Examinando por Autor "Olivar, Luis Carlos"
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Ítem Age-specific waist circumference cutoff-points for abdominal obesity diagnosis: a personalized strategy for a large Venezuelan population(Springer, 2021) Bermudez, Valmore; Salazar, Juan; Martínez, María Sofía; Olivar, Luis Carlos; Nava, Manuel; Rojas, Milagros; Ortega, Ángel; Añez, Roberto; Toledo, Alexandra; Rojas, Joselyn; Chacín, Maricarmen; Rodríguez, Johel E.; D'Marco, Luis; Cano, ClímacoBackground Evidence shows that the ageing process is a determining factor in fat distribution, composition, and functionality. The goal of this research was to determine cut-off points for waist circumference according to age in the adult population from Maracaibo city, Venezuela. Methodology The Metabolic Syndrome Prevalence Study is a descriptive, cross-sectional study with multi-stage randomized sampling. In this post-hoc analysis 1902 individuals ≥18 years and from both sexes were evaluated. Waist circumference ROC curves were built for each age group and sex, using metabolic phenotypes for classification. Results 52.2% (n = 992) were women, and the mean age was 38.7 ± 2. Cut-off points obtained for the <30 years age group were: 91 cm for women (Sensitivity: 96,8%, Specificity: 97,7%) and 94 cm for men (Sensitivity:100%, Specificity: 99,2%); for 30–49 years: women 94 cm (Sensitivity: 93.7%, Specificity: 97.1%) and men 95 cm (Sensitivity: 97.3%, Specificity: 100%); for ≥50 years: women 94 cm (Sensitivity: 91.8%, Specificity: 86.7%) and men 101 cm (Sensitivity: 100%, Specificity: 100%) Conclusion The use of specific cut-off points according to age groups is proposed to determine abdominal obesity in Maracaibo city due to the underestimation seen in young people and the overestimation observed in older people when using a unique cut-off point.Ítem Cigarette smoking and metabolic syndrome components: a cross-sectional study from Maracaibo City, Venezuela [version 1; referees: 1 approved with reservations](F1000 Research Ltda, 2018-05-22) Bermudez, Valmore; Olivar, Luis Carlos; Torres, Wheeler; Navarro, Carla; Gonzalez, Robys; Morocho, Alicia; Mindiola, Andres; Chacin, Maricarmen; Arias, Victor; Añez, Roberto; Salazar, Juan; Riaño Garzon, Manuel; Diaz Camargo, Edgar; Judith Bautista, Maria; Rojas, JoselynBackground: A growing body of evidence suggests that cigarette smoking can cause the onset of metabolic syndrome prior to cardiovascular diseases. Therefore, the objective of this study was to evaluate the relationship between smoking habit and metabolic syndrome components in an adult population from Maracaibo city, Venezuela. Methods: The Maracaibo City Metabolic Syndrome Prevalence Study is a descriptive, cross-sectional study with random and multi-stage sampling. In this sub-study, 2212 adults from both genders were selected. On the basis of their medical background, they were classified as smokers, non-smokers and former smokers. Metabolic syndrome was defined according to Harmonizing 2009 criteria, using population-specific abdominal circumference cut-off points. The association between risk factors was evaluated using a logistic regression model. Results: In the studied population, 14.8% were smokers, 15.4% were former smokers. In the multivariate analysis, the presence of metabolic syndrome (smokers: OR, 1.54; 95% CI, 1.11–2.14; p=0.010) and its components were related to cigarette smoking, with the exception of hyperglycemia. High blood pressure was inversely associated with current smoking status (smokers: OR, 0.70 (0.51–0.95); p=0.025).Ítem Hormona paratiroidea, aldosterona e hipertensión arterial ¿una amenaza infravalorada?(Cooperativa servicios y suministros 212518 RS, 2017) Rojas, Joselyn; Olivar, Luis Carlos; Chávez Castillo, Mervin; Martínez, María Sofia; Wilches-Durán, SandraEl Hiperparatiroidismo primario (HPTP) es un trastorno endocrino frecuente caracterizado por una secreción autónoma de hormona paratiroidea (PTH). Si bien, su variante asintomática es la más frecuentemente encontrada en la práctica clínica (la cual se diagnostica incidentalmente), las complicaciones óseas y renales afectan de forma importante la calidad de vida del paciente. Sin embargo, el espectro de manifestaciones de este trastorno no se limita al metabolismo mineral, puesto que las concentraciones elevadas de PTH se asocian a un mayor riesgo de alteraciones metabólicas como el síndrome metabólico, diabetes mellitus 2 y enfermedades cardiovasculares. En este ámbito, la hipertensión arterial (HTA), relacionada con aproximadamente 9,4 millones de muerte al año, ha sido considerada una manifestación no clásica del HPTP. La interacción PTH-Aldosterona ha surgido como un importante eslabón para tratar de explicar esta relación, planteándose diversos mecanismos teóricos que posicionan a la PTH como estimulador directo de la síntesis de aldosterona en las células de la zona glomerular. Sin embargo, estos mecanismos teóricos han estado rodeados de controversia en su aspecto epidemiológico y clínico, existiendo aún muy pocos estudios poblacionales explorando este vínculo y su relación con la morbimortalidad cardiovascular, por lo que es necesario mayor investigación en el área con el fin de conocer el verdadero impacto de estos mecanismos en la salud de los individuos. Esta revisión resume aspectos del metabolismo del calcio, al igual que los principales mecanismos subyacentes al vínculo HPTP-HTA, y los datos epidemiológicos disponibles sobre el tópico, a fin de brindar un mejor entendimiento sobre este novel planteamiento.Ítem Insulin resistance indices and coronary risk in adults from Maracaibo city, Venezuela: A cross sectional study [version 1; referees: 1 approved with reservations](is published by F1000 Research Ltd, 2018-03) Salazar, Juan; Bermúdez, Valmore; Olivar, Luis Carlos; Torres, Wheeler; Palmar, Jim; Añez, Roberto; Ordoñez, Maria Gratzia; Rivas, José Ramón; Martínez, María Sofía; Hernández, Juan Diego; Graterol, Modesto; Rojas, JoselynBackground: Insulin resistance (IR) is a metabolic disorder related to atherosclerosis. Its measurement is of great importance not only as a marker of diabetes but also for cardiovascular disease. The aim of this research study was to evaluate the relationship between various IR indices and coronary risk in an adult population from Maracaibo city, Venezuela. Methods: The Maracaibo City Metabolic Syndrome Prevalence Study is a descriptive, cross-sectional study with random and multi-stage sampling. In this sub study, 1272 individuals of both genders were selected with the measurement of basal insulin and coronary risk according to the Framingham-Wilson formula calibrated for our population. The insulin resistance indices evaluated were HOMA2-IR, triglycerides and glucose index (TyG) and triglycerides/HDL ratio (TG/HDL). The predictive capacity and association between each index and the coronary risk event in 10 years were determined. Results: Of the evaluated population, 55.2% were female, 34.8% had a coronary risk ≥5% in 10 years, with the TG/HDL and TyG indices showing the highest AUC 0.712 (0.681-0.743) and 0.707 (0.675-0.739), respectively; compared to HOMA2-IR. Both were also the indices most associated with increased coronary risk, especially TG/HDL ≥3 with a higher association [OR = 2.83 (1.74-4.61); p<0.01] after multivariable adjustment. Conclusions: TyG (≥4.5) and TG/HDL (≥3) indices showed a great predictive capacity of higher coronary risk, with being TG/HDL more associated even after adjusting for abdominal obesity and hs-CRP. Therefore, these represent useful tools for determining IR.Ítem Non-HDL cholesterol is better than LDL-c at predicting atherosclerotic cardiovascular disease risk factors clustering, even in subjects with near-to-normal triglycerides: A report from a Venezuelan population(F1000 Research Ltd., 2018-09-20) Bermúdez, Valmore; Torres, Wheeler; Salazar, Juan; Martínez, María Sofía; Rojas, Edward; Olivar, Luis Carlos; Lameda, Victor; Ortega, Ángel; Ramírez, Paola; Rojas, Milagros; Rastogi, Sheena; D’Addosio, Rosanna; Hoedebecke, Kyle; Graterol, Modesto; Graterol, Resemily; Wilches, Sandra; Cabrera de Bravo, Mayela; Rojas-Quintero, JoselynBackground: Non-high density lipoprotein cholesterol (non-HDL-c) has emerged as an important tool in primary prevention of atherosclerotic cardiovascular disease (ASCVD), especially among those at high risk. The main objective of this study was to evaluate the predictive value of non-HDL-c for the coexistence aggregation of multiple ASCVD risk factors and compare this with LDL-c in general subjects with normal or near normal triglycerides from Maracaibo city in Venezuela. Methods: This is a descriptive, cross-sectional study with a randomized multistage sampling. 2026 subjects were selected for this study, all were adults ≥18 years old of both genders and inhabitants of Maracaibo city, Venezuela. A complete history and physical medical assessment was performed. A multivariate logistic regression model was used to determine the odds ratio (CI95%) for the coexistence of multiple risk factors for ASCVD. Results: The median (p25-p75) of non-HDL-c was 143 mg/dL (114-174 mg/dL). 52.1% (n=1056) of the sample were women, with a median of 144 mg/dL (115-174 mg/dL) among women and 143 mg/dL (114-17 4mg/dL) among men; p=0.740. Individuals ≥50 years old, smokers, those with hypertension, obesity, diabetes, high waist circumference and elevated hs-C Reactive Protein, all had higher levels of non-HDL-c. A lower median was observed among those <30 years of age with elevated physical activity levels in their leisure time. Non-HDL-c between 130-159 mg/dL (OR=2.44; CI 95%=1.48-4.02; p<0.001) and ≥160 mg/dL (OR=3.28; CI 95%=1.72-6.23; p<0.001) was associated with greater risk of coexistent multiple risk factors for ASCVD, albeit LDL-c was not significant in the multivariate model. Conclusions: Elevated non-HDL-c was associated with conglomeration of multiple risk factors for ASCVD. This suggests evaluation of non-HDL-c may be of better utility in primary care for early identification of subjects for high risk of ASCVD. Future research might focus on the influence of non-HDL-c in cardiovascular mortality.Ítem The Role of the α Cell in the Pathogenesis of Diabetes: A World beyond the Mirror(MDPI, 2021) Martínez, María Sofía; Manzano, Alexander; Olivar, Luis Carlos; Nava, Manuel; Salazar, Juan; D'Marco, Luis; Ortiz, Rina; Chacín, Maricarmen; Guerrero-Wyss, Marion; Cabrera de Bravo, Mayela; Cano, Clímaco; Bermúdez, Valmore; Angarita, LisseType 2 Diabetes Mellitus (T2DM) is one of the most prevalent chronic metabolic disorders, and insulin has been placed at the epicentre of its pathophysiological basis. However, the involvement of impaired alpha (α) cell function has been recognized as playing an essential role in several diseases, since hyperglucagonemia has been evidenced in both Type 1 and T2DM. This phenomenon has been attributed to intra-islet defects, like modifications in pancreatic α cell mass or dysfunction in glucagon’s secretion. Emerging evidence has shown that chronic hyperglycaemia provokes changes in the Langerhans’ islets cytoarchitecture, including α cell hyperplasia, pancreatic beta (β) cell dedifferentiation into glucagon-positive producing cells, and loss of paracrine and endocrine regulation due to β cell mass loss. Other abnormalities like α cell insulin resistance, sensor machinery dysfunction, or paradoxical ATP-sensitive potassium channels (KATP) opening have also been linked to glucagon hypersecretion. Recent clinical trials in phases 1 or 2 have shown new molecules with glucagon-antagonist properties with considerable effectiveness and acceptable safety profiles. Glucagon-like peptide-1 (GLP-1) agonists and Dipeptidyl Peptidase-4 inhibitors (DPP-4 inhibitors) have been shown to decrease glucagon secretion in T2DM, and their possible therapeutic role in T1DM means they are attractive as an insulin-adjuvant therapy.