MY YEARS AS COEDITOR OF THE REVISTA DE INVESTIGACIóN CLíNICA AND THE 1993-1998 READERS OF OUR JOURNAL.

Some information on our readers during my years as coeditor of the Revista de Investigación Clínica are presented on the basis that readers, unlike editors, have no conflict of interest in evaluating scientific publications. The information provided is restricted to the past 6 years (1993-1998) of my 11 years as coeditor since the number of reader visits to our on-line articles began in 1993. The nearly 500 articles published in the 6-year lapse were visited by more than 1 million readers with an outstanding 1998 year of almost 100 articles and near a quarter of a million visits. These figures suggest that our journal became at the end of the 20th Century a valuable information source for physicians in Mexico. It was the original idea that led Salvador Zubirán to launch this journal in 1948.

THE EVOLVING HISTORY OF THE REVISTA DE INVESTIGACIóN CLíNICA.

The Revista de Investigación Clínica (RIC) was established in 1948. It has been published continuously for 73 years. Until 2009, it was the journal of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (formerly Hospital de Enfermedades de la Nutrición, and later named Instituto Nacional de la Nutrición), and thereafter it became the official journal of the Mexican National Institutes of Health. The history of this journal may be divided into four eras or periods, each distinctly characterized by the trends, and particular editorial policies imposed by the Editor-in-Chief and Editorial Committee in turn. The RIC, since 2015 known as RIC -Clinical and Translational Investigation-, is currently a nationally and internationally recognized scientific journal. This article briefly reviews the most outstanding historical features of the RIC since its foundation.

Prevalence of obesity and diabetes in the socioeconomic transition of rural Mayas of Yucatan from 1962 to 2000.

Background: The Mayas of the State of Yucatan in Mexico are the only aboriginal group with obesity and diabetes data before 1997. Objective: To analyze socioeconomic trends associated with the increase in obesity and diabetes seen in rural Yucatan from 1962 to 2000. Methods: Body weight, height and venous Fasting Blood Glucose (FBG) were measured in 263 rural Maya adults participating in a 2000 nutrition survey. Results: Diabetes (FBG > 125 mg/dL) and obesity (BMI ≥ 30 kg/m2) were 10.6% and 35.7%, respectively. These results contrast with those of a 1962 survey where diabetic prevalence was 2.3% and 0% in women and men respectively, with widespread adult pellagra and malnutrition. An important socioeconomic transition that took place in Yucatan during this lapse appeared to be associated to the obesity and diabetes increase. Conclusions: Rural Yucatan evolved from malnutrition conditions to high prevalence of obesity and diabetes in less than 40 years. This change was associated with the transition from an agroindustry-based economy, characterized by high-energy expenditure and low protein intake, to lower energy requirements of a Government-subsidized economy with larger food supply.

Tamaño de muestra de protocolos clínicos.

El cálculo del tamaño de muestra en los protocolos clínicos que se revisan en el comité institucional del Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán tiene básicamente tres tipos de problemas: datos insuficientes para recalcular el tamaño de la muestra, uso de ecuaciones obsoletas que no toman en cuenta el error beta y uso de una ecuación que no corresponde al diseño del estudio. En este documento discutimos los cuatro datos que deben ser incluidos en los protocolos de los estudios clínicos aleatorizados que comparan medicamentos versus placebo en los estudios de superioridad y versus control activo en los estudios de no inferioridad.Sample size calculation in clinical protocols submitted to the review board of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán frequently has three types of problems: insufficient data for sample size recalculation, use of obsolete equations that do not take the beta error into account, and use of equations that do not correspond to the study design. In this document, we discuss the four data that should be included in the clinical protocols of randomized controlled trials that compare drugs versus placebo in superiority trials, and versus active controls in non-inferiority studies.

End-of-life decisions in perinatal care: A view from health-care providers in Mexico.

OBJECTIVE: To examine the opinions of a perinatal health team regarding decisions related to late termination of pregnancy and severely ill newborns. MATERIALS AND METHODS: An anonymous questionnaire was administered to physicians, social workers, and nurses in perinatal care. Differences were evaluated using the chi square and Student's t tests. RESULTS: When considering severely ill fetuses and newborns, 82% and 93% of participants, respectively, opted for providing palliative care, whereas 18% considered feticide as an alternative. Those who opted for palliative care aimed to diminish suffering and those who opted for intensive care intended to protect life or sanctity of life. There was poor knowledge about the laws that regulate these decisions. CONCLUSIONS: Although there is no consensus on what decisions should be taken with severely ill fetuses or neonates, most participants considered palliative care as the first option, but feticide or induced neonatal death was not ruled out.

Legality and age influence end of life decisions in Mexican physicians.

PURPOSE: To test in two groups of physicians-in-training a simplified questionnaire exploring their acceptance of Physician Assisted Death (PAD), Therapy Withdrawal upon family request (WD), and Personalized PAD (PPAD) on whether the participant would seek PAD for him/herself. MATERIAL AND METHODS: A 4-item questionnaire was answered by 212 residents in different stages of training and grouped as beginners (1st and 3d year internal medicine residents, n = 76) and advanced (5th to 8th year residents of different internal medicine or oncology subspecialties, n = 136). The response options to the PAD and WD questions included a conditioned yes (CYes) dealing with legalization of PAD or the existence of a patient's previous written agreement to WD. RESULTS: Beginners had significantly more Yes plus C-Yes answers than advanced for questions regarding PAD (82 vs. 55%), WD (95 vs. 75%) and PPAD (76 vs. 56%). The importance of legal aspects implied in the conditioned answers can be seen in two findings: a) A sizable 29% of participants conditioned their Yes answers for both questions whereas only 9% gave an unconditioned Yes to both. b) A cross-classification of the PAD and WD answers showed that 13% of participants reversed their No in PAD to C-Yes in WD. CONCLUSIONS: Our simplified questionnaire operated well and was able to confirm the increase in acceptance of PAD and WD by young Mexican physicians, and the need of legislation regarding end of life decisions in our country.

The modernization of cooking techniques in two rural Mayan communities of Yucatán: the case of lard frying.

The objective of this article is to provide information on cooking techniques used by two rural communities of Yucatán. We used a 24-hour recall method with 275 participants consuming 763 dishes. Dishes were classified according to cooking technique: 205 were lard-fried (27%), 169 oil-fried (22%), and 389 boiled/grilled (51%). The smaller more secluded community (San Rafael) consumed more fried dishes than the larger community (Uci) (54% versus 45%) and used more lard-frying than Uci (65% versus 46%). The more extensive use of lard in the smaller community appears to be due to fewer modernizing influences such as the availability and use of industrialized vegetable oils.

[Four years of raw mortality in an intensive care unit]. / Cuatro años de mortalidad cruda en una Unidad de Cuidados Intensivos.

OBJECTIVE: To characterize magnitude and variability of raw mortality in a Mexican Intensive Care Unit (ICU). MATERIAL AND METHODS: Demographic and clinical data were analyzed in 1,746 patients discharged from the ICU of the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran. The data was obtained from an administrative database and covered four years (2003-2006). RESULTS: Overall ICU-mortality was 23% (410/1746) and was associated with two binary variables (higher mortality in weekend admissions and non-surgical cases) and three multicategorical variables (gradient of increasing mortality with increasing age, increasing diagnostic risk and increasing number of high-rish diagnoses). First biennium mortality was significantly higher than in the second biennium (29% us 19%). This higher mortality was not associated with the high risk categories of the five variables described above nor with other ICU-variables such as number of nurses and admission and discharge criteria. The only biennium difference was a higher number of physicians (specialists + residents) in the second biennium (16-20 versus 14-15 in the first). CONCLUSIONS: The four-year long-term ICU-mortality showed a significant decrease in the second biennium. Number of physicians was the only variable associated with the decreased mortality.

Weekly iron as a safe alternative to daily supplementation for nonanemic pregnant women.

BACKGROUND: We undertook this study to compare the effectiveness and safety of antenatal daily and weekly supplementation with iron, folic acid, and vitamin B(12) in healthy, pregnant women who were not anemic at gestational week 20. METHODS: Women with singleton pregnancies and blood hemoglobin (Hb) >115 g/L at gestational week 20 (equivalent to 105 g/L at sea level) were randomly assigned to two groups, one consuming one tablet containing 60 mg iron, 200 mug folic acid and 1 mug vitamin B(12) daily (DS, n = 56); the other consuming two tablets once weekly (WS, n = 60). Blood Hb and serum ferritin concentrations were measured every 4 weeks from weeks 20 to 36, and pregnancy outcomes were evaluated. RESULTS: Mild anemia and hypoferritinemia throughout pregnancy occurred less frequently in DS than WS. None of the 116 women had Hb concentrations <103 g/L at any evaluation point. In contrast, hemoconcentration (Hb >145 g/L) from gestational week 28 onwards occurred in 11% in DS and 2% in WS. We observed ex post facto that hemoconcentration at gestational week 28 was associated with a significantly higher relative risk of low birth weight (RR 6.23, 95% CI 1.46-26.57) and premature delivery (RR 7.78, 95% CI 1.45-24.74). CONCLUSIONS: In women who were nonanemic at gestational week 20, both schemes (DS and WS) prevented the occurrence of Hb levels <100 g/L. DS women had a higher incidence of hemoconcentration. Hemoconcentration was associated with increased risk of low birth weight and premature delivery.

Changes in the household calorie supply during the 1994 economic crisis in Mexico and its implications on the obesity epidemic.

To characterize the effects of the 1994 economic crisis on calorie sources of Mexican households, five nutrition surveys done every leap year (1992-2000) in national representative samples (> 10,000 households) were analyzed. Each household was visited during 7 days to collect data on foods purchased, exchanged or home-grown and their monetary value. We selected 88 food items to calculate kilocalories/ person/day and cost in pesos/megacalorie (CPMC) for rural-urban strata (localities < 2500, > or = 2500). The food items were classified in 8 groups and the summation of kilocalories and CPMCs of items in each group were our units of analysis. Linear regressions for 1992-2000 were performed, and slopes and intercepts were used to characterize changes. Available calories showed very little change at the height of the economic crisis. Expensive calories (meat in urbans, eggs and milk in rurals, and industrialized meat and soft drinks in both) tended to increase, whereas the most inexpensive staples (cereals, legumes, sugars) decreased their share in both strata. An increase in obesigenic calories was seen, notably in soft drinks, despite a cost increase second only to meat. Main conclusions were: (1) the economic crisis did not affect total calories availability in Mexican households; (2) the 1992-2000 trends in calorie sources were contrary to any crisis effect in rurals and urbans (i.e., expensive foods increased and inexpensive staples decreased); (3) there were sizable rural-urban differences in number, source, and cost of calories; and (4) obesigenic calories increased and soft drinks emerged as a food with its own dynamic.

Clinical findings as predictors of positivity of head-up tilt table test in neurocardiogenic syncope.

BACKGROUND: Neurocardiogenic (vasovagal) syncope occurs frequently and can be diagnosed with the head-up tilt table (HUTT) test. Our objective in this study was to identify clinical predictors of the positivity of HUTT test in neurocardiogenic syncope. METHODS: We conducted a prospective study of 117 cases (81 women and 36 men, 13-85 years of age) referred to our Institution for HUTT testing. The ability of 10 symptoms and signs of clinical history to predict HUTT positivity were evaluated using logistic regression analysis. RESULTS: We observed a low rate of test-negative cases (24%) and 89 positives. Nearly all positives (87/89) were neurocardiogenic, principally of vasodepressor and mixed types (43 and 34 cases, respectively) and a few were cardioinhibitory (10, mostly young males). Regression analysis established that dizziness, nausea, and diaphoresis in past history were associated with HUTT positivity nearly 25 times more frequently than when absent. CONCLUSIONS: Our three conclusions are that syncope in absence of heart disease accompanied by dizziness, nausea, and diaphoresis may be treated as neurocardiogenic in settings where no HUTT is available. In addition, our low rate of negative tests may have been the result of our reexamining referrals prior to deciding test performance, and high frequency of young males in cardioinhibitory syncope needs further research.

[The second biennial of the External Quality Evaluation Program in Urinalysis (PEECU)]. / El segundo bienio del Programa de Evaluación Externa de Calidad en Uroanálisis (PEECU).

OBJECTIVE: To characterize the participation of clinical laboratories in the second biennial of an external quality assurance scheme for urinalysis in Mexico. METHODS: The participants received 32 control samples in 8 shipments of 4 controls each during the biennial 1999-2000. The controls were in the form of tablets to be dissolved in 12 mL of water to mimic urine. The participants performed dipstick assays of pH, specific gravity (SG) and 8 analytes (proteins, glucose, ketones, blood, bilirubin, nitrites, urobilinogen, leukocytes) in the controls. Expected control values were assigned by 10-15 replicate automated assays using dipsticks and apparatus of a single provider (Bayer). Participants' results were transformed to scores ranging from zero (perfect result) to 400 (worst possible). Score differences were analyzed using nonparametric methods (Kruskal-Wallis and Mann-Whitney). RESULTS: The best results were seen for nitrites, ketones and proteins (mean global scores = 3-5) and the worst for SG (score = 45) with intermediate scores of 10-13 for the other six. CONCLUSIONS: The scores improved for the second biennial from a grand mean of 17 in the first significantly down to 12 in the second. The number of participants has been increasing yearly and there has been a decrease of participants who do not report at least 3 out of 4 yearly shipments. We confirmed that automated readings yield better scores than visual readings.

[A predictive model of mortality in the ICU of a Mexico City hospital]. / Un modelo predictivo de mortalidad en una UCI de un hospital de la ciudad de México.

OBJECTIVE: To explore the associations of mortality with routine logbook information as a preliminary to developing a quality control system in an ICU. METHODS: The ICU logbook contained seven variables of 2,745 consecutive cases hospitalized from Jan-01-1998 to Dec-31-2002. The univariate association of ICU mortality with five predictive and two non-predictive variables was explored. Gender was the only one unassociated. A logistic regression predictive model of mortality of three variables was generated (cause of hospitalization, age and type of patient). RESULTS: The global mortality was 27%. The highest risk was for non-surgery patients aged 80+ years with multiple organic failure, sepsis and/or pneumonia. They had a relative risk of 18.1 versus the reference group (surgical cases aged 20-39 with less severe illnesses). Three additional simple predictors were identified as potentially useful and are to be included in an updated logbook. CONCLUSIONS: 1. The logbook information appeared to be useful in monitoring ICU quality of service as six logbook variables were associated to mortality. 2. Our predictive model has the potential to operate as an index of severity of disease and may improve by the inclusion of additional information. 3. Its usefulness is to be compared prospectively with well-established predictors (Apache II and others).

Clinimetric testing in mexican elders: associations with age, gender, and place of residence.

AIM: To evaluate the ability of five clinimetric instruments to discriminate between subjects >60 years of age living at home versus those living in a residency. METHODS: Trained nutritionists applied five instruments (cognition/depression/functionality/nutrition/appetite) to 285 subjects with majorities of women (64%), aged <80 years (61%), and home residents (54%). RESULTS: Multivariable regression models were generated for each instrument using age, gender, and residency as independent variables. Age was associated with worsening scores in the five instruments whereas residency showed association in three instruments, and gender in two. Score-age regressions by place of residency showed differences suggesting that Mundet residents had increasingly worse scores with increasing age than home dwellers for cognition, depression, and nutrition. Also, living at home prevented the worsening of depression with increasing age. In contrast, functionality and appetite deteriorated at a similar rate for home and Mundet residents suggesting an inability of these two instruments to discriminate between settings. Score-age regressions by gender suggested that males have less cognitive problems at 60 and 80 years of age but not at 100 years, and better appetite than women at all ages. CONCLUSION: Increasing age proved to be associated to worsening scores in the five instruments but only three were able to detect differences according to setting. An interesting observation was that living at home appeared to prevent the depression increase with increasing age seen in Mundet residents.

Physician-assisted death. Opinions of Mexican medical students and residents.

BACKGROUND AND AIMS: To explore opinions of young residents and medical students on physician-assisted death (PAD). METHODS: A questionnaire was answered by 140 residents at the beginning of their residency and 99 third- or fourth-year medical students (46 attended religiously administered medical schools [RAMS] and 53 lay-administered medical schools [LAMS]). Main questions were agreement with PAD, therapy withdrawal (TW) and personalized PAD (PPAD) on whether participants themselves would seek help to die. RESULTS: There were no differences of acceptance between residents and students but LAMS students had significantly higher agreement than RAMS students for PAD (68 vs. 33%), TW (79 vs. 39%) and PPAD (57 vs. 48%). LAMS students were also more willing to agree to a physician prescribe/inject a lethal drug, even if PAD were not legalized. However, legality was also an important issue, i.e., 25-58% of those unsure or opposed to PAD would reverse the decision if PAD were legalized, and 42-54% of those unwilling to TW would also reverse if written consent of the patient existed. Overall acceptance of residents and students was significantly higher than our previous study in nearly 1,000 older physicians (50 vs. 39% for PAD and 58 vs. 48% for TW). CONCLUSIONS: PAD and TW acceptability seems to be increasing in Mexico, probably as a result of evolving social attitudes that appeared to be counteracted by a more conservative upbringing at home in our young RAMS students.

End-of-life decisions in perinatal care: A view from health-care providers in Mexico / Decisiones sobre el final de la vida en la atención perinatal: Una visión del equipo de salud en México

Objective. To examine the opinions of a perinatal health team regarding decisions related to late termination of pregnancy and severely ill newborns. Materials and Methods. An anonymous questionnaire was administered to physicians, social workers, and nurses in perinatal care. Differences were evaluated using the chi square and Student's t tests. Results. When considering severely ill fetuses and newborns, 82% and 93% of participants, respectively, opted for providing palliative care, whereas 18% considered feticide as an alternative. Those who opted for palliative care aimed to diminish suffering and those who opted for intensive care intended to protect life or sanctity of life. There was poor knowledge about the laws that regulate these decisions. Conclusions. Although there is no consensus on what decisions should be taken with severely ill fetuses or neonates, most participants considered palliative care as the first option, but feticide or induced neonatal death was not ruled out.

Objetivo. Explorar la opinión del equipo de salud sobre las decisiones relacionadas con la atención de fetos y neonatos gravemente enfermos. Material y métodos. Se aplicó un cuestionario anónimo a médicos, trabajadoras sociales y enfermeras perinatales. Las diferencias se evaluaron con las pruebas chi cuadrada y t de Student. Resultados. Al tratar fetos y neonatos gravemente enfermos, 82 y 93% de los participantes optaron, respectivamente, por atención paliativa. El 18% consideró el feticidio como alternativa. Quienes optaron por atención paliativa, lo hicieron para disminuir el sufrimiento, mientras que los que eligieron cuidados intensivos lo hicieron para proteger la vida o la sacralidad de la vida. Nuestro estudio mostró un pobre conocimiento de las leyes que regulan estas decisiones. Conclusiones. Aun cuando no existe un consenso sobre las decisiones que deben tomarse con fetos o neonatos gravemente enfermos, la mayoría consideró como primera opción los cuidados paliativos, aunque el feticidio y la muerte neonatal inducida no se descartaron.

[Obesity, body morphology, and blood pressure in urban and rural population groups of Yucatan]. / Obesidad, morfología corporal y presión arterial en grupos urbanos y rurales de Yucatán.

OBJECTIVE: To characterize body morphology and blood pressure of adults of the Mexican state of Yucatan. MATERIAL AND METHODS: Rural-urban differences in weight, height, waist, and hip circumferences, and blood pressure were analyzed in 313 urban and 271 rural subjects. RESULTS: No rural-urban differences in prevalence of obesity and overweight were found. Hypertension was marginally higher in urban subjects. Rural abnormal waist circumference was higher in young men and young women. Comparison with two national surveys and a survey in the aboriginal population (rural mixtecos) showed similar prevalence of obesity as ENSA-2000 and higher than mixtecos and ENEC-1993. Abnormal waist circumference was intermediate between ENSANUT-2006 and mixtecos and hypertension was intermediate between ENEC and mixtecos. CONCLUSION: The Maya and mestizo population of Yucatan showed a high prevalence of obesity and abnormal waist circumference not accompanied by a comparable higher hypertension frequency. This finding requires further confirmation.