Automatic imagine analyzer to assess retinal vessel caliber (Altair) tool validation for the analysis of retinal vessels

Objective: To assess the reliability and validity of the tool Automatic image analyzer to assess retinal vessel caliber (ALTAIR) to analyze the vascularization of the retina and cardiovascular risk prediction. Design and method: Cross-sectional of tools validation study. We included 250 subjects in total, aged 62 +/- 9 years, 51% males. We have made a validation of reliability analyzing the intraclass correlation (ICC) intra observer, inter observer and inter device (compared with AVindex calculator) to the thickness, area and length of arteries and veins of the retina in 3 concentric circles from the disc in 120 retinographies. The concurrent validity was performed with 250 subjects and 497 retinographies, analyzing the relationship with age, blood pressure, parameters of vascular structure and function, renal function and cardiovascular risk estimated with scales. Results: In the sample, the 32% are obese, 68% hypertensive and 17% diabetic. The interobserver ICC for thickness, area and length of veins and arteries ranged from 0.809 to length of arteries to 0.916 to veins area. The intra observer ICC for intra thickness, area and length of veins and arteries ranged from 0.640 for the length of the veins and 0.906 for the area of the arteries and the inter device ICC was for arteriovenous ratio (AVR) 0.887, thickness of arteries 0.590 and veins thickness 0.677. We found a moderate correlation of the age (r between 0.30 and 0.50, p < 0.001) with the retinal vascular parameters analyzed. In multiple linear regression analysis after adjusting for age and sex, the association of AVR and arterial thickness with the diastolic blood pressure and albumin creatinine ratio and arterial area and length with systolic arterial blood pressure and carotid intima-media thickness remains. Also the thickness area and length of the vessels show an association with cardiovascular risk estimated SCORE scale. Conclusions: The ALTAIR tool shows a good reliability in the concordance inter observers, intra observer and inter device measurements and a concordant validity to show an association with vascular parameters, target organ damage and cardiovascular risk

Central blood pressure and pulse wave velocity: relationship to target organ damage and cardiovascular morbidity-mortality in diabetic patients or metabolic syndrome. An observational prospective study. LOD-DIABETES study protocol

<p>Abstract</p> <p>Background</p> <p>Diabetic patients show an increased prevalence of non-dipping arterial pressure pattern, target organ damage and elevated arterial stiffness. These alterations are associated with increased cardiovascular risk.</p> <p>The objectives of this study are the following: to evaluate the prognostic value of central arterial pressure and pulse wave velocity in relation to the incidence and outcome of target organ damage and the appearance of cardiovascular episodes (cardiovascular mortality, myocardial infarction, chest pain and stroke) in patients with type 2 diabetes mellitus or metabolic syndrome.</p> <p>Methods/Design</p> <p><b>Design</b>: This is an observational prospective study with 5 years duration, of which the first year corresponds to patient inclusion and initial evaluation, and the remaining four years to follow-up.</p> <p><b>Setting</b>: The study will be carried out in the urban primary care setting.</p> <p><b>Study population</b>: Consecutive sampling will be used to include patients diagnosed with type 2 diabetes between 20-80 years of age. A total of 110 patients meeting all the inclusion criteria and none of the exclusion criteria will be included.</p> <p><b>Measurements</b>: Patient age and sex, family and personal history of cardiovascular disease, and cardiovascular risk factors. Height, weight, heart rate and abdominal circumference. Laboratory tests: hemoglobin, lipid profile, creatinine, microalbuminuria, glomerular filtration rate, blood glucose, glycosylated hemoglobin, blood insulin, fibrinogen and high sensitivity C-reactive protein. Clinical and 24-hour ambulatory (home) blood pressure monitoring and self-measured blood pressure. Common carotid artery ultrasound for the determination of mean carotid intima-media thickness. Electrocardiogram for assessing left ventricular hypertrophy. Ankle-brachial index. Retinal vascular study based on funduscopy with non-mydriatic retinography and evaluation of pulse wave morphology and pulse wave velocity using the SphygmoCor system. The medication used for diabetes, arterial hypertension and hyperlipidemia will be registered, together with antiplatelet drugs.</p> <p>Discussion</p> <p>The results of this study will help to know and quantify the prognostic value of central arterial pressure and pulse wave velocity in relation to the evolution of the subclinical target organ damage markers and the possible incidence of cardiovascular events in patients with type 2 diabetes mellitus.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov Identifier: NCT01065155</p

Predictive Ability of Machine-Learning Methods for Vitamin D Deficiency Prediction by Anthropometric Parameters

Background: Vitamin D deficiency affects the general population and is very common among elderly Europeans. This study compared different supervised learning algorithms in a cohort of Spanish individuals aged 35–75 years to predict which anthropometric parameter was most strongly associated with vitamin D deficiency. Methods: A total of 501 participants were recruited by simple random sampling with replacement (reference population: 43,946). The analyzed anthropometric parameters were waist circumference (WC), body mass index (BMI), waist-to-height ratio (WHtR), body roundness index (BRI), visceral adiposity index (VAI), and the Clinical University of Navarra body adiposity estimator (CUN-BAE) for body fat percentage. Results: All the anthropometric indices were associated, in males, with vitamin D deficiency (p < 0.01 for the entire sample) after controlling for possible confounding factors, except for CUN-BAE, which was the only parameter that showed a correlation in females. Conclusions: The capacity of anthropometric parameters to predict vitamin D deficiency differed according to sex; thus, WC, BMI, WHtR, VAI, and BRI were most useful for prediction in males, while CUN-BAE was more useful in females. The naïve Bayes approach for machine learning showed the best area under the curve with WC, BMI, WHtR, and BRI, while the logistic regression model did so in VAI and CUN-BAE

Automatic image analyzer to assess retinal vessel caliber (ALTAIR) Tool Validation for the analysis of retinal vessels

Objective: To assess the reliability and validity of the tool Automatic image analyzer to assess retinal vessel caliber (ALTAIR) to analyze the vascularization of the retina and cardiovascular risk prediction. Design and method: Cross-sectional of tools validation study. We included 250 subjects in total, aged 62 +/- 9 years, 51% males. We have made a validation of reliability analyzing the intraclass correlation (ICC) intra observer, inter observer and inter device (compared with AVindex calculator) to the thickness, area and length of arteries and veins of the retina in 3 concentric circles from the disc in 120 retinographies. The concurrent validity was performed with 250 subjects and 497 retinographies, analyzing the relationship with age, blood pressure, parameters of vascular structure and function, renal function and cardiovascular risk estimated with scales. Results: In the sample, the 32% are obese, 68% hypertensive and 17% diabetic. The interobserver ICC for thickness, area and length of veins and arteries ranged from 0.809 to length of arteries to 0.916 to veins area. The intra observer ICC for intra thickness, area and length of veins and arteries ranged from 0.640 for the length of the veins and 0.906 for the area of the arteries and the inter device ICC was for arteriovenous ratio (AVR) 0.887, thickness of arteries 0.590 and veins thickness 0.677. We found a moderate correlation of the age (r between 0.30 and 0.50, p < 0.001) with the retinal vascular parameters analyzed. In multiple linear regression analysis after adjusting for age and sex, the association of AVR and arterial thickness with the diastolic blood pressure and albumin creatinine ratio and arterial area and length with systolic arterial blood pressure and carotid intima-media thickness remains. Also the thickness area and length of the vessels show an association with cardiovascular risk estimated SCORE scale. Conclusions: The ALTAIR tool shows a good reliability in the concordance inter observers, intra observer and inter device measurements and a concordant validity to show an association with vascular parameters, target organ damage and cardiovascular risk