Víctor Herrera

Major Cardiovascular Risk Factors in Latin America: A Comparison with the United States. The Latin American Consortium of Studies in Obesity (LASO)

Background Limited knowledge on the prevalence and distribution of risk factors impairs the planning and implementation of cardiovascular prevention programs in the Latin American and Caribbean (LAC) region. Methods and Findings Prevalence of hypertension, diabetes mellitus, abnormal lipoprotein levels, obesity, and smoking were estimated from individual-level patient data pooled from population-based surveys (1998–2007, n = 31,009) from eight LAC countries and from a national survey of the United States (US) population (1999–2004) Age and gender specific prevalence were estimated and age-gender adjusted comparisons between both populations were conducted. Prevalence of diabetes mellitus, hypertension, and low high-density lipoprotein (HDL)-cholesterol in LAC were 5% (95% confidence interval [95% CI]: 3.4, 7.9), 20.2% (95% CI: 12.5, 31), and 53.3% (95% CI: 47, 63.4), respectively. Compared to LAC region’s average, the prevalence of each risk factor tended to be lower in Peru and higher in Chile. LAC women had higher prevalence of obesity and low HDL-cholesterol than men. Obesity, hypercholesterolemia, and hypertriglyceridemia were more prevalent in the US population than in LAC population (31 vs. 16.1%, 16.8 vs. 8.9%, and 36.2 vs. 26.5%, respectively). However, the prevalence of low HDL-cholesterol was higher in LAC than in the US (53.3 vs. 33.7%). Conclusions Major cardiovascular risk factors are highly prevalent in LAC region, in particular low HDL-cholesterol. In addition, marked differences do exist in this prevalence profile between LAC and the US. The observed patterns of obesity-related risk factors and their current and future impact on the burden of cardiovascular diseases remain to be explained.

Interethnic differences in the accuracy of anthropometric indicators of obesity in screening for high risk of coronary heart disease

Background:Cut points for defining obesity have been derived from mortality data among Whites from Europe and the United States and their accuracy to screen for high risk of coronary heart disease (CHD) in other ethnic groups has been questioned.Objective:To compare the accuracy and to define ethnic and gender-specific optimal cut points for body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) when they are used in screening for high risk of CHD in the Latin-American and the US populations.Methods:We estimated the accuracy and optimal cut points for BMI, WC and WHR to screen for CHD risk in Latin Americans (n=18 976), non-Hispanic Whites (Whites; n=8956), non-Hispanic Blacks (Blacks; n=5205) and Hispanics (n=5803). High risk of CHD was defined as a 10-year risk ⩾20% (Framingham equation). The area under the receiver operator characteristic curve (AUC) and the misclassification-cost term were used to assess accuracy and to identify optimal cut points.Results:WHR had the highest AUC in all ethnic groups (from 0.75 to 0.82) and BMI had the lowest (from 0.50 to 0.59). Optimal cut point for BMI was similar across ethnic/gender groups (27 kg/m2). In women, cut points for WC (94 cm) and WHR (0.91) were consistent by ethnicity. In men, cut points for WC and WHR varied significantly with ethnicity: from 91 cm in Latin Americans to 102 cm in Whites, and from 0.94 in Latin Americans to 0.99 in Hispanics, respectively.Conclusion:WHR is the most accurate anthropometric indicator to screen for high risk of CHD, whereas BMI is almost uninformative. The same BMI cut point should be used in all men and women. Unique cut points for WC and WHR should be used in all women, but ethnic-specific cut points seem warranted among men.

The Latin American Consortium of Studies in Obesity (LASO).

Current, high‐quality data are needed to evaluate the health impact of the epidemic of obesity in Latin America. The Latin American Consortium of Studies of Obesity (LASO) has been established, with the objectives of (i) Accurately estimating the prevalence of obesity and its distribution by sociodemographic characteristics; (ii) Identifying ethnic, socioeconomic and behavioural determinants of obesity; (iii) Estimating the association between various anthropometric indicators or obesity and major cardiovascular risk factors and (iv) Quantifying the validity of standard definitions of the various indexes of obesity in Latin American population. To achieve these objectives, LASO makes use of individual data from existing studies. To date, the LASO consortium includes data from 11 studies from eight countries (Argentina, Chile, Colombia, Costa Rica, Dominican Republic, Peru, Puerto Rico and Venezuela), including a total of 32 462 subjects. This article describes the overall organization of LASO, the individual studies involved and the overall strategy for data analysis. LASO will foster the development of collaborative obesity research among Latin American investigators. More important, results from LASO will be instrumental to inform health policies aiming to curtail the epidemic of obesity in the region.

The trajectory of IGF-1 across age and duration of type 1 diabetes.

Individuals with type 1 diabetes may have low IGF‐1, related to insulinopenia and insulin resistance. There are few longitudinal studies of IGF‐1 levels to establish its pattern in type 1 diabetes with duration and age, and to examine whether IGF‐1 tracks within individuals over time. We examine age and duration trends, and the relationship of IGF‐1 to gender, glycaemic control, insulin level and other factors.

The association of tobacco control policies and the risk of acute myocardial infarction using hospital admissions data.

Objective To evaluate the association of a nationwide comprehensive smoking ban (CSB) and tobacco tax increase (TTI) on the risk of acute myocardial infarctions (AMI) in Panama for the period of 2006 – 2010 using hospital admissions data. Methods Data of AMI cases was gathered from public and private hospitals in the country for the period of January 1, 2006 to December 31, 2010. The number of AMI cases was calculated on a monthly basis. The risk of AMI was estimated for the pre-CSB period (January 2006 to April 2008) and was used as a reference point. Three post-intervention periods were examined: (1) post-CSB from May 2008 to April 2009 (12 months); (2) post-CSB from May 2009 to November 2009 (7 months); and (3) post-TTI from December 2009 to December 2010 (13 months). Relative risks (RR) of AMI were estimated for each post intervention periods by using a Poisson regression model. Mortality registries for the country attributed to myocardial infarction (MI) were obtained from January 2001 to December 2012. The annual percentage change (APC) of the number of deaths from MI was calculated using Joinpoint regression analysis. Results A total sample size of 2191 AMI cases was selected (monthly mean number of cases 36.52±8.24 SD). Using the pre-CSB as a reference point (RR = 1.00), the relative risk of AMI during the first CSB period, the second CSB period and post-TTI were 0.982, 1.049, and 0.985, respectively. The APC of deaths from MI from January 2001 to April 2008 was 0.5%. From January 2001 to June 2010 the APC trend was 0.47% and from July 2010 to December 2012 the APC was –0.3%. Conclusions The implementation of a CSB and TTI in Panama were associated with a decrease in tobacco consumption and a reduction of the RR of AMI.

Assessment of the Possible Association of Air Pollutants PM10, O3, NO2 With an Increase in Cardiovascular, Respiratory, and Diabetes Mortality in Panama City: A 2003 to 2013 Data Analysis

AbstractIn recent years, Panama has experienced a marked economic growth, and this, in turn, has been associated with rapid urban development and degradation of air quality. This study is the first evaluation done in Panama on the association between air pollution and mortality. Our objective was to assess the possible association between monthly levels of PM10, O3, and NO2, and cardiovascular, respiratory, and diabetes mortality, as well as the seasonal variation of mortality in Panama City, Panama.The study was conducted in Panama City, using air pollution data from January 2003 to December 2013. We utilized a Poisson regression model based on generalized linear models, to evaluate the association between PM10, NO2, and O3 exposure and mortality from diabetes, cardiovascular, and respiratory diseases. The sample size for PM10, NO2, and O2 was 132, 132, and 108 monthly averages, respectively.We found that levels of PM10, O3, and NO2 were associated with increases in cardiovascular, respiratory, and diabetes mortality. For PM10 levels ≥ 40 &mgr;g/m3, we found an increase in cardiovascular mortality of 9.7% (CI 5.8–13.6%), and an increase of 12.6% (CI 0.2–24.2%) in respiratory mortality. For O3 levels ≥ 20 &mgr;g/m3 we found an increase of 32.4% (IC 14.6–52.9) in respiratory mortality, after a 2-month lag period following exposure in the 65 to <74 year-old age group. For NO2 levels ≥20 &mgr;g/m3 we found an increase in respiratory mortality of 11.2% (IC 1.9–21.3), after a 2-month lag period following exposure among those aged between 65 and <74 years.There could be an association between the air pollution in Panama City and an increase in cardiovascular, respiratory, and diabetes mortality. This study confirms the urgent need to improve the measurement frequency of air pollutants in Panama.

Temporal variation of Trypanosoma cruzi discrete typing units in asymptomatic Chagas disease patients

Chagas disease caused by Trypanosoma cruzi is a public health problem in Latin America. This parasite displays a high genetic diversity evidenced in six Discrete Typing Units (DTUs) namely TcI-TcVI. The aim of this study was to observe the temporal variation of the DTUs in asymptomatic patients at three different times (10 days interval). The results showed that intermittence is the rule in the bloodstream of Chagas disease patients. The patients showed different detectable DTUs with short time intervals, which favors the clonal histiotropic model and the multiclonality structure of this parasite.

Sociodemographic factors related to handgrip strength in children and adolescents in a middle income country: The SALUS study

To determine sociodemographic factors associated with handgrip (HG) strength in a representative sample of children and adolescents from a middle income country.

Vitamin D deficiency and pre-eclampsia in Colombia: PREVitD study

PURPOSE Pre-eclampsia is a multisystem disorder characterized by new-onset hypertension and proteinuria during pregnancy. Pre-eclampsia remains a major cause of maternal death in low-income countries. Vitamin D has a very diverse biological role in cardiovascular diseases. This study will evaluate the association of vitamin D levels and relevance to pre-eclampsia. METHODS We conducted a case-control study of women recruited from the GenPE (Genetics and Pre-eclampsia) Colombian registry. This is a multicenter case-control study conducted in eight Colombian cities. 25-Hydroxyvitamin D (25(OH)D) concentration was measured using liquid-chromatography-tandem mass spectrometry from 1013 women with pre-eclampsia and 1015 mothers without pre-eclampsia (controls). RESULTS Fifty-two percent of women with pre-eclampsia were vitamin D deficient. The 25(OH)D concentrations were significantly lower in the pre-eclampsia (mean 29.99 ng/mL; 95% CI: 29.40-30.58 ng/mL) group compared to controls (mean 33.7 ng/mL; 95% CI: 33.20-34.30 ng/mL). In the unadjusted model, maternal vitamin D deficiency, defined by maternal 25(OH)D concentration <30 ng/mL, was associated with an increased probability of suffering from pre-eclampsia (OR 2.10; 95% CI, 1.75-2.51). After adjusting for covariates, a similarly increased probability of having pre-eclampsia was observed (OR 2.18; 95% CI, 1.80-2.64) among women with vitamin D deficiency, relative to controls. CONCLUSION Although the results suggest that low maternal concentrations of 25(OH)D increase pre-eclampsia risk, this evidence may not be indicative of a causal association. Future studies are needed to confirm a definite causal relationship between concentrations of vitamin D and the risk of pre-eclampsia, by means of powered clinical trials.

An assessment of public health surveillance of Zika virus infection and potentially associated outcomes in Latin America

BackgroundWe evaluated whether outbreaks of Zika virus (ZIKV) infection, newborn microcephaly, and Guillain-Barré syndrome (GBS) in Latin America may be detected through current surveillance systems, and how cases detected through surveillance may increase health care burden.MethodsWe estimated the sensitivity and specificity of surveillance case definitions using published data. We assumed a 10% ZIKV infection risk during a non-outbreak period and hypothetical increases in risk during an outbreak period. We used sensitivity and specificity estimates to correct for non-differential misclassification, and calculated a misclassification-corrected relative risk comparing both periods. To identify the smallest hypothetical increase in risk resulting in a detectable outbreak we compared the misclassification-corrected relative risk to the relative risk corresponding to the upper limit of the endemic channel (mean + 2 SD). We also estimated the proportion of false positive cases detected during the outbreak. We followed the same approach for microcephaly and GBS, but assumed the risk of ZIKV infection doubled during the outbreak, and ZIKV infection increased the risk of both diseases.ResultsZIKV infection outbreaks were not detectable through non-serological surveillance. Outbreaks were detectable through serologic surveillance if infection risk increased by at least 10%, but more than 50% of all cases were false positive. Outbreaks of severe microcephaly were detected if ZIKV infection increased prevalence of this condition by at least 24.0 times. When ZIKV infection did not increase the prevalence of severe microcephaly, 34.7 to 82.5% of all cases were false positive, depending on diagnostic accuracy. GBS outbreaks were detected if ZIKV infection increased the GBS risk by at least seven times. For optimal GBS diagnosis accuracy, the proportion of false positive cases ranged from 29 to 54% and from 45 to 56% depending on the incidence of GBS mimics.ConclusionsCurrent surveillance systems have a low probability of detecting outbreaks of ZIKV infection, severe microcephaly, and GBS, and could result in significant increases in health care burden, due to the detection of large numbers of false positive cases. In view of these limitations, Latin American countries should consider alternative options for surveillance.