Marcadores de funcionamiento renal en pacientes infectados por SARS-CoV-2. Revisión rápida de la literatura.

 Objetivo. Resumir la evidencia científica sobre las altera-ciones renales asociadas con la infección por SARS-CoV-2. Material y métodos. Se realizó una revisión rápida con la metodología Cochrane. Resultados. La enfermedad renal crónica (ERC) preexistente en pacientes con SARS-CoV-2 varió de 1 a 38% y la lesión renal aguda (LRA), de 2.9 a 86.4%. El pronóstico de la infección fue peor en pacientes con ERC y en aquellos con reserva renal remanente (RRR) intacta que desarrollaron LRA. El riesgo de muerte fue mayor (riesgo relativo combinado = 1.49; IC95%: 1.09-2.04) en pacientes infectados por SARS-CoV-2 con ERC preexistente. Los mar-cadores de RRR mostraron alteraciones en pacientes con SARS-CoV-2 graves y fatales; el marcador más utilizado fue la creatinina sérica. Conclusiones. La evidencia científica muestra la relevancia de la evaluación y monitoreo perma-nente de la RRR en pacientes hospitalizados por SARS-CoV-2 para mejorar el pronóstico de aquellos con ERC preexistente, así como de aquellos sin ERC que desarrollan LRA.

[Predictors of kidney function in a cohortof Mexican adults]. / Predictores de la función renal en una cohorte de adultos mexicanos.

OBJECTIVE: Our aim was to examine prospectively predictors of subclinical renal alterations among adults without chronic kidney disease. MATERIALS AND METHODS: We analyzed data from a cohort of Mexican adults (n=757). Kidney function (2010) was assessed with the estimated glomerular filtration rate (eGFR-Cr), serum creatinine and uric acid. Predictors of each kidney function marker (2004) were identified with linear and logistic regression models. RESULTS: 33% had an eGFR-Cr 40 years old and users of antihypertensive medication; and higher among those with a high protein intake. Serum creatinine predictors were similar to those observed for eGFR-Cr. Uric acid decreased in men, among those with obesity, hypertension and high cholesterol. CONCLUSIONS: Conventional kidney function biomarkers are useful to identify subclinical alterations. Some predictors of kidney function are potentially modifiable, therefore susceptible for intervention among high-risk groups.

OBJETIVO: Examinar prospectivamente los predictores de alteraciones subclínicas de la función renal en adultos sin diagnóstico previo de enfermedad renal crónica. MATERIAL Y MÉTODOS: Se analizaron datos de una cohorte de adultos mexicanos (n=757). La función renal (2010) se midió mediante la tasa de filtración glomerular estimada (TFGECr), creatinina y ácido úrico séricos. Los predictores (2004) se identificaron con modelos de regresión lineal y logística. RESULTADOS: Se clasificó 33% con TFGE-Cr disminuida.La TFGE-Cr fue menor en hombres, en >40 años y en usuarios de antihipertensivos; y fue mayor en aquellos con consumo proteico alto. Los predictores de la creatinina fueron similares a los de la TFGE-Cr. El ácido úrico disminuyó en participantes hombres, con obesidad, hipertensión e hipercolesterolemia. CONCLUSIONES: Los biomarcadores séricos convencionales son útiles para identificar alteraciones subclínicas de la función renal. Algunos predictores de la función renal son potencialmente modificables, por tanto susceptibles de intervención.

Patterns of beverage consumption and risk of CHD among Mexican adults.

CHD is becoming an increasing priority worldwide, as it is one of the main causes of death in low- and middle-income countries lately. This study aims to evaluate the association between beverage consumption patterns and the risk of CHD among Mexican adult population. We performed a cross-sectional analysis using data from 6640 adults participating in the Health Workers' Cohort Study. Factor analysis was performed to identify beverage patterns using sex-specific Framingham prediction algorithms to estimate CHD risk. The prevalence of moderate to high CHD risk was 17·8 %. We identified four major beverage consumption patterns, which were categorised as alcohol, coffee/tea, soft drinks and low-fat milk. We observed a lower risk of CHD (OR=0·61; 95 % CI 0·46, 0·80; and OR=0·58; 95 % CI 0·43, 0·79, respectively) among participants in the upper quintile of alcohol or low-fat milk consumption compared with those in the bottom quintile. In contrast, a higher consumption of soft drinks was positively associated with CHD risk (OR=1·64; 95 % CI 1·21, 2·20) when compared with other extreme quintiles. Finally, coffee/tea consumption was not significantly associated with CHD risk. Our findings suggest that a beverage pattern characterised by a higher intake of sugar-sweetened beverages may be associated with an increased risk of CHD among the Mexican adult population, whereas patterns of moderate alcohol intake and low-fat milk may be associated with a reduced risk.

Ventilatory efficiency response is unaffected by fitness level, ergometer type, age or body mass index in male athletes.

The aim of this study was to evaluate the ventilatory efficiency (V E/VCO2 slope) and the respiratory control (Vt/Ti slope) in a wide range of athletes and describe the influence of fitness level, age, ergometer type or BMI on these parameters. Ninety-one males (30.4±10.53 years; 175.52±7.45 cm; 71.99±9.35 kg) were analysed retrospectively for the study. Ventilatory efficiency reacted similarly in athletes independently of the fitness level, age, BMI or the ergometer used for testing. No significant differences were found in V E/VCO2 slope and the Vt/Ti slope between variables analyzed (P>0.05). The slope of the predictive equations was similar in all cases studied in V E/VCO2 slope and the Vt/Ti slope. Moreover, the central control impulse of respiration was not affected by the variables studied. These observations suggest that ventilatory efficiency (V E/VCO2 slope) could be a variable fixed by the respiratory system which tends to respond similarly in athletes.

Exercise Performance, Muscle Oxygen Extraction and Blood Cell Mitochondrial Respiration after Repeated-Sprint and Sprint Interval Training in Hypoxia: A Pilot Study.

This study aimed to investigate and compare the effects of repeated-sprint (RSH) and sprint interval training in hypoxia (SIH) on sea level running and cycling performance, and to elucidate potential common or divergent adaptations of muscle perfusion and -oxygenation as well as mitochondrial respiration of blood cells. Eleven team-sport athletes performed either RSH (3x5x10s, 20s and 5min recovery between repetitions and sets) or SIH (4x30s, 5min recovery) cycling training for 3weeks (3 times/week) at a simulated altitude of 2,200m. Before and three days after the training period, a Wingate and a repeated cycling sprint test (5x6s, 20s recovery) were performed with a 30min resting period between the tests. Four to five days after the training, participants performed a repeated running sprint test (RSA, 6x17m back and forth, 20s recovery) and a Yo-Yo intermittent recovery test (YYIR2) with 1 hour active recovery between tests. The order of the tests as well as the duration of the resting periods remained the same before and after the training period. During the cycling tests near-infrared spectroscopy was performed on the vastus lateralis. In four participants, mitochondrial respiration of peripheral blood mononuclear cells (PBMC) and platelets was measured before and after training. YYIR2 running distance increased by +96.7 ± 145.6 m after RSH and by +100.0 ± 51.6 m after SIH (p = 0.034, eta² = 0.449). RSA mean running time improved by -0.138 ± 0.14s and -0.107 ± 0.08s after RSH and SIH respectively (p = 0.012, eta² = 0.564). RSH compared to SIH improved re-oxygenation during repeated sprinting. Improvements in repeated cycling were associated with improvements in re-oxygenation (r = 0.707, p <0.05). Mitochondrial electron transfer capacity normalized per PBMC count was decreased in RSH only. This study showed that cycling RSH and SIH training improves sea-level running performance. Our preliminary results suggest that RSH and SIH training results in different patterns of muscular oxygen extraction and PBMC mitochondrial respiration, without effect on platelets respiration.

Influence of mealtime habits on the risk of weight gain and obesity in Mexican adults.

OBJECTIVE: To prospectively examine the extent to which mealtime habits influences the risk of weight gain and obesity in Mexican adults. DESIGN: We performed a prospective cohort study. The Mealtime Habits Quality (MHQ) scale was used for assessing participants' MHQ; the outcomes of interest were gain ≥5 % of body weight, developing overweight/obesity and abdominal obesity, after 7 years of follow-up. In order to estimate the independent effect of MHQ on anthropometric indicators, generalized linear models were computed to obtain adjusted relative risks (95 % CI). SETTING: The state of Morelos, Mexico. SUBJECTS: Mexican adults (n 837) aged 18-70 years participating in a cohort study. RESULTS: Compared with participants classified in the higher MHQ category, individuals in the middle and lower MHQ groups had a 4·1 (2·5, 6·7) and 6·2 (3·9, 9·7) fold greater risk of gain ≥5 % of body weight, respectively; 6·6 (2·8, 15·5) and 8·6 (3·7, 19·8) fold greater risk of becoming overweight/obese, respectively; and 3·8 (2·0, 7·3) and 5·3 (2·8, 9·8) fold greater risk of developing abdominal obesity, respectively. CONCLUSIONS: This study provides evidence about the influence of a set of mealtime habits on obesity indicators, showing that greater adherence to unadvisable mealtime habits increases the risk of developing unhealthy anthropometric indicators. Since the meal is one of the most important sources of food intake, and consequently weight status, the MHQ scale can be a useful population tool to predict weight gain and obesity.

Mealtime habits and risk of developing the metabolic syndrome or insulin resistance among Mexican adults.

Meals are an important source of food intake, contributing to body weight and health status. Previous studies have examined the relationship between isolated mealtime behaviours and the metabolic syndrome (MetS). The aim of this study was to examine the influence over time of ten interrelated mealtime habits on the risk of developing the MetS and insulin resistance (IR) among Mexican adults. We conducted a prospective cohort study with a sample of 956 health workers. The Mealtime Habits Quality (MHQ) scale is based on four mealtime situations (availability of time to eat, distractions while eating, environmental and social context of eating, and familiar or cultural eating habits), which were used to assess the participants' MHQ at the baseline (2004-2006) and follow-up (2010-2012) evaluations. The MetS was assessed using criteria from the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) and the International Diabetes Federation (IDF). IR was defined using the homoeostasis model assessment. Crude and adjusted relative risks were calculated to estimate the relationship between MHQ and the risk of developing the MetS or IR. Participants classified in the lower MHQ category had an 8·8 (95 % CI 3·1, 25) and 11·1 (95 % CI 3·4, 36·1) times greater risk of developing the MetS (using the NCEP-ATP III and IDF criteria, respectively), and an 11·2 times (95 % CI 3·9, 31·5) greater likelihood of developing IR, compared with those in the higher MHQ group. This prospective study reveals that individuals who engaged in more undesirable than recommended mealtime behaviours had a >10-fold risk of developing the MetS or IR.

Health workers cohort study: methods and study design.

OBJECTIVE:: To examine different health outcomes that are associated with specific lifestyle and genetic factors. MATERIALS AND METHODS:: From March 2004 to April 2006, a sample of employees from three different health and academic institutions, as well as their family members, were enrolled in the study after providing informed consent. At baseline and follow-up (2010-2013), participants completed a self-administered questionnaire, a physical examination, and provided blood samples. RESULTS:: A total of 10 729 participants aged 6 to 94 years were recruited at baseline. Of these, 70% were females, and 50% were from the Mexican Social Security Institute. Nearly 42% of the adults in the sample were overweight, while 20% were obese. CONCLUSION:: Our study can offer new insights into disease mechanisms and prevention through the analysis of risk factor information in a large sample of Mexicans.

Breathing Pattern Response after 6 Weeks of Inspiratory Muscle Training during Exercise.

(1) Background: The breathing pattern is defined as the relationship between the tidal volume (VT) and breathing frequency (BF) for a given VE. The aim of this study was to evaluate whether inspiratory muscle training influenced the response of the breathing pattern during an incremental effort in amateur cyclists. (2) Methods: Eighteen amateur cyclists completed an incremental test to exhaustion, and a gas analysis on a cycle ergometer and spirometry were conducted. Cyclists were randomly assigned to two groups (IMTG = 9; CON = 9). The IMTG completed 6 weeks of inspiratory muscle training (IMT) using a PowerBreathe K3® device at 50% of the maximum inspiratory pressure (Pimax). The workload was adjusted weekly. The CON did not carry out any inspiratory training during the experimental period. After the 6-week intervention, the cyclists repeated the incremental exercise test, and the gas analysis and spirometry were conducted. The response of the breathing pattern was evaluated during the incremental exercise test. (3) Results: The Pimax increased in the IMTG (p < 0.05; d = 3.1; +19.62%). Variables related to the breathing pattern response showed no differences between groups after the intervention (EXPvsCON; p > 0.05). Likewise, no differences in breathing pattern were found in the IMTG after training (PREvsPOST; p > 0.05). (4) Conclusions: IMT improved the strength of inspiratory muscles and sport performance in amateur cyclists. These changes were not attributed to alterations in the response of the breathing pattern.

Optimal Dose and Type of Physical Activity to Improve Glycemic Control in People Diagnosed With Type 2 Diabetes: A Systematic Review and Meta-analysis.

BACKGROUND: The optimal dose or type of physical activity to control glycosylated hemoglobin (HbA1c) in people with diabetes remains unknown. Current guidelines do not include consideration of baseline HbA1c for activity prescription. PURPOSE: To examine the dose-response relationship between physical activity and HbA1c (%) in individuals with type 2 diabetes. DATA SOURCES: A systematic search was performed in Embase, MEDLINE, Scopus, CINAHL, SPORTDiscus, and Web of Science. STUDY SELECTION: We included trials that involved participants diagnosed with type 2 diabetes that included any type of physical activity as intervention. DATA EXTRACTION: Pre- and postintervention HbA1c data, population and interventions characteristics, and descriptive statistics were collected to calculate change scores for each study arm. DATA SYNTHESIS: We used Bayesian random-effects meta-analyses to summarize high-quality evidence from 126 studies (6,718 participants). The optimal physical activity dose was 1,100 MET min/week, resulting in HbA1c reductions, ranging from -1.02% to -0.66% in severe uncontrolled diabetes, from -0.64% to -0.49% in uncontrolled diabetes, from -0.47% to -0.40% in controlled diabetes, and from -0.38% to -0.24% in prediabetes. LIMITATIONS: The time required to achieve these HbA1c reductions could not be estimated due to the heterogeneity between interventions' duration and protocols and the interpersonal variability of this outcome. CONCLUSIONS: The result of this meta-analysis provide key information about the optimal weekly dose of physical activity for people with diabetes with consideration of baseline HbA1c level, and the effectiveness of different types of active interventions. These results enable clinicians to prescribe tailored physical activity programs for this population.

Risk of recurrent Helicobacter pylori infection 1 year after initial eradication therapy in 7 Latin American communities.

IMPORTANCE: The long-term effectiveness of Helicobacter pylori eradication programs for preventing gastric cancer will depend on recurrence risk and individual and community factors. OBJECTIVE: To estimate risk of H. pylori recurrence and assess factors associated with successful eradication 1 year after treatment. DESIGN, SETTING, AND PARTICIPANTS: Cohort analysis of 1463 randomized trial participants aged 21 to 65 years from 7 Latin American communities, who were treated for H. pylori and observed between September 2009 and July 2011. INTERVENTIONS: Randomization to 1 of 3 treatment groups: 14-day lansoprazole, amoxicillin, and clarithromycin (triple therapy); 5-day lansoprazole and amoxicillin followed by 5-day lansoprazole, clarithromycin, and metronidazole (sequential); or 5-day lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant). Participants with a positive (13)C-urea breath test (UBT) 6 to 8 weeks posttreatment were offered voluntary re-treatment with 14-day bismuth-based quadruple therapy. MEASUREMENTS: Recurrent infection after a negative posttreatment UBT and factors associated with successful eradication at 1-year follow-up. RESULTS: Among participants with UBT-negative results who had a 1-year follow-up UBT (n=1091), 125 tested UBT positive, a recurrence risk of 11.5% (95% CI, 9.6%-13.5%). Recurrence was significantly associated with study site (P = .03), nonadherence to initial therapy (adjusted odds ratio [AOR], 2.94; 95% CI, 1.31-6.13; P = .01), and children in the household (AOR, 1.17; 95% CI, 1.01-1.35 per child; P = .03). Of the 281 with positive posttreatment UBT results, 138 completed re-treatment, of whom 93 tested UBT negative at 1 year. Among the 1340 who had a 1-year UBT, 80.4% (95% CI, 76.4%-83.9%), 79.8% (95% CI, 75.8%-83.5%), and 77.8% (95% CI, 73.6%-81.6%) had UBT-negative results in the triple, sequential, and concomitant groups, respectively (P = .61), with 79.3% overall effectiveness (95% CI, 77.1%-81.5%). In a single-treatment course analysis that ignored the effects of re-treatment, the percentage of UBT-negative results at 1 year was 72.4% (95% CI, 69.9%-74.8%) and was significantly associated with study site (P < .001), adherence to initial therapy (AOR, 0.26; 95% CI, 0.15-0.42; P < .001), male sex (AOR, 1.63; 95% CI, 1.25-2.13; P < .001), and age (AOR, 1.14; 95% CI, 1.02-1.27 per decade; P = .02). One-year effectiveness among all 1463 enrolled participants, considering all missing UBT results as positive, was 72.7% (95% CI, 70.3%-74.9%). CONCLUSIONS AND RELEVANCE: One year after treatment for H. pylori infection, recurrence occurred in 11.5% of participants who had negative posttreatment UBT results. Recurrence determinants (ie, nonadherence and demographics) may be as important as specific antibiotic regimen in determining the long-term success of H. pylori eradication interventions. Study findings are relevant to the feasibility of programs for the primary prevention of gastric cancer in high-incidence regions of Latin America. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01061437.

Trends of Antihypertensive, Antidiabetic, and Nonsteroidal Anti-Inflammatory Drugs Use among the Health Workers Cohort Study, Mexico 2004 to 2018.

Background: Hypertension and type 2 diabetes (T2D) are the most prevalent noncommunicable diseases in Mexico and worldwide. According to international practice management guidelines, the principal chronic management therapy is daily oral medication. Aim: We aim to describe the trends of antihypertensive, antidiabetic, and nonsteroidal anti-inflammatory (NSAID) drugs use among the Mexican adult population from 2004-2018. Methods: We analyzed data from the Health Workers Cohort Study (HWCS) for males and females aged >18 years. We calculated the prevalence of chronic diseases and utilization for every kind of antihypertensive, antidiabetic, and NSAIDs (measured by self-reported utilization) at baseline and two follow-ups (2004, 2010, and 2017). Trends were analyzed using Fisher's exact test. Results: Hypertension prevalence increased from 19.8 to 30.3%, higher than T2D prevalence from 7.0 to 12.8% through fourteen years of follow-up. Like the self-reported dual therapy, the proportion of patients using beta-blockers and angiotensin II receptor blockers increased. Regarding T2D, the prevalence of metformin utilization increased to 83.9%. The utilization of common NSAIDs, mainly for muscular pain, remained around 13 to 16%. Conclusions: Our findings showed a changing prevalence of drug utilization for hypertension and T2D between 2004 and 2018 and consistent use of NSAIDs in the adult Mexican population.

14-day triple, 5-day concomitant, and 10-day sequential therapies for Helicobacter pylori infection in seven Latin American sites: a randomised trial.

BACKGROUND: Evidence from Europe, Asia, and North America suggests that standard three-drug regimens of a proton-pump inhibitor plus amoxicillin and clarithromycin are significantly less effective for eradication of Helicobacter pylori infection than are 5-day concomitant and 10-day sequential four-drug regimens that include a nitroimidazole. These four-drug regimens also entail fewer antibiotic doses than do three-drug regimens and thus could be suitable for eradication programmes in low-resource settings. Few studies in Latin America have been done, where the burden of H pylori-associated diseases is high. We therefore did a randomised trial in Latin America comparing the effectiveness of four-drug regimens given concomitantly or sequentially with that of a standard 14-day regimen of triple therapy. METHODS: Between September, 2009, and June, 2010, we did a randomised trial of empiric 14-day triple, 5-day concomitant, and 10-day sequential therapies for H pylori in seven Latin American sites: Chile, Colombia, Costa Rica, Honduras, Nicaragua, and Mexico (two sites). Participants aged 21-65 years who tested positive for H pylori by a urea breath test were randomly assigned by a central computer using a dynamic balancing procedure to: 14 days of lansoprazole, amoxicillin, and clarithromycin (standard therapy); 5 days of lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant therapy); or 5 days of lansoprazole and amoxicillin followed by 5 days of lansoprazole, clarithromycin, and metronidazole (sequential therapy). Eradication was assessed by urea breath test 6-8 weeks after randomisation. The trial was not masked. Our primary outcome was probablity of H pylori eradication. Our analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, registration number NCT01061437. FINDINGS: 1463 participants aged 21-65 years were randomly allocated a treatment: 488 were treated with 14-day standard therapy, 489 with 5-day concomitant therapy, and 486 with 10-day sequential therapy. The probability of eradication with standard therapy was 82·2% (401 of 488), which was 8·6% higher (95% adjusted CI 2·6-14·5) than with concomitant therapy (73·6% [360 of 489]) and 5·6% higher (-0·04% to 11·6) than with sequential therapy (76·5% [372 of 486]). Neither four-drug regimen was significantly better than standard triple therapy in any of the seven sites. INTERPRETATION: Standard 14-day triple-drug therapy is preferable to 5-day concomitant or 10-day sequential four-drug regimens as empiric therapy for H pylori infection in diverse Latin American populations. FUNDING: Bill & Melinda Gates Foundation, US National Institutes of Health.

[Genetic epidemiology research designs]. / Diseños de investigación en epidemiología genética.

This article describes the features of the epidemiologic research designs most commonly used in genetic association studies. Case-control studies are efficient in evaluating associations between candidate genes and disease. Cohort studies, in contrast, yield a greater degree of causality but are not efficient for the initial exploration to identify gene-disease associations. Cross-sectional studies are less expensive, require less time, and are useful for estimating the prevalence of diseases, risk factors, and genetic variants. Family-based studies have been successful in finding alleles that confer greater risk for developing Mendelian inheritance disorders.

Cancer survivor inspiratory muscle training: systematic review and Bayesian meta-analysis.

BACKGROUND: The long-term impact of cancer treatment is associated with respiratory dysfunction and physical fitness impairment. Although inspiratory muscle training (IMT) has been shown as an effective exercise therapy in cancer survivors, there is no evidence on the optimal dose, application moment nor specific population effects of this intervention. The main objective of this meta-analysis is to analyse the effects of IMT on pulmonary function, physical fitness and quality of life (QoL) in cancer survivors. METHODS: This systematic review and meta-analysis was preregistered in the International Prospective Register of Systematic Reviews (PROSPERO) register and conducted according to the Preferred Reporting for Systematic Reviews and Meta-analysis statement. We used a Bayesian multilevel random-effects meta-analysis model to pool the data. Multilevel metaregression models were used to examine the conditional effects of our covariates. Convergence and model fit were evaluated through specific model parameters. Sensitivity analyses removing influential cases and using a frequentist approach were carried out. RESULTS: Pooled data showed that IMT intervention is effective to improve pulmonary function (standardised mean difference=0.53, 95% credible interval 0.13 to 0.94, SE=0.19). However, IMT did not present statistically significant results on physical fitness and QoL. Metaregression analyses found that the type of cancer, the moment of application and the evaluation tool used had significant moderation effects on pulmonary function. CONCLUSION: IMT could be an important part in the management of side effects suffered by cancer survivors. Considering the current evidence, this intervention is highly recommended in patients diagnosed with oesophageal and lung cancers. IMT may provide superior benefits before the biological treatment and after the surgery. PROSPERO REGISTRATION NUMBER: 304909.

Exposure to the pesticide DDT and risk of diabetes and hypertension: Systematic review and meta-analysis of prospective studies.

BACKGROUND: Experimental evidence suggests that p,p'-DDE might be involved in the development of diabetes and hypertension (HTN); however, the evidence in humans is inconclusive. OBJECTIVE: To summarize the epidemiological evidence for the association of p,p'-DDT exposure and its breakdown products with the risk of diabetes and HTN from prospective studies. METHODS: We performed a systematic review and meta-analysis based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Eligible studies (prospective) were search in PubMed, Web of Science, EBSCO, and SciELO databases (July 11, 2020). Different search algorithms were used for diabetes and HTN. Pooled odds ratios (ORs) were estimated from meta-analysis with random effects for each exposure and outcome. RESULTS: A total of 23 prospective studies were included in this review, 16 assessed diabetes and seven HTN; very few measured p,p'-DDT. Exposure to p,p'-DDE was associated with a slightly increased risk of type 2 diabetes (T2D) (pooled OR = 1.44; 95%CI: 1.00, 2.07; p = 0.049) and HTN (pooled OR = 1.21; 95%CI: 1.07, 1.38). Dose-response meta-analysis suggested a non-linear relation between p,p'-DDE and T2D. Exposure to p,p'-DDE was not associated with gestational diabetes (pooled OR = 1.01; 95%CI: 0.94, 1.09); similarly, p,p'-DDT was not associated with T2D (pooled OR = 1.03; 95%CI: 0.79, 1.35). CONCLUSIONS: Evidence from prospective studies suggests that exposure to p,p'-DDE, the main breakdown product of p,p'-DDT, might increase the risk of developing T2D; such increase may be apparent only at low levels. Exposure to p,p'-DDE may also increase the risk of having HTN; however, further evidence is required.

[Intimate partner violence and depression among adult women working in a health facility in Mexico]. / Violencia de pareja y depresión en mujeres que trabajan en una institución de salud de México.

OBJECTIVE: To assess the effect of intimate partner violence on the risk of depression and depressive symptoms among adult women. METHOD: We analyzed data from the Mexican Health Workers' Cohort study (n=470). Type and severity of intimate partner violence was ascertained between 2004 and 2011. Self-reported medical diagnosis of depression (2011) was the main outcome; depressive symptoms ascertained with the Centre for Epidemiologic Studies-Depression (CES-D) scale was the secondary outcome. Random-effects regressions were run to model the risk of depression (logistic) and depressive symptoms (linear) in relation to intimate partner violence. RESULTS: 41.9% women experienced intimate partner violence at baseline. The incidence of depression was 7.2%. The risk of depression increased with any type of IPV (adjusted odds ratio [aOR]=2.9; 95% confidence interval [95%CI]: 1.4-6.2) and with physical (aOR=4.3; 95%CI: 1.8-10.1), psychological (aOR=3.1; 95%CI: 1.4-6.6) and sexual (aOR=3.1; 95%CI: 1.2-8.2) violence. Depressive symptoms (CES-D) increased slightly with physical and sexual intimate partner violence. CONCLUSIONS: Intimate partner violence was associated with a higher risk of depression in this sample of women working in a Mexican health facility. Our results indicate the need to develop infrastructure, to implement strategies of attention and counselling, and to provide a safe environment in the workplace for women who experience intimate partner violence.

The Second Wind in McArdle Patients: Fitness Matters.

Background: The "second wind" (SW) phenomenon-commonly referring to both an initial period of marked intolerance to dynamic exercise (e.g., brisk walking) that is not followed by perceived improvement and disappearance of previous tachycardia (i.e., the actual "SW") until 6-10 min has elapsed-is an almost unique feature of McArdle disease that limits adherence to an active lifestyle. In this regard, an increase in the workload eliciting the SW could potentially translate into an improved patients' exercise tolerance in daily life. We aimed to determine whether aerobic fitness and physical activity (PA) levels are correlated with the minimum workload eliciting the SW in McArdle patients-as well as with the corresponding heart rate value. We also compared the SW variables and aerobic fitness indicators in inactive vs. active patients. Methods: Fifty-four McArdle patients (24 women, mean ± SD age 33 ± 12 years) performed 12-min constant-load and maximum ramp-like cycle-ergometer tests for SW detection and aerobic fitness [peak oxygen uptake (VO2 peak) and workload and ventilatory threshold] determination, respectively. They were categorized as physically active/inactive during the prior 6 months (active = reporting ≥150 min/week or ≥75 min/week in moderate or vigorous-intensity aerobic PA, respectively) and were also asked on their self-report of the SW. Results: Both peak and submaximal indicators of aerobic fitness obtained in the ramp tests were significantly correlated with the workload of the SW test, with a particularly strong correlation for the VO2 peak and peak workload attained by the patients (both Pearson's coefficients > 0.70). Twenty (seven women) and 24 patients (18 women) were categorized as physically active and inactive, respectively. Not only the aerobic fitness level [∼18-19% higher values of VO2 peak (ml⋅kg-1⋅min-1)] but also the workload of the SW tests was significantly higher in active than in inactive patients. All the inactive patients reported that they experienced the SW during walking/brisk walking in daily life, whereas active patients only reported experiencing this phenomenon during more strenuous activities (very brisk walking/jogging and bicycling). Conclusion: A higher aerobic fitness and an active lifestyle are associated with a higher workload eliciting the so-called SW phenomenon in patients with McArdle disease, which has a positive impact on their exercise tolerance during daily living.

[Case crossover studies: a conceptual and methodological approach]. / Estudio epidemiológico de casos y autocontroles: una aproximación conceptual y metodológica.

Case crossover studies are considered as a variant of case control studies, and they have been included in the scientific literature since approximately eighteen years ago. They have also been used in epidemiological research on acute or intermittent exposures that may lead to a number of events including heart attack or cardiac arrest, injuries, asthma, etc. Application of this particular study design requires defining concepts such as: triggers, induction time, case period and control period. Its use is limited in studies on chronic exposures. On the other hand, this type of design may reduce selection and misclassification bias, confounding, and overmatching. Another advantage is that it requires a small sample size because the same case can be used as its own control in one or several periods. Nevertheless, sample size calculation must be assessed as a matched case-control study. This is a type of study in which theoretical principles are accomplished in a sui generis manner.

Body mass index associated with elevated blood pressure in Mexican school-aged adolescents.

OBJECTIVE: To evaluate the relationship between blood pressure and body mass index among adolescents. METHODS: A 14-month period cross-sectional study was carried out among 2387 adolescents attending public schools in the state of Morelos, Mexico between 2005 and 2007. We measured blood pressure during four visits, obtaining elevated blood pressure prevalence according to the guidelines for children and adolescents of the United States National Educational Program on High Blood Pressure (at least three visits needed to assess elevated blood pressure on the basis of 95th percentile specific for gender, age and height). We used specific body mass index percentiles for age and gender. We employed multiple linear and Cox proportional hazards models to identify factors related to elevated blood pressure. RESULTS: The overall prevalence of elevated blood pressure was 3.9%. Multiple linear models showed that overweight subjects had systolic and diastolic blood pressures that were 5.1 and 2.5 mmHg higher, respectively, compared with adolescents with a normal body mass index, while obese subjects had 11.3 and 6.2 mmHg higher levels, respectively. Cox proportional hazards models indicated high risk of elevated blood pressure among overweight (RR, 3.6; 95%CI, 1.5-8.5) and obese subjects (RR, 14.2; 95%CI, 7.2-27.75) compared with adolescents with a normal body mass index. CONCLUSION: Our results suggest that a higher body mass index is associated with elevated systolic and diastolic blood pressure levels, indicating the importance of incorporating strategies for ongoing screening and for promoting educational programs on healthy lifestyles to prevent hypertension in adolescents.