were daily smokers, and compared these with routine care, less intense interventions or placebo.

STUDY APPRAISAL AND SYNTHESIS METHODS

Data from eligible studies were manually extracted by two authors and reviewed by a third. The quality of the reviews was evaluated using the AMSTAR scale, and risk of bias was measured with the Rob-2 tool and GRADE level of evidence.

RESULTS

The meta-analysis included 63 RCTs (n = 19849 women). The interventions found to be effective were: financial incentives (RR:1.77; 95%CI:1.21-2.58), counseling (RR:1.27; 95%CI:1.13-1.43) and long-term nicotine replacement therapy (NRT) (RR:1.53; 95%CI:1.16-2.01). Short-term NRT, bupropion, digital interventions, feedback, social support, and exercise showed no effectiveness. The GRADE level of evidence was moderate-to-high for all interventions, with the exception of long-term NRT.

CONCLUSIONS

Non-pharmacological interventions for smoking cessation are the most effective for pregnant women. The moderator analysis suggests that pregnant women of low socioeconomic status might benefit less from smoking cessation interventions than women of a high socioeconomic status. These women are usually heavier smokers that live in pro-smoking environments and could require more intensive and targeted interventions.

Low adherence to the Mediterranean diet is associated with increased prevalence and number of atherosclerotic plaques in the ILERVAS cohort

BACKGROUND AND AIMS

Current research on the association between dietary patterns and subclinical atherosclerotic disease (SAD) is still limited, and published results are inconsistent and often consist of small population sizes. We aimed to evaluate the association between the Mediterranean diet (MDiet) and SAD in a large cohort of Mediterranean individuals.

METHODS

This was a cross-sectional study that included 8116 subjects from the ILERVAS cohort. The presence of atherosclerotic plaques (AP) was assessed by ultrasound examination. Adherence to the MDiet was assessed using the 14-item Mediterranean Diet Adherence Score (MEDAS). Inclusion criteria were subjects with at least one cardiovascular risk factor. Exclusion criteria were a clinical history of diabetes, chronic kidney disease, or a prior cardiovascular event. Bivariable and multivariable models were performed.

RESULTS

Compared with subjects without SAD, participants with SAD were older and had a higher frequency of smoking habit, hypertension, dyslipidemia, HbA1c and waist circumference. The adjusted multivariable analysis showed that a higher MEDAS was associated with a lower risk of AP (incidence rate ratios [IRR] 0.97, 95% CI [0.96-0.98]; p<0.001). Furthermore, moderate or high adherence to the MDiet was associated with a lower number of AP compared with a low MDiet adherence (IRR 0.90, 95% CI [0.87-0.94]; p<0.001). In both models, female sex was associated with a lower risk of AP.

CONCLUSIONS

Our findings point to a potentially protective role of MDiet for SAD in a Mediterranean population with low-to-moderate cardiovascular risk. Further research is needed to establish a causal relationship between both variables.

Are liver contour and bone fusion comparable to fiducials for IGRT in liver SBRT?

Introduction

Liver stereotactic body radiotherapy (SBRT) is increasingly being used to treat tumours. The purpose of this study was to compare the differences in patient positioning when using implanted fiducials as surrogates compared to alternative methods based on liver contour or bone registration.

Material and methods

Eighteen patients treated with SBRT who underwent a fiducial placement procedure were included. Fiducial guidance was our gold standard to guide treatment in this study. After recording the displacements, when fusing the planning CT and CBCT performed in the treatment unit using fiducials, liver contour and bone reference, the differences between fiducials and liver contour and bone reference were calculated. Data from 88 CBCT were analyzed. The correlation between the displacements found with fiducials and those performed based on the liver contour and the nearest bone structure as references was determined. The mean, median, variance, range and standard deviation of the displacements with each of the fusion methods were obtained. μ, Ʃ, and σ values and margins were obtained.

Results

Lateral displacements of less than 3 mm with respect to the gold standard in 92% vs. 62.5% of cases using liver contour and bone references, respectively, with 93.2% vs. 65.9% in the AP axis and SI movement in 69.3% vs. 51.1%. The errors μ, σ and Ʃ of the fusions with hepatic contour and bone reference in SI were 0.26 mm, 4 mm and 3 mm, and 0.8 mm, 5 mm and 3 mm respectively.

Conclusion

Our study showed that displacements were smaller with the use of hepatic contour compared to bone reference and comparable to those obtained with the use of fiducials in the lateral, AP and SI motion axes. This would justify that hepatic contouring can be a guide in the treatment of patients in the absence of fiducials.

Cumulative tobacco consumption has a dose-dependent effect on atheromatosis burden and improves severe atheromatosis prediction in asymptomatic middle-aged individuals: The ILERVAS study

BACKGROUND AND AIMS

Sex-specific impact of cumulative tobacco consumption (CTC) on atheromatosis extension and total plaque area remains unknown. We aimed to determine the impact of CTC in atheromatosis localization and burden.

METHODS

We performed a cross-sectional analysis in 8330 asymptomatic middle-aged individuals. 12-territory vascular ultrasounds in carotid and femoral arteries were performed to detect atheromatous plaque presence and to measure total plaque area. Adjusted regressions and conditional predictions by smoking habit or CTC (stratified in terciles as low (≤13.53), medium (13.54-29.3), and high (>29.3 packs-year)) were calculated. Severe atheromatosis (SA, ≥3 territories with atheroma plaque) was predicted with the Systematic COronary Risk Evaluation 2 (SCORE2) model. The improvement of SA prediction after adding CTC was evaluated.

RESULTS

CTC was associated with an increased risk of atheromatosis, stronger in femoral than in carotid artery, but similar in both sexes. A dose-dependent effect of CTC on the number of territories with atheroma plaque and total plaque area was observed. Addition of CTC to the SCORE2 showed a higher sensitivity, accuracy, and negative predictive value in males, and a higher specificity and positive predictive value in females. In both sexes, the new SCORE2-CTC model showed a significant increase in AUC (males: 0.033, females: 0.038), and in the integrated discrimination index (males: 0.072; females: 0.058, p < 0.001). Age and CTC were the most important clinical predictors of SA in both sexes.

CONCLUSIONS

CTC shows a dose-dependent association with atheromatosis burden, impacts more strongly in femoral arteries, and improves SA prediction.

Mortality attributable to environmental tobacco smoke exposure in Spain in 2020

INTRODUCTION AND OBJECTIVES

Exposure to environmental tobacco smoke (ETS) is associated with increased mortality and morbidity. The objective of this study was to estimate the impact of ETS exposure in Spain on mortality in 2020 in the population aged 35 years and over.

METHODS

A method of estimating attributable mortality (AM) based on the prevalence of ETS exposure was applied. Prevalence data were obtained from a representative study conducted in Spain and the relative risks were derived from a meta-analysis. AM point estimates are presented along with 95% confidence intervals (95% CI), calculated using a bootstrap naive procedure. AM, both overall and by smoking habit, was estimated for each combination of sex, age group, and cause of death (lung cancer and ischemic heart disease). A sensitivity analysis was performed.

RESULTS

A total of 747 (95% CI 676-825) deaths were attributable to ETS exposure, of which 279 (95% CI 256-306) were caused by lung cancer, and 468 (95% CI 417-523) by ischemic heart disease. Three-quarters (75.1%) of AM occurred in men and 60.9% in non-smokers. When chronic obstructive pulmonary disease and cerebrovascular disease are included, the burden of AM is estimated at 2242 deaths.

CONCLUSIONS

ETS exposure is associated with 1.5% of all deaths from lung cancer and ischemic heart disease in the population aged 35 and over. These data underline the need for health authorities to focus on reducing exposure to ETS in all settings and environments.

Silver jubilee: 25 years of the first demonstration of the direct effect of phosphate on the parathyroid cell

Although phosphorus is an essential element for life, it is not found in nature in its native state but rather combined in the form of inorganic phosphates (PO₄^3-), with tightly regulated plasma levels that are associated with deleterious effects and mortality when these are out of bounds. The growing interest in the accumulation of PO₄^3- in human pathophysiology originated in its attributed role in the pathogenesis of secondary hyperparathyroidism (SHPT) in chronic kidney disease. In this article, we review the mechanisms by which this effect was justified and we commemorate the important contribution of a Spanish group led by Dr. M. Rodríguez, just 25 years ago, when they first demonstrated the direct effect of PO₄^3- on the regulation of the synthesis and secretion of parathyroid hormone by maintaining the structural integrity of the parathyroid glands in their original experimental model. In addition to demonstrating the importance of arachidonic acid (AA) and the phospholipase A2-AA pathway as a mediator of parathyroid gland response, these findings were predecessors of the recent description of the important role of PO₄^3- on the activity of the calcium sensor-receptor, and also fueled various lines of research on the importance of PO₄^3- overload not only for the pathophysiology of SHPT but also in its systemic pathogenic role.

Development and Validation of a Personalized, Sex-Specific Prediction Algorithm of Severe Atheromatosis in Middle-Aged Asymptomatic Individuals: The ILERVAS Study

Background

Although European guidelines recommend vascular ultrasound for the assessment of cardiovascular risk in low-to-moderate risk individuals, no algorithm properly identifies patients who could benefit from it. The aim of this study is to develop a sex-specific algorithm to identify those patients, especially women who are usually underdiagnosed.

Methods

Clinical, anthropometrical, and biochemical data were combined with a 12-territory vascular ultrasound to predict severe atheromatosis (SA: ≥ 3 territories with plaque). A Personalized Algorithm for Severe Atheromatosis Prediction (PASAP-ILERVAS) was obtained by machine learning. Models were trained in the ILERVAS cohort (n = 8,330; 51% women) and validated in the control subpopulation of the NEFRONA cohort (n = 559; 47% women). Performance was compared to the Systematic COronary Risk Evaluation (SCORE) model.

Results

The PASAP-ILERVAS is a sex-specific, easy-to-interpret predictive model that stratifies individuals according to their risk of SA in low, intermediate, or high risk. New clinical predictors beyond traditional factors were uncovered. In low- and high-risk (L&amp;H-risk) men, the net reclassification index (NRI) was 0.044 (95% CI: 0.020–0.068), and the integrated discrimination index (IDI) was 0.038 (95% CI: 0.029–0.048) compared to the SCORE. In L&amp;H-risk women, PASAP-ILERVAS showed a significant increase in the area under the curve (AUC, 0.074 (95% CI: 0.062–0.087), p-value: &lt; 0.001), an NRI of 0.193 (95% CI: 0.162–0.224), and an IDI of 0.119 (95% CI: 0.109–0.129).

Conclusion

The PASAP-ILERVAS improves SA prediction, especially in women. Thus, it could reduce the number of unnecessary complementary explorations selecting patients for a further imaging study within the intermediate risk group, increasing cost-effectiveness and optimizing health resources.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT03228459].

POS0804 TOCILIZUMAB IN LARGE-VESSEL GIANT CELL ARTERITIS AND TAKAYASU ARTERITIS: MULTICENTRIC OBSERVATIONAL COMPARATIVE STUDY

Background

Tocilizumab (TCZ) has shown to be effective for large vessel vasculitis including giant cell arteritis (GCA) and Takayasu arteritis (TAK) (1-5). However, LVV-GCA and TAK show different demographic and clinical features that may influence on TCZ therapeutic response.

Objectives

To compare the effectiveness of TCZ in patients with LVV-GCA and patients with TAK.

Methods

Observational multicenter study of patients with LVV-GCA and TAK who received TCZ. Outcome variables were: a) proportion of patients who achieved complete clinical improvement along with normalization of laboratory markers (CRP ≤0.5mg/dL and/or ESR ≤ 20 mm/1st hour) at 12 months b) complete improvement in imaging techniques. A comparative study between patients with LVV-GCA and TAK was performed.

Results

We evaluated 70 LVV-GCA and 57 TAK patients who received TCZ. Main clinical and demographic characteristic are described in Table 1. Patients with TAK were younger, had longer disease duration, had received more commonly previous biologic therapy and were receiving higher doses of prednisone at baseline. TCZ intravenous administration was more common in TAK patients (80.7% vs 48.6%; p<0.01). Follow-up time after TCZ onset was similar in both groups. At 12 months, about 75% of patients achieved complete clinical improvement and ESR/CRP normalization in both groups. A follow-up imaging technique was performed in 37 LVV-GCA patients after a mean time of 12.9±6.0 months and 38 TAK patients after 9.5±5.0 months. Complete improvement in imaging techniques was only observed in 18.9% and 21.1% of patients with LVV-GCA and TAK, respectively (Figure 1).

Table 1.LVV-GCA (n=70)TAK (n=57)pGeneral featuresAge (years), mean ± SD67.2 ± 10.540.5 ± 16.3< 0.01Sex (female), n (%)51 (72.9)49 (86)0.07Disease evolution before TCZ onset (months), median [IQR]5 [2-15]12 [3-37]<0.01Baseline laboratory parametersESR (mm/1st hour), median [IQR]32 [12.5-54.7]31 [10-52]0.82CRP (mg/dL), median [IQR]1.4 [0.5-2.4]1.4 [0.5-3.5]0.41Baseline prednisone dose (mg/day), median [IQR]15 [10-20]30 [15-50]< 0.01Previous therapyConventional DMARDs, n(%)45 (64.3)44(77.2)0.51Biologic therapy, n (%)0(0)12 (21.1)<0.01TCZ therapyIntravenous, n (%)34 (48.6)46 (80.7)< 0.01Combined with MTX, n(%)24 (34.3)24 (42.1)0.37Follow-up time after TCZ onset, median [IQR]20 [10-36]18 [7-41]0.73Complete clinical improvement and ESR/CRP normalization at 12 months, n/N (%)35/47 (74.4)30/39 (76.9)0.79Complete improvement in imaging techniques, n/N(%)7/37 (18.9)8/38 (21.1)0.85

CRP: C-reactive protein; DMARDs: Disease-modifying anti-rheumatic drugs ESR: erythrocyte sedimentation rate; GCA: giant cell arteritis; IQR: interquartile range; LVV: large vessel; MTX: methotrexate; n: Number of patients; N: total number of patients: TCZ: tocilizumab; TAK:takayasu

Figure 1.

Conclusion

The effectiveness of TCZ was similar in patients with LVV-GCA and TAK, despite a more refractory disease in TAK patients. A discordance between clinical and imaging activity improvement was observed in both LVV-GCA and TAK, as reported in previous studies (3).

References

[1]Calderón-Goercke M, et al. Semin Arthritis Rheum 2019; 49:126-35. https://doi.org/10.1016/j.semarthrit.2019.01.003

[2]Prieto-Peña D et al. Ther Adv Musculoskelet Dis. 2021;13:175. PMID: 34211589.

[3]Prieto Peña D et al. Clin Exp Rheumatol. 2021;39 Suppl 129:69-75. PMID: 33253103.

[4]González-Gay MA, et al. Expert Opin Biol Ther. 2019;19:65-72. doi: 10.1080/14712598.2019.1556256.

[5]Prieto-Peña D, et al. Semin Arthritis Rheum. 2019;48(4):720-727. doi: 10.1016/j.semarthrit.2018.05.007

Disclosure of Interests

None declared

Weak Association between Skin Autofluorescence Levels and Prediabetes with an ILERVAS Cross-Sectional Study

A large body of evidence demonstrates a relationship between hyperglycemia and increased concentrations of advanced glycation end-products (AGEs). However, there is little information about subcutaneous AGE accumulation in subjects with prediabetes, and whether or not this measurement could assist in the diagnosis of prediabetes is unclear. A cross-sectional study was conducted in 4181 middle-aged subjects without diabetes. Prediabetes (n = 1444) was defined as a glycosylated hemoglobin (HbA1c) level between 39 and 47 mmol/mol (5.7 to 6.4%), and skin autofluorescence (SAF) measurement was performed to assess AGEs. A multivariable logistic regression model and receiver operating characteristic curve were used. The cohort consisted of 50.1% women with an age of 57 [52;62] years, a BMI of 28.3 [25.4;31.6] kg/m2, and a prevalence of prediabetes of 34.5%. Participants with prediabetes showed higher SAF than control participants (2.0 [1.7;2.2] vs. 1.9 [1.7;2.2], p < 0.001). However, HbA1c was not significantly correlated with SAF levels (r = 0.026, p = 0.090). In addition, the SAF level was not independently associated with prediabetes (OR = 1.12 (0.96 to 1.30)). Finally, there was no good cutoff point for SAF to identify patients with prediabetes (AUC = 0.52 (0.50 to 0.54), sensitivity = 0.61, and 1-specificity = 0.56). Given all of this evidence, we can conclude that although there is an increase in SAF levels in participants with prediabetes, the applicability and clinical relevance of the results is low in this population.

Prevalence and Predictors of Cerebral Microangiopathy Determined by Pulsatility Index in an Asymptomatic Population From the ILERVAS Project

Background: Little is known about the prevalence of cerebral microangiopathy (CM), which is related to cognitive impairment, in an asymptomatic population. Pulsatility index (PI) is an easily measurable parameter of cerebral vascular resistance in transcranial duplex of the middle cerebral artery (MCA) study. We aimed to determine the prevalence of CM measured by PI of MCA in low to moderate vascular risk subjects. Methods: We included 3,721 subjects between 45 and 70 years without previous history of vascular disease or diabetes mellitus and with at least one other vascular risk factor from the cross-sectional study ILERVAS (Lleida, Spain). Patients underwent transcranial duplex to determine MCA-PI. Possible CM was defined by MCA-PI >1.1. Carotid and femoral arteries ultrasound registration was done to determine the presence, the number, and the area of atheromatous plaques. Body mass index (BMI), pulse pressure (PP) and laboratory data were also recorded. Results: 439 (11.8%) subjects were excluded due to the low quality of transcranial duplex images. Median age was 57 [IQR 52, 62] years. Possible CM was found in 424 (12.9%) subjects. CM patients had higher prevalence of plaques than non-CM (77.4 vs. 66.4%, p < 0.001). PI showed a positive linear correlation with the number of territories with plaques (r = 0.130, p < 0.001), and the total plaque area (r = 0.082, p < 0.001). The predictors of possible CM were the age, male gender, and PP. Conclusions: In low-to-moderate vascular risk asymptomatic population, the proportion of abnormal brain microvascular bed determined by MCA-PI is not negligible. The planned 10-year follow-up will describe the clinical relevance of these findings.

Customized Fiber Post Improves the Bond Strength and Dentinal Penetrability of Resin Cementation System to Root Dentin

OBJECTIVE

This study aimed to evaluate the effect of fiber post customization on the bond strength (24 hours and 6 months), resin cement thickness, and dentinal penetrability of Adper Scotchbond Multi-Purpose - RelyX ARC (AS-RA), RelyX U200 (R2), and Scotchbond Universal - RelyX Ultimate (SU-RU) cementation systems to root dentin from the cervical-, middle-, and apical-thirds of the post space.

METHODS

One hundred twenty bovine incisors were endodontically treated. After post space preparation, the roots were divided into six groups, according to the luting protocols (AS-RA, R2, SU- RU) and the type of fiber post [noncustomized post (NC) and customized post (C)]. Customization procedures were peformed using a resin composite (Z350 XT). 24 hours (n=60) or 6 months later (n=60), specimens from the cervical-, middle-, and apical-thirds of the post space were submitted to cementation system thickness measurement, bond strength evaluation, and dentinal penetrability analysis with Confocal Laser Scanning Microscopy (CLSM). Failure mode was classified as adhesive, cohesive, or mixed. Data were submitted to ANOVA and Tukey tests (α=0.05).

RESULTS

Cementation protocols with customized fiber posts presented the lowest cementation system thickness, regardless of the cementation system or post space-third (p<0.05), and the highest bond strength values (p<0.05), regardless of the third space (p>0.05), for both periods (24 hours or 6 months). The comparison of push-out bond strength values between 24 hours and 6 months showed a reduction in all groups for the cervical-third (p<0.05). For the middle-third, only noncustomized groups showed reduction (p<0.05). For the apical-third, no reduction was observed (p>0.05).

CONCLUSIONS

Anatomical customization favored both the bond strength of cements to dentin and the dentinal penetrability, but with lower cementation system thickness, regardless of cement composition and adhesive strategy.

A new inertial navigation system for guiding implant placement. An in-vitro proof-of-concept study

The aim of this study was to assess the potential use of a new advanced inertial navigation system for guiding dental implant placement and to compare this approach with standard stereolithographic template guiding. A movement processing unit with a 9-axis absolute orientation sensor was adapted to a surgical handpiece and wired to a computer navigation interface. Sixty implants were placed by 10 operators in 20 jaw models. The 30 implants of the test group were placed in 10 models guided by the new inertial navigation prototype. The 30 implants of the control group were placed in another 10 models using a CAD-CAM template. Both groups were subdivided into experienced and non-experienced operators. Pre- and postoperative computer tomography images were obtained and matched to compare the planned and final implant positions. Four deviation parameters (global, angular, depth, and lateral deviation) were defined and calculated. The primary outcome was the angular deviation between the standard stereolithographic approach and the new inertial navigation system. Results showed no significant differences between both groups, suggesting that surgical navigation based on inertial measurement units (IMUs) could potentially be useful for guiding dental implant placement. However, more studies are still needed to translate this new approach into clinical practice.

Phenomenological model for the prediction of Moringa oleifera extracted oil using a laboratory Soxhlet apparatus

Moringa oleifera is an oilseed crop with poten­tial for biodiesel production. The second step in this process is the extraction of oil. Extraction in hot water, with a Soxhlet apparatus and the ultrasound technique are the most commonly used methods. The aim of the present work was to obtain a phenomenological model for the Moringa oleifera oil extraction process using Soxhlet. Effective diffusivity for Moringa oil through the kernels is obtained, using the kinetics of the extraction process (experimentally determined) and the Fick’s diffusion second law for non-steady state. The value of 0.685·10-12 m2/s fully matched reports on effective diffusion coefficient for other solids. It was also verified from the statistical analysis and a linear fit for experimental data that the model can be used to describe the oil extraction process of Moringa oleifera in the Soxhlet extractor, responding to the diffusive phenomenon (process controlled by internal resistance).

Evaluation of Tooth Sensitivity of In-office Bleaching with Different Light Activation Sources: A Systematic Review and a Network Meta-analysis

OBJECTIVES

A systematic review and network meta-analysis were performed to answer the following research question: Are there differences in the risk and the intensity of tooth sensitivity (TS) among eight light activation systems for in-office bleaching in adults?

METHODS

Randomized controlled trials (RCTs) that compared at least two different in-office bleaching light activations were included. The risk of bias (RoB) was evaluated with the RoB tool version 1.0 from the Cochrane Collaboration tool. A random-effects Bayesian mixed treatment comparison (MTC) model was used independently for high- and low-concentration hydrogen peroxide. The certainty of the evidence was evaluated using the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) approach. A comprehensive search was performed in PubMed, Bridge Base Online (BBO), Latin American and Caribbean Health Sciences Literature database (LILACS), Cochrane Library, Scopus, Web of Science, and grey literature without date and language restrictions on April 23, 2017 (updated on September 26, 2019). Dissertations and theses, unpublished and ongoing trials registries, and IADR (International Association for Dental Research) abstracts (2001-2019) were also searched.

RESULTS

After title and abstract screening and the removal of duplicates, 32 studies remained. Six were considered to be at low RoB, three had high RoB, and the remaining had an unclear RoB. The MTC analysis showed no significant differences among the treatments in each network. In general, the certainty of the evidence was graded as low due to unclear RoB and imprecision.

CONCLUSION

There is no evidence that the risk and intensity of TS are affected by light activation during in-office bleaching.

Long-term outcomes of spinal SBRT. Is it important to select the treatment time?

PURPOSE

SBRT (stereotactic body radiation therapy) is widely used as a curative treatment in tumoral lesions and has become a fundamental tool for the treatment of spine metastasis. In this study, we present survival and toxicity outcomes of spine SBRT after a 2-year follow-up.

METHODS/PATIENTS

Data from spine SBRT treatments performed at our institution between March 2012 and February 2020 was collected. Medical records, including demographic, primary tumor, and treatment characteristics were reviewed. Patient follow-up included clinical evaluation, imaging, and blood tests. Toxicity was recorded according to CTCAE v4.0.

RESULTS

We analyzed 73 consecutive spine SBRT treatments in 60 patients. 39.7% of the cases had primary breast cancer and 23.3% had prostate cancer. Most cases (87.7%) were treated with a single SBRT fraction of 16 Gy. Median follow-up was 26.1 months (range 1.7-78.6), and 1- and 2-year overall survival (OS) rates were 96.9% and 84.2%, respectively. Local control (LC) rates at 1- and 2-years were 76.3% and 70.6%, respectively. Multivariate analysis identified histology as a prognostic factor for both OS and LC. Patients who underwent spine SBRT 6 months after the spinal lesion diagnosis had LC at 2 years of 88%, vs 61.7% for those who underwent SBRT before this period. No grade III or higher toxicity was reported. The vertebral compression fracture (VCF) rate was 4.1%.

CONCLUSION

Spine SBRT at our institution showed a 2-year LC of 70.6%, without G3 toxicities. Delaying SBRT at least 6 months to administer systemic treatment was related to an improvement in local control.

Risk factors associated with valvular calcification in patients with chronic kidney disease. Analysis of NEFRONA study

INTRODUCTION

Patients with chronic kidney disease (CKD) are at high risk of cardiovascular morbidity and mortality. Subclinical cardiac structural alterations have prognostic value in these patients. The aim was to analyse the prevalence of valvular calcification, the evolution and the relationship with different risk factors.

MATERIAL AND METHODS

Part of the sample of the NEFRONA study was randomly selected. Aortic and mitral valve calcification were analysed in echocardiograms performed at the baseline visit and at 24 months.

RESULTS

We included 397 patients, the estimated basal glomerular filtrate (eGFR) was 33 ml/min with significant decrease to 30.9 ml/min. There was an increase in the area of carotid and femoral plaque, as well as an increase in patients with aortic and mitral calcification at 24 months. A positive association of mitral calcification at 24 months with age, ankle-brachial index (ABI) and calcium-phosphorus product (CaxP) at baseline visit was observed, without association with eGFR. Aortic calcification at 24 months was positively associated with age, phosphorous and total carotid plaque area at baseline, with no relationship to eGFR.

CONCLUSIONS

A significant prevalence of valvular calcification was observed in patients with CKD without known cardiovascular disease.Two-year progression was observed independently of the eGFR. Patients with higher risk of mitral valve calcification were those with older age, higher ABI and CaxP product. Patients with a higher risk of aortic calcification were those with older age, higher phosphorous levels and larger area of carotid plaque. Identifying these higher risk patients would help to avoid future cardiovascular events intensifying follow-ups.

High Incidence of Adverse Outcomes in Haemodialysis Patients with Diabetes with or without Diabetic Foot Syndrome: A 5-Year Observational Study in Lleida, Spain

Background: We evaluated whether, in subjects receiving haemodialysis (HD), the presence of diabetic foot syndrome (DFS) was associated with increased mortality compared with subjects with diabetes mellitus (DM) without DFS and with non-diabetic subjects. Methods: Retrospective, observational study in 220 subjects followed for six years. We calculated and compared the frequency and 5-year cumulative incidence of all-cause mortality, cardiovascular (CV) mortality, CV events, major adverse CV events (MACE), and new foot ulcer (FU) or amputation. We also examined prognostic factors of all-cause and CV mortality based on baseline characteristics. Results: DM patients had a 1.98 times higher probability of all-cause mortality than those without DM (p = 0.001) and 2.42 times higher likelihood of CV mortality and new FU or amputation (p = 0.002 and p = 0.008, respectively). In the DM cohort, only the risk of a new FU or amputation was 2.69 times higher among those with previous DFS (p = 0.021). In patients with DM, older age was the only predictor of all-cause and CV mortality (p = 0.001 and p = 0.014, respectively). Conclusions: Although all-cause and CV mortality were increased on HD subjects with DM, the presence of DFS did not modify the excess risk. Additional studies are warranted to further explore the impact of DFS in subjects with DM undergoing HD.

Prevalence of Obstructive Sleep Apnoea and Its Association With Atherosclerotic Plaques in a Cohort of Subjects With Mild-Moderate Cardiovascular Risk

INTRODUCTION

Classic cardiovascular risk factors do not explain all the cardiovascular events. Obstructive sleep apnoea (OSA) has been proposed as a potential and prevalent cardiovascular risk factor. Our study aimed to describe the prevalence of OSA in a middle-aged cohort with mild-moderate cardiovascular risk and evaluate its association with atherosclerotic disease.

METHODS

This is an observational cross-sectional ancillary study of the ILERVAS project which was aimed to study subclinical arterial disease in a cohort with mild-moderate cardiovascular risk. In a sample of consecutive subjects, we performed a sleep study and evaluate OSA prevalence and its association with carotid and femoral atheroma plaques and atherosclerotic burden.

RESULTS

Overall, 966 subjects with a median age of 57 years (25-75th percentile; 52-62) and a body mass index (BMI) of 28.5kg/m² (25.6-31.6) were included. Of these, 72.6% (69.7%-75.3%) had OSA (apnoea-hypopnoea index (AHI)≥5/h); 35.7% (32.8%-38.8%) had mild OSA (AHI 5-14.9/h) and 36.9% (33.9%-39.9%) had moderate/severe OSA (AHI≥15/h). Mean oxygen saturation and the percentage of time with oxygen saturation<90% (CT90) were associated with atherosclerotic burden (e^β (95%CI) 0.932 (0.892, 0.974); 1.005 (1.002, 1.009), respectively) and total plaque (OR (95%CI) 0.88 (0.797,0.971); 1.013 (1.004,1.021), respectively). No association with the AHI or oxygen desaturation index was found.

CONCLUSIONS

This study confirms a high prevalence of OSA in patients with mild-moderate cardiovascular risk and shows an association between atherosclerotic burden, total and femoral plaque with CT90 and mean oxygen saturation, suggesting the importance of OSA-related hypoxaemia in the induction of atherosclerotic disease.

[Risk factors associated with valvular calcification in patients with chronic kidney disease. Analysis of NEFRONA Study]

INTRODUCTION

Patients with chronic kidney disease (CKD) are at high risk of cardiovascular morbidity and mortality. Subclinical cardiac structural alterations have prognostic value in these patients. The aim was to analyse the prevalence of valvular calcification, the evolution and the relationship with different risk factors.

MATERIAL AND METHODS

Part of the sample of the NEFRONA study was randomly selected. Aortic and mitral valve calcification were analysed in echocardiograms performed at the baseline visit and at 24 months.

RESULTS

We included 397 patients, the estimated basal glomerular filtrate (eGFR) was 33ml/min with significant decrease to 30.9ml/min. There was an increase in the area of carotid and femoral plaque, as well as an increase in patients with aortic and mitral calcification at 24 months. A positive association of mitral calcification at 24 months with age, ankle-brachial index (ABI) and calcium-phosphorus product (CaxP) at baseline visit was observed, without association with eGFR. Aortic calcification at 24 months was positively associated with age, phosphorous and total carotid plaque area at baseline, with no relationship to eGFR.

CONCLUSIONS

A significant prevalence of valvular calcification was observed in patients with CKD without known cardiovascular disease.Two-year progression was observed independently of the eGFR. Patients with higher risk of mitral valve calcification were those with older age, higher ABI and CaxP product. Patients with a higher risk of aortic calcification were those with older age, higher phosphorous levels and larger area of carotid plaque. Identifying these higher risk patients would help to avoid future cardiovascular events intensifying follow-ups.

Hyperbaric oxygen and radiation therapy: a review

About 5% of cancer patients treated with radiotherapy will have severe late-onset toxicity. Hyperbaric oxygen therapy (HBOT) has been used as a treatment for radiation injuries for decades, with many publications presenting data from small series or individual cases. Moreover, we know that the hypoxic areas of tumours are more resistant to radiation. HBOT increases the oxygen tension in tissues and, theoretically, it should enhance the efficiency of radiotherapy. To better understand how HBOT works, we carried out this bibliographic review. We found Grade B and C evidence that at pressures exceeding 2 absolute atmospheres (ata), HBOT reduced late-onset radiation injuries to the head and neck, bone, prostate and bladder. It also appeared to prevent osteoradionecrosis after exodontia in irradiated areas. Finally, HBOT at 2 ata increased the effectiveness of radiation in head and neck tumours and achieved promising results in the local control of high-grade gliomas.

Subclinical atheromatosis localization and burden in a low-to-moderate cardiovascular risk population: the ILERVAS study

INTRODUCTION AND OBJECTIVES

There is a discrepancy between risk assessment based on cardiovascular risk factors (CVRF) and atheromatosis burden. The objective was to identify the prevalence of subclinical diseases with common risk factors, such as atheromatosis, occult kidney disease, prediabetes, and diabetes in a middle-aged population with low-to-moderate cardiovascular risk; to assess the vascular distribution, and severity of subclinical atheromatosis.

METHODS

Randomized, interventional, longitudinal clinical trial. The intervention consisted of vascular ultrasound examination in the carotid and femoral arteries assessing 12 territories, combined with clinical, anthropometric, lifestyle, and biochemical parameters. Inclusion criteria consisted of women (aged 50-70 years) and men (aged 45-65 years) with at least 1 CVRF. Exclusion criteria consisted of a clinical history of diabetes, chronic kidney disease, or a prior CV event. Here, baseline characteristics of the ILERVAS cohort are shown.

RESULTS

A total of 8330 middle-aged asymptomatic participants, 50.7% women, were enrolled. The presence of 1-2 CVRF was found in 74.8% and adherence to the Mediterranean diet was low in 52.8%. Several previously unknown chronic diseases were diagnosed, such as dyslipidemia (21.1%), hypertension (15.3%), kidney disease (15.4%), obesity (10.6%), and diabetes (2.3%). Subclinical atheromatosis was found in 71.4% of participants, localized in common femoral (54.5%), carotid bifurcation (41.1%) and internal carotid (22%). Intermediate atheromatosis (2-3 territories with atheroma plaque) was found in 32.6%, and generalized atheromatosis (>3 territories) in 19.7. Total plaque area was higher in men (0.97 cm² vs 0.58 cm², P<.001). Total plaque area was also higher in the femoral artery, and increased with the number of CVRF.

CONCLUSIONS

Subclinical atheromatosis was highly prevalent in a middle-aged population with low-to moderate cardiovascular risk, with 1 in 5 participants having generalized atheromatosis. ClinicalTrials.gov Identifier: NCT03228459.

The change of teeth color, whiteness variations and its psychosocial and self-perception effects when using low vs. high concentration bleaching gels: a one-year follow-up

Background

Dental bleaching in traditional concentrations generates greater sensitivity. In this respect, new systems of lower concentration of hydrogen peroxide for tooth bleaching appeared, with color stability unknown over time. The aim of this study was to compare the change and stability of color with low-concentration (6%) hydrogen peroxide gel in an in-office bleaching setting relative to conventional 37.5% gel, including their effects on psychosocial and esthetic self-perception, after 1 year.

Methods

Patients (n = 25) were assessed at 12 months post bleaching treatment (whitening with 6% chemo-activated alkaline formula gel versus 37.5% traditional concentration gel). Color changes were measured objectively using total variation in color (ΔE), and subjectively using Vita Classical and Vita Bleached scale (ΔSGU) by calibrated evaluators (Kappa = 0.85). The Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) and Oral Health Impact Profile (OHIP-14) aesthetic questionnaires were used to measure the self-perception and the psychosocial impact of the bleaching protocols.

Results

The effect (ΔE) of 37.5% HP (8.37 ± 2.73) was significantly better than that of 6% HP (5.27 ± 2.53) in terms of color rebound after 1 year of follow-up. There were significant differences in psychosocial impact and esthetic self-perception measurements prior to bleaching versus one-year post-whitening time points; positive effects were maintained.

Conclusions

Low concentration (6%) achieved effective bleaching with good stability after 1 year, accompanied by a positive psychosocial impact and enhanced self-perception at follow-up.

Trial registration

NCT03217994 (before enrollment of the first participant). Data register: July 14, 2017.

Circulating ADAMs are associated with renal and cardiovascular outcomes in chronic kidney disease patients

BACKGROUND

A disintegrin and metalloproteinase (ADAM) 17, also known as tumour necrosis factor α-converting enzyme (TACE), is a metalloproteinase that releases the ectodomains of most growth factors, cytokines, receptors and enzymes and has been associated with the presence of chronic kidney disease (CKD) and cardiovascular (CV) disease. The role of circulating ADAMs in the progression of renal function and CV events in CKD patients is unknown.

METHODS

A total of 2570 subjects from an observational and multicentre study with CKD Stages 3-5, CKD Stage 5D and controls without any history of CV disease were studied. Circulating ADAM activity was assessed using a fluorometric technique. Progression of renal disease was defined as a 30% increase in serum creatinine or dialysis requirement after 24 months of follow-up. CV outcomes were assessed after 48 months of follow-up.

RESULTS

Patients with advanced CKD had higher ADAM activity as compared with patients with moderate CKD or controls. Male patients with progression of CKD had higher ADAM levels at baseline compared with patients with stable renal function {22.19 relative fluorescence units/μL/h [95% confidence interval (CI) 11.22-37.32] versus 12.15 (7.02-21.50)}. After multivariate adjustment, higher ADAM activity was identified as a risk factor for progression of CKD in male patients [30% increase in the creatinine odds ratio (OR) 2.72 (95% CI 1.58-4.68), P < 0.001; dialysis requirement OR 3.00 (95% CI 1.65-5.46), P < 0.001; dialysis requirement or 30% increase in the creatinine OR 3.15 (95% CI 2.06-4.81), P < 0.001]. ADAM activity was also identified as an independent risk factor for CV events [hazard ratio (HR) 1.68 (95% CI 1.20-2.36), P = 0.003].

CONCLUSIONS

High ADAMs activity levels are independently associated with CKD progression in males and with CV events in CKD patients.

AB0925 MULTIPLE FRACTURES DUE TO IRON-INDUCED AND FGF23-MEDIATED HYPOPHOSPHATAEMIC OSTEOMALACIA: AN UNKNOWN ADVERSE EFFECT

Background:

The use of a specific and widely used type of intravenous ferrotherapy, ferric carboxymaltose (FCM), has been linked to the development of an asymptomatic and transient hypophosphataemia. However, in recent years it has been published that it can generate a severe hypophosphataemic osteomalacia (HPO) mediated by fibroblast growth factor 23 (FGF23) that is associated with high morbidity1. It is a potentially serious adverse effect whose prevalence is unknown and that clinicians may know little about.

Objectives:

To know the clinical and biochemical characteristics of this adverse effect and make it visible in the medical community.

Methods:

Observational descriptive study of three cases of patients assessed in the Rheumatology department of our hospital who were referred for study of recurrent fractures and diagnosed of FGF23-mediated HPO due to FCM. Demographic, clinical and laboratory data of the patients are described.

Results:

The clinical and laboratory characteristics of the patients are shown in table 1. All patients presented clinical and biochemical features compatible with FGF23-mediated HPO (mean of FGF levels 240 kRU/L, NR 0-145). All had multiple insufficiency fractures (Fx) and/or avascular necrosis (AN), with hip involvement in all 3 cases. Other causes of HPO were ruled out in all of them using PET18F-FDG, octreotide scintigraphy, abdominal magnetic resonance and PET68Ga-DOTATOC, and a genetic study of hypophosphataemic rickets was also performed in case 1. In all patients FCM was discontinued and phosphate levels were progressively normalized allowing the withdrawal of oral phosphate and calcitriol replacement therapy. After metabolic normalization, none presented new Fx or AN.

Table 1.

Clinical and biochemical characteristics of the patients

Case 1Case 2Case 3Age (years)a367543Medical historyCrohn’s disease (CD), right hemicolectomy. CD-associated spondyloarthritisSmall bowel angiodysplasiasAntisintetase syndrome. Uterine fibroids.Cause of anemiaGastrointestinal bleeding and malabsorptionGastrointestinal bleedingGynecological bleedingFe-CBX start date10/201008/201302/2018Fe-CBX discontinuation date10/201811/201806/2018Total time Fe-CBX (months)96634FracturesAN: left calcaneus posterior tuberosity, astragaline dome, right femoral headFx: left talus, tibial pylon, tibia-astragaline and ischiopubial branch; right 2nd metatarsal, distal tibia, posterior tuberosity of calcaneusFx both femoral necks and right sacral wingAN both femoral headsBone densitometryLS: Z-score-2.4FN: Z-score -2.4LS: Z-score -0.5FN: Z-score -1.3Phosphate, mg/dL (NR 2.5-4.5)a1.81.61.3Calcium, mg/dL (NR 8.6-10.2)a9.18.39.01,25(OH)zD3, ng/ml (NR 30-100)a54127PTH, pg/ml (NR 12-65)a71223104AP, UI/L (NR 46-116)a11314086Ph-exc, mg/24h (NR 400-1300)a16091630489TPR, % (NR 73-87)a58.350.270.7FGF-23, kRU/L (NR 0-145)a183335201Time to normalizationb1048

aDuring treatment with FCM.bOf serum phosphate levels since FCM discontinuation in months. LS: Lumbar spine. FN: Femoral neck. NR: Normality range..PTH: Parathyroid hormone. AP: Alkaline phosphatase. Ph-exc: 24-hour urine phosphate excretion. Ph-cl: phosphate clearance. TPR: Tubular phosphate reabsorption. Data highlighted in bold indicate altered values.

Conclusion:

Treatment with FCM can cause severe FGF23-mediated HPO, multiple fractures and a great decrease in the quality of life. Since it can be potentially serious and easily reversible, it is important to favor the dissemination of these new cases and the knowledge of this disease. The need to monitor phosphate and/or FGF23 levels in patients receiving this intravenous iron therapy should be evaluated.

References:

[1]Bishay RH, Ganda K, Seibel MJ. Long-term iron polymaltose infusions associated with hypophosphataemic osteomalacia: a report of two cases and review of the literature. Ther Adv Endocrinol Metab. 2017;8(1-2):14–19. doi:10.1177/2042018816678363

Disclosure of Interests:

Elisa Fernández: None declared, Carolina Tornero: None declared, Victoria Navarro-Compán Consultant of: Abbvie, Lilly, Novartis, Pfizer, UCB, Speakers bureau: AbbVie, MSD, Lilly, Novartis, Pfizer, UCB, Gemma Bonilla: None declared, Chamaida Plasencia: None declared, Alejandro Balsa Grant/research support from: BMS, Roche, Consultant of: AbbVie, Gilead, Lilly, Pfizer, UCB, Sanofi, Sandoz, Speakers bureau: AbbVie, Lilly, Sanofi, Novartis, Pfizer, UCB, Roche, Nordic, Sandoz, Pilar Aguado: None declared

OP0180 DIAGNOSTIC VALIDITY OF ULTRASOUND INCLUDING EXTRA-CRANIAL ARTERIES IN GIANT CELL ARTERITIS

Background:

Giant cell arteritis (GCA) is a chronic vasculitis of the medium and large arteries. The involvement of large vessel (LV) either isolated or associated with cranial artery is frequent, so it is necessary to use imaging techniques for diagnosis, because the biopsy in these cases is not useful. European League Against Rheumatism (EULAR) recommends an early imaging test in patients with suspected GCA, and ultrasound of temporal±axillary arteries is recommended as the first imaging modality in patients with suspected predominantly cranial GCA (1).

Objectives:

To assess the validity of Colour Doppler ultrasound (CDUS) of temporal superficial arteries (TA) and LV (axillary, subclavian and carotid) in the diagnosis of GCA, using as gold standard the patient’s definitive clinical diagnosis. Analyse if routine ultrasound examination of LV improves the diagnostic accuracy.

Methods:

This was an observational, descriptive and analytical study of 198 consecutive patients with GCA suspicion. A baseline CDUS of the TA and LV was performed. Ultrasound diagnosis was made according to the OMERACT (Outcome Measures in Rheumatology) definitions of halo sign and was established as a limit of average intimal thickness ≥ 0.34 mm for superficial temporal arteries and ≥ 1 mm for axillary, subclavian and carotid arteries. Statistical analysis was performed using SPSS version 25.

Results:

Eighty-seven patients (43.9%) were CDUS compatible with GCA, and 111 patients (56.1%) had a negative CDUS. Among the patients with positive CDUS three different patterns were detected: 45 patients (51.7%) had an exclusive cranial involvement, 31 (35.6%) had a mixed pattern with involvement of both TA and LV and 11 (12.6%) had an exclusive LV involvement. The validity (sensitivity and specificity) and security (positive predictive value and negative predictive value) of diagnostic are shown in table.

When we analyse patients with LV involvement, 87.8% have axillary artery involvement, 77.4% subclavian involvement and 34.4% carotids involvement. If we only explored the axillary arteries, 12.2% of patients with LV involvement would not be diagnosed. However, if we explored axillary and subclavian arteries, 100% of patients with LV involvement would be diagnosed.

Conclusion:

Half of the patients with GCA have LV involvement and up to 12.8% exclusively LV affectation in our series. Adding CDUS exploration of LV arteries to TA increases both sensitivity and diagnostic specificity. The minimum ultrasound examination of LV should include both axillary and subclavian arteries.

References:

[1]Dejaco C, Ramiro S, Duftner C, et al. EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice. Ann Rheum Dis. 2018;77(5):636–3

SensitivitySpecificityPositive predictive valueNegative predictive valueCDUS TA and LV97,7%97,3%96,6%98,2%CDUS TA83,9%97,3%96,1%88,5%

Disclosure of Interests:

Irene Monjo: None declared, Elisa Fernández: None declared, Diana Peiteado: None declared, Alejandro Balsa Grant/research support from: BMS, Roche, Consultant of: AbbVie, Gilead, Lilly, Pfizer, UCB, Sanofi, Sandoz, Speakers bureau: AbbVie, Lilly, Sanofi, Novartis, Pfizer, UCB, Roche, Nordic, Sandoz, Eugenio de Miguel Grant/research support from: Yes (Abbvie, Novartis, Pfizer), Consultant of: Yes (Abbvie, Novartis, Pfizer), Paid instructor for: yes (AbbVie, Novartis, Pfizer, MSD, BMS, UCB, Roche, Grunental, Janssen, Sanofi), Speakers bureau: yes (AbbVie, Novartis, Pfizer, MSD, BMS, UCB, Roche, Grunental, Janssen, Sanofi)

AB0476 GIANT CELL ARTERITIS: A DISEASE WITH DIFFERENT SUBSETS

Background:

Giant cell arteritis (GCA) is the most common form of autoimmune vasculitis in the elderly. Some evidence indicates that GCA is a heterogeneous disease in terms of symptoms, immune pathology and response to treatment1.

Objectives:

To analyze whether the identification by image of cranial vessels (VC) or large vessels (VG) involvement allows to characterize different clinical subsets of the disease.

Methods:

Descriptive observational study of the last 87 consecutive patients with a new diagnosis of GCA in our hospital. All patients had a CV and LV CDUS exam that included axillary, subclavian, vertebral and carotid arteries or a Positron Emission Tomography (PET-CT). The OMERACT (Outcome Measures in Rheumatology) definitions of halo sign were used for ultrasound diagnosis and IMT limits were established as ≥ 0.34 mm for superficial temporal arteries and ≥ 1 mm for axillary, subclavian and carotid arteries; a clear halo sign was used in the vertebral arteries. The radiologist’s report and the liver/vascular wall index were used for the definition of positive PET-CT. The medical records of these patients were reviewed and their demographic, clinical and laboratory data were compared between the different patterns of GCA. The statistical significance limit was set at P < 0.05. Statistical analyses were performed by using SPSS version 25.

Results:

Out of 198 patients with suspected GCA who underwent a CDUS or PET-CT between November 2016 and November 2019, 87 were diagnosed of GCA. Three different patterns were detected: 44 patients (50.6%) had an exclusive cranial pattern, 31 (35.6%) had a mixed pattern with involvement of both CV and LV and 12 (13.8%) had an exclusive large vessel pattern. The differences between these 3 subsets are shown in table 1. Patients with a LV pattern had more fever and polymyalgia rheumatica than patients with CV involvement and fewer ischemic visual disturbances than those with mixed pattern, reaching statistical significance. In addition, they tended to have fewer other ischemic symptoms (headache, jaw claudication) and more general symptoms than patterns with CV involvement. Regarding laboratory values, the erythrocyte sedimentation rate was significantly higher in the exclusive CV involvement group and lower in those with only LV involvement.

Table 1.

Characteristics of the patients with the different patterns

Cranial pattern (n = 44; 50.6%)Mixed pattern(n = 31; 35.6%)Large vessel pattern(n = 12; 13.8%)p-valueAge, years (mean, SD)78 ± 776 ± 774 ± 110.291Male sex12 (27.3%)14 (45.2%)5 (41.6%)0.252ESR, mm/h (mean, SD)78.7 ± 33.763.9 ± 33.052.1 ± 33.50.031*CRP, mg/L (mean, SD)55.8 ± 46.668.3 ± 63.685.9 ± 89.30.801Headache36 (81.8%)25 (80.6%)8 (66.6%)0.704Jaw claudication12 (27.3%)5 (16.1%)1 (8.3%)0.249Ischemic visual disturbances9 (20.4%)11 (35.5%)0 (0%)0.041#PMR18 (40.9%)13 (41.9%)8 (66.6%)0,018*0,029#General symptoms17 (38.6%)13 (41.9%)8 (66.6%)0.132Fever5 (11.4%)3 (9.7%)6 (50%)0.005*#

SD: standard deviation. ESR: erythrocyte sedimentation rate. CRP: C reactive protein. PMR: polymyalgia rheumatica.

*Statistically significant difference between cranial pattern and large vessel pattern.

#Statistically significant difference between mixed pattern and large vessel pattern.

Conclusion:

Imaging in GCA allow us to establish different patterns of involvement (cranial, mixed, large vessel) that correspond to different clinical subsets. The patients with LV subset debut with a lower ESR and have more fever and polymyalgia rheumatica and less ischemic symptoms.

References:

[1]van der Geest KSM, Sandovici M, van Sleen Y, et al. Review: What Is the Current Evidence for Disease Subsets in Giant Cell Arteritis?. Arthritis Rheumatol. 2018;70(9):1366–1376. doi:10.1002/art.40520

Disclosure of Interests: :

Elisa Fernández: None declared, Irene Monjo: None declared, Gemma Bonilla: None declared, Diana Peiteado: None declared, Chamaida Plasencia: None declared, Alejandro Balsa Grant/research support from: BMS, Roche, Consultant of: AbbVie, Gilead, Lilly, Pfizer, UCB, Sanofi, Sandoz, Speakers bureau: AbbVie, Lilly, Sanofi, Novartis, Pfizer, UCB, Roche, Nordic, Sandoz, Eugenio de Miguel Grant/research support from: Yes (Abbvie, Novartis, Pfizer), Consultant of: Yes (Abbvie, Novartis, Pfizer), Paid instructor for: yes (AbbVie, Novartis, Pfizer, MSD, BMS, UCB, Roche, Grunental, Janssen, Sanofi), Speakers bureau: yes (AbbVie, Novartis, Pfizer, MSD, BMS, UCB, Roche, Grunental, Janssen, Sanofi)

Geographic distribution of chronic obstructive pulmonary disease prevalence in Africa, Asia and Australasia

OBJECTIVE: To visualise spatial data on chronic obstructive pulmonary disease (COPD) prevalence in Africa, Asia and Australasia using a Geographic Information System (GIS) inverse distance weighted (IDW) interpolation technique.DESIGN: Prevalence rates from population surveys on individuals aged ≥40, with spirometry-confirmed COPD, were searched systematically. The prevalence observed in 59 selected surveys and the geographic coordinates of the places where they were conducted informed a GIS computer programme. The prevalence was represented by an ascending chromatic scale (blue-green-yellow-orange-brown-red) in the GIS maps.RESULTS: IDW-interpolation GIS maps were obtained of all the geographic areas investigated, and even from regions lacking data. Areas of high/very high prevalence were found in: Southern Africa and in most of the Central and Eastern Africa regions; in practically all of Central Asia; in the western regions of Southern Asia; in the southern regions of the East European Plain and the West Siberian Plain of Northern Asia; and in the Malay Archipelago. Intermediate prevalence predominated in Oceania and in most of the other regions of Africa and Asia.CONCLUSION: Despite some biases inherent to the interpolation method used in the present study, our approach provided an understandable visual perspective of the COPD prevalence distribution in these geographic regions.

Characteristic limits of 230Th in alpha spectrometry with 229Th as tracer, calculated by simulating interfering tails and overlapping peaks

This study explores the effect of ²²⁹Th tracer tail interference on the determination of the sensitivity of ²³⁰Th alpha spectrometry of samples with environmental levels of radioactivity. Tracer peak tail interference was calculated with Suma-Alpha, whilst Visual Basic for Applications (VBA in Excel©) software was used to study the variation in sensitivity in terms of the amount of tracer added. Unnecessary increases in the amount of tracer or extended sample measuring times were observed to have adverse effects on method sensitivity (Detection Limit- L_d).

Protective role of renal proximal tubular alpha-synuclein in the pathogenesis of kidney fibrosis

Kidney fibrosis is a highly deleterious process and a final manifestation of chronic kidney disease. Alpha-(α)-synuclein (SNCA) is an actin-binding neuronal protein with various functions within the brain; however, its role in other tissues is unknown. Here, we describe the expression of SNCA in renal epithelial cells and demonstrate its decrease in renal tubules of murine and human fibrotic kidneys, as well as its downregulation in renal proximal tubular epithelial cells (RPTECs) after TGF-β1 treatment. shRNA-mediated knockdown of SNCA in RPTECs results in de novo expression of vimentin and α-SMA, while SNCA overexpression represses TGF-β1-induced mesenchymal markers. Conditional gene silencing of SNCA in RPTECs leads to an exacerbated tubulointerstitial fibrosis (TIF) in two unrelated in vivo fibrotic models, which is associated with an increased activation of MAPK-p38 and PI3K-Akt pathways. Our study provides an evidence that disruption of SNCA signaling in RPTECs contributes to the pathogenesis of renal TIF by facilitating partial epithelial-to-mesenchymal transition and extracellular matrix accumulation.

Tobacco control strategies in psychiatric services in catalonia (Spain)

Introduction

Mortality and morbidity due to smoking in people with mental illnesses are higher than in the general population. However, smoking continues to be allowed in psychiatric premises of many countries despite being prohibited in workplaces including health care services.

Objective

To describe tobacco control strategies undertaken in psychiatric inpatient services and day centers in Catalonia.

Aims

To study tobacco control strategies in psychiatric services in order to identify unmet needs.

Methods

A cross-sectional study including all psychiatric services offering public service in Catalonia (n = 192). The managers answered an on-line questionnaire with 24 items grouped in four dimensions: staff's training & commitment, clinical intervention, management of smoking areas, and communication of smoke-free policies.

Results

186 of the managers (96.9%) responded to the questionnaire. Results showed low levels of implementation of tobacco control strategies, especially in the training and intervention dimensions. 41.0% of the services usually intervened in their patients’ tobacco use but an overall 65.9% didn’t have pharmacotherapy for smoking cessation available. 47.3% of the managers stated that their staff had not enough knowledge on smoking cessation interventions. 38.9% of the services had smoking indoor areas. Day Centers showed the lowest implementation of tobacco control measures while services belonging to the Network of Smoke-free Hospitals showed the highest implementation.

Conclusions

Current Spanish partial law has failed to promote a desirable tobacco control in psychiatric services. There is a need to extend tobacco control policies, specifically in terms of smoking intervention and training, together with a higher availability of resources.

Are Obesity Indices Useful for Detecting Subclinical Atheromatosis in a Middle-Aged Population?

OBJECTIVE

There is a close relationship between excess adiposity and cardiovascular disease. Although body mass index (BMI) is the most used approach to estimate excess weight, other anthropometric indices have been developed to measure total body and abdominal adiposity. Here, our objective was to assess the usefulness of these anthropometric indices to detect subclinical atheromatous disease.

METHODS

A cross-sectional study with 6,809 middle-aged subjects (mean age, 57 [53-63] years) with low to moderate cardiovascular risk from the ILERVAS project. Measures of total body fat (BMI, Clínica Universidad de Navarra - Body Adiposity Estimator [CUN-BAE], and Deurenberg's formula) and central adiposity (waist and neck circumferences, conicity index, waist-to-height ratio, Bonora's equation, the A body adiposity index, and body roundness index) were performed in all participants. Bilateral carotid and femoral ultrasound vascular studies allowed the identification of subjects with plaque. -Results: All measured indices were significantly higher in males with subclinical carotid or femoral plaques (p ≤ 0.021 for all). Also, a positive and significant correlation between all indices and the number of affected territories was found (p ≤ 0.013 for all). From the ROC analysis, all measurements identified patients with asymptomatic atheromatosis but none of them helped make clinical decisions. Regarding females, the results were less conclusive.

CONCLUSION

Obesity indices are related to subclinical atheromatosis, especially in men, in a large cohort of middle-aged subjects. However, the indices could not detect the presence of arterial plaque, so, when used in isolation, are unlikely to be decisive.

Characteristics of atheromatosis in the prediabetes stage: a cross-sectional investigation of the ILERVAS project

Background

Prediabetes has recently been associated with subclinical atheromatous disease in the middle-aged population. Our aim was to characterize atheromatous plaque burden by the number of affected territories and the total plaque area in the prediabetes stage.

Methods

Atheromatous plaque burden (quantity of plaques and total plaque area) was assessed in 12 territories from the carotid and femoral regions using ultrasonography in 6688 non-diabetic middle-aged subjects without cardiovascular disease. Prediabetes was defined by glycosylated hemoglobin (HbA1c) between 5.7 and 6.4% according to the American Diabetes Association guidelines.

Results

Prediabetes was diagnosed in 33.9% (n = 2269) of the ILERVAS participants. Subjects with prediabetes presented a higher prevalence of subclinical atheromatous disease than participants with HbA1c < 5.7% (70.4 vs. 67.5%, p = 0.017). In the population with prediabetes this was observed at the level of the carotid territory (p < 0.001), but not in the femoral arteries. Participants in the prediabetes stage also presented a significantly higher number of affected territories (2 [1;3] vs. 1 [0;3], p = 0.002), with a positive correlation between HbA1c levels and the number of affected territories (r = 0.068, p < 0.001). However, atheromatosis was only significantly (p = 0.016) magnified by prediabetes in those subjects with 3 or more cardiovascular risk factors. The multivariable logistic regression model showed that the well-established cardiovascular risk factors together with HbA1c were independently associated with the presence of atheromatous disease in participants with prediabetes. When males and females were analyzed separately, we found that only men with prediabetes presented both carotid and femoral atherosclerosis, as well as an increase of total plaque area in comparison with non-prediabetic subjects.

Conclusions

The prediabetes stage is accompanied by an increased subclinical atheromatous disease only in the presence of other cardiovascular risk factors. Prediabetes modulates the atherogenic effect of cardiovascular risk factors in terms of distribution and total plaque area in a sex-dependent manner.

Trial registration NCT03228459 (clinicaltrials.gov)

Six-month Follow-up of the Effect of Nonvital Bleaching on IL-1β and RANK-L: A Randomized Clinical Trial

Objectives:

It has been reported that bleaching generates an increase in the activity of osteoclasts in vitro. We quantified the RANK-L and IL-1β biomarkers in a double-blind, randomized clinical trial evaluating the in vivo effect of hydrogen peroxide (35%) and peroxide carbamide (37%) six months after whitening.

Methods and Materials:

Fifty volunteers participated, each with color change in a nonvital tooth. Fifty teeth were randomly divided into two groups (n=25), and the teeth were bleached using either 35% hydrogen peroxide (G1) or 37% carbamide peroxide (G2). Intracoronal bleaching was carried out by a technical “walking bleach” over four sessions. Gingival crevicular fluid samples were collected and used to quantify the IL-1β and RANK-L secreted levels. Samples of six periodontal sites (three vestibular and three palatal) were collected for up to six months (at the beginning of the study [baseline] and at one week, one month, and six months posttreatment). The color change was visually monitored using the Vita Bleached Guide (ΔSGU).

Results:

Comparing each time to baseline assessment, a significant increase in the levels of IL-1β and RANK-L across time points was detected (p&lt;0.05). The color change was 4 in G1 and G2, and a statistically significant difference (p&lt;0.05) was found at the month time point between the groups. Using the Spearman test, a strong correlation (&gt;0.8) between the IL-1β and RANK-L levels in both groups at all time points was detected.

Conclusions:

Nonvital bleaching using a technical walking bleach induces an increase in the IL-1β and RANKL production in periodontal tissues, which persists for six months after treatment. Both biomarkers were highly correlated in both groups and at all time points.

Skin Autofluorescence Measurement in Subclinical Atheromatous Disease: Results from the ILERVAS Project

Aim: Advanced glycation end-products (AGEs) have been involved in the atherogenic process in the high-risk population. The goal of this study was to demonstrate that AGEs are related to subclinical atheromatous disease in subjects with low to moderate vascular risk.

Methods: A cross-sectional study in which 2,568 non-diabetic subjects of both sexes without cardiovascular disease were included. Subcutaneous content of AGEs was assessed by skin autofluorescence (SAF) and subclinical atheromatous disease was measured by assessing the atheromatous plaque burden in carotid and femoral regions using ultrasonography. In addition, serum pentosidine, carboxymethyl-lysine (CML) and AGE receptors (RAGE) were assessed in a nested case-control study with 41 subjects without plaque and 41 individuals subjects with generalized disease.

Results: Patients with atheromatous plaque had a higher SAF than those with no plaque (1.9 [1.7 to 2.3] vs. 1.8 [1.6 to 2.1] arbitrary units (AU), p % 0.001). The SAF correlated with the total number of affected regions (r = 0.171, p < 0.001), increasing progressively from 1.8 [1.6 to 2.1] AU in those without atheromatous disease to 2.3 [1.9 to 2.7] AU in patients with ≥ 8 plaques (p < 0.001). A correlation was also observed between SAF and the total plaque area (r = 0.113, p < 0.001). The area under the Receiver Operating Characteristic curve was 0.65 (0.61 to 0.68) for identifying male subjects with atheromatous disease. The multivariable logistic regression model showed a significant and independent association between SAF and the presence of atheromatous disease. However, no significant differences in serum pentosidine, CML, and RAGE were observed.

Conclusions: Increased subcutaneous content of AGEs is associated with augmented atheromatous plaque burden. Our results suggest that SAF may provide clinically relevant information to the current strategies for the evaluation of cardiovascular risk, especially among the male population.

Lung function measurements in the prediabetes stage: data from the ILERVAS Project

AIMS

Patients with type 2 diabetes have been considered a susceptible group for pulmonary dysfunction. Our aim was to assess pulmonary function on the prediabetes stage.

METHODS

Pulmonary function was assessed in 4,459 non-diabetic subjects, aged between 45 and 70 years, without cardiovascular disease or chronic pulmonary obstructive disease from the ongoing study ILERVAS. A "restrictive spirometric pattern", an "abnormal FEV1" and an "obstructive ventilatory defect" were assessed. Prediabetes was defined by glycosylated hemoglobin (HbA1c) between 5.7 and 6.4% according to the American Diabetes Association criteria.

RESULTS

Population was composed of 52.1% women, aged 57 [53;63] years, a BMI of 28.6 [25.8;31.8] kg/m², and with a prevalence of prediabetes of 29.9% (n = 1392). Subjects with prediabetes had lower forced vital capacity (FVC: 93 [82;105] vs. 96 [84;106], p < 0.001) and lower forced expired volume in the first second (FEV1: 94 [82;107] vs. 96 [84;108], p = 0.011), as well as a higher percentage of the restrictive spirometric pattern (16.5% vs. 13.6%, p = 0.015) and FEV1 < 80% (20.3% vs. 17.2%, p = 0.017) compared to non-prediabetes group. In the prediabetes group, HbA1c was negatively correlated with both pulmonary parameters (FVC: r = - 0.113, p < 0.001; FEV1: r = - 0.079, p = 0.003). The multivariable logistic regression model in the whole population showed that there was a significant and independent association between HbA1c with both restrictive spirometric pattern [OR = 1.42 (1.10-1.83), p = 0.008] and FEV1 < 80% [OR = 1.50 (1.19-1.90), p = 0.001].

CONCLUSIONS

The deleterious effect of type 2 diabetes on pulmonary function appears to be initiated in prediabetes, and it is related to metabolic control. TRIAL REGISTRATION CLINICALTRIALS.GOV: NCT03228459.

Subclinical atherosclerosis burden predicts cardiovascular events in individuals with diabetes and chronic kidney disease

Background

Individuals with diabetes have remarkably high rates of cardiovascular morbidity and mortality. However, the incremental cardiovascular risk in diabetes is heterogeneous and has often been related to renal involvement. The purpose of this study was to analyse the prognostic value of subclinical atherosclerosis in determining the incidence of first cardiovascular events (CVEs) in individuals with diabetes and chronic kidney disease (CKD) compared to CKD individuals without diabetes.

Methods

We included data from individuals with CKD with and without diabetes, free from pre-existing cardiovascular disease, from the NEFRONA cohort. Participants underwent baseline carotid and femoral ultrasound and were followed up for 4 years. All CVEs during follow-up were registered. Bivariate analysis and Fine–Gray competing risk models were used to perform the statistical analysis.

Results

During the mean follow-up time of 48 months, a total of 203 CVE was registered. 107 CVE occurred among participants without diabetes (19.58 per 1000 person-years) and 96 CVE occurred among participants with diabetes (44.44 per 1000 person-years). Following the competing risk analysis, the variables predicting CVEs in CKD individuals without diabetes were the number of territories with plaque at baseline (HR 1.862, 95% CI [1.432;2.240]), age (HR 1.026, 95% CI [1.003;1.049]) and serum concentrations of 25-OH vitamin D (HR 0.963, 95% CI [0.933;0.094]). The only variable predicting CVEs among CKD participants with diabetes was the number of territories with plaque at baseline (HR 1.782, 95% CI [1.393, 2.278]). For both models, concordance (C) index yielded was over 0.7.

Conclusions

The burden of subclinical atherosclerosis is the strongest predictor of future CVEs in diabetic individuals with CKD. Early detection of subclinical atherosclerotic burden by multiterritorial vascular ultrasound could improve CVE prediction in this population.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0897-y) contains supplementary material, which is available to authorized users.

Consensus of the Iberoamerican Oculoplastic Society for diagnosis and management of facial dystonia

OBJECTIVE

To propose guidelines for the diagnosis and treatment of facial dystonia prepared by a group of experts in orbit and oculoplastics from the Iberoamerican Oculoplastic Society.

MATERIAL AND METHODS

An interactive discussion between the expert panel and those attending the 6th Iberoamerican Society of Oculoplastics Congress, which took place at the Hospital Nuestra Señora de la Luz in Mexico City on 22 October 2018, providing their personal experience based on evidence for diagnosis and treatment of facial dystonia. Around 200 ophthalmologists specialised in oculoplastics from North, Central and South America, Spain, and Portugal were involved. Discussion was focused on the following themes: pathophysiology, diagnosis, medical management, and surgical management.

CONCLUSIONS

Facial dystonia diagnosis is clinical; therefore, image studies are rarely needed. The ophthalmologist is generally the first physician to be consulted, and is able to be the treating physician, with the exception of specific cases of hemifacial spasm where management with neurosurgery may be beneficial. Botulinum toxin is the treatment of choice. Treatment with oral neuroleptics and myectomy of the orbicularis oculi muscle are reserved for refractory cases, since these do not have an adequate clinical response as first choice treatments. Persistent use of botulinum toxin does not modify the natural course of the disease.

Dissimilar Impact of a Mediterranean Diet and Physical Activity on Anthropometric Indices: A Cross-Sectional Study from the ILERVAS Project

There is a close relationship between lifestyle behaviors and excess adiposity. Although body mass index (BMI) is the most used approach to estimate excess weight, other anthropometric indices have been developed to measure total body and abdominal adiposity. However, little is known about the impact of physical activity and adherence to a Mediterranean diet on these indices. Here we report the results of a cross-sectional study with 6672 middle-aged subjects with low to moderate cardiovascular risk from the Ilerda Vascular (ILERVAS) project. The participants' adherence to physical activity (International Physical Activity Questionnaire short form) and MedDiet (Mediterranean Diet Adherence Screener) was evaluated. Measures of total adiposity (BMI, Clínica Universidad de Navarra-Body Adiposity Estimator (CUN-BAE), and Deurenberg's formula), central adiposity (waist and neck circumferences, conicity index, waist to height ratio, Bonora's equation, A body adiposity index, and body roundness index), and lean body mass (Hume formula) were assessed. Irrespective of sex, lower indices of physical activity were associated with higher values of total body fat and central adiposity. This result was constant regardless of the indices used to estimate adiposity. However, the association between MedDiet and obesity indices was much less marked and more dependent on sex than that observed for physical activity. Lean body mass was influenced by neither physical activity nor MedDiet adherence. No joint effect between physical activity and MedDiet to lower estimated total or central adiposity indices was shown. In conclusion, physical activity is related to lower obesity indices in a large cohort of middle-aged subjects. MedDiet showed a slight impact on estimated anthropometric indices, with no joint effect when considering both lifestyle variables. ClinTrials.gov Identifier: NCT03228459.

Comparative study of extracellular recording methods for analysis of afferent sensory information: Empirical modeling, data analysis and interpretation

BACKGROUND

Physiological studies of sensorial systems often require the acquisition and processing of data extracted from their multiple components to evaluate how the neural information changes in relation to the environment changes. In this work, a comparative study about methodological aspects of two electrophysiological approaches is described.

NEW METHOD

Extracellular recordings from deep vibrissal nerves were obtained by using a customized microelectrode Utah array during passive mechanical stimulation of rat´s whiskers. These recordings were compared with those obtained with bipolar electrodes. We also propose here a simplified empirical model of the electrophysiological activity obtained from a bundle of myelinated nerve fibers.

RESULTS

The peripheral activity of the vibrissal system was characterized through the temporal and spectral features obtained with both recording methods. The empirical model not only allows the correlation between anatomical structures and functional features, but also allows to predict changes in the CAPs morphology when the arrangement and the geometry of the electrodes changes.

COMPARISON WITH EXISTING METHOD(S)

This study compares two extracellular recording methods based on analysis techniques, empirical modeling and data processing of vibrissal sensory information.

CONCLUSIONS

This comparative study reveals a close relationship between the electrophysiological techniques and the processing methods necessary to extract sensory information. This relationship is the result of maximizing the extraction of information from recordings of sensory activity.