Papers by Gonzalo Alburqueque valdivia
International journal of chronic obstructive pulmonary disease, 2018
We aimed to study the adverse outcomes of symptomatic and asymptomatic non-obstructed individuals... more We aimed to study the adverse outcomes of symptomatic and asymptomatic non-obstructed individuals and those with mild COPD longitudinally in participants from three Latin-American cities. Two population-based surveys of adults with spirometry were conducted for these same individuals with a 5- to 9-year interval. We evaluated the impact of respiratory symptoms (cough, phlegm, wheezing or dyspnea) in non-obstructed individuals, and among those classified as Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 1, COPD on exacerbation frequency, mortality and FEV decline, compared with asymptomatic individuals without airflow obstruction or restriction. Non-obstructed symptomatic individuals had a marginal increased risk of mortality (HR 1.3; 95% CI 0.9-1.94), increased FEV decline (-4.5 mL/year; 95% CI -8.6, -0.4) and increased risk of 2+ exacerbations in the previous year (OR 2.6; 95% CI 1.2-6.5). Individuals with GOLD stage 1 had a marginal increase in mortality (HR 1...
Environmental pollution (Barking, Essex : 1987), Jan 6, 2018
Temuco is a mid-size city representative of severe wood smoke pollution in southern Chile; howeve... more Temuco is a mid-size city representative of severe wood smoke pollution in southern Chile; however, little is known about the indoor air quality in this region. A field measurement campaign at 63 households in the Temuco urban area was conducted in winter 2014 and is reported here. In this study, indoor and outdoor (24-hr) PM2.5 and its elemental composition were measured and compared. Infiltration parameters and outdoor/indoor contributions to indoor PM2.5 were also determined. A statistical evaluation of how various air quality interventions and household features influence indoor PM2.5 was also performed. This study determined median indoor and outdoor PM2.5 concentrations of 44.4 and 41.8 μg/m3, respectively. An average infiltration factor (0.62 ± 0.06) was estimated using sulfur as a tracer species. Using a simple mass balance approach, median indoor and outdoor contributions to indoor PM2.5 concentrations were then estimated as 12.5 and 26.5 μg/m3, respectively; therefore, 68%...
BMJ open, Jan 11, 2017
Clinical onset of chronic obstructive pulmonary disease (COPD) is the point at which the disease ... more Clinical onset of chronic obstructive pulmonary disease (COPD) is the point at which the disease is first identifiable by physicians. It is a poorly defined stage which seems to include both mild spirometric and non-spirometric disease, and could be described as early grade COPD, for practical purposes. While dyspnoea; chronic bronchitis and CT imaging evidence of emphysema and airway disease may be present very early, the lone significance of dyspnoea, the most relevant symptom in COPD in identifying these individuals, has been scarcely assessed.The Searching Clinical COPD Onset (SOON) Study was designed primarily to detect clinical, physiological and structural differences between dyspnoeic and non-dyspnoeic individuals with early grade COPD. It is hypothesised that presence of dyspnoea in early disease may identify a subtype of individuals with reduced exercise capacity, notwithstanding of their spirometry results. In addition, dyspnoeic individuals will share worse quality of li...
International journal of chronic obstructive pulmonary disease, 2017
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) report provides a framework for... more The Global Initiative for Chronic Obstructive Lung Disease (GOLD) report provides a framework for classifying COPD reflecting the impacts of disease on patients and for targeting treatment recommendations. The GOLD 2017 introduced a new classification with 16 subgroups based on a composite of spirometry and symptoms/exacerbations. Data from the population-based PLATINO study, collected at baseline and at follow-up, in three sites in Latin America were analyzed to compare the following: 1) the distribution of COPD patients according to GOLD 2007, 2013, and 2017; 2) the stability of the 2007 and 2013 classifications; and 3) the mortality rate over time stratified by GOLD 2007, 2013, and 2017. Of the 524 COPD patients evaluated, most of them were classified as Grade I or II (GOLD 2007) and Group A or B (GOLD 2013), with ≈70% of those classified as Group A in GOLD 2013 also classified as Grade I in GOLD 2007 and the highest percentage (41%) in Group D (2013) classified as Grade III (200...
PloS one, 2017
Lung-function decline is one of the possible mechanisms leading to Chronic Obstructive Pulmonary ... more Lung-function decline is one of the possible mechanisms leading to Chronic Obstructive Pulmonary Disease (COPD). We analyzed data obtained from two population-based surveys of adults (n = 2026) conducted in the same individuals 5-9 years (y) after their baseline examination in three Latin-American cities. Post BronchoDilator (postBD) FEV1 decline in mL/y, as %predicted/y (%P/y) and % of baseline/y (%B/y) was calculated and the influence of age, gender, BMI, baseline lung function, BD response, exacerbations rate evaluated using multivariate models. Expressed in ml/y, the mean annual postBD FEV1 decline was 27 mL (0.22%P, 1.32%B) in patients with baseline COPD and 36 (0.14%P, 1.36%B) in those without. Faster decline (in mL/y) was associated with higher baseline lung function, with significant response to bronchodilators, older age and smoking at baseline, also in women with chronic cough and phlegm, or ≥2 respiratory exacerbations in the previous year, and in men with asthma. Lung fu...
The lancet. Diabetes & endocrinology, Mar 23, 2017
Worldwide implementation of risk-based cardiovascular disease (CVD) prevention requires risk pred... more Worldwide implementation of risk-based cardiovascular disease (CVD) prevention requires risk prediction tools that are contemporarily recalibrated for the target country and can be used where laboratory measurements are unavailable. We present two cardiovascular risk scores, with and without laboratory-based measurements, and the corresponding risk charts for 182 countries to predict 10-year risk of fatal and non-fatal CVD in adults aged 40-74 years. Based on our previous laboratory-based prediction model (Globorisk), we used data from eight prospective studies to estimate coefficients of the risk equations using proportional hazard regressions. The laboratory-based risk score included age, sex, smoking, blood pressure, diabetes, and total cholesterol; in the non-laboratory (office-based) risk score, we replaced diabetes and total cholesterol with BMI. We recalibrated risk scores for each sex and age group in each country using country-specific mean risk factor levels and CVD rates....
PLOS ONE, 2015
¶ Membership of the Platino group is provided in the Acknowledgments.
Revista médica de Chile, 2005
Microsatellite marker AGAT of the mineralocorticoid receptor gene is associated with plasma renin... more Microsatellite marker AGAT of the mineralocorticoid receptor gene is associated with plasma renin activity in patients with essential hypertension Background: Hypertensive states could result from constitutive activation of mineralorticoid receptor (MR) that generates salt retention and blood pressure elevation. Moreover, microsatellite regions can be associated to the regulation of the gene expression, producing subtle pathologies. Aim: To determine the influence of microsatellite marker AGAT of the mineralocorticoid receptor gene in the plasma renin activity (PRA) and serum aldosterone (SA) levels of essential hypertensives (HT). Patients and Methods: We studied 292 HT patients and 57 normotensive (NT) controls. Blood samples were collected for PRA, SA and DNA isolation. Subjects were genotyped according to the length of the tetranucleotide AGAT repeat using polymerase chain reaction and polyacrylamide gel electrophoresis. Based on the normal distribution, we considered 13 to 15 repeats as a habitual (H) length and less than 13 or more than 15 repeats, as non-habitual (non-H). Results: We detected 8 different lengths in the AGAT repeat (allele) in both groups, ranging from 9-17 repeats, where the allele 11 was not detected in either hypertensive or normotensive groups. The allelic distribution was different in both groups (χ 2 =37.57, 4GL, p <0.001). In hypertensive patients, the H group showed higher PRA levels (median (Q1-Q3)) than the non-H group: 1.3 (0-7-3.5) vs 1.0 (0.5-2.3) ng/mL*h, p <0.05. The SA levels did not show differences between both groups, but the SA*PRA product was higher in the H group than the no-H group: 9.3 (3.0-24.6) vs 6.5 (2.5-14.6) p <0.05. In normotensive patients, no differences were observed in PRA, SA and SA*PRA between both groups. Conclusion: These results show association between the length of the AGAT repeat with the PRA in HT, suggesting a plausible role in the control of the MR gene expression, and secondarily in the regulation of blood pressure (
C106. DETERMINANTS OF CONTROL AND SEVERITY OF ASTHMA AND COPD, 2012
Revista médica de Chile, 2013
Serum folate and vitamin B 12 in older people. Results from the Chilean national health survey 20... more Serum folate and vitamin B 12 in older people. Results from the Chilean national health survey 2009-2010 Background: Supraphysiological levels (SFL) of serum folate (SF) derived from flour fortification with folic acid (FA) could be risky among older adults with low vitamin B12 (B12) levels. Aim: To describe and analyze SF and B12 levels in older Chileans and to identify risk groups.
Public Health Nutrition, 2015
ObjectiveTo analyse the relationship between serum folate (SF), vitamin B12 and impaired cognitiv... more ObjectiveTo analyse the relationship between serum folate (SF), vitamin B12 and impaired cognitive function in the Chilean elderly.DesignWe analysed the relationships between impaired cognitive function and age, SF (µg/l) and vitamin B12 (pg/ml) with Student’s t test, as well as between impaired cognitive function and gender, educational level, residence area, diabetes and hypertension with the χ2 test. Multiple logistic regressions with interactions were estimated to assess the impact of SF on impaired cognitive function according to these methods.SettingChile.SubjectsOlder adults (>65 years, n 1051), drawn from representative households of a national prevalence study, assessed using the Modified Mini Mental Status Examination (MMMSE). Individuals with altered MMMSE scores (≤13 points) were sequentially assessed using the Pfeffer Functional Activities Questionnaire (PFAQ).ResultsMultivariate models using the MMMSE demonstrated an increased risk of impaired cognitive function for...
Revista médica de Chile, 2013
Thyroid stimulating hormone reference values derived from the 2009-2010 Chilean National Health S... more Thyroid stimulating hormone reference values derived from the 2009-2010 Chilean National Health Survey Background: The determination of thyroid stimulating hormone (TSH) reference values is critical for the diagnosis of thyroid diseases. Aim: To explore and discuss different definitions to establish TSH reference values using a Chilean national survey sample. Material and Methods: The 2009-2010 Chilean National Health Survey recruited 5,416 participants between the ages of 15 and 96 years, from all geographic regions of Chile, including urban and rural zones. TSH was measured in a random subsample of 2,785 adults. Median value, 2.5 and 97.5 percentiles were described in three different populations: total survey population, "disease-free population" and the "laboratory kit disease free population". Results: TSH values were higher among women, the elderly and the less educated population. The 97.5 percentile value in the disease-free population was 7.46 uUI/ml. Using this value as a cutoff , hypothyroidism prevalence would be 4.8% in Chile and estimated pharmacological treatment coverage would be 58%. When laboratory kit cutoffs are used, prevalence rises to 22% and treatment coverage drops to 12%. The 2.5 percentile value in the disease-free population was 0.83 uUI/ml, which yields an estimated hyperthyroidism prevalence of 3.89%. Conclusions: Median TSH concentration values in the Chilean "disease-free population" are higher than those proposed by laboratory kits and those of developed countries. TSH values in the general population of Chile are also higher in women, the elderly and the less educated population.
npj Primary Care Respiratory Medicine, 2014
BACKGROUND: Spirometry is the gold standard for diagnosing chronic obstructive pulmonary disease ... more BACKGROUND: Spirometry is the gold standard for diagnosing chronic obstructive pulmonary disease (COPD). Although there are a number of different guideline criteria for deciding who should be selected for spirometric screening, to date it is not known which criteria are the best based on sensitivity and specificity. AIMS: Firstly, to evaluate the proportion of subjects in the PLATINO Study that would be recommended for spirometry testing according to Global initiative for Obstructive Lung Disease (GOLD)-modified, American College of Chest Physicians (ACCP), National Lung Health Education Program (NLHEP), GOLD and American Thoracic Society/European Respiratory Society (ATS/ERS) criteria. Secondly, we aimed to compare the sensitivity, specificity, and positive predictive and negative predictive values, of these five different criteria. METHODS: Data from the PLATINO study included information on respiratory symptoms, smoking and previous spirometry testing. The GOLD-modified spirometry indication criteria are based on three positive answers out of five questions: the presence of cough, phlegm in the morning, dyspnoea, age over 40 years and smoking status. RESULTS: Data from 5,315 subjects were reviewed. Fewer people had an indication for spirometry (41.3%) according to the GOLD-modified criteria, and more people had an indication for spirometry (80.4%) by the GOLD and ATS/ERS criteria. A low percentage had previously had spirometry performed: GOLD-modified (14.5%); ACCP (13.2%); NLHEP (12.6%); and GOLD and ATS/ERS (12.3%). The GOLD-modified criteria showed the least sensitivity (54.9) and the highest specificity (61.0) for detecting COPD, whereas GOLD and ATS/ERS criteria showed the highest sensitivity (87.9) and the least specificity (20.8). CONCLUSION: There is a considerable difference in the indication for spirometry according to the five different guideline criteria. The GOLD-modified criteria recruit less people with the greatest sum of sensitivity and specificity.
PLoS ONE, 2014
Objective: To determine whether the presence of chronic obstructive lung disease (COPD) and reduc... more Objective: To determine whether the presence of chronic obstructive lung disease (COPD) and reduction of lung function parameters were predictors of mortality in a cohort. Materials/Patients and Methods: Population based cohorts were followed in Montevideo, Santiago and Sao Paulo during 5, 6 and 9 years, respectively. Outcomes included all-cause, cardiovascular, respiratory and cancer mortality; exposures were COPD, forced expiratory volume in one second (FEV 1) and forced vital capacity (FVC). Cox regression was used for analyses. Sensitivity, specificity, positive and negative predictive values, receiver operator characteristics curves and Youden's index were calculated. Results: Main causes of death were cardiovascular, respiratory and cancer. Baseline COPD was associated with overall mortality (HR = 1.43 for FEV 1 /FVC,LLN; 2.01 for GOLD 2-4; 1.46 for GOLD 1-4; 1.50 for FEV 1 /FEV 6 ,LLN). For cardiovascular mortality, significant associations were found with GOLD 2-4 (HR = 2.68) and with GOLD 1-4 (HR = 1.78) for both genders together (not among women). Low FEV 1 was risk for overall and respiratory mortality (both genders combined). FVC was not associated with overall mortality. For most COPD criteria sensitivity was low and specificity high. The area under the curve for FEV 1 was greater than for FVC for overall and cardiovascular mortality. Answer to the Question: COPD and low FEV 1 are important predictors for overall and cardiovascular mortality in Latin America.
Archivos de Bronconeumología ((English Edition)), 2007
*Al final del artículo se indican los restantes miembros del grupo PLATINO. Este estudio se ha su... more *Al final del artículo se indican los restantes miembros del grupo PLATINO. Este estudio se ha subvencionado por un fondo para la investigación de Boehringer-Ingelheim, pero la compañía no influyó en el análisis ni en la preparación del manuscrito.
Atmospheric Environment, 2014
ABSTRACT Indoor and outdoor PM2.5 sampling campaigns were carried out at Santiago, Chile (6 milli... more ABSTRACT Indoor and outdoor PM2.5 sampling campaigns were carried out at Santiago, Chile (6 million inhabitants, 33.5 degrees S, 70.6 degrees W) in spring 2012. A pair of samplers was placed inside each household studied and an additional pair of samplers was placed at a fixed outdoor location for measuring trace elements and elemental (EC) and organic carbon (OC) in Teflon and quartz filters, respectively. A total of 47 households in downtown Santiago were included in this study. Mean outdoor and indoor PM2.5 concentrations were 19.2 and 21.6 mu g/m(3), respectively. Indoor concentrations of PM2.5 were affected by socioeconomic status (p = 0.048) but no such evidence was found for PM2.5 species, except lead (p = 0.046). Estimated species infiltration factors were 0.70 (+/-0.19), 0.98 (+/-0.21), 0.80 (+/-0.12) and 0.80 (+/-0.03) for PM2.5, OC, EC and sulfur, respectively. Estimated household infiltration factors had a median of 0.75, mean of 0.78, standard deviation of 0.18 and interquartile range (IQR) 0.67-0.86. For the very first time, Positive Matrix Factorization (PMF3) was applied to an indoor PM2.5 chemical composition data set measured at Santiago. Source identification was carried out by inspection of key species and by comparison with published source profiles; six sources were identified. Three of them were outdoor contributions: motor vehicles with 5.6 (+/-0.7) mu g/m(3), street dust with 2.9 (+/-0.5) mu g/m(3) and secondary sulfates with 3.4 (+/-0.5) mu g/m(3). The indoor sources were: indoor dust with 1.6 (+/-0.3) mu g/m(3), cleaning and cooking with 2.3 (+/-03) mu g/m(3) and cooking and environmental tobacco smoke with 6.1 (+/-0.7) mu g/m(3). There is potential for further reducing PM2.5 population exposure in the short term -by improving ventilation of indoor air and controlling indoor sources - and in the long term - with filtration of outdoor air and household improvements to reduce air change rates.
The Lancet, 2005
Background Both the prevalence and mortality attributable to chronic obstructive pulmonary diseas... more Background Both the prevalence and mortality attributable to chronic obstructive pulmonary disease (COPD) seem to be increasing in low-income and middle-income countries, but few data are available. The aim of the PLATINO study, launched in 2002, was to describe the epidemiology of COPD in five major Latin American cities: São Paulo (Brazil), Santiago (Chile), Mexico City (Mexico), Montevideo (Uruguay), and Caracas (Venezuela). Methods A two-stage sampling strategy was used in the five areas to obtain probability samples of adults aged 40 years or older. These individuals were invited to answer a questionnaire and undergo anthropometry, followed by prebronchodilator and postbronchodilator spirometry. We defined COPD as a ratio less than 0•7 of postbronchodilator forced expiratory volume in the first second over forced vital capacity. Findings Complete information, including spirometry, was obtained from 963 people in São Paulo, 1173 in Santiago, 1000 in Mexico City, 885 in Montevideo, and 1294 in Caracas. Crude rates of COPD ranged from 7•8% (78 of 1000; 95% CI 5•9-9•7) in Mexico City to 19•7% (174 of 885; 17•2-22•2) in Montevideo. After adjustment for key risk factors, the prevalence of COPD in Mexico City remained significantly lower than that in other cities. Interpretation These results suggest that COPD is a greater health problem in Latin America than previously realised. Altitude may explain part of the difference in prevalence. Given the high rates of tobacco use in the region, increasing public awareness of the burden of COPD is important.
International Orthopaedics, 1998
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Papers by Gonzalo Alburqueque valdivia