Association of diet quality and body mass index in Mexican adults: a pseudo-panel analysis.

INTRODUCTION: most studies that analyze the relationship between diet quality and obesity have a cross-sectional design; an alternative whit repeated cross-sectional data is a pseudo-panel design. OBJECTIVE: to estimate the association between trends in dietary patterns, defined by a diet quality index, and body mass index (BMI) of Mexican adults between 2006 and 2016. METHODOLOGY: a pseudo-panel analysis was performed using data from cross-sectional surveys: National Health and Nutrition Surveys of México (ENSANUTs) 2006 and 2012 and the Midway National Health and Nutrition Survey 2016 (ENSANUTMC). Cohorts (n = 108) were constructed by grouping adults 20-59 years old by sex (men n = 6,081 and women n = 11,404), education level, and year of birth. The association between diet quality (defined with the Healthy Eating Index-2015) and BMI was estimated using a fixed effects model, adjusting for sociodemographic characteristics. RESULTS: a one-point increase in the proportion of women with high diet quality was associated with 4.1 points lower BMI (p = 0.014) compared with women with low diet quality when excluding sub-reporters of energy, the same association is observed when physical activity is included in the model. No association was found between diet quality and BMI in men, possibly because of the existence of latent classes within sociodemographic strata, which does that the quality of the diet is inversely associated with the BMI, only in some categories of the strata. CONCLUSIONS: these results contribute to the evidence in the longitudinal analysis between diet and BMI, highlighting the importance of differentiating the population by sex and sociodemographic characteristics. These results are input for public policy creation that promotes improving the quality of the population's diet as part of multisectoral strategies to reduce overweight and obesity in Mexican adults.

Association between avocado consumption and diabetes in Mexican adults: Results from the 2012, 2016, and 2018 Mexican National Health and Nutrition Surveys.

BACKGROUND: Avocado contains numerous vitamins, minerals, and phytochemicals, which can contribute to reducing the risk of metabolic syndrome and diabetes. However, limited studies have examined the association between avocados and diabetes risk. OBJECTIVE: This study aimed to examine the association between avocado consumption and diabetes by sex in Mexican adults. DESIGN: This was a cross-sectional study. PARTICIPANTS: /setting: Participants included a subsample of adults (>=20 years old) from the 2012, 2016, and 2018 Mexican National Health and Nutrition Survey (ENSANUT). Avocado consumption was assessed using a seven-day, semi-quantitative food-frequency questionnaire, and participants were classified as avocado consumers (consuming any amount of avocado) or non-consumers. MAIN OUTCOME MEASURES: Participants were considered to have diabetes if they answered "yes" to "Has a doctor ever told that you have diabetes or high blood sugar?" STATISTICAL ANALYSES PERFORMED: This analysis assessed the association between avocado intake and diabetes using multivariate logistic models by sex and adjusted for relevant covariates. RESULTS: Of 28,239 ENSANUT 2012, 2016, and 2018 participants, 25,640 met the criteria (i.e., have diabetes outcome and plausible energy and avocado intakes) for this study. Over half of the participants were women, and approximately 45% were avocado consumers, with an average (standard error) avocado consumption of 34.7 (0.9) among men and 29.8 (0.8) grams/day among women. Avocado consumers had lower odds of diabetes in both unadjusted (OR: 0.762, 95% CI: 0.639-0.907) and adjusted (OR: 0.792, 95% CI: 0.632-0.993) models among women but not men (OR: 1.192, 95% CI: 0.907-1.566 and OR: 0.914, 95% CI: 0.675-1.239 for both unadjusted and adjusted models, respectively). CONCLUSIONS: Avocado consumption was associated with a lower risk of diabetes, which remained significant even when adjusted for relevant covariates. However, this finding was observed in only women, not men, underscoring the importance of personalized nutrition in diabetes care and prevention.

Cannabis use is associated with reduced access to kidney transplantation and an increased risk of acute rejection post-transplant.

BACKGROUND: The association between cannabis use and access to waitlisting, transplantation, and post-transplant outcomes remains uncertain. METHODS: Patients referred for kidney transplant (KT) to the University Health Network from January 1, 2003, to June 30, 2020, and followed until December 31, 2020, were included. Predictors of reported cannabis use were examined using a logistic regression model. The association between cannabis use and time to clearance for KT, undergoing KT, and post-transplant outcomes was evaluated using Cox proportional hazards models. RESULTS: Among 3734 patients, the prevalence of reported cannabis use was 11.8%. Cannabis use was associated with a lower likelihood of KT clearance (adjusted hazard ratio [aHR] .82 [95% confidence interval (CI): .72, .94]). Once cleared for KT, cannabis use did not predict the subsequent receipt of KT (aHR .92, [95% CI: .79, 1.08]). Among 2091 KT recipients, cannabis use was associated with a higher likelihood of biopsy-proven acute rejection (aHR 1.55, [95% CI: 1.06, 2.27]). The relative hazard of death-censored graft failure was similarly elevated (aHR 1.60 [95% CI: .95, 2.72]). Cannabis use did not predict total graft failure (aHR 1.33 [95% CI: .90, 1.96]), death with graft function (aHR 1.06 [95% CI: .59, 1.89]), or hospital readmission in the first-year post-transplant (aHR 1.26 [95% CI: .95, 1.68]). CONCLUSIONS: Cannabis users have less access to transplantation and an increased risk of acute rejection, possibly leading to more graft loss. Further studies are warranted to understand possible mechanisms for the increased risk of allograft immune injury among cannabis users.

Kidney Biopsy in Management of Lupus Nephritis: A Case-Based Narrative Review.

Kidney involvement in patients with lupus highly increases morbidity and mortality. In recent years, several reports have emphasized the dissociation between clinical and histological findings and highlighted the role of kidney biopsy as an instrument for diagnosis and follow-up of lupus nephritis. The kidney biopsy at initial diagnosis allows an early diagnosis, assessment of activity and chronicity, and detection of nonimmune complex nephritis. A kidney biopsy repeated months after treatment aids in the detection of persistent histological inflammation, which has been linked to the occurrence of future kidney relapses. A kidney biopsy at a relapse detects histological changes including chronic scarring. Finally, a kidney biopsy in patients with a clinical response undergoing maintenance immunosuppression may aid therapy tapering and/or suspension. The evidence supporting the use of a kidney biopsy in different scenarios across the course of lupus nephritis is heterogeneous, with most reports assessing the value for the diagnosis of a first or relapsing flare. In contrast, less evidence suggests additional therapeutic-modifying information derived from repeat posttreatment biopsies and biopsies to evaluate treatment tapering or suspension. In this clinical case-based review, we examine the role of kidney biopsy as a tool to improve clinical outcomes of patients with lupus nephritis.

Exploring Differences in Dietary Diversity and Micronutrient Adequacy between Costa Rican and Mexican Adolescents.

Diet diversity becomes especially relevant during adolescence to satisfy the adequate micronutrient intake. Diet diversity (DD) and micronutrient probability of adequacy (PA) were studied in 818 Costa Rican (CR) and 1202 Mexican (MX) adolescents aged 13-18 years. DD was compared using the Minimum Dietary Diversity (MDD) score. Receiver-operating characteristic (ROC) curves were employed to identify the optimal MDD for each sample from the respective countries. The mean MDD for the overall CR sample was 4.17 ± 1.43 points, and for the MX sample, the mean MDD was 4.68 ± 1.48 points. The proportion of adolescents with a DD was significantly higher in Costa Rica than in Mexico (66.5% vs. 55.6%; p < 0.0001). Also, DD was higher in rural Costa Rican adolescents, while no difference was found in the MX adolescents by area of residence. CR adolescents reported significantly higher PA than MX participants for 6 of the 11 micronutrients assessed. The calcium PA in MX adolescents was significantly higher than in the CR sample (MX: 0.84 vs. CR: 0.03; p < 0.0001), while low PA was obtained for iron in both countries (CR: 0.01 vs. MX: 0.07; p < 0.0001). In Costa Rica and Mexico, nutritional interventions and assessing the compliance of food-fortifying programs are needed to improve the PA of diverse micronutrients.

Tendencia del consumo de frutas, verduras y leguminosas en adultos mexicanos. Ensanut 2012-2022.

OBJETIVO: Evaluar el consumo y porcentaje de adultos en apego a recomendaciones de la Organización Mundial de la Salud (OMS) e EAT-Lancet Commission on Food, Planet, Health sobre consumo de frutas, verduras y leguminosas, y sus cambios en el periodo de 2012-2022. Material y métodos. Se analizó información de 29 757 adultos >20 años, obtenida del cuestionario semicuantitativo de frecuencia de consumo de alimentos de las Encuestas Nacionales de Salud y Nutrición 2012-2022. Se estimó el consumo de frutas, verduras y leguminosas mediante modelos de regresión cuantílica y el porcentaje de población que cumplió las recomendaciones de consumo de la OMS y de una dieta de salud planetaria con modelos de regresión logit. Todos los modelos se ajustaron por covariables. RESULTADOS: De 2012 a 2020-2022, el consumo de frutas se mantuvo constante (113.5-131 g/día) y el de verduras incrementó (de 83 a 109 g/día), mientras que el consumo de leguminosas disminuyó (de 10 a 7.7 g/día). Se encontró bajo porcentaje de adultos (<40%) que cumplieron las recomendaciones, sobre todo de leguminosas (<1.5%), situación que se mantuvo constante a lo largo de los 10 años analizados. CONCLUSIONES: Existe una tendencia a la disminución en el consumo de leguminosas y el consumo de frutas y verduras sigue siendo bajo.

Cambios en el consumo de frutas, verduras y leguminosas en población mexicana menor de 20 años, Ensanut 2012 a 2022.

OBJETIVO: Estimar cambios en el consumo de frutas, verduras y leguminosas y su cumplimiento según recomendaciones internacionales en población menor de 20 años de México. Material y métodos. En 31 083 menores de 20 años con información de frecuencia de consumo de alimentos de las Encuestas Nacionales de Salud y Nutrición 2012, 2016, 2018 y 2020-2022, se estimó el cambio en el consumo de frutas, verduras y leguminosas ajustados mediante modelos de regresión cuantílica y la probabilidad de cumplimiento de las recomendaciones de ingesta de EAT-Lancet y la Organización Mundial de la Salud mediante modelos de regresión logit. RESULTADOS: Entre 2012 y 2020-2022 se observó un incremento en la mediana de consumo de 15% en frutas y 23.5% en verduras. La probabilidad de cumplimiento de recomendaciones de EAT-Lancet fue de 42.6% para frutas y 13.6% para verduras en 2020-2022. El consumo de leguminosas disminuyó 17.4% en 10 años. Conclusión. La población mexicana menor de 20 años se encuentra muy lejos de alcanzar las recomendaciones de consumo para la salud planetaria, a pesar de los incrementos modestos en el consumo de frutas y verduras. Se debe poner especial atención en el consumo de leguminosas por su disminución alarmante en estos grupos de edad. Es esencial realizar más investigación en este tema.

Sobrepeso, obesidad y consumo de azúcares en población escolar y adolescente de México. Ensanut 2020-2022.

OBJETIVO: Analizar la asociación de la contribución de los azúcares con sobrepeso y obesidad (Sp+Ob) en población escolar y adolescente. Material y métodos. En una muestra de 2 844 escolares y adolescentes de 5 a 19 años se determinó el estado de Sp+Ob según los patrones de crecimiento de la Organización Mundial de la Salud, así como el consumo de azúcares totales, añadidos e intrínsecos (%kcal/día) con información de un cuestionario de frecuencia de consumo de alimentos. Se estimó la probabilidad ajustada de presentar Sp+Ob mediante modelos de regresión logística con interacción entre el consumo de azúcares y la condición de bienestar. RESULTADOS: La prevalencia de Sp+Ob fue del 41% en la población de 5 a 19 años y más de 60% excedió el límite recomendado de consumo de azúcares añadidos del 10% de energía; las bebidas endulzadas fueron el grupo que más contribuyó a este consumo elevado. La probabilidad de presentar Sp+Ob a mayores consumos de azúcar añadido fue significativamente mayor en el tercil alto de condición de bienestar (0.59) vs. el bajo (0.30). CONCLUSIONES: El Sp+Ob y el consumo de azúcares añadidos son elevados en la población de 5 a 19 años en México. Se requiere fortalecer, focalizar y diversificar las estrategias de atención a estos problemas considerando las diferencias sociodemográficas de la población.

Consumidores de grupos de alimentos en población mexicana. Ensanut Continua 2020-2022.

OBJETIVO: Actualizar las estimaciones del porcentaje de población mexicana que consume grupos de alimentos recomendables y no recomendables de manera habitual. Material y métodos. Con información derivada del cuestionario semicuantitativo de frecuencia de consumo de alimentos de diferentes grupos de edad de la población participante en la Encuesta Nacional de Salud y Nutrición Continua de 2020 a 2022, se estimó el porcentaje de consumidores de trece grupos de alimentos de relevancia para la salud. RESULTADOS: Los grupos de alimentos mayormente consumidos en toda la población fueron el agua sola (>83%) y las bebidas endulzadas (>76%). Cerca de la mitad de la población menor de 20 años consumieron botanas, dulces y postres, cifra que es similar al porcentaje de consumidores de frutas y mayor al de consumidores de verduras (<30%). En todos los grupos de edad los consumidores de leguminosas no superan el 26%. Conclusión. La fracción de la población mexicana que consume bebidas endulzadas es muy alta en todos los grupos de edad, mientras que para alimentos saludables es baja. Se necesita profundizar en el análisis de las causas de estas diferencias y diseñar acciones encaminadas a aumentar la calidad de la dieta en la población mexicana.

Short Stature Modifies the Waist-to-height Ratio cut-off Points as an Indicator of Cardiovascular Risk in Mexican Adult Women and Men.

BACKGROUND: Waist-to-height ratio (WHtR) is one of the anthropometric measures associated with cardiovascular risk (CVR). However, WHtR cut-off points may vary depending according to population characteristics, including sex and height. OBJECTIVE: To identify optimal WHtR cut-off points to predict CVR factors by sex in Mexican adults according to height. MATERIAL AND METHODS: Information from adults >20 years (n = 3550) from the 2016 National Health and Nutrition Survey were analyzed. Prevalence of high WHtR, CVR factors (glucose and insulin, lipid profile (total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides) and blood pressure were estimated by sex and height (short height <1.60 and <1.50 m in men and women, respectively). The maximum proximity procedure was used to establish the point of maximum simultaneous sensitivity and specificity using the operating characteristic curve of the receiver. The estimates were stratified by sex and height condition. RESULTS: The WHtR cut-off points identified to predict CVR were higher than those suggested for international use (≥0.5), being significantly higher (p <0.0001) for women (0.61) than for men (0.56). Also, the WHtR cut-off points were higher for short stature (men 0.58 and 0.56, women 0.63 and 0.58, with short and normal stature, respectively). CONCLUSIONS: The WHtR cut-off points for predicting CVR in the Mexican population were higher than 0.5 in both sexes and it was higher for individuals with short stature. The identified cut-off points may be an additional tool in screening the adult population in Mexico to predict CVR.

Establishing an effective clinical data collecting tool for optimal evaluation of native and allograft renal biopsies.

Introduction: Percutaneous kidney biopsy is the gold standard method to reach a precise diagnosis in most medical kidney diseases, which positively impacts patient care by personalizing the treatment. Accurate diagnosis in the pathology report for medical kidney diseases requires clinicopathological correlation, and clinical data is not always reachable to the nephropathologist. This study aimed to create a standardized, paperless requisition form compatible with medical renal biopsies. Methods: An initial form was prepared for native and allograft renal biopsies according to the current classification of medical kidney diseases. We invited 33 nephropathologists working in Canadian healthcare institutions to answer survey questions about the need to include a particular aspect of clinical information. According to the responses, we modified the experimental form. Eighty nephrologists were asked to complete a clinical data-collecting form given out as PDF files. The time for completing the form and clinicians' satisfaction were assessed. Results: The experimental form survey was answered by 20 out of 33 nephropathologists (61%) from 14 Canadian healthcare centers. The agreement rate on the questions was from 38.89% to 100.00% (average 83.33% and 77.14% for the native and the allograft section, respectively). Seventeen out of 80 nephrologists and their assistants (21%) responded by completing 22 PDF forms. The time required to finish a PDF form was 10.4 min on average. Nephrologists considered the form time-consuming and suggested making it more clinically relevant. Only seven nephrologists responded to the satisfaction survey; four (57%) were satisfied. Conclusions: Medical information is critical in renal pathology diagnoses. A uniform paperless clinical data requisition form was evolved through an agreement by Canadian nephropathologists.

Ultra-processed foods consumption reduces dietary diversity and micronutrient intake in the Mexican population.

BACKGROUND: Currently, 30% of the total energy intake in the Mexican diet comes from ultra-processed foods. Although its consumption is associated with high intakes of added sugar and saturated fats and low intakes of dietary fibre, there is no evidence regarding its association with dietary diversity and micronutrient intake. The present study evaluated the association between ultra-processed foods consumption with dietary diversity and micronutrient intake in Mexico. METHODS: Ultra-processed foods items were identified in a 24-h recall from a sample of 10,087 participants aged ≥ 1 year. The minimum dietary diversity (MDD) was established by using the Food and Agriculture Organization 10 food group indicators with unprocessed, minimally processed and processed foods. The study conducted multiple linear regression models to evaluate the association between quintiles of energy contribution of ultra-processed foods with dietary diversity and micronutrient intake. RESULTS: A high consumption of ultra-processed foods was associated with a low dietary diversity and micronutrients intake. The association between ultra-processed foods and MDD was not linear (47.1%, 57.1%, 52.5%, 45.0% and 28.0% of participants achieved the MDD). On the other hand, the association was linear and negatively associated with: niacin, pantothenic acid, pyridoxine, folate, vitamin B12 , vitamin C, vitamin E, zinc, calcium, magnesium, potassium and phosphorus (p < 0.05). CONCLUSIONS: These findings are relevant in the context of the double burden of malnutrition currently faced in Mexico. Increasing dietary diversity and micronutrient intake is essential by discouraging ultra-processed foods consumption. However, other strategies are also needed to promote the dietary diversity and increase the consumption of unprocessed and minimally processed foods.

Antibody-mediated rejection: prevention, monitoring and treatment dilemmas.

PURPOSE OF REVIEW: Antibody-mediated rejection (AMR) has emerged as the leading cause of late graft loss in kidney transplant recipients. Donor-specific antibodies are an independent risk factor for AMR and graft loss. However, not all donor-specific antibodies are pathogenic. AMR treatment is heterogeneous due to the lack of robust trials to support clinical decisions. This review provides an overview and comments on practical but relevant dilemmas physicians experience in managing kidney transplant recipients with AMR. RECENT FINDINGS: Active AMR with donor-specific antibodies may be treated with plasmapheresis, intravenous immunoglobulin and corticosteroids with additional therapies considered on a case-by-case basis. On the contrary, no treatment has been shown to be effective against chronic active AMR. Various biomarkers and prediction models to assess the individual risk of graft failure and response to rejection treatment show promise. SUMMARY: The ability to personalize management for a given kidney transplant recipient and identify treatments that will improve their long-term outcome remains a critical unmet need. Earlier identification of AMR with noninvasive biomarkers and prediction models to assess the individual risk of graft failure should be considered. Enrolling patients with AMR in clinical trials to assess novel therapeutic agents is highly encouraged.

Westernized and Diverse Dietary Patterns Are Associated With Overweight-Obesity and Abdominal Obesity in Mexican Adult Men.

Introduction: The prevalence of overweight and obesity in Mexican adults is very high. To identify the dietary characteristics related with this disorder is necessary to design intervention. The objective was to analyze the association between dietary patterns and obesity in Mexican adults. Materials and Methods: This is a cross-sectional study carried out in Mexican adults (20-59 years old) participating in the Halfway National Health and Nutrition Survey 2016. Participants (n = 5,735) were classified as having normal weight, overweight-obesity and by their abdominal circumference as having abdominal obesity or not. With information from a 7-day food frequency questionnaire, we used a K-means cluster analysis to derive dietary patterns and calculated a healthy diet indicator to evaluate quality. The association between dietary patterns and overweight-obesity and abdominal obesity was assessed with Poisson regression models adjusted by some characteristics. Results: We identified a Rural pattern characterized by tortilla, legumes and egg consumption; a Diverse pattern, characterized by fruits, meat and poultry, vegetables, and dairy beverages, and desserts; and a Westernized pattern, characterized by sweetened non-dairy beverages, fast food, bakery and cookies, candies and salty snacks. In men, Westernized pattern was associated with overweight-obesity (PR = 1.11, 95% CI 0.97-1.27), and abdominal obesity (PR = 1.15, 95% CI 1.00-1.33), the Diverse pattern was associated with overweight-obesity (PR = 1.18, 95% CI 1.00-1.38), and abdominal obesity (PR = 1.27, 95% CI 1.07-1.50), compared with the Rural pattern. In women, these dietary patterns were not associated with obesity. Discussion: Westernized and Diverse patterns are associated with overweight and obesity and abdominal obesity in men. Gender-specific recommendations and surveillance are necessary in the Mexican adult population.

Sustainability of Diets in Mexico: Diet Quality, Environmental Footprint, Diet Cost, and Sociodemographic Factors.

Background: Little is known about the current intake of sustainable diets globally and specifically in middle-income countries, considering nutritional, environmental and economic factors. Objective: To assess and characterize the sustainability of Mexican diets and their association with sociodemographic factors. Design: Dietary data of 2,438 adults within the National Health and Nutrition Survey 2012 by integrating diet quality measured by the Healthy Eating Index (HEI-2015), diet cost, and four environmental indicators were analyzed: land use (LU), biodiversity loss (BDL), carbon footprint (CFP), and blue water footprint (BWFP). We defined healthier more sustainable diets (MSD) as those with HEI-2015 above the overall median, and diet cost and environmental indicators below the median. Logistic regression was used to evaluate the association of sociodemographic factors with MSD. Results: MSD were consumed by 10.2% of adults (4% of urban and 22% of rural), who had lower intake of animal-source foods, unhealthy foods (refined grains, added sugar and fats, mixed processed dishes and sweetened beverages), fruits, and vegetables, and higher intake of whole grains than non-MSD subjects. Characteristics of MSD vs. non-MSD (urban; rural) were: HEI-2015 (62.6 vs. 51.9; 66.8 vs. 57.6), diet-cost (1.9 vs. 2.8; 1.9 vs. 2.5 USD), LU (3.3 vs. 6.6; 3.2 vs. 5.9 m2), BDL (105 vs. 780; 87 vs. 586 species × 10-10), BWFP (244 vs. 403; 244 vs. 391 L), and CFP (1.6 vs. 4.4; 1.6 vs. 3.7 kg CO2eq). Adults from rural vs. urban (OR 2.7; 95% CI: 1.7, 4.1), or from the South (OR 2.1; 95% CI: 1.1, 3.9), Center (OR 2.3; 95% CI: 1.3, 4.4) vs. the North were more likely to consume MSD, while adults with high vs. low socioeconomic status were less likely (OR 0.17; 95% CI: 0.09, 0.3). Conclusions: The MSD is a realistic diet pattern mainly found in disadvantaged populations, but diet quality is still sub-optimal. Increased consumption of legumes, fruits, and vegetables, and a reduction in unhealthy foods, is required to improve nutritional quality of diets while ensuring their environmental sustainability.

Pegylated Liposomal Doxorubicin and Kidney-Limited Thrombotic Microangiopathy in a Kidney Transplant Recipient: A Case Report.

A 64-year-old man with Kaposi sarcoma in clinical remission after treatment with pegylated liposomal doxorubicin and a history of deceased-donor kidney transplantation 4 years prior presented with a slowly progressive increase in his serum creatinine level, well-controlled hypertension, stable subnephrotic-range proteinuria, and bland urinary sediment. An allograft kidney biopsy demonstrated thrombotic microangiopathy, without clinical or laboratory features of systemic involvement. Based on the timing of drug initiation preceding thrombotic microangiopathy, complete recovery after drug withdrawal, and the absence of other etiologies, it was concluded that pegylated liposomal doxorubicin was the likely cause of kidney-limited thrombotic microangiopathy. When pegylated liposomal doxorubicin was resumed, the patient developed hypertension and kidney allograft dysfunction. A new kidney biopsy was not performed because of the overall risk benefit. The case highlights the importance of recognizing novel etiologies of thrombotic microangiopathy in kidney transplant patients with malignancy. Although Kaposi sarcoma has not been linked to thrombotic microangiopathy, pegylated liposomal doxorubicin has been increasingly associated with drug-induced thrombotic microangiopathy. To our knowledge, this is the first case report that etiologically links pegylated liposomal doxorubicin to kidney-limited thrombotic microangiopathy in a kidney transplant patient.

How to Ask the Right Question and Find the Right Answer: Clinical Research for Transplant Nephrologists.

Clinical research is about asking and answering questions. Before solutions relevant to clinical problems can be sought, clinicians must frame questions in ways that are answerable using the methods of clinical research. Different types of questions are best answered using specific study designs. Each design has inherent strengths and limitations. In this review article, we provide an approach to asking answerable clinical research questions, review the major study designs, describe their strengths and weaknesses, and link the study designs to their intended purposes.

A Semi-quantitative Food Frequency Questionnaire Has Relative Validity to Identify Groups of NOVA Food Classification System Among Mexican Adults.

BACKGROUND: Ultra-processed foods are recognized as indicators of an unhealthy diet in epidemiological studies. In addition to ultra-processed foods, the NOVA food classification system identifies three other groups with less processing. Unprocessed foods that, together with minimally processed foods (MPF), make NOVA group 1, NOVA group 2 is processed culinary ingredients, and NOVA group 3 is processed foods. OBJECTIVE: To assess the relative validity of the semi-quantitative food frequency questionnaire (SFFQ) to estimate the energy intake for each group NOVA classification system by comparing it with two 24 h-dietary-recall (24DRs) Mexican adults. METHODS: We analyzed dietary information from 226 adults included <60 and ≥60 years with complete SFFQ and two 24DRs from the National Health and Nutrition Survey 2012. We reported mean differences, Spearman correlation coefficients, intra-class correlations coefficients, Bland-Altman plots, and weighted kappa between measures. RESULTS: The percentage energy intake from unprocessed and minimally processed foods group, Spearman correlation coefficients was 0.54 in adults <60 years and 0.42 in adults ≥60 years, while ultra-processed foods group was 0.67 and 0.48, respectively. The intra-class correlation coefficients in the unprocessed and minimally processed foods group was 0.51 in adults <60 years and 0.46 in adults ≥60 years, and for the ultra-processed foods group were 0.71 and 0.50, respectively. Bland-Altman plots indicated reasonably consistent agreement for unprocessed and minimally processed foods group and ultra-processed foods group in adults <60 years and adults in the ≥60 age group. Weighted kappa was 0.45 in the ultra-processed foods group to adults <60 years and was 0.36-≥60 years. CONCLUSION: The SFFQ had acceptable validity to rank the percentage of energy intake from unprocessed and minimally processed foods group and ultra-processed foods group in Mexican adults, both in adults under 60 years and who were 60 years old or older.

Dietary Sodium and Potassium Intake: Data from the Mexican National Health and Nutrition Survey 2016.

Population studies have demonstrated an association between sodium and potassium intake and blood pressure levels and lipids. The aim of this study was to describe the dietary intake and contribution of sodium and potassium to the Mexican diet, and to describe its association with nutrition status and clinical characteristics. We analyzed a national survey with 4219 participants. Dietary information was obtained with a 24-h recall. Foods and beverages were classified according to level of processing. The mean intake (mg/d) of Na was 1512 in preschool children, 2844 in school-age children, 3743 in adolescents, and 3132 in adults. The mean intake (mg/d) of K was 1616 in preschool children, 2256 in school-age children, 2967 in adolescents, and 3401 in adults. Processed and ultra-processed foods (UPF) contribute 49% of Na intake in preschool children, 50% in school-age children, 47% in adolescents, and 39% in adults. Adults with high Na intake had lower serum concentrations of cholesterol, HDL-c, and LDL-c. A significant proportion of the Mexican population has a high intake of Na (64-82%) and low K (58-73%). Strategies to reduce Na and increase K intake need to reduce the possibility of having high BP and serum lipid disturbances.