[Risk management system to reduce COVID-19 infection in health personnelSistema de gestão de riscos para reduzir o contágio de COVID-19 em profissionais de saúde]

Objective

To assess the occupational factors associated with the occurrence of COVID-19 in health personnel who were exposed to different magnitudes of risk and who followed the United Nations crisis management policy for COVID-19.

Methods

Cross-sectional survey conducted between April and May 2021. The low-risk group (LRG) were considered to be those who had minimal contact with patients; the medium-risk group (MRG) had contact with non-COVID-19 patients and did not perform instrumental airway intervention; and the high-risk group (HRG) were those who cared for COVID-19 patients and performed instrumental intervention with aerosol generation. Diagnosed COVID-19 disease and the presence of positive IgG antibodies for SARS-CoV-2 measured with Elecsys® anti-SARS-CoV-2 were considered as outcomes.

Results

Outcome recorded in 43.8% of the LRG, versus 46.7% in the MRG (odds ratio [OR]: 1.125; 95% confidence interval [CI 95% ]: 0.896-1.414; p = 0.311), and 48.6% in the HRG (OR: 1,214; CI 95%: 0.964-1.530; p= 0.10).

Conclusion

Belonging to the high-risk group and the medium-risk group, based on the degree of exposure to confirmed COVID-19 patients in the work area, was not associated with a higher occurrence of disease or seroconversion.

Risk symptoms for progression in Covid-19. Telemedicine cohort study

Not available.

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.

Effect of a ready-to-use supplementary food on the recovery of preschool children with malnutrition

INTRODUCTION

In developing countries, protein-energy malnutrition causes 60% of deaths in children < 5 years of age.

OBJECTIVE

To evaluate the effect of a ready-to-use supplementary food (RUSF) on moderate acute malnutrition (MAM) in preschool children.

METHOD

Clinical trial that included 155 children with MAM (weight/height Z-score > -3 and ≤ -2). Each child received RUSF in the form of biscuits, four per day (250 kcal), for 12 months. The tutor received education on nutrition, health and hygiene. Recovery (weight/height Z-score > -2) at four, six, and 12 months was assessed using intent-to-treat (ITT) and per protocol (PP) analyses. Changes in chronic malnutrition were also analyzed.

RESULTS

In the first semester, adequate RUSF consumption was observed in 61% of the children, and in 42% in the second semester. In the ITT analysis, 78% were identified to have recovered, with 38% reaching normal nutritional values; in the PP analysis, > 90% recovered and > 40% reached normal values. Recovery from chronic malnutrition was also observed.

CONCLUSIONS

The consumption of RUSF and an educational program reduced MAM.

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.

Sensitivity and specificity of increased pulse pressure as a diagnostic test for K/DOQI stage III-b CKD

Background

Increased pulse pressure (IPP) is associated with an estimated glomerular filtration ≤ 60/mL/min/1.73 m²; thus, it can be useful as a diagnostic test to identify people with K/DOQI stage III-b chronic kidney disease (CKD).

Objective

To determine the usefulness of IPP as a diagnostic test for K/DOQI stage III-b CKD.

Method

Diagnostic test study that included adult patients without comorbidities, registered in the Health Workers Cohort. The CKD-EPI formula was used to calculate glomerular filtration. Pulse pressure was determined by subtracting diastolic from systolic blood pressure. Sensitivity, specificity, positive predictive value, negative predictive value and prevalence were calculated using standard formulas. A ROC curve was generated to determine the area under the curve.

Results

A total of 6,215 patients were included. An IPP ≥ 50 mmHg was observed to have a sensitivity of 74 %, specificity of 70 %, positive predictive value of 1 %, negative predictive value of 100 % and a prevalence of 1 %. The inflection point in the ROC curve to identify K/DOQI III-b CKD was 0.71.

Conclusion

An IPP ≥ 50 mmHg is useful as a diagnostic test to identify people with K/DOQI stage III-b CKD.

Back to the clinic. Methods II. The Architecture of Clinical Research. Subject interaction, maneuvers and disease throughout time

Medicine is characterized by the application of the scientific method through clinical judgment, by correct interpretation and use of the clinical course and/or natural history of the disease; its best description is observed in the architecture of clinical research. Through a temporal sequence, this model explains the phenomenon of causality with three sections: baseline status, maneuver, and outcome. The baseline status assesses who the patient is, where does he come from, his general conditions, the diagnosis, stage and aggressiveness of the pathology, complications, previous therapies, socioeconomic-cultural level, habits, therapeutic indications or contraindications, and the expected evolution is anticipated. In the maneuver, risk or prognostic factors, specific or symptomatic treatment, and general measures can be evaluated. In the outcome, early and late evolution are monitored. The model also allows the causes of follow-up loss to be determined. Anticipating patient evolution by recognizing his condition, disease, and expected effect of medical decisions allows acting in advance, since waiting for the manifestations of the evolutionary process of disease results in detriment to the patient.

U-shaped-aggressiveness of SARS-CoV-2: Period between initial symptoms and clinical progression to COVID-19 suspicion. A population-based cohort study

Background

Early identification of different COVID-19 clinical presentations may depict distinct pathophysiological mechanisms and guide management strategies.

Objective

To determine the aggressiveness of SARS-CoV-2 using symptom progression in COVID-19 patients.

Design

Historic cohort study of Mexican patients. Data from January-April 2020 were provided by the Health Ministry.

Setting

Population-based. Patients registered in the Epidemiologic Surveillance System in Mexico.

Participants

Subjects who sought medical attention for clinical suspicion of COVID-19. All patients were subjected to RT-PCR testing for SARS-CoV-2.

Measurements

We measured the Period between initial symptoms and clinical progression to COVID-19 suspicion (PISYCS) and compared it to the primary outcomes (mortality and pneumonia).

Results

65,500 patients were included. Reported fatalities and pneumonia were 2176 (3.32%), and 11568 (17.66%), respectively. According to the PISYCS, patients were distributed as follows: 14.89% in <24 hours, 43.25% between 1–3 days, 31.87% between 4–7 days and 9.97% >7 days. The distribution for mortality and pneumonia was 5.2% and 22.5% in <24 hours, 2.5% and 14% between 1–3 days, 3.6% and 19.5% between 4–7 days, 4.1% and 20.6% >7 days, respectively (p<0.001). Adjusted-risk of mortality was (OR [95% CI], p-value): <24 hours = 1.75 [1.55–1.98], p<0.001; 1–3 days = 1 (reference value); 4–7 days = 1.53 [1.37–1.70], p<0.001; >7 days = 1.67 [1.44–1.94], p<0.001. For pneumonia: <24 hours = 1.49 [1.39–1.58], p<0.001; 1–3 days = 1; 4–7 days = 1.48 [1.41–1.56], p<0.001; >7 days = 1.57 [1.46–1.69], p<0.001.

Limitations

Using a database fed by large numbers of people carries the risk of data inaccuracy. However, this imprecision is expected to be random and data are consistent with previous studies.

Conclusion

The PISYCS shows a U-shaped SARS-CoV-2 aggressiveness pattern. Further studies are needed to corroborate the time-related pathophysiology behind these findings.

Surgical and Pharmacological Outcomes in Acromegaly: Real-Life Data From the Mexican Acromegaly Registry

CONTEXT

Acromegaly registries constitute a valuable source of therapeutic outcome information in real-life.

OBJECTIVE

The objective of this work is to analyze surgical and pharmacological outcomes in the Mexican Acromegaly Registry (MAR).

DESIGN AND METHODS

Data were extracted from the MAR informatic platform. Surgical remission was defined by a postoperative postglucose (GH) of less than 1 ng/mL and an insulin-like growth factor 1 (IGF-1) of less than 1.2 × upper limit of normal (ULN). Pharmacological remission was defined by a basal GH of less than 1 ng/mL and an IGF-1 of less than 1.2 × ULN.

RESULTS

A total of 650 surgical outcomes were analyzed (94.6% transsphenoidal). Surgical remission was achieved in 40.15%, whereas 44.15% remained biochemically active. Persistently active disease after surgery was significantly associated with harboring an invasive macroadenoma, a basal GH of greater than 10 ng/mL, and/or an IGF-1 of greater than 2 × ULN at diagnosis on bivariate and multivariate analysis. The outcome of monotherapy with first-generation somatostatin analogs (SSAs) was evaluated in 267 patients (adjunctive in 65%), of whom 28.4% achieved remission. Persistently active disease was significantly associated with harboring an invasive macroadenoma as well as with pretreatment basal GH and IGF-1 levels of greater than 10 ng/mL and greater than 2 × ULN, respectively, on bivariate and multivariate analysis. Combined therapy with SSA and cabergoline was analyzed in 100 patients, of whom 19% achieved remission and 44% remained active; in this subset of patients, only a pretreatment IGF-1 of greater than 2 × ULN was significantly associated with persistent disease activity.

CONCLUSION

Surgical and pharmacological outcomes in acromegaly are highly dependent on tumor size/invasiveness as well as on the degree of hypersomatotropinemia.

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.

Moderate acute malnutrition prevention with a ready-to-use supplementary food in pre-school children from rural communities

INTRODUCTION

Child malnutrition in Mexico reaches a prevalence as high as 27.5 % in rural areas.

OBJECTIVE

To assess the effectiveness of a ready-to-use supplementary food (RUSF) to correct mild acute malnutrition and prevent moderate acute malnutrition in preschool children from rural communities.

METHOD

Randomized clinical trial, with assignment to two groups: group with RUSF (RUSF-g) or group without it (non-RUSF-g); children aged from two to five years, with weight-for-height Z-scores (WHZ) between -2 and -1 and low socioeconomic status were included. All received education on nutrition, health and hygiene twice monthly; the RUSF-g children had to consume one portion of the supplement every day. WHZ was assessed at baseline and at four, six, and 12 months. The comparison between groups was carried out with Cox proportional hazards model.

RESULTS

With regard to mild acute malnutrition correction in the RUSF-g, 68.7 versus 52.1 % in the control group was observed in the intent-to-treat analysis, with a hazard ratio (HR) = 1.25; in the per-protocol analysis of first semester, a HR = 1.48 was observed, and in the second semester, HR = 1.56. One patient progressed to moderate acute malnutrition.

CONCLUSIONS

The RUSF-g showed a significantly higher resolution of mild acute malnutrition.

INTRODUCCIÓN

La desnutrición infantil en México alcanza prevalencias de 27.5 % en zonas rurales.

OBJETIVO

Evaluar la efectividad de un suplemento alimenticio listo para consumir (SALC) para corregir desnutrición aguda leve y prevenir desnutrición aguda moderada en preescolares de comunidades rurales.

MÉTODO

Ensayo clínico aleatorizado por grupos: con y sin SALC (g-SALC y g-S/SALC); se incluyeron niños de dos a cinco años, con puntuaciones-Z de peso para la talla (pZ-P/T) mayor de −2 y menor de −1 y nivel socioeconómico bajo. Todos recibieron educación sobre nutrición, salud e higiene dos veces al mes; los niños del g-SALC debieron consumir diariamente una porción del suplemento. Se evaluó pZ-P/T al inicio y a los cuatro, seis y 12 meses. La comparación entre grupos se realizó con el modelo de riesgos proporcionales de Cox.

RESULTADOS

Respecto a la recuperación de desnutrición aguda leve, en g-SALC se observó 68.7 versus 52.1 % en el grupo control en el análisis de intención para tratar, con una razón de riesgo (HR) = 1.25; en el análisis por protocolo del primer semestre se observó una HR = 1.48 y en el segundo semestre, HR = 1.56. Un paciente progresó a desnutrición aguda moderada.

CONCLUSIONES

El g-SALC mostró resolución significativamente mayor de desnutrición aguda leve.

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.

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.

Association of V249I and T280M variants of fractalkine receptor CX3CR1 with carotid intima-media thickness in a mexican population with type 2 diabetes

OBJECTIVE

To evaluate the association of the V249I and T280M variants of CX3CR1 fractalkine gene with carotid intima-media thickness in Mexican subjects with and without type 2 diabetes.

METHODS

We analyzed the V249I and T280M variants of the CX3CR1 receptor by TaqMan assays in 111 subjects with type 2 diabetes and 109 healthy controls. Hemoglobin A1c, glucose, and lipid profile were determined.

RESULTS

A significant increase in carotid intima-media thickness was observed in type 2 diabetes patients (0.979 ± 0.361 mm) compared to healthy controls (0.588 ± 0.175 mm). In subjects carrying the MM variant of the T280M polymorphism, hemoglobin A1c was higher (p = 0.008). Classic risk factors for atherosclerosis showed no differences between carriers of the T280M and V249I variants. Controls with the II249 genotype associated with carotid intima-media thickness (0.747 ± 0.192 mm; p = 0.041), and this difference remained significant even after adjusting factors such as age, gender, and body mass index (OR: 7.7; 95% CI: 1.269-47.31; p = 0.027).

CONCLUSIONS

V249I genotype of the fractalkine receptor showed a protector role in patients with type 2 diabetes. The T280M genotype is associated with increased carotid intima-media thickness in Mexican individuals with or without type 2 diabetes.

Association of V249I and T280M variants of fractalkine receptor CX3CR1 with carotid intima-media thickness in a mexican population with type 2 diabetes

OBJECTIVE

To evaluate the association of the V249I and T280M variants of CX3CR1 fractalkine gene with carotid intima-media thickness in Mexican subjects with and without type 2 diabetes.

METHODS

We analyzed the V249I and T280M variants of the CX3CR1 receptor by TaqMan assays in 111 subjects with type 2 diabetes and 109 healthy controls. Hemoglobin A1c, glucose, and lipid profile were determined.

RESULTS

A significant increase in carotid intima-media thickness was observed in type 2 diabetes patients (0.979 ± 0.361 mm) compared to healthy controls (0.588 ± 0.175 mm). In subjects carrying the MM variant of the T280M polymorphism, hemoglobin A1c was higher (p = 0.008). Classic risk factors for atherosclerosis showed no differences between carriers of the T280M and V249I variants. Controls with the II249 genotype associated with carotid intima-media thickness (0.747 ± 0.192 mm; p = 0.041), and this difference remained significant even after adjusting factors such as age, gender, and body mass index (OR: 7.7; 95% CI: 1.269-47.31; p = 0.027).

CONCLUSIONS

V249I genotype of the fractalkine receptor showed a protector role in patients with type 2 diabetes. The T280M genotype is associated with increased carotid intima-media thickness in Mexican individuals with or without type 2 diabetes.

A comprehensive intervention for adverse drug reactions identification and reporting in a Pediatric Emergency Department

BACKGROUND

Physicians identify from 45.7 to 96.2 % of Adverse Drug Reactions (ADRs) in their patients, with under-reporting ranging from 6 to 100 %. In order to improve ADR reporting, several interventions have been evaluated in different studies, but not with regard to ADR identification. In addition, it is not known whether some patient characteristics might influence on ADR identification and reporting by physicians.

OBJECTIVES

(a) To assess the effectiveness of a comprehensive intervention directed to Emergency Department physicians and coordinated by a pharmacist in a tertiary care pediatric hospital on ADR identification and reporting. (b) To assess if some of the children’s characteristics might influence on ADR identification and reporting. Setting The Emergency Department of the Hospital Infantil de México “Federico Gómez”, which is a national pediatric institute of health in México.

METHODS

A Quasi-experimental, pre-post test trial was designed. During the intervention, the pharmacist gave talks on Pharmacovigilance and on the program for electronic capture of data, took part in patient visits, left reminders, improved accessibility to ADR report format and performed feedback activities. To classify and quantify correctly identified ADRs and ADRs reported to the Institutional Pharmacovigilance Center (IPC), 1136 clinical records were reviewed. The models were adjusted for patient variables.

MAIN OUTCOME MEASURES

Total ADRs, ADRs correctly identified by physicians, ADRs reported to the IPC by physicians. Results Before the intervention, 97 % of ADRs were correctly identified and 6.1 % reported by physicians. During the intervention, 99.6 % were correctly identified and 41.2 % were reported, and after the intervention, 99.6 and 41.7 %, respectively. Identification during the intervention showed a sevenfold increase with regard to preintervention and was maintained post-intervention. ADR reporting during the intervention showed a 14-fold increase with regard to pre-intervention and was maintained during post-intervention.

CONCLUSION

Physicians do identify ADRs, but fail to report them. The intervention increased ADR correct identification and reporting. The effect was maintained after the intervention.

Levels of serum estradiol and lifestyle factors related with bone mineral density in premenopausal Mexican women: a cross-sectional analysis

BACKGROUND

Many factors, such as heredity, ethnicity, nutrition and other lifestyle factors, have been related to bone mineral density in postmenopausal women. Additionally, bone mass has been significantly associated with decreased estrogen levels. However, fewstudies have been conducted on premenopausal women. The present study was designed to estimate the relationship between low bone mineral density and levels of serum estradiol and lifestyle factors in premenopausal Mexican women.

METHODS

A cross-sectional study was conducted in 270 women between 40 and 48 years of age who participate in the Health Workers Cohort Study. Information on socio-demographic and lifestyle factors were obtained through a self-administered questionnaire. Body mass index and serum estradiol were measured with standard procedures; bone mineral density was assessed using dual-energy X-ray absorptiometry. Multiple linear and logistic regression models were computed to evaluate the relationship between low bone mineral density and levels of serum estradiol and lifestyle factors.

RESULTS

In linear regression analysis levels of estradiol, body mass index, physical activity, and vitamin D intake were positively related to bone mineral density. Age, cigarette smoking and caffeine were inversely associated with BMD. Finally, the odds of low bone mineral density increase significantly when the premenopausal women had low levels of serum estradiol (OR = 4.93, 95 % CI: 2.14, 11.37).

CONCLUSION

These data support that low serum estradiol, advancing age, lower physical activity, lower vitamin D intake, cigarette smoking, and higher amount of caffeine intake are linked to low bone mineral density in premenopausal Mexican women.

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).

Prevalence of Cognitive Impairment in Recently Diagnosed Type 2 Diabetes Patients: Are Chronic Inflammatory Diseases Responsible for Cognitive Decline?

OBJECTIVE

To estimate the prevalence of cognitive impairment (CI) among patients recently diagnosed with type 2 diabetes (RDD) and to identify any relationships between CI and RDD comorbidities.

METHODS

One thousand seven hundred twelve patients with RDD participated in a cross-sectional study. The patients' sociodemographic and clinical data were registered.

RESULTS

The sample population had an average age of 51 ± 11 years, and 63.26% of the patients were female. CI was diagnosed in 38 patients (2.2%) and was more common among both females (2.8% vs. 1.3%, p = 0.063) and the elderly (0% at an age ≤ 30 years vs. 10.4% at an age > 70 years, p = 0.0001). Rheumatoid arthritis (present in 15.8% vs. absent in 2.1%) and asthma (13% vs. 2.1%) correlated significantly with CI based on the results of our logistic regression analysis.

CONCLUSION

Age, female gender, rheumatoid arthritis and asthma are risk factors for CI in the setting of RDD.

Carotid Intima-Media Thickness, Ankle-Arm Index, and Inflammation Profile in Mexican Patients with Early and Late Onset Type 2 Diabetes

BACKGROUND

Type 2 diabetes is strongly linked to an increased incidence of cardiovascular outcomes. Carotid artery intima-media thickness and ankle-arm index are non-invasive complementary measures as subclinical markers of atherosclerosis.

OBJECTIVE

To evaluate the association of carotid intima-media thickness, ankle-arm index, and inflammation profile in Mexican patients with early- and late-onset type 2 diabetes mellitus.

MATERIAL AND METHODS

We included 145 subjects at an academic medical center: 77 patients with early-onset (< 40 years of age) and 33 patients with late-onset (≥ 40 years) type 2 diabetes mellitus, and 35 healthy volunteers. Clinical history, anthropometrics, blood chemistry, lipids profile, glycosylated hemoglobin A1c, cytokines, and high-sensitivity C-reactive protein were determined; carotid and lower limb ultrasound were taken. Groups were compared with ANOVA or Kruskal-Wallis, Student's t or Mann-Whitney U. Spearman or Pearson correlation and logistic regression analysis were used.

RESULTS

There were anthropometric and biochemical differences between the three groups. Concentrations of interleukin-1β, -4 and -6 were significantly higher in patients with late versus early onset diabetes. There were differences in carotid intima-media thickness and ankle-arm index between early and late onset. Age, body mass index, high-density lipoprotein cholesterol, high-sensitivity C-reactive protein, waist circumference, and glycosylated hemoglobin A1c showed direct correlation with carotid intima-media thickness, while ankle-arm index showed inverse correlation with blood pressure, glycosylated hemoglobin A1c, time with disease, age at onset, triglycerides, and fibrinogen. Multivariate analysis showed an association between carotid intima-media thickness and disease duration; ankle-arm index with disease duration and high-sensitivity C-reactive protein; while only body mass index associated with end diastolic flow velocity.

CONCLUSIONS

Our findings suggest that carotid intima-media thickness and ankle-arm index are associated with inflammation markers and could be included in the evaluation of type 2 diabetes mellitus patients, according to disease onset and duration. There are important differences in interleukin concentrations between early- and late-onset type 2 diabetes mellitus. Additionally, measurement of high-sensitivity C-reactive protein is suggested in patients with abnormal ankle-arm index.

Bone speed of sound throughout lifetime assessed with quantitative ultrasound in a Mexican population

The purpose of this study was to assess the bone speed of sound (SoS) through lifetime of a large Mexican population sample by determining the SoS from the radius and tibia using quantitative ultrasound (QUS). This is a cross-sectional evaluation of participants in the Mexican Health Workers Cohort Study. QUS measurements were performed using Sunlight Omnisense 8000P; Z- and T-scores were calculated for both sexes at the distal third of the radius and midshaft tibia, both on the nondominant side. A locally weighted regression smoothing scatterplot model was used to identify different phases of bone accretion and loss. A total of 9128 participants aged 1-75 yr were measured with QUS. Bone SoS accretion began 5 yr earlier in girls than boys (p<0.05). Maximal SoS or peak bone SoS was noted at 28 yr in the radius and at 22 yr in the tibia. Postmenopausal women (45-50 yr) showed significant SOS decrease at both sites (p<0.05) compared with men. Using the locally weighted regression smoothing scatterplot model, we found 5 different phases that constitute the biological development of bone over the life course, from ages 1-6, 7-12, 12-25, 25-50, and 50-75 yr (p<0.05). Our study shows the age- and sex-dependent changes and different phases of bone development expressed by SoS measurements of the radius and tibia. The values reported in this study can be used as a reference for urban Mexican population.

[Clinical research XXIV. From clinical judgment to ethics in research on humans]

Bioethics in research is an essential part of the structured review process of an article and it is based on three fundamental principles: respect for persons, beneficence and justice. In addition to not providing valid knowledge, a research with inadequate design, execution and statistical analysis is not ethical either, since these methodological deficiencies will produce information that will not be useful and, therefore, the risks that the participants were exposed to will have been in vain. Beyond scientific validity, there are other aspects that outline if an investigation is ethical, such as the clinical and social value of a study, a fair selection of participants, favorable risk-benefit balance, an independent review, the informed consent and respect for participants and potential participants. Throughout the article here presented, the documents that profile the behavior of investigators to protect the participants, such as the Declaration of Helsinki, the national regulations that rule us and the differences between research without risk, with minimal risk and with greater than minimal risk are discussed. That like in daily life, behavior in research involving human participants must be self-regulated, ie, people with knowledge of the existence of the law discover that the man is outside the realm of nature where work is done under the necessity of natural causality, and falls within the scope of the will; only if the man is free to decide their actions may be a law regulating their action.

Predictors of hyperlipidemia during the first half of pregnancy in Mexican women

OBJECTIVE

To determine the predictors of hypercholesterolemia and of hypertriglyceridemia during the first half of pregnancy in Mexican women.

METHODS

Cross-sectional comparative study of pregnant women with less than 21 weeks of gestational age.

MEASUREMENTS

Demographic information, obstetric history, prepregnancy body mass index, cholesterol and triglycerides. Cross tabulations and multiple logistic regression were used for statistical analysis.

RESULTS

230 participants; 61 women with normal prepregnancy body mass index, 108 with overweight, and 61 with obesity. Dyslipidemia was defined as elevated cholesterol (>180 mg/dL) or triglycerides (>170 mg/dL). After adjusting by potential confounders, independent predictors of hypercholesterolemia included being overweight (OR=2.8, 95% CI 1.4-5.9), being obese (OR=3.7 95% CI 1.6-8.4) or being on the second trimester of pregnancy. The same predictors were found for hypertriglyceridemia, respectively OR=2.8, 95% CI 1.4-5.6, OR=2.9, 95% CI 1.3-6.5, OR=2.6, 95% CI 1.4-4.7.

CONCLUSION

Mexican women with prepregnancy overweight or obesity have greater risk of suffering hypercholesterolemia and hypertriglyceridemia during pregnancy. Women in the second trimester had higher levels of both lipids as compared to the first one. This is the first Mexican study that confirms the increase of lipids as gestational age progresses.

[Clinical research XXIII. From clinical judgment to meta-analyses]

Systematic reviews (SR) are studies made in order to ask clinical questions based on original articles. Meta-analysis (MTA) is the mathematical analysis of SR. These analyses are divided in two groups, those which evaluate the measured results of quantitative variables (for example, the body mass index -BMI-) and those which evaluate qualitative variables (for example, if a patient is alive or dead, or if he is healing or not). Quantitative variables generally use the mean difference analysis and qualitative variables can be performed using several calculations: odds ratio (OR), relative risk (RR), absolute risk reduction (ARR) and hazard ratio (HR). These analyses are represented through forest plots which allow the evaluation of each individual study, as well as the heterogeneity between studies and the overall effect of the intervention. These analyses are mainly based on Student's t test and chi-squared. To take appropriate decisions based on the MTA, it is important to understand the characteristics of statistical methods in order to avoid misinterpretations.

[Clinical research XXII. From clinical judgment to Cox proportional hazards model]

Survival analyses are commonly used to determine the time of an event (for example, death). However, they can be used also for other clinical outcomes on the condition that these are dichotomous, for example healing time. These analyses only consider the relationship of one variable. However, Cox proportional hazards model is a multivariate analysis of the survival analysis, in which other potentially confounding covariates of the effect of the main maneuver studied, such as age, gender or disease stage, are taken into account. This analysis can include both quantitative and qualitative variables in the model. The measure of association used is called hazard ratio (HR) or relative risk ratio, which is not the same as the relative risk or odds ratio (OR). The difference is that the HR refers to the possibility that one of the groups develops the event before it is compared with the other group. The proportional hazards multivariate model of Cox is the most widely used in medicine when the phenomenon is studied in two dimensions: time and event.

Sweetened beverage consumption and the risk of hyperuricemia in Mexican adults: a cross-sectional study

BACKGROUND

The prevalence of hyperuricemia has doubled worldwide during the last few decades. The substantial increase in sweetened beverage (SB) consumption has also coincided with the secular trend of hyperuricemia. Recent studies do show that the consumption of SB can induce hyperuricemia. However, the association between SB and hyperuricemia remains unclear. The aim of this study was to evaluate the association between SB consumption and levels of uric acid in Mexican adults.

METHODS

We performed a cross-sectional analysis of data from selected adults participating in the baseline assessment of the Health Workers Cohort Study. A total of 6,705 participants of both sexes between ages 18 and 70 years were included. SB intake was estimated using a validated semi-quantitative food frequency questionnaire. Biochemical and anthropometric information was collected using standard procedures. Hyperuricemia was defined as uric acid levels ≥ 7.0 mg/dL in men and ≥ 5.8 mg/dL in women. The association of interest was assessed by multiple logistic regression models.

RESULTS

The odds ratios (OR) for hyperuricemia in men who consume 0.5-1 SB/day was 1.59 (95% CI; 1.05-2.40) and 2.29 (95% CI; 1.55-3.38) for those who consume ≥3 SB/day when compared to men who consume less than half a SB/day. In women, the OR for hyperuricemia for those who consume >1.0- < 3.0 SB/day was 1.33 (95% CI; 1.04-1.70) and 1.35 (95% CI; 1.04-1.75) for those who consume ≥3 SB/day when compared to women who consume less than half a SB/day, independent of other covariables. Men and women with high SB consumption and a body mass index (BMI) ≥ 25 Kg/m2 had greater risk for hyperuricemia than men and women with low SB consumption and normal BMI < 25 Kg/m2.

CONCLUSIONS

Our findings suggest that the consumption of SB is associated with an increased risk of hyperuricemia in Mexican adults. However, longitudinal research is needed to confirm the association between SB intake and hyperuricemia.

[Clinical research XXI. From the clinical judgment to survival analysis]

Decision making in health care implies knowledge of the clinical course of the disease. Knowing the course allows us to estimate the likelihood of occurrence of a phenomenon at a given time or its duration. Within the statistical models that allow us to have a summary measure to estimate the time of occurrence of a phenomenon in a given population are the linear regression (the outcome variable is continuous and normally distributed -time to the occurrence of the event-), logistic regression (outcome variable is dichotomous, and it is evaluated at one single interval), and survival curves (outcome event is dichotomous, and it can be evaluated at multiple intervals). The first reference we have of this type of analysis is the work of the astronomer Edmond Halley, an English physicist and mathematician, famous for the calculation of the appearance of the comet orbit, recognized as the first periodic comet (1P/Halley's Comet). Halley also contributed in the area of health to estimate the mortality rate for a Polish population. The survival curve allows us to estimate the probability of an event occurring at different intervals. Also, it leds us to estimate the median survival time of any phenomenon of interest (although the used term is survival, the outcome does not need to be death, it may be the occurrence of any other event).

[Clinical research XX. From clinical judgment to multiple logistic regression model]

The complexity of the causality phenomenon in clinical practice implies that the result of a maneuver is not solely caused by the maneuver, but by the interaction among the maneuver and other baseline factors or variables occurring during the maneuver. This requires methodological designs that allow the evaluation of these variables. When the outcome is a binary variable, we use the multiple logistic regression model (MLRM). This multivariate model is useful when we want to predict or explain, adjusting due to the effect of several risk factors, the effect of a maneuver or exposition over the outcome. In order to perform an MLRM, the outcome or dependent variable must be a binary variable and both categories must mutually exclude each other (i.e. live/death, healthy/ill); on the other hand, independent variables or risk factors may be either qualitative or quantitative. The effect measure obtained from this model is the odds ratio (OR) with 95 % confidence intervals (CI), from which we can estimate the proportion of the outcome's variability explained through the risk factors. For these reasons, the MLRM is used in clinical research, since one of the main objectives in clinical practice comprises the ability to predict or explain an event where different risk or prognostic factors are taken into account.

Carotid intima media thickness, oxidative stress, and inflammation in children with chronic kidney disease

OBJECTIVE

We evaluated the association between inflammation and oxidative stress with carotid intima media thickness (cIMT) and elasticity increment module (E(inc)) in pediatric patients with chronic kidney disease (CKD).

METHODS

This analytical, cross-sectional study assessed 134 children aged 6-17 years with CKD. Anthropometric measurements and biochemistry of intact parathyroid hormone (iPTH), high-sensitivity C-reactive protein (CRP), interleukin (IL)-6, IL-1β, reduced glutathione (GSH), malondialdehyde, nitric oxide, and homocysteine were recorded. Bilateral carotid ultrasound (US) was taken. Patients were compared with controls for cIMT and E(inc) using ≥ 75 percentile (PC).

RESULTS

Mean cIMT was 0.528 ± 0.089 mm; E(inc) was 0.174 ± 0.121 kPa × 10(3); cIMT negatively correlated with phosphorus (r -0.19, p =0.028) and the calcium × phosphorus (Ca × P) product (r -0.26, p =0.002), and positively with iPTH (r 0.19,p =0.024). After adjusting for potential confounders, hemodialysis (HD) (β=0.111, p =<0.001), automated peritoneal dialysis (APD) (β=0.064, p =0.026), and Ca x P product(β=-0.002, p =0.015) predicted cIMT (R(2)=0.296). In patients on dialysis, HD (β=0.068, p =0.010), low-density lipoprotein cholesterol (LDL-C) (β=0.001, p =0.048), and GSH(β=-0.0001, p=0.041) independently predicted cIMT (R(2)=0.204); HD, hypoalbuminemia, and high iPTH increased the risk of increased cIMT. In dialysis, E(inc) was inversely associated with GSH, and in predialysis, Ca × P correlated with/predicted E(inc) (β=0.001, p =0.009).

CONCLUSIONS

cIMT and E(inc) strongly associate with several biochemical parameters and GSH but not with other oxidative stress or inflammation markers.

[Clinical research XIX. From clinical judgment to analysis of covariance]

The analysis of covariance (ANCOVA) is based on the general linear models. This technique involves a regression model, often multiple, in which the outcome is presented as a continuous variable, the independent variables are qualitative or are introduced into the model as dummy or dichotomous variables, and factors for which adjustment is required (covariates) can be in any measurement level (i.e. nominal, ordinal or continuous). The maneuvers can be entered into the model as 1) fixed effects, or 2) random effects. The difference between fixed effects and random effects depends on the type of information we want from the analysis of the effects. ANCOVA effect separates the independent variables from the effect of co-variables, i.e., corrects the dependent variable eliminating the influence of covariates, given that these variables change in conjunction with maneuvers or treatments, affecting the outcome variable. ANCOVA should be done only if it meets three assumptions: 1) the relationship between the covariate and the outcome is linear, 2) there is homogeneity of slopes, and 3) the covariate and the independent variable are independent from each other.

[From clinical judgment to linear regression model.]

When we think about mathematical models, such as linear regression model, we think that these terms are only used by those engaged in research, a notion that is far from the truth. Legendre described the first mathematical model in 1805, and Galton introduced the formal term in 1886. Linear regression is one of the most commonly used regression models in clinical practice. It is useful to predict or show the relationship between two or more variables as long as the dependent variable is quantitative and has normal distribution. Stated in another way, the regression is used to predict a measure based on the knowledge of at least one other variable. Linear regression has as it's first objective to determine the slope or inclination of the regression line: Y = a + bx, where "a" is the intercept or regression constant and it is equivalent to "Y" value when "X" equals 0 and "b" (also called slope) indicates the increase or decrease that occurs when the variable "x" increases or decreases in one unit. In the regression line, "b" is called regression coefficient. The coefficient of determination (R²) indicates the importance of independent variables in the outcome.

[Clinical research XVII. χ(2) test, from the expected to the observed]

When you want to show if there is a statistical association or differences between categorical variables, it is recommended to use the χ(2) test. This nonparametric test is one of the most used in clinical research; it contrasts nominal or ordinal qualitative variables that are observed in clinical practice. This test calculates the p value that determines whether differences between groups are real or due to chance. The χ(2) test is the basis of other tests to analyze qualitative ordinal variables as χ(2) for linear trend, which compares three groups with two outcomes or McNemar test, which contrasts two related samples (a before and afterward comparison) or Mantel-Haenszel χ(2), which controls for potential confounding variables. When using small samples, where the expected results are less than 5, Fisher's exact test should be used. These tests are the most widely used in the medical literature; however, they do not give us the magnitude or the direction of the event and a proper interpretation that requires clinical judgment is needed.

[Medical practice and clinical research: keys to generate knowledge and improve care]

The increased quality in medical care may be immediately accomplished if clinical research is integrated into daily clinical practice. In the generation of medical knowledge are four steps: an unanswered question awakened from clinical practice, the critical analysis of specialized literature, the development of a research protocol, and, finally, the publication of outcomes. Decision making and continuous training are becoming part of an effective strategy of medical attention improvement.

[Clinical research XVI. Differences between medians with the Mann-Whitney U test]

If you want to prove that there are differences between two groups with quantitative variables with non-normal distribution, the Mann-Whitney U test is used. This test is opposite of the Student t test that uses quantitative variables with a normal distribution. If you want to compare three or more nonrelated groups, the Kruskal-Wallis test is applied. When two related samples are compared, the Wilcoxon test is the best option (a before and after maneuver comparison); when three related samples are compared, the Friedman test is used. These tests correspond to the parametric opposing paired t test and ANOVA, respectively.

[Clinical research XV. From the clinical judgment to the statistical model. Difference between means. Student's t test]

Among the test to show differences between means, the Student t test is the most characteristic. Its basic algebraic structure shows the difference between two means weighted by their dispersion. In this way, you can estimate the p value and the 95 % confidence interval of the mean difference. An essential feature is that the variable from which the mean is going to be calculated must have a normal distribution. The Student t test is used to compare two unrelated means (compared between two maneuvers), this is known as t test for independent samples. It is also used to compare two related means (a comparison before and after a maneuver in just one group), what is called paired t test. When the comparison is between more than two means (three or more dependent means, or three or more independent means) an ANOVA test (or an analysis of variance) it is used to perform the analysis.

[Clinical research XIV. From the clinical judgment to the statistical model]

A statistical test is incomprehensible when it is out of context, so it is necessary to identify the details of the phenomenon of causality in the clinical course of the disease and to integrate the statistical model. Thus, the statistical tests used will try to characterize baseline, maneuver and the outcome, and will show the relationship between them. When we read the results in clinical research, the first thing that the author describes are general characteristics of the population, starting with number of patients evaluated and selected, average age, gender, and number of subjects meeting the outcome. This is extremely important because with the same criteria two studies may contain populations completely opposite. Posterior description usually continues through tables that follow a logical sequence, which allow us to integrate the statistical model to clinical judgment: baseline characteristics of the population and its distribution in each of the maneuvers, characteristics of the main and peripheral maneuvers, main effect of the maneuver on the outcome, and the impact of principal maneuver in the outcome, but adjusted for any variable that can alter this impact.

[Clinical research. XIII. Research design contribution in the structured revision of an article]

The quality of information obtained in accordance to research design is integrated to the revision structured in relation to the causality model, used in the article "Reduction in the Incidence of Nosocomial Pneumonia Poststroke by Using the 'Turn-mob' Program", which corresponds to a clinical trial design. Points to identify and analyze are ethical issues in order to safeguard the security and respect for patients, randomization that seek to create basal homogeneous groups, subjects with the same probability of receiving any of the maneuvers in comparison, with the same pre maneuver probability of adherence, and which facilitate the blinding of outcome measurement and the distribution between groups of subjects with the same probability of leaving the study for reasons beyond the maneuvers. Other aspects are the relativity of comparison, the blinding of the maneuver, the parallel application of comparative maneuver, early stopping, and analysis according to the degree of adherence. The analysis in accordance with the design is complementary, since it is done based on the architectural model of causality, and the statistical and clinical relevance consideration.

[Clinical research XII. From the clinical judgment to the transversal design]

A longitudinal study, such as a cohort or clinical trial, has the virtue of following the logical sequence in which occurs the components of causality phenomenon. However, in a cross-sectional survey, this logical sequence does not exist, because the three components are measured at one time: the basal state, maneuver, and result. However, the design of "clinical judgment" helps us to rebuild these components artificially in the time sequence in which they occurred. The way the population is assembled and how information is obtained, transversally and retrospectively, carries the risk of bias. While trying to associate a probable maneuver to an outcome in a pathological situation is difficult and often causes bias, a cross-sectional survey is the best to show the development of healthy people simulating a longitudinal study, like the height and weight estimation according to age. This type of design has been called "a longitudinal cross sectional study."

Metformin decreases plasma resistin concentrations in pediatric patients with impaired glucose tolerance: a placebo-controlled randomized clinical trial

The objective was to determine the effect of metformin on the concentrations of resistin and other markers of insulin resistance or inflammation (C-reactive protein, cytokines, body weight, HbA1c, among others) in minors with glucose intolerance. Patients aged 4 to 17 years with glucose intolerance were studied. They were randomized to receive 850 mg of either metformin or placebo twice daily for 12 weeks, during which all followed an iso-caloric diet and an exercise program. High sensitivity C-reactive protein, TNF-alpha, IL-6, IL1-beta, resistin, leptin, adiponectin, glucose, insulin, HbA1c, lipid profile and transaminases were measured at the beginning and at the end of the period. Fifty-two patients were included, 11.9±2.6 years old; 28 (12 males/16 females) received metformin and 24 placebo (11 males/13 females). Baseline characteristics were similar between groups (except for body mass index, which in the metformin group was slightly higher). Percentage weight loss was greater in the metformin group (-5.86% vs 2.75%, P<.05). At study end, there were statistically significant differences in resistin concentrations, even after adjusting for confounding variables (F=7.714; P<.006). Also, metformin was associated with a significant decrease in HOMA-IR index (P=.032) and HbA1c levels (P=.001), but no change was observed in the concentration of other markers of inflammation. Metformin resulted in significant reductions of plasma resistin levels in minors with glucose intolerance. This change is independent of its effects on body weight. In contrast, metformin did not alter the concentration of inflammatory markers.