Research on aging during the Venezuelan humanitarian crisis: the experience of the Maracaibo aging study.

BACKGROUND: Venezuela is in the throes of a complex humanitarian crisis that is one of the worst in decades to impact any country outside of wartime. This case analysis describes the challenges faced by the ongoing Maracaibo Aging Study (MAS) during the deteriorating conditions in Venezuela. When the MAS began in 1997, it focused on memory-related disorders. Since then, strategic planning and proactive community participation allowed us to anticipate and address logistical, funding, and ethical challenges, and facilitated the enrollment and retention of more than 2500 subjects over 55 years of age. All participants, who are residents of the city of Maracaibo, Venezuela, underwent various assessments on several occasions. Here, we discuss how our approach to implementing a longitudinal, population-based study of age-related conditions has allowed our research program to continue throughout this period of political, economic, and social upheaval. DISCUSSION: As the social context in Venezuela became more complicated, new challenges emerged, and strategies to sustain the study and participation were refined. We identified five main mechanisms through which the evolving humanitarian crisis has affected implementation of the MAS: 1) community dynamics; 2) morale of researchers, staff, and participants; 3) financial feasibility; 4) components of the research process; and 5) impact on the health of staff, participants, and their families. Strategies to compensate for the impact on these components were implemented, based on inputs from community members and staff. Improved communication, greater involvement of stakeholders, broadening the scope of the project, and strengthening international collaboration have been the most useful strategies. Particular demands emerged, related to the increased mortality and comorbidities of participants and staff, and deterioration of basic services and safety. CONCLUSION: Although the MAS has faced numerous obstacles, it has been possible to continue a longitudinal research project throughout the humanitarian crisis, because our research team has engaged the community deeply and developed a sense of mutual commitment, and also because our project has provided funding to help keep researchers employed, somewhat attenuating the brain drain.

Glaucomatous Optic Neuropathy Associated with Nocturnal Dip in Blood Pressure: Findings from the Maracaibo Aging Study.

PURPOSE: To determine which nocturnal blood pressure (BP) parameters (low levels or extreme dipper status) are associated with an increased risk of glaucomatous damage in Hispanics. DESIGN: Observational cross-sectional study. PARTICIPANTS: A subset (n = 93) of the participants from the Maracaibo Aging Study (MAS) who met the study eligibility criteria were included. These participants, who were at least 40 years of age, had measurements for optical tomography coherence, visual field (VF) tests, 24-hour BP, office BP, and intraocular pressure <22 mmHg. METHODS: Univariate and multivariate logistic regression analyses under the generalized estimating equations (GEE) framework were used to examine the relationships between glaucomatous damage and BP parameters, with particular attention to decreases in nocturnal BP. MAIN OUTCOME MEASURES: Glaucomatous optic neuropathy (GON) based on the presence of optic nerve damage and VF defects. RESULTS: The mean age was 61.9 years, and 87.1% were women. Of 185 eyes evaluated, 19 (26.5%) had signs of GON. Individuals with GON had significantly lower 24-hour and nighttime diastolic BP levels than those without. However, results of the multivariate GEE models indicated that the glaucomatous damage was not related to the average systolic or diastolic BP levels measured over 24 hours, daytime, or nighttime. In contrast, extreme decreases in nighttime systolic and diastolic BP (>20% compared with daytime BP) were significant risk factors for glaucomatous damage (odds ratio, 19.78 and 5.55, respectively). CONCLUSIONS: In this population, the link between nocturnal BP and GON is determined by extreme dipping effects rather than low nocturnal BP levels alone. Further studies considering extreme decreases in nocturnal BP in individuals at high risk of glaucoma are warranted.

Association of Variability and Hypertensive Loads in 24-h Blood Pressure With Mortality and Cardiovascular Risk.

BACKGROUND: Evidence shows that high 24-h blood pressure (BP) variability increases cardiovascular risk. We investigated whether 24-h BP variability relates to mortality and cardiovascular risk due to inherent variability and/or hypertensive loads in 24-h BP. METHODS: A total of 1,050 participants from the Maracaibo Aging Study (mean age, 66 years; women, 67.2%) underwent 24-h ambulatory BP monitoring and were followed between 2001 and 2016. To evaluate inherent BP variability, we used average real variability (ARV) as it captures variability among consecutive BP readings. 24-h systolic BP load was the proportion (%) of systolic BP readings ≥130 mm Hg during the daytime and ≥110 during the nighttime. Our primary endpoint was total mortality and major adverse cardiovascular endpoints (MACE). Statistics included Cox proportional models. RESULTS: During a median follow-up of 8.3 years, 299 participants died and 210 experienced MACE. Each +2 mm Hg (corresponding to 1-standard deviation) higher 24-h systolic ARV (mean value, 9.0 ±â€…2.0 mm Hg) was associated with higher hazard ratios (HRs) for mortality by 1.28-fold (95% confidence interval [CI], 1.14-1.43) and for MACE by 1.24-fold (95% CI, 1.08-1.42). Each 30% higher 24-h systolic BP load (median value, 63%) was associated with mortality and MACE with HRs of 1.29 (95% CI, 1.15-1.46) and 1.28 (95% CI, 1.10-1.48); respectively. After models were additionally adjusted by BP level, only ARV was associated with mortality (HR, 1.17; 95% CI, 1.04-1.33) and MACE (HR, 1.16; 95% CI, 1.00-1.34). CONCLUSIONS: High ARV and hypertensive loads in 24-h systolic BP were associated with mortality and cardiovascular risk, however, only ARV is associated independently of the BP level.

Subclinical Magnetic Resonance Imaging Markers of Cerebral Small Vessel Disease in Relation to Office and Ambulatory Blood Pressure Measurements.

Background: Twenty-four-hour and nighttime blood pressure (BP) levels are more strongly associated with cardiovascular risk than office or daytime BP measurements. However, it remains undocumented which of the office and ambulatory BP measurements have the strongest association and predictive information in relation to the presence of type I, or arteriolosclerosis type, cerebral small vessel diseases (CSVD). Methods: A subset of 429 participants from the Maracaibo Aging Study [aged ≥40 years (women, 73.7%; mean age, 59.3 years)] underwent baseline brain magnetic resonance imaging (MRI) to visualize CSVD, which included log-transformed white matter hyperintensities (log-WMH) volume and the presence (yes/no) of lacunes, cerebral microbleeds (CMB), or enlarged perivascular spaces (EPVS). Linear and logistic regression models were applied to examine the association between CSVD and each +10-mmHg increment in the office and ambulatory systolic BP measurements. Improvement in the fit of nested logistic models was assessed by the log-likelihood ratio and the generalized R 2 statistic. Results: Office and ambulatory systolic BP measurements were related to log-WMH (ß-correlation coefficients ≥0.08; P < 0.001). Lacunes and CMB were only associated with ambulatory systolic BP measurements (odds ratios [OR] ranged from 1.31 [95% confidence interval, 1.10-1.55] to 1.46 [1.17-1.84], P ≤ 0.003). Accounted for daytime systolic BP, both the 24-h (ß-correlation, 0.170) and nighttime (ß-correlation, 0.038) systolic BP measurements remained related to log-WMH. When accounted for 24-h or daytime systolic BP levels, the nighttime systolic BP retained the significant association with lacunes (ORs, 1.05-1.06; 95% CIs, ≥1.01 to ≤ 1.13), whereas the 24-h and daytime systolic BP levels were not associated with lacunes after adjustments for nighttime systolic BP (ORs, ≤ 0.88; 95% CI, ≥0.77 to ≤ 1.14). On top of covariables and office systolic BP, ambulatory systolic BP measurements significantly improved model performance (1.05% ≥ R 2 ≤ 3.82%). Compared to 24-h and daytime systolic BP, nighttime systolic BP had the strongest improvement in the model performance; for WMH (1.46 vs. 1.05%) and lacunes (3.06 vs. ≤ 2.05%). Conclusions: Twenty-four-hour and nighttime systolic BP were the more robust BP measurements associated with CSVD, but the nighttime systolic BP level had the strongest association. Controlling ambulatory BP levels might provide additional improvement in the prevention of CSVD.

Open-Angle Glaucomatous Optic Neuropathy Is Related to Dips Rather Than Increases in the Mean Arterial Pressure Over 24-H.

BACKGROUND: Mean arterial pressure (MAP) drives ocular perfusion. Excessive 24-h MAP variability relates to glaucoma, however, whether this is due to dips or increases in the blood pressure (BP) is undocumented. We investigated the association of open-angle glaucoma (OAG) in relation to the 5 largest MAP dips/increases over 24-h, henceforth called dips/blips. METHODS: In the Maracaibo Aging Study (MAS), 93 participants aged ≥40 y (women, 87.1%; mean age, 61.9 y) underwent baseline ophthalmological and 24-h ambulatory BP monitoring assessments. OAG was the presence of optic nerve damage and visual field defects. Statistical methods included logistic regression and the generalized R2 statistic. For replication, 48 OAG cases at the Leuven Glaucoma Clinic were matched with 48 controls recruited from Flemish population. RESULTS: In the MAS, 26 participants had OAG. OAG compared to non-OAG participants experienced longer and deeper dips (116.5 vs. 102.7 minutes; to 60.3 vs. 66.6 mm Hg; -21.0 vs. -18.0 mm Hg absolute or 0.79 vs. 0.81 relative dip compared to the preceding reading). The adjusted odds ratios associated with dip measures ranged from 2.25 (95% confidence interval [CI], 1.31-4.85; P = 0.009) to 3.39 (95% CI, 1.36-8.46; P = 0.008). On top of covariables and 24-MAP level/variability, the dip measures increased the model performance (P ≤ 0.025). Blips did not associate with OAG. The case-control study replicated the MAS observations. CONCLUSIONS: Dips rather than increases in the 24-h MAP level were associated with increased risk for OAG. An ophthalmological examination combined with 24-h BP monitoring might be precautious steps required in normotensive and hypertensive patients at risk of OAG.

Normal-tension glaucomatous optic neuropathy is related to blood pressure variability in the Maracaibo Aging Study.

Hypoperfusion of the optic nerve might be involved in the pathogenesis of normal-tension glaucomatous optic neuropathy (GON). Mean arterial pressure (MAP) drives ocular perfusion, but no previous studies have addressed the risk of GON in relation to blood pressure (BP) variability, independent of BP level. In a cross-sectional study, 93 residents of Maracaibo, Venezuela, underwent optical coherence tomography, visual field assessments and 24-h ambulatory BP monitoring between 2011 and 2016. We investigated the association of normal-tension GON with or without visual field defects with reading-to reading variability of 24-h MAP, as captured by variability independent of the MAP level (VIMmap). Odds ratios (ORs) were adjusted for 24-h MAP level and for a propensity score of up to five risk factors. Among the 93 participants (87.1% women; mean age, 61.9 years), 26 had open-angle normal-tension GON at both eyes; 14 had visual field defects; and 19 did not have visual field defects. The OR ratios for normal-tension GON, expressed per 1-SD increment in VIMmap (2 mm Hg), were 2.17 (95% confidence interval, 1.33-3.53) unadjusted; 2.20 (1.35-3.61) adjusted for 24-h MAP level only; 1.93 (1.10-3.41) with additional adjustment for age, educational attainment, high-density lipoprotein (HDL) cholesterol and office hypertension; and 1.95 (1.10-3.45) in models including intraocular pressure. We confirmed our a priori hypothesis that BP variability, most likely operating via hypoperfusion of the optic nerve, is associated with normal-tension GON. 24-H ambulatory BP monitoring might therefore help stratify the risk of normal-tension GON.

White matter hyperintensities mediate the association of nocturnal blood pressure with cognition.

OBJECTIVE: To test the hypotheses that hypertension and nocturnal blood pressure are related to white matter hyperintensity (WMH) volume, an MRI marker of small vessel cerebrovascular disease, and that WMH burden statistically mediates the association of hypertension and dipping status with memory functioning, we examined the relationship of hypertension and dipping status on WMH volume and neuropsychological test scores in middle-aged and older adults. METHODS: Participants from the community-based Maracaibo Aging Study received ambulatory 24-hour blood pressure monitoring, structural MRI, and neuropsychological assessment. Four hundred thirty-five participants (mean ± SD age 59 ± 13 years, 71% women) with available ambulatory blood pressure, MRI, and neuropsychological data were included in the analyses. Ambulatory blood pressure was used to define hypertension and dipping status (i.e., dipper, nondipper, and reverse dipper based on night/day blood pressure ratio <0.9, 0.9-1, and >1, respectively). Outcome measures included regional WMH and memory functioning derived from a neuropsychological test battery. RESULTS: The majority of the participants (59%) were hypertensive. Ten percent were reverse dippers, and 40% were nondippers. Reverse dipping in the presence of hypertension was associated with particularly elevated periventricular WMH volume (F 2,423 = 3.78, p = 0.024) and with lowered memory scores (F 2,423 = 3.911, p = 0.021). Periventricular WMH volume mediated the effect of dipping status and hypertension on memory (ß = -4.1, 95% confidence interval -8.7 to -0.2, p < 0.05). CONCLUSION: Reverse dipping in the presence of hypertension is associated with small vessel cerebrovascular disease, which, in turn, mediates memory functioning. These results point toward reverse dipping as a marker of poor nocturnal blood pressure control, particularly among hypertensive individuals, with potentially pernicious effects on cerebrovascular health and associated cognitive function.

Nighttime Blood Pressure Interacts with APOE Genotype to Increase the Risk of Incident Dementia of the Alzheimer's Type in Hispanics.

BACKGROUND: Dementia of the Alzheimer's type (DAT) impacts Hispanics disproportionately, with almost a twofold elevated risk of developing DAT, as well as earlier onset of the disease, than in non-Hispanic Whites. However, the role of main risk factors for DAT, such as APOE-ɛ4 and blood pressure (BP) levels, remains uncertain among Hispanics. OBJECTIVE: To investigate the association of APOE-ɛ4 and BP levels, measures with 24-h ambulatory BP monitoring, with incidence of DAT in an elderly cohort of Hispanics. METHODS: 1,320 participants from the Maracaibo Aging Study, free of dementia at the baseline, and with ambulatory BP measurements and APOE genotype available were included. Adjusted Cox proportional models were performed to examine 1) the incidence of DAT and 2) the relationship between BP levels and DAT according to APOE genotypes. Models were adjusted by competing risk of death before the onset of DAT. Model performance was assessed by likelihood test. RESULTS: The average follow-up time was 5.3 years. DAT incidence was 5.8 per 1000 person-year. APOE-ɛ4 carriers had a higher risk of DAT. In unadjusted analyses, conventional, 24-h, and nighttime systolic BP levels were significantly higher in participants who developed DAT and of APOE-ɛ4 carriers (p < 0.05). After adjustment for competing risks, only higher nighttime systolic BP was associated with DAT incidence, but only among subjects carrying APOE-ɛ4. CONCLUSION: In this Hispanic population, both APOE-ɛ4 genotype and assessment of nocturnal systolic BP (rather than diurnal or office BP) were necessary to estimate DAT risk.

Black Hispanics have a worse cardiovascular risk profile than mixed Hispanics in Venezuela.

In order to characterize components of the metabolic syndrome (MS) in Venezuelan black Hispanics and compare these metabolic abnormalities with those found in the predominant mixed Hispanic population, 2336 mixed Hispanics (69% women) and 281 black Hispanics (60% women), aged 20-78 years, without prior history of diabetes and/or cardiovascular disease were evaluated in a population-based study in Zulia State, Venezuela. Blood pressure (BP), waist circumference, as well as fasting insulin, fasting blood glucose (FBG), triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C) levels were measured. The criteria proposed by the National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATP III) to identify those with metabolic abnormalities were used. We found that black Hispanics showed higher frequency of age-adjusted elevated BP than mixed Hispanics in both men (66.9% vs. 52.3%, p < 0.01) and women (39.3% vs. 30.4%, p < 0.05). In men, elevated FBG was also more frequent in black Hispanics (32.7%) than in mixed Hispanics (22.3%), despite the lack of significant differences in fasting insulin, HOMA-insulin resistance and HOMA-beta cell function values. In women low HDL-C and higher abdominal obesity were more common in black Hispanics (71.8% and 54.1%, respectively) than in mixed Hispanics (56.2% and 44.5%, respectively), despite the greater frequency of high TG in mixed Hispanics (22.6%) when compared to black Hispanics (13.3%). Furthermore, in logistic regression analysis black Hispanic race was independently associated with higher risk for hypertension, fasting hyperglycemia, and low HDL-C. These results suggest that black Hispanics have worse cardiovascular risk profile than mixed Hispanics in Zulia State, with higher BP, higher FBG, more abdominal obesity, and lower HDL-C. Identification and intervention of these high-risk subjects are important strategies for diabetes and cardiovascular disease prevention in Venezuela.

[Basal insulin levels in a Zulia State population in Venezuela]. / Niveles basales de insulina en una población del estado Zulia, Venezuela.

This study examines the basal insulin levels in a population from Zulia state (Venezuela). A total of 1703 subjects (1175 women and 528 men) from five different sanitary regions (Maracaibo, La Guajira, Perijá, Sur del Lago de Maracaibo, y Costa Oriental del Lago de Maracaibo) were studied. Weight, height, waist and hip circumferences, and blood pressure were determined. A blood sample was taken after a 12-h overnight fast to determine serum glucose, triglycerides, total cholesterol and HDL-C using enzymatic methods and insulin by radioimmunoassay. According to ATP III criteria two groups were established: a group without metabolic abnormalities (138 subjects) and a group with some metabolic abnormalities 84.8% of subjects of the non metabolic alteration groups and 80.4% of the group with some metabolic alteration were of mixed race. Non metabolic altered lean subjects (BMI <25 Kg/m2) had the lowest (p < 0.0001) basal insulin levels compared to the ones with overweight from the same group and the obese with metabolic abnormalities. This study proposes to consider a cutoff basal insulin levels of 13 microU/mL for women and 11 microU/mL for men, over 20 years of age, in the Zulia state region of Venezuela.

Prevalence and risk factors associated with the metabolic syndrome and dyslipidemia in White, Black, Amerindian and Mixed Hispanics in Zulia State, Venezuela.

Studies have highlighted the association between insulin resistance (IR) and several cardiovascular (CV) risk factors, including hypertension (HTN), obesity, dyslipidemia (i.e. high triglyceride and low HDL-cholesterol) and glucose intolerance, in a cluster known as the metabolic syndrome (MS). There are few data on the frequency of the MS and dyslipidemia in developing countries, and none in South America. To estimate the prevalence of the MS and its components in Zulia State, Venezuela, and to establish associated demographic and clinical factors, we evaluated 3108 Hispanic men and women aged 20 years or older from a cross-sectional survey of a random representative sample from each health district in Zulia State, Venezuela (1999-2001). Prevalence of the MS and dyslipidemia was defined according to the National Cholesterol Education Program (NCEP)/Adult Treatment Panel III (ATP III) criteria. The age-adjusted prevalence of MS and dyslipidemia was 31.2% and 24.1%, respectively, with higher rates in men than in women. Prevalence rates increased with age and with the degree of obesity. MS prevalence was lower in Amerindian (17.%) compared to Black (27.2%), White (33.3%) and Mixed (37.4%) men, but no differences were found among women. Overall, low HDL-cholesterol (65.3%), abdominal obesity (42.9%) and HTN (38.1%) were the most frequent MS components. After adjusting for age, sex and race groups, family history of diabetes, obesity and HTN were associated with the MS. Sedentary lifestyle also increased the risk of MS, event after adjusting for the same covariates, obesity and the degree of IR. These results suggest that MS is found in approximately one-third of the Venezuelan adult population in Zulia State, with higher prevalence in men related to the presence of dyslipidemia. Lifestyle interventions in MS subjects are needed in Venezuela to halt the burden of CV disease and diabetes.

Black hispanics have a worse cardiovascular risk profile than mixed hispanics in Venezuela

Con el propósito de caracterizar los componentes del síndrome metabólico en hispanos negros de Venezuela y comparar dichas anormalidades metabólicas con aquellas encontradas en la población predominante de hispanos mezclados, se estudiaron 2236 hispanos mezclados (69 por ciento mujeres) y 281 hispanos negros (60 por ciento mujeres), de 20 años o más, sin historia previa de diabetes y/o enfermedad cardiovascular en un estudio poblacional en el Estado Zulia de Venezuela. Se midieron la tensión arterial (TA), circunferencia de cintura, así como insulina y glicemia basal, triglicéridos (TG) y colesterol de las lipoproteínas de alta densidad (HDL-C). Para definir la presencia de anormalidades metabólicas se usaron los criterios del Programa Nacional de Educación del Colesterol/Panel del Tratamiento del Adulto III (NCEP/ATP III). Se encontró que los hispanos negros tenían mayor frecuencia de TA elevada - ajustada para la edad que los Hispanos mezclados tanto en los hombres (69,9 por ciento vs. 52,3 por ciento, p < 0,01) como en las mujeres (39,3 por ciento vs. 30,4 por ciento, p < 0,05). En los hombres, la elevación de la glicemia en ayunas fue más frecuente en los hispanos negros (32,7 por ciento) que en los hispanos mezclados (22,3 por ciento) a pesar de la falta de diferencias significativas en los valores de insulina, HOMA-insulino resistencia y HOMA-célula beta. En las mujeres, el HDL-C bajo y la obesidad abdominal fueron más comunes en las hispanas negras (71,8 por ciento y 54,1 por ciento, respectivamente) que en las hispanas mezcladas (56,2 por ciento y 44,5 por ciento, respectivamente), a pesar de la mayor frecuencia de hipertrigliceridemia en las hispanas mezcladas (22,6 por ciento) comparadas con las hispanas negras (13,3 por ciento). En análisis de regresión logística se observó que la raza hispana negra se asocia independientemente con mayor riesgo de hipertensión, hiperglicemia y HDL-C bajo.

Factores nutricionales y metabólicos como riesgo de enfermedades cardiovasculares en una población adulta de la ciudad de Maracaibo, Estado Zulia, Venezuela / Nutritional and metabolic risk factors as cardiovascular diseases among an adult population of Maracaibo, Venezuela

Con el propósito de analizar los factores nutricionales y metabólicos de riesgo de enfermedades cardiovasculares (ECV) presentes en un grupo de individuos de la ciudad de Maracaibo, se realizó este estudio en 209 voluntarios entre 20 y 89 años (145 mujeres y 64 hombres), a quienes se les practicó: a) evaluación antropométrica: índice de masa corporal (IMC) y cociente cintura cadera (CCC) y examen físico: presión arterial sistólica (PAS) y diastólica (PAD); b) evaluación dietética (recordatorio de 24 horas) y c) evaluación bioquímica: glicemia (GLI), triglicéridos (TG), colesterol total (COL), HDL-C, LDL-C y VLDL-C, por métodos enzimáticos. Se investigó además: edad, antecedentes familiares de alteraciones metabólicas (A.F.A.M.), hábito tabáquico, hábito alcohólico, actividad física. Más del 50 por ciento de los sujetos estudiados tuvo un IMC > 25; 64 por ciento de mujeres presentó un valor de CCC > 0,8; 34 y 28 por ciento de hombres y mujeres respectivamente tuvieron un alto consumo de grasa (A.C.G.); 36 por ciento de hombres tuvieron hipertrigliceridemia y niveles elevados de VLDL-C; las HDL-C estuvieron disminuidas en 41 por ciento de las mujeres y 30 por ciento de los hombres; los A.F.A.M. ocuparon una alta frecuencia (85 por ciento en mujeres y 78 por ciento en hombres) seguido por el sedentarismo (64 y 79 por ciento en hombres y mujeres respectivamente); la edad afectó de manera significativa (p < 0.05) los valores de CCC, PAS, PAD, GLI, COL, TG, HDL-C, LDL y VLDL-C; la dieta resultó hipocalórica, hiperproteica, normograsa e hipohidrocarbonada. Se concluye que la población estudiada puede ser considerada a riesgo de ECV, ya que tanto los factores nutricionales y metabólicos, así como los otros factores de riesgo analizados, estuvieron presentes en un elevado porcentaje de individuos estudiados

Niveles basales de insulina en una población del estado Zulia Venezuela / Basal insulin levels in a Zulia state population in Venezuela

El objetivo del presente estudio fue establecer los niveles basales de insulina en una población del estado Zulia. Se estudiaron 1703 individuos (1175 mujeres y 528 hombres) de 5 subregiones sanitarias del Estado Zulia (Maracaibo, Guajira, Perijá, Sur del Lago de Maracaibo, y Costa Oriental del Lago de Maracaibo). A cada individuo se le determinó peso, talla, circunferencia de cintura y cadera y presión arterial. Se calculó el índice de masa corporal (IMC, Kg/m2). Después de 12 horas de ayuno, se tomaron muestras de sangre venosa y se determinaron las concentraciones de glicemia, triglicéridos, colesterol total y HDL-C empleando métodos enzimáticos, e insulina por radioinmunoensayo. De acuerdo a los criterios del ATP III se establecieron 2 grupos: sin alteraciones metabólicas (138 individuos) y con alguna alteración metabólica (1565 individuos). El 84,8 por ciento de los sujetos sin alteraciones metabólicas y el 80,4 por ciento de los sujetos con alteraciones, se caracterizaron por ser de raza mezclada. Los individuos delgados (IMC < 25 Kg/m2) sin alteraciones metabólicas, presentaron los valores más bajos de insulina basal (p < 0,0001), comparados con los sujetos con sobrepeso del mismo grupo y con los individuos con alteraciones metabólicas. Este estudio propone considerar como puntos de corte para los niveles de insulina basal valores de 13 µU/mL para las mujeres y 11µU/mL para los hombres mayores de 20 años de la región zuliana

Puentes miocárdicos sobre las arterias coronarias: prevalencia en el Servicio de Hemodinamia de la Unidad de Cardiología Merida. Período 1988-1993 / Coronary artery by pass: incidence in the hemodinamic Service in the Cardio Vascular United

Se revisaron 223 cineangiografias, en forma retrospectiva, realizadas durante el período comprendido desde 1988 a 1993. se encontraron 7 casos con puentes miocardicos (PM), distribuidos así: 2 casos en los años 1988 a 1991 y 5 casos en los años 1992 a 1993. Del total de 223 coronariografías habían 3 casos de PM con coronarias sanas y 4 casos asociados a enfermedad obstructiva de las arterias coronarias. Nuestros hallazgos parecen indicar que los PM en esta población estudiada son poco frecuentes (3 por ciento en el período 1988 a 1993 y 5 por ciento en el período 1992 a 1993). La ubicación de estos PM fue en su mayoría, a nivel del tercio próximal de la arteria descendente anterior. La patología cardiovascular subyacente en estos casos de PM fue: Hipertensión arterial en 3 casos, miocardiopatía dilatada en 1 caso y tres no tenían anormalidades. Los tres pacientes con PM sin enfermedad coronaria, tuvieron una prueba de esfuerzo submáxima positiva para isquemia, y uno de estos mostró además un estudio de tallium positivo por hipocaptación en región apical. De los 4 casos de PM restantes, con enfermedad isquémica coronaria, sólo 1 mostró una prueba de esfuerzo positiva para isquemia. Ninguno de estos pacientes fueron sometidos a tratamiento quirúrgico