Association Between Changes in Sleep, Nap Duration and Bone Mineral Density in Mexican Adults

Studies have found associations between sleep, nap duration, and bone mineral density (BMD). However, the longitudinal relationship between sleep, nap duration, and BMD has not been explored. We evaluated the association between the change in sleep and nap duration and BMD in Mexican adults. Data come from 1,337 adult participants of the Health Workers Cohort Study (341 were men and 996 were women, including 450 women < 45 years old and 546 ≥ 45 years old), with two study waves. At each wave, sleep and nap duration was assessed using self-administered questionnaires and BMD in g/cm2 was determined by dual X-ray absorptiometry. We used fixed-effect regression models stratified by sex and adjusted for BMI, diet, physical activity, vitamin supplements, and hormone replacement therapy. Women who changed from < 7 to ≥ 7 h/day of sleep from baseline to follow-up were associated with increases in the total hip (β = 0.012 g/cm2; 95% CI: 0.002, 0.022) and lumbar spine BMD (β = 0.024 g/cm2; 95% CI: 0.009, 0.039). Furthermore, most of these associations were observed in women ≥ 45 years. For women, a changing from 0 to > 60 min/day of napping was associated with a significant increase in total hip BMD of 0.012 g/cm2 (95% CI: 0.004, 0.024) and lumbar spine BMD of 0.027 g/cm2 (95% CI: 0.009, 0.045). No significant associations were observed for men. Our results suggest that increased sleep and nap duration are associated with gains in BMD in Mexican women, emphasizing sleep's role in promoting bone health and supporting established recommendations.

Outbreak of Fusarium solani Meningitis in Immunocompetent Persons Associated With Neuraxial Blockade in Durango, Mexico, 2022-2023

Background

Fungal meningitis can be associated with epidural anesthesia procedures. Fusariosis is a rare infection typically affecting immunocompromised patients and rarely causes meningitis. During 2022-2023, public health officials responded to a large outbreak of Fusarium solani meningitis associated with epidural anesthesia in Durango, Mexico.

Methods

The public health response and epidemiological and clinical features of patients affected by this outbreak were described. Coordinated actions were addressed to identify the etiological agent, determine its drug susceptibility, develop diagnostic tests, and implement clinical and epidemiological protocols. Retrospective analyses of clinical variables and outcomes were performed to determine association with better patient survival.

Results

A total of 1801 persons exposed to epidural anesthesia were identified, of whom 80 developed meningitis. Fusarium solani was found in 3 brain biopsies and showed susceptibility to voriconazole and amphotericin B. After F solani polymerase chain reaction (PCR) implementation, 57 patients with meningitis were PCR-screened, and 31 (38.8%) had a positive result. Most patients were female (95%), and cesarean section was the most common surgical procedure (76.3%). The case fatality rate was 51.3% (41 patients) and the median hospitalization duration was 39.5 days (interquartile range, 18-86 days). Seventy-one patients (88.8%) received voriconazole/amphotericin B and 64 subjects (80%) additionally received steroids. Cox regression analysis showed an increased lethality risk in patients who received antifungal treatment after 5 days (hazard ratio, 2.1 [95% confidence interval, 1.01-4.48], P < .05).

Conclusions

The F solani meningitis outbreak in Durango was an unprecedented medical challenge. Timely treatment and effective healthcare management were associated with better survival outcomes.

[The track of the clinical researcher]

In this issue, the students of the Maestría en Ciencias de la Salud Program, who are generally doctors, publish their work in the format of architectural design. The architectural design, allows to demonstrate in a schematic way, the objective, basal state, maneuver and outcome of their investigations. In this issue of the Revista Médica del IMSS, architectural design is used explicitly for the first time in a scientific publication. This innovation was achieved thanks to the collaboration of the editors and students of the Maestría en Ciencias de la Salud Program.

[ROC curves: general characteristics and their usefulness in clinical practice]

The use of diagnostic tests to determine the presence or absence of a disease is essential in clinical practice. The results of a diagnostic test may correspond to numerical estimates that require quantitative reference parameters to be transferred to a dichotomous interpretation as normal or abnormal and thus implement actions for the care of a condition or disease. For example, in the diagnosis of anemia it is necessary to define a cut-off point for the hemoglobin variable and create two categories that distinguish the presence or absence of anemia. The method used for this process is the preparation of diagnostic performance curves, better known by their acronym in English as ROC (Receiver Operating Characteristic). The ROC curve is also useful as a prognostic marker, since it allows defining the cut-off point of a quantitative variable that is associated with greater mortality or risk of complications. They have been used in different prognostic markers in COVID-19, such as the neutrophil/lymphocyte ratio and D-dimer, in which cut-off points associated with mortality and/or risk of mechanical ventilation were identified. The ROC curve is used to evaluate the diagnostic performance of a test in isolation, but it can also be used to compare the performance of two or more diagnostic tests and define which one is more accurate. This article describes the basic concepts for the use and interpretation of the ROC curve, the interpretation of an area under the curve (AUC) and the comparison of two or more diagnostic tests.

[Factors associated with benzodiazepines dependence in insomnia patients]

Background

The use of benzodiazepines as a treatment for insomnia can have side effects such as impaired coordination causing falls in adults and even dependence.

Objective

To assess the factors associated with dependence on benzodiazepines in patients with insomnia.

Methods

Observational, cross-sectional, prospective, and analytical study, at the first level of care. Patients older than 18 years with a diagnosis of insomnia and a benzodiazepine prescription were selected. The dependency was measured with the International Neuropsychiatric Interview.

Results

107 patients were included. Median age 67 years, predominantly female (72%), 74% attended secondary school or more, 71% had more than 3 years of diagnosis, 84% used clonazepam. The 54% presented dependency. In the bivariate analysis, schooling RM 0.392 (95%CI: 0.15-0.96) p = 0.038, moderate and severe clinical insomnia RM 3.618 (95%CI: 1.44-9.08) p = 0.005 and more than 3 years of diagnosis RM 2.428 (95%CI: 1.03-5.71) p = 0.040. In the multivariate model, schooling (p = 0.084), years of diagnosis (p = 0.062) and frequency of consumption (p = 0.065) obtained an R2 of 0.13.

Conclusions

Primary schooling showed a lower risk of presenting dependence on benzodiazepines. The risk was increased in those with more than 3 years of diagnosis, and in those with moderate and severe insomnia.

[Impact of attend to day care associated with healthy weight in infants and preschoolers]

Background

Being overweight affects millions of infants and preschoolers in the world, affecting their quality and life expectancy. Exposure to day care centers may play an important role in preventing unhealthy weight (UW).

Objective

To point out the prevalence and association of day care exposure and other factors associated with UW in infants and preschoolers.

Methods

An analytical cross-sectional study was carried out. Infant population aged 6-47 months without comorbidities that compromised their nutritional status were included, and those with formal childcare different from the selected day care were excluded. Exposure to day care, and other factors (perinatal, physical activity, nutritional, and familiar) were evaluated. A z score > 1 SD was considered UW. Prevalence, odds ratios (OR), 95% confidence intervals (95%CI) and adjusted RM by low birth weight, initiation of complementary feeding, consumption of sugary drinks, daytime naps, maternal nutritional status, and family income quintile through logistic regression.

Results

The overall prevalence of UW was 17.84% (95%CI: 14.93-21.16), 11.84 (95%CI: 8.54-16.14) for children exposed to day care, and 23.78% (95%CI: 19.21-29.02) in unexposed infant population, showing significant differences between both prevalences (p < 0.001). The adjusted OR for UW presentation was 0.39 (95% CI: 0.23-0.66).

Conclusions

Exposure to IMSS day care has shown to be a possible protective environment against the development of a UW.

[Numerical expression of the clinical course of the disease. Data management]

Data management "behind the scenes" refers to collection, cleaning, imputation, and demarcation; and despite of being indispensable processes, they are usually neglected and thus, generate erroneous information. During the collection are errors: omission of covariates, deviation from the objective, and insufficient quality. The omission of covariates distorts the result attributed to the main manoeuvre. Deviation from the primary objective commonly occurs when the outcome is rare, delayed, or subjective and promotes substitution by non-equivalent surrogate variables. Moreover, insufficient quality occurs due to inadequate instruments, omission of the measurement procedure, or measurements out of context, such as attribution at the wrong time or equivalent. Furthermore, cleaning implies identifying erroneous, extreme, and missing values, which may or may not be imputed, depending on the percentage. The values of the manoeuvre or the outcome are never imputed, nor are patients eliminated due to a lack of values. Finally, the demarcation of each variable seeks to give it a clinical meaning about the outcome, for which a hierarchical sequence of criteria is followed: 1) previous clinical study, 2) expert agreement, 3) clinical judgment of the investigator/investigators, and 4) statistics. Acting without quality controls in data management frequently causes involuntary lies and confuses instead of clarifying.

[Severe post-COVID-19 dialysis dependence and inpatient acute kidney injury]

Background

COVID-19 challenged our health system, within the broad clinical spectrum acute kidney injury was presented as a catastrophic event, acute kidney injury and the risk of dependency after dialysis constitute a clinical problem with high repercussions in the funcionality.

Objective

To identify risk factors for dialysis dependence after acute kidney injury from COVID-19.

Material and methods

A retrospective observational cohort study was carried out at the Hospital de Especialidades del Centro Médico Nacional Siglo XXI, of the Mexican Institute of Social Security, from March 2020 to March 2021. 317 patients were included, we performed descriptive statistics, we compared differences between the stages of acute kidney injury, finding a difference in obesity with a frequency of 2.2% in stage 1, 20.82% stage 2 and 14.51% stage 3, with p value = 0.018.

Results

We found dialysis dependence one year after hospital-acquired acute kidney injury induced by COVID-19 in 58 patients (18.9%), we analyzed by KDIGO stage, in those patients who had AKI KDIGO 1 (2.83%) it depended on dialysis at one year, in the KDIGO stage 2 (3.78%), in the KDIGO stage 3 (11.67%).

Conclusions

Our study allowed us to identify that the risk factors associated with dialysis dependence are: male gender, type 2 diabetes mellitus, obesity, cardiovascular disease.

Breast Cancer in Pregnant Young Women: Clinicopathological Profile, Survival, and Pregnancy Outcomes

Background Breast cancer is one of the most common cancer types diagnosed during pregnancy; the presence of any neoplasm in pregnant women faces clinical dilemmas and challenges in cancer and pregnancy management. Pregnancy-associated breast cancer (PABC) is defined as breast cancer diagnosed during pregnancy or within one year after delivery. The aim of this study was to describe tumor clinicopathological characteristics and pregnancy outcomes in PABC patients. Materials and methods This is a retrospective cohort assessing PABC patients. Qualitative variables were compared using Fisher's exact test. Kaplan-Meier method was used to calculate survival. Cox regression and logistic regression methods were used to estimate the hazard ratio (HR) and odds ratio (OR), respectively. Results We assessed 16 PABC patients. Women ≤ 35 years of age were mainly diagnosed at advanced stage (88.8%) with ER-negative disease (77.8%). Patients with >4 pathological lymph nodes (25%; p = 0.001) and ER-negative disease (50%; p = 0.646) showed poor five-year overall survival (OS). In the multivariate analysis, nodal involvement was the main predictor associated with poorer OS (HR = 1.4, 90% confidence interval [CI]: 1.14 to 1.8). The following risk factors might influence the risk of preterm delivery: maternal older age, gestational age at diagnosis, and intrauterine exposure to chemotherapy, but an adjusted OR of 0.61 (90% CI: 0.34 to 1), 0.80 (90% CI: 0.66 to 0.9), and 0.013 (90% CI: 0.00 to 0.9), respectively, did not statistically support such an effect. Conclusions Younger women with PABC had a more aggressive pathological profile that might partly explain the poor OS. Obstetrical adverse events related to preterm delivery should be avoided with better planning of specialized strategies.

[Comment on article "Risk factors associated with preterm birth in a second level hospital"]

Preterm birth is a worldwide problem with a high economic impact and morbimortality in children. Therefore, the literature has focused on finding modifiable factors associated with this entity, such as the study "Risk factors associated with preterm birth in a second level hospital," which concluded that "100% of risk factors associated with preterm birth are potentially preventable". Our team reanalyzed the results and found in the regression model that premature rupture of membranes was the only variable associated with preterm birth. This variable is not 100% preventable, so the results found are different from the authors' conclusions.

Combined Nutrition in Very-Low-Birth-Weight Preterm Infants in the Neonatal Intensive Care Unit

Background Adequate nutritional support is crucial for achieving optimal growth and development in very-low-birth-weight (VLBW) preterm infants. This study evaluated the efficacy of combined nutrition (CN) (parenteral plus enteral nutrition (EN)) as an alternative nutrition protocol for VLBW infants in the neonatal intensive care unit (NICU). Methods This retrospective cohort study collected clinical and growth data from the medical records of VLBW infants weighing between 1,000 and 1,500 grams in the NICU of the Hospital of Obstetrics and Gynecology "Dr. Víctor Manuel Espinosa de los Reyes Sánchez" of the Centro Médico Nacional "La Raza" Instituto Mexicano del Seguro Social, Mexico. Parenteral nutrition (PN) alone or CN (PN plus EN) was used for nutritional management. Statistical tests, such as Student's t-test, Mann-Whitney U test, and chi-square test as appropriate, were used to compare the clinical characteristics and growth data of the two groups, and relative risk was calculated to determine the probability of comorbidities according to feeding type. Statistical significance was set at p<0.05. Results The study included 90 VLBW infants, with 27 receiving PN alone and 63 receiving CN. No statistically significant differences were found concerning sex, age, or Apgar score. The CN group showed better weight gain with statistically significant differences at 28 days (p=0.002), with no increase in the relative risk of necrotizing enterocolitis (NEC) or other complications. Conclusions The CN protocol met the caloric and nutritional needs, without increasing morbidity and mortality. The protocol had a positive impact on weight gain and a shorter NICU stay and should be considered as a nutritional alternative for VLBW infants.

Risk Assessment of Dyslipidemias, Hyperglycemia, Hyperuricemia, and Hypertension Utilizing Self-Reported Body Silhouettes

OBJECTIVE

Self-reported body silhouette is an anthropometric instrument that has been utilized as a screening tool for underweight, overweight, obesity, and other abnormal anthropometric variables. Herein, we analyzed the risk associated with the self-reported body silhouette in the scope of dyslipidemias, hyperglycemia, hyperuricemia, and hypertension.

METHODS

Adult participants of the Health Workers Cohort Study enrolled between March 2004 and April 2006 were included. Then, risk analysis was performed considering dyslipidemias as serum triglycerides, high total cholesterol, high LDL-C, low HDL-C, hyperglycemia, hyperuricemia, and hypertension.

RESULTS

A total of 2,297 males and 5,003 females were analyzed. The median ages of the studied population was 39 (30-49) and 41 (31-50) years for males and females, respectively. Overall, there is a stepwise increase in the risk of presenting dyslipidemias, hyperglycemia, hyperuricemia, and hypertension as the self-reported body silhouette number increases, this tendency was observed in both males and females.

CONCLUSION

Self-reported body silhouette is a useful risk assessment tool for dyslipidemias, hyperglycemia, hyperuricemia, and hypertension in Mexican adults. Applications of questioners containing this silhouette might be considered a valuable public health instrument due to their low cost, relative simplicity, and absence of specialized equipment, training, or respondent knowledge.

Self-reported body silhouettes: a diagnostic instrument for anthropometric parameters

OBJECTIVE

Routine body size measurement of anthropometric values requires professionals, standardized techniques, and calibrated tools. Therefore, there is a need for easier screening tools such as the self-reported body silhouette (Self-bosi). The aim of this study was to analyze the performance of Self-bosi as a proxy of anthropometric values.

STUDY DESIGN

Prospective analytic study of the Health Workers Cohort Study.

METHODS

Adult participants of the Health Workers Cohort Study were included. Then, through the calculation sensitivity and specificity of Self-bosi to detect abnormal waist circumference (WC) (≥90 cm for male and ≥80 cm for female participants), elevated body fat percentage (BF%) (≥25% for male and ≥35% for female participants), as well as overweight and obesity (≥25 kg/m²) and obesity (≥30 kg/m²).

RESULTS

A total of 2471 male and 5940 female participants were analyzed. Overall, Self-bosi discriminate high WC values (area under the curve [AUC]; male participants: 0.80, female participants: 0.82); increased BF% (AUC: male participants: 0.78, female participants: 0.83); overweight and obesity (AUC: male participants: 0.81, female participants: 0.86); and obesity (AUC: male participants: 0.83, female participants: 0.89).

CONCLUSION

Self-bosi is an accurate method to assess increased WC, BF%, obesity, and overweight-obesity in Mexican adults. Given its simplicity and low-cost of the self-reported body silhouette, it might be considered a useful anthropometric screening instrument in large scale epidemiological research.

Impact of Systemic Lupus Erythematosus on Pregnancy: Analysis of a Large 10-Year Longitudinal Mexican Cohort

BACKGROUND

Pregnancy in patients with systemic lupus erythematosus is considered a high risk one since it is associated with a higher rate of maternal-fetal complications compared with the pregnancies in healthy women.

OBJECTIVES

The aim of this study was to describe the maternal-fetal outcomes in a cohort of Mexican patients with systemic lupus erythematosus and to identify risk factors associated with adverse maternal and fetal outcomes.

PATIENTS AND METHODS

A cohort of pregnant lupus patients was analyzed. Maternal-fetal complications were described, and clinical, biochemical, and immunological variables associated with obstetric adverse outcomes were studied. Descriptive statistics, comparison of variables using appropriate tests, and finally logistic regression analysis were performed to identify potential risk factors for adverse maternal and fetal outcomes.

RESULTS

A total of 351 pregnancies were included in a 10-year period. The most frequently observed maternal adverse outcomes were lupus flare (35%) and preeclampsia (14.5%). Active lupus before pregnancy (hazards ratio [HR], 3.7; 95% confidence interval [CI], 1.1-12.5; p = 0.003) was a predictor for these complications, whereas the use of antimalarial drugs (HR, 0.4; 95% CI, 0.2-0.7; p = 0.007) was a protective factor. The most frequent fetal adverse outcomes were preterm birth (38.1%), miscarriages (10%), and low birth weight babies (28%), and very low birth weight newborns (11%). Proteinuria in early pregnancy (HR, 7.1; 95% CI, 1.01-50.3; p = 0.04) and preeclampsia (HR, 9.3; 95% CI, 1.7-49.7; p = 0.009) were risk factors associated with these complications.

CONCLUSIONS

Variables related to systemic lupus erythematosus activity predict an adverse maternal outcome, whereas proteinuria in early pregnancy and preeclampsia are associated with an adverse fetal outcome.

Risk factors associated with SARS-CoV-2 pneumonia in the pediatric population

INTRODUCCIÓN

Hasta ahora existen pocos estudios sobre las características clínicas de la población pediátrica con neumonía por COVID-19. El objetivo de este estudio fue analizar los datos que se asocian con el desarrollo de neumonía en niños y adolescentes con infección por SARS-CoV-2 en México.

MÉTODOS

Se llevó a cabo un análisis secundario de la base de datos de la Dirección General de Epidemiología del Gobierno Mexicano. Se incluyeron menores de 19 años con infección por SARS-CoV-2 confirmada mediante la prueba de retrotranscripción acoplada a la reacción en cadena de la polimerasa (RT-PCR). La variable dependiente fue el diagnóstico de neumonía. Se calcularon las razones de momios (RM) y los intervalos de confianza del 95% (IC95%). Se realizaron modelos de regresión logística múltiple para ajustar los factores asociados a neumonía.

RESULTADOS

Se incluyeron 1443 niños con diagnóstico de COVID-19. La mediana de edad de los participantes fue de 12 años (rango intercuartilar 25-75: 5-16). La neumonía se presentó en 141 niños (9.8%). Los principales factores de riesgo fueron edad < 3 años (RM: 3.5; IC95%: 2.45-5.03), diabetes u obesidad (RM: 12.6; IC95%: 4.62-34.91) e inmunocompromiso (RM: 7.03; IC95%: 3.97-13.61).

CONCLUSIONES

Los niños con COVID-19 menores de 3 años y con comorbilidad, especialmente diabetes u obesidad, y los inmunocomprometidos presentan mayor riesgo de desarrollar neumonía.

BACKGROUND

Currently, there are a few studies on the clinical characteristics of the pediatric population with COVID-19 and pneumonia. This study aimed to analyze data associated with the development of pneumonia in children and adolescents with SARS-CoV-2 infection throughout Mexico.

METHODS

We conducted a secondary analysis of the database of the Dirección General de Epidemiología of the Mexican Government. We included children under the age of 19 who were confirmed with SARS-CoV-2 infection by reverse transcription-polymerase chain reaction (RT-PCR) test. The dependent variable was the diagnosis of pneumonia. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated. Multiple logistic regression models were performed to adjust factors associated with pneumonia.

RESULTS

A total of 1443 children with a COVID-19 diagnosis were included. The median age of the participants was 12 years (interquartile range 25, 75: 5, 16). Pneumonia occurred in 141 children (9.8%). The main risk factors were age < 3 years (OR, 3.5; 95%CI, 2.45-5.03); diabetes or obesity (OR, 12.6; 95%CI, 4.62-34.91); and immunocompromise (OR, 7.03; 95%CI, 3.97-13.61).

CONCLUSIONS

Children < 3 years with COVID-19 and comorbidities, especially diabetes or obesity, and immunocompromised patients have a higher risk of developing pneumonia.

[The relevance and irrelevance of charts in clinical research]

Charts are a visual aid that is used in articles in order to highlight the results of an investigation. They allow illustrating the results with the purpose of making them clearer. Charts, just like statistical tests, are selected based on the objective of the study, the types of variable, and the statistical analyzes to be illustrated. Some of the most commonly used charts in clinical practice are frequency histograms, which illustrate qualitative variables or frequencies; also error charts, that are used for normally distributed quantitative variables; box plots or violin plots are used for distribution-free quantitative variables, and survival curves are for variables that include the person-time variable. The aforementioned charts can be used to illustrate the comparisons between maneuvers and outcome depending on the type of variable that is being analyzed. When two groups are compared and the dependent variable is dichotomous, forest plots are used; for multivariate models, the chart depends on the type of analysis. As for logistic regression and linear regression, tree diagrams are used; and scatter plots are used for linear regression. Survival plots are used for Cox proportional hazards. Although charts can be very useful, if they are misused, they can show differences where there are none, which leads to a misinterpretation of the studies. In this article, we will use examples to complement the topics that were previously addressed in the articles of this series.

Predictors of anthracycline-induced cardiotoxicity in a retro-prolective cohort of children surviving cancer

Introduction

Cardiotoxicity is an adverse reaction associated with the use of anthracyclines.

Objective

To estimate the factors associated with the development of anthracycline cardiotoxicity in pediatric patients surviving cancer.

Method

Retro-prolective cohort of children diagnosed with cancer and treated with anthracyclines. Baseline echocardiographic determination of ejection fraction (LVEF0) was carried out before the start of treatment and again at 12 months (LVEF1). Demographic characteristics and treatment were obtained from the medical record. A multiple logistic regression (MLR) model was constructed; LVEF1 < 50 % was the dependent variable, which was adjusted for the main confounding variables.

Results

Sixty-five patients were included, out of which 36.9 % were females and 56.8 % had a solid tumor. LVEF0 was 74.79 ± 7.3 % and LVEF1, 67.96 ± 6.7 % (p = 0.001); 60 % developed cardiotoxicity. In the MLR, only a cumulative dose > 430 mg was associated with cardiotoxicity (p = 0.001).

Conclusions

In Mexican children, an anthracycline cumulative dose > 430 mg should be avoided in order to prevent cardiotoxicity.

Height and weight progression patterns in Mexican children aged between 6 and 12 years and differences with Ramos-Galván growth charts 40 years later

Introduction

Children and adolescents weight and height are a reflection of the health status and socioeconomic development of a population.

Objective

To evaluate height and weight progression patterns of Mexican children and compare them with Dr. Ramos-Galván growth charts 40 years later.

Method

Cross-sectional survey conducted on the population of the National Physical Activation Program "Ponte al 100", which includes boys and girls aged six to 12 years.

Results

43,670 boys and 44,103 girls were assessed, stratified by gender and age. The height progression pattern between six and 12 years was 21 cm in males and 22 cm in females, whereas the weight progression pattern was 9.86 and 10.05 kg, respectively, for males and females. The proportion of six- and 12-year-old boys who were overweight was 11.2 and 9 %, while 14.7 and 15 % were obese. The proportion of six- and 12-year-old girls who were overweight was 8.2 and 9.1 %, whereas 21.7 and 13.3 %, respectively, were obese. When the obtained values were compared with those of Dr. Ramos Galván growth charts for boys and girls, the average difference was 2 cm.

Conclusions

No secular height or weight increase within the last 40 years was documented.

[List of Ethical Principles for Medical Research Involving Human Subjects]

The ethical principles of a research proposal are not contained only in a paragraph or in the informed consent form; actually, they are an essential part of the whole protocol from the beginning to the end. In a complementary manner to the regulatory and educative documents, our objective in this article is to propose a checklist of questions so researches can ensure they have included the necessary information and precautions to meet the ethical considerations that are required for every research with human beings, which shall be called List of Ethical Principles for Medical Research Involving Human Subjects. We propose questions that researchers must ask themselves when they compose the background, justification, objectives, research question, hypothesis, selection criteria, sample size calculation, sampling, research design, statistical analysis plan, ethical aspects, publication plan, and references.

Factors associated with death in children with COVID-19 in Mexico

INTRODUCTION

Most children affected by SARS-CoV-2 are reported to be asymptomatic, and COVID-19-related mortality in them is low; in Mexico, there is a lack of information on the subject in this population group.

OBJECTIVE

To assess the risk factors associated with mortality in Mexican children with COVID-19.

METHOD

Secondary analysis of the General Directorate of Epidemiology database. Children younger than 19 years, in whom SARS-CoV-2 infection was confirmed by RT-PCR, were included.

RESULTS

1443 children were included. Median age was eight years; 3.3 % were admitted to the intensive care unit, 1.8 % required assisted mechanical ventilation, and mortality was 1.9 %. In multivariate models, the development of pneumonia was the main risk factor for mortality, with an odds ratio (OR) of 6.45 (95 % CI: 1.99, 20.89); patients who required intubation had an OR of 8.75 (95 % CI: 3.23, 23.7).

CONCLUSIONS

Children with COVID-19 exhibit high mortality in Mexico, and avoiding pneumonia should therefore be tried in them, especially in children younger than four years, with cardiovascular risk or immunosuppression.

INTRODUCCIÓN

Se informa que la mayoría de los niños afectados por SARS-CoV-2 cursan asintomáticos y que en ellos la mortalidad por COVID-19 es baja; en México se desconoce la información al respecto en este grupo de la población. ­.

OBJETIVO

Evaluar los factores de riesgo asociados a mortalidad en niños mexicanos con COVID-19.

MÉTODO

Análisis secundario de la base de datos de la Dirección General de Epidemiología. Se incluyeron niños menores de 19 años, en quienes se confirmó SARS-CoV-2 mediante RT-PCR.

RESULTADOS

Se incluyeron 1443 niños. La mediana de edad fue de ocho años; 3.3 % ingresó a la unidad de cuidados intensivos, 1.8 % requirió ventilación mecánica asistida y la mortalidad fue de 1.9 %. En los modelos multivariados, el desarrollo de neumonía constituyó el principal factor de riesgo de mortalidad, con razón de momios (RM) de 6.45 (IC 95 % 1.99, 20.89); los pacientes que requirieron intubación tuvieron RM de 8.75 (IC 95 % 3.23, 23.7).

CONCLUSIONES

Los niños con COVID 19 tienen alta mortalidad en México, por lo que en ellos se debe procurar evitar la neumonía, especialmente en los menores de cuatro años, con riesgo cardiovascular o inmunosupresión.

Comment on article "Improvement of radiodiagnostic congruence in the first level of care"

La implementación de una estrategia de verificación de -congruencia radiodiagnóstica podría ayudar a disminuir el número de estudios radiológicos solicitados y mejorar su congruencia. En el estudio que comentamos se muestra que la congruencia radiodiagnóstica pasó de un 73.4% a un 81.9% al utilizar la estrategia. En esta carta se solicitan detalles de la estrategia y datos para calcular intervalos de confianza del 95%. Esta información nos ayudará a apreciar mejor el -estudio. The implementation of a strategy to verify the radiodiagnostic consistency may help decrease the number of radiological studies requested and improve their consistency. The study that triggered this commentary shows that the radiodiagnostic consistency increased from 73.4% to 81.9% when using a strategy. This letter is intended to request the authors of the study, the details of the strategy and data to calculate 95% confidence intervals. This data will help us to further appreciate the value of the study.

[The importance of national medical journals in a global world]

National medical journals are important because they focus on local clinical problems, peer communication, and fostering critical reading among healthcare workers. The actors involved in the development of the journals must fulfill their purposes to improve the quality of the publications of the national journals and contribute to improve the quality of care.

[Comment to the article «Frecuency of diagnosis of bone lesions in cases of anterior glenohumeral dislocation»]

No Abstract available.

[Correlation: not all correlation entails causality]

The concept of correlation entails having a couple of observations (X and Y), that is to say, the value that Y acquires for a determined value of X; the correlation makes it possible to examine the trend of two variables to be grouped together. We know that, with increasing age, blood pressure figures also increase, therefore, if we want to answer a research question like "what is the connection between age and blood pressure?" the relevant statistical test is a correlation test. This test makes it possible to quantify the magnitude of the correlation between two variables, but it is also helpful for predicting values. If these variables had a perfect correlation, the value of the variable Y could be deduced by knowing the value of X. Because of these advantages, the correlation is one of the most frequently used tests in the clinical setting since, in addition to measuring the direction and magnitude of the association of two variables, it is one of the foundations for prediction models, such as linear regression model, logistic regression model and Cox proportional hazards model.

[Tasa libre de litos sin complicación mayor como definición de éxito en nefrolitotomía percutánea]

Introduction

Success in percutaneous nephrolithotomy (PCNL) is defined as a stone-free status; however, major complications are highly common and have been reported as a secondary outcome.

Objective

To propose a new definition of PCNL success that comprises a stone free rate without major complications and a risk scale to predict this outcome.

Methods

Historical cohort of patients undergoing PCNL. The included variables were age, gender, urine culture, Charlson's comorbidity index (CCI) and complex stones. Success was defined as a stone free status with or without Clavien grade ≤ 2 complication; intermediate success: with stones, with or without Clavien grade ≤ 2 complication; and failure: with or without stones with Clavien grade ≤ 2 complication. Bivariate analysis was performed to identify which factors are associated with the outcome. The independent weight of each factor was calculated by multiple logistic regression analysis.

Results

568 procedures were included, 59% of which were in females. Median age was 49 years; 65%, 22% and 13% of cases were classified as success, intermediate success and failure, respectively. Female sex, positive urine culture, complex stones and severe CCI were associated with failure.

Conclusions

The likelihood of success was directly proportional to the number of risk factors.

[Comment to the article “Stunting, overweight and obesity during the nutrition transition in schoolchildren of Arandas, Jalisco, Mexico”]

No abstract

De vuelta a la clínica. Métodos I. Diseños de investigación. Mayor calidad de información, mayor certeza a la respuesta

Research designs refer to the way information is obtained and are limited by ethical, economic and temporal viability. Research designs are standardized strategies to reduce biases, which in the architectural model of research are identified in the baseline state, the maneuver and the outcome; hence, there are no specific designs for each question. The design with the lowest probability of bias is the clinical trial, followed by cohort and case-control studies and, finally, by cross-sectional surveys. Among the main characteristics that give merit to research designs are the following: population inquiry, which refers to the situation of the population in relation to the clinical course/natural history of the disease; the maneuver, or action that is expected to modify the baseline state, which can be observational or experimental; follow-up, or documented monitoring that is given to each subject, which can be longitudinal or cross-sectional; and directionality, which can prolective or retrolective and refers to the timing of data collection for research purposes. It will always be better having a valuable question, even when answered with a design with higher risk of bias, than a question that is irrelevant or has no applicability.

De vuelta a la clínica: sin justificación no existe pregunta de investigación que valga

A clinical research question requires the concurrence of clinical experience and knowledge on methodology and statistics in that who formulates it. Initially, a research question should have a structure that clearly establishes what is that which is being sought (consequence or outcome), in whom (baseline status), and by action of what (maneuver). Subsequently, its reasoning must explore four aspects: feasibility and reasonableness of the questioning, lack of a prior answer, relevance of the answer to be obtained, and applicability. Once these aspects are satisfactorily covered, the question can be regarded as being "clinically relevant", which is different from being statistically significant, which refers to the probability of the result being driven by chance, which does not reflect the relevance of the question or the outcome. One should never forget that every maneuver entails adverse events that, when serious, discredit good results. It is imperative to have the possible answer estimated from within the structure of the question. The function of clinical research is to corroborate or reject a hypothesis, rather than to empirically test to find out what the outcome is.

Enteral Docosahexaenoic Acid Reduces Analgesic Administration in Neonates Undergoing Cardiovascular Surgery

Background: Neonates undergoing surgery require analgesic medication to ameliorate acute pain. These medications produce negative side effects. Docosahexaenoic acid (DHA) has an antinociceptive effect in animals, but this has not been evaluated in human neonates. We evaluated the DHA effect on cumulative dose and duration of analgesics administered to neonates undergoing cardiovascular surgery. Methods: A secondary analysis was performed with data from a clinical trial, in which enteral DHA was administered perioperatively compared with sunflower oil (SO). Present study assessed the antinociceptive effect of DHA by measuring the cumulative dose and duration of analgesics administered during postoperative stay in a neonatal intensive care unit. Multivariate linear regression models were performed. Results: Seventeen neonates received DHA and 18 received SO in the control group. Compared with the control group, the DHA group received lower cumulative dose (14.6 ± 2.2 vs. 25.2 ± 4.8 μg/kg, p = 0.029) and shorter duration of buprenorphine (2 days (1-8) vs. 4.5 days (1-12); p = 0.053). After adjusting for confounders, the DHA group received significantly lesser buprenorphine (β = -27 μg/kg, p = 0.028; R2 model = 0.90) for shorter duration (β = -9 days, p = 0.003; R2 model = 0.94). No differences in fentanyl or ketorolac were detected. Conclusions: Buprenorphine administration was reduced in neonates who received DHA, suggesting that DHA likely has analgesic effects.

Reference Values of Total Lean Mass, Appendicular Lean Mass, and Fat Mass Measured with Dual-Energy X-ray Absorptiometry in a Healthy Mexican Population

The aim of this study was to develop age- and gender-specific reference values of total lean body mass (LBM), appendicular lean body mass (ALBM), and fat mass (FM) by dual-energy X-ray absorptiometry (DXA) data in a healthy Mexican population. A cross-sectional analysis was conducted on 9518 healthy subjects 7-89 years of age participating in the baseline measurement of the Health Workers Cohort Study. Using DXA, LBM, ALBM, and FM were measured. Using these data, LBM index (LBMI), ALBM index (ALBMI), and fat mass index (FMI) were calculated. LMI, ALMI, and FMI were calculated as the LBM, ALBM, and FM kg divided by the height in meters squared. Males and females were analyzed separately; sex-specific means and standard deviations for LBM, ALBM, FM, LBMI, ALBMI, and FMI were calculated. A total of 2829 males and 6694 females were included in the final analysis. Strong sex gaps were observed after 12 years in LBM, ALBM, LBMI, and ALBMI (P < 0.01). LBM and ALBM values continue to increase for males up to age 20; females plateaued approximately after age 15. Significant sex differences were also observed for FM and FMI. Significant sex- and age-related differences exist in LBM, ALBM, and FM in the Mexican population. In addition, given the null data available in this area, these reference values may be useful in the evaluation of a variety of childhood and adult abnormalities involving lean body mass deficits, mainly in the assessment of muscle wasting, with important medical and epidemiological uses.

Comparison of International Reference Values for Bone Speed of Sound in Pediatric Populations: Meta-analysis

The aim of this study was to compare international reference values (RV) for tibial and radial speed of sound (SoS) assessed by quantitative ultrasound (QUS) in pediatric populations. These values were compared by age and country of origin in a systematic review with meta-analysis from studies published on QUS (Sunlight Omnisense). A search was carried out in electronic databases. Nine studies with 6963 patients were included in the meta-analysis. For the newborn populations, 3 studies (from Italy, Portugal, and Israel) were used. These studies included subjects with 27-42 wk gestational age. The mean difference (Portugal-Israel) was found to be 23.62 m/s [95% confidence interval [CI] 6.29, 40.95]. Additionally, no difference was found between Italy-Portugal (p = 0.69), or Italy-Israel (p = 0.28). In pediatric populations, we compared 8 studies from Canada, Mexico, Israel, Greece, Portugal, and Turkey. No significant differences found for SoS RV between Israel-Turkey, Israel-Greece, or Israel-Canada (p > 0.05). Significant differences were found in Mexico-Israel -105.29 m/s (95% CI -140.05, -70.54) (p < 0.001); Mexico-Portugal -115.14 m/s (95% CI -164.86, -65.42) (p < 0.001); Mexico-Greece: -239.14 m/s (95% CI -267.67, -210.62) (p < 0.001); Mexico-Turkey: -115.14 m/s (95% CI -164.86, -65.42) (p < 0.001); Mexico-Canada: -113.51 m/s (95% CI -140.25, -86.77) (p < 0.001).This study demonstrates that there are differences in SoS-RV obtained by tibial and radial QUS in pediatric populations between Mexico and other countries (Israel, Portugal, Greece, Turkey, and Canada).

[Anthracycline-induced cardiotoxicity: report of fatal cases]

BACKGROUND

Anthracyclines are effective drugs in pediatrics cancer treatment. However, anthracycline-induced cardiotoxicity (AIC) is a serious adverse drug reaction that affects the survival in patients treated for childhood cancer.

CLINICAL CASES

Case 1: Nine-year-old girl with stage IV Hodgkin lymphoma with 12 epirubicin doses and a cumulative dose of 576 mg/m2. After last chemotherapy dose, the patient was admitted with systemic inflammatory response, asthenia and adinamia. Echocardiography: LVEF of 22%, SF 11% and moderate mitral regurgitation. Patient died 2 days after diagnosed with dilated cardiomyopathy secondary to anthracyclines. Case 2: Fifteen-year-old girl with stage IV Burkitt lymphoma with two epirubicin doses and a cumulative dose of 90 mg/m2. After the last cycle, the patient developed several infectious foci. Echocardiography: LVEF of 49%, SF 20% and dilated left ventricle with septal flattening. Patient died 13 days after diagnosis of dilated cardiomyopathy by anthracyclines.

CONCLUSION

AIC is a problem in pediatric patients receiving anthracyclines, monitoring is essential to detect the onset of cardiac damage to provide an intervention to prevent heart failure progress.

[Effectiveness of the outpatient treatment of the community-acquired pneumonia: systematic review and meta-analysis]

BACKGROUND

Community-acquired pneumonia is an important cause of mortality and morbidity worldwide. Therefore, our aim was to assess the efficacy and safety of outpatient treatment of community-acquired pneumonia.

METHODS

We systematically reviewed randomized clinical trials evaluating efficacy and safety of outpatient treatment (OPT) compared with inpatient treatment (IPT) of community-acquired pneumonia in patients without added co-morbidity. Relative Risk (RR) and 95 % confidence interval (95 % CI) were calculated.

RESULTS

From 4088 reviewed articles, two articles were included for meta-analysis, including 2324 patients. One study was conducted in adults, and the other was carried out in pediatric patients. Treatment setting was not significantly associated with treatment failure (RR 0.84 [95% CI 0.68, 1.02]). Death occurred in 6 of 2324 with no difference between the two groups (RR 0.56 [95 % CI 0.12-2.61]). Finally, no differences were seen in hospital readmission between groups (RR 0.82 [95 % CI 0.52-1.30]).

CONCLUSION

Evidence shows that treatment setting of community-acquired pneumonia is not statistically associated with treatment failure or mortality.

Cisplatin Nephrotoxicity and Longitudinal Growth in Children With Solid Tumors: A Retrospective Cohort Study

Cisplatin, a major antineoplastic drug used in the treatment of solid tumors, is a known nephrotoxin. This retrospective cohort study evaluated the prevalence and severity of cisplatin nephrotoxicity in 54 children and its impact on height and weight.We recorded the weight, height, serum creatinine, and electrolytes in each cisplatin cycle and after 12 months of treatment. Nephrotoxicity was graded as follows: normal renal function (Grade 0); asymptomatic electrolyte disorders, including an increase in serum creatinine, up to 1.5 times baseline value (Grade 1); need for electrolyte supplementation <3 months and/or increase in serum creatinine 1.5 to 1.9 times from baseline (Grade 2); increase in serum creatinine 2 to 2.9 times from baseline or need for electrolyte supplementation for more than 3 months after treatment completion (Grade 3); and increase in serum creatinine ≥3 times from baseline or renal replacement therapy (Grade 4).Nephrotoxicity was observed in 41 subjects (75.9%). Grade 1 nephrotoxicity was observed in 18 patients (33.3%), Grade 2 in 5 patients (9.2%), and Grade 3 in 18 patients (33.3%). None had Grade 4 nephrotoxicity. Nephrotoxicity patients were younger and received higher cisplatin dose, they also had impairment in longitudinal growth manifested as statistically significant worsening on the height Z Score at 12 months after treatment. We used a multiple logistic regression model using the delta of height Z Score (baseline-12 months) as dependent variable in order to adjust for the main confounder variables such as: germ cell tumor, cisplatin total dose, serum magnesium levels at 12 months, gender, and nephrotoxicity grade. Patients with nephrotoxicity Grade 1 where at higher risk of not growing (OR 5.1, 95% CI 1.07-24.3, P=0.04). The cisplatin total dose had a significant negative relationship with magnesium levels at 12 months (Spearman r=-0.527, P=<0.001).

High prevalence of hypovitaminosis D in Mexicans aged 14 years and older and its correlation with parathyroid hormone

A sample of 585 healthy subjects 14 years and older was studied to estimate the status of 25-hydroxyvitamin D (25(OH)D) and its correlation with parathyroid hormone in healthy Mexicans. In 43.6 % of the sample, levels of vitamin D were below 20 ng/mL and showed an inverse relationship with parathyroid hormone (PTH; p < 0.01).

PURPOSE

The purpose of the present study was to estimate the status of 25-hydroxyvitamin D (25(OH)D) and its correlation with parathyroid hormone in healthy Mexicans.

METHODS

A cross-sectional study of 585 healthy subjects 14 years and older was carried out. A questionnaire including all relevant demographics, medical history, and lifestyle factors was applied by trained interviewers. Morning fasting blood was collected in all subjects for estimation of 25(OH)D using liquid chromatography-tandem mass spectrometry and PTH hormone-intact molecule by RIA.

RESULTS

Of the group of 585 subjects, 54.1 % were women; the sample was divided in three age groups (14-29, 30-50, and >51). Only 9.6 % of the total sample had levels of 25(OH)D above 30 ng/mL; 46.8 % were between 20 and 29 ng/mL, and 43.6 % were below 20 ng/mL. Regarding PTH, a three-phase model was identified using regression smoothing scatterplot (LOESS), with two thresholds of 25(OH)D of 19 and 29 ng/mL. Phase 1 (25(OH)D <19 ng/mL) showed an inverse relationship with PTH (p < 0.01); phases 2 and 3 showed no significant relationship.

CONCLUSION

Our results show that 43.6 % of the Mexicans in this study have deficient concentration levels of vitamin D. The cutoff point of 20 ng/mL of 25(OH)D established by the Institute of Medicine has a biological and statistically significant relationship with PTH levels in the Mexican population, independently of principal confounding factors. Like many other countries, Mexico could be included in the global epidemic of hypovitaminosis D.