[Intermittent fasting: effects in diverse clinical settings]. / Ayuno intermitente: efectos en diversos escenarios clínicos.

Introduction: Introduction: intermittent fasting plans propose to limit food intake during specific periods as nutritional therapeutic strategies to treat different metabolic conditions in various clinical entities. However, the heterogeneity between each context of intermittent fasting could generate different results in metabolic parameters. Objective: to evaluate the clinical application of intermittent fasting and to discern whether it offers advantages over other traditional strategies. Methods: structured questions were formulated (PICO), and the methodology followed the guidelines established by the PRISMA 2020 statement. The search was conducted in different databases (PubMed, Cochrane Library and Google Scholar). Results: we found 3,962 articles, of which 56 were finally included; 3,906 articles that did not directly or indirectly answer the structured questions were excluded. Conclusions: compared to conventional diets, the various AI schemes do not generate advantages or disadvantages in terms of weight loss and lipid profile, although in the alternate-day variant there are greater insulin reductions than those observed in the continuous energy restriction. The heterogeneity of the interventions, the populations studied, the comparators, the results, and the type of design make it impossible to extrapolate the effects found in all clinical scenarios and generalize the recommendations.

Introducción: Introducción: los esquemas de ayuno intermitente (AI) proponen limitar la ingestión de alimentos durante periodos específicos. Se han propuesto como estrategia dietoterapéutica para tratar distintas condiciones metabólicas en diversos padecimientos, sin embargo, la heterogeneidad entre cada contexto de ayuno intermitente pudiera generar diferentes resultados en parámetros metabólicos. Objetivo: evaluar la aplicación clínica del ayuno intermitente y discernir si ofrece ventajas sobre otras estrategias tradicionales. Métodos: se formularon preguntas estructuradas (PICO) y la metodología se apegó a las guías establecidas por la declaración PRISMA 2020. Se realizó una búsqueda de literatura científica en las plataformas de PubMed, Cochrane Library y Google Scholar. Resultados: se encontraron 3.962 artículos, de los cuales se incluyeron finalmente 56, eliminando 3.906 trabajos que no contestaban directa o indirectamente las preguntas estructuradas. Conclusiones: frente a las dietas convencionales, los diversos esquemas de AI no generan ventajas ni desventajas en cuanto a pérdida de peso o perfil lipídico, aunque en la variante a días alternos se producen mayores reducciones de insulina a las observadas en la restricción energética continua. La heterogeneidad de las intervenciones y poblaciones estudiadas, así como los comparadores, los desenlaces y el tipo de diseño imposibilitan extrapolar los efectos a todos los escenarios clínicos y generalizar las recomendaciones.

Cephalopelvic disproportion as primary diagnosis for cesarean section: Role of neonatal birthweight in relation to maternal height at a Hospital in Merida, Mexico.

OBJECTIVE: To analyze the association between newborn and maternal characteristics and the risk for cesarean section (CS) due to cephalopelvic disproportion (CPD) and non-CPD causes compared to vaginal deliveries (VD) in a sample of infants and mothers from Merida, Yucatan, Mexico. METHODS: The final sample consisted of 3453 single, live, and term infants born between January 2016 and May 2017 at the Maternal-Infant Hospital in Merida and their mothers (aged ≥19 years). The mode of delivery was established as the dependent variables: (a) VD, (b) CS due to CPD, and (c) non-CPD CS. Independent variables were maternal height and weight, the number of previous VD, newborn weight, and neonatal birthweight (BW) index/maternal height index. A multinomial regression model was used to analyze the association between newborn and maternal characteristics and outcome variable. RESULTS: By mode of delivery, 2124 (62%) births corresponded to VD, 1042 (30%) to non-CPDCS, and 287 (8%) to CS due to CPD. Mothers who had CS due to CPD weighed more at the end of their pregnancy and were shorter. Maternal age and weight increased the risk for having CS due to CPD compared to VD and maternal height, and the number of previous VD reduces the risk for experiencing CS due to CPD compared to vaginal births. The relative risk ratio for higher neonatal BW/maternal height index was significant for CS due to CPD and non-CPD CS. CONCLUSION: According to our results from a public hospital in Merida, Mexico, CPD is a result of the interrelation of maternal and fetal size, rather than an independent result of maternal height or BW.