Folatos y embarazo, conceptos actuales: ¿Es necesaria una suplementación con Acido Fólico? / Folate and pregnancy, current concepts: It is required folic acid supplementation?

El aporte de folatos durante el embarazo es esencial para un desarrollo fetal y placentario adecuados y para la salud del individuo a largo plazo. Su deficiencia puede inducir alteraciones y patologías fetales como bajo peso al nacer, recién nacidos de pre término y defectos del tubo neural (DTN). Por ello, varios países han decidido implementar políticas públicas de fortificación de alimentos con ácido fólico (AF). Chile inició la fortificación de la harina de trigo con AF en el año 2000, logrando reducir en un 43% la prevalencia de DTN. Sin embargo, además de la elevada ingesta de pan de nuestra población (principal alimento fortificado con AF), muchas mujeres embarazadas consumen suplementos de AF, lo que podría estar superando las concentraciones máximas de AF recomendadas. Adicionalmente, si la dieta materna es reducida en vitamina B12 (vit B12), se alteraría la razón óptima folatos/vit B12 lo que modificaría la metilación de genes específicos y otras vías metabólicas pudiendo afectar el desarrollo fetal y la salud de los recién nacidos a largo plazo. Creemos que, transcurridos 17 años del inicio de la fortificación de la harina de trigo con AF, es necesario evaluar los posibles efectos secundarios de un alto consumo de AF, no solo durante el embarazo, sino también en la población general. Presentamos antecedentes acerca del mecanismo de acción de folatos y vit B12 a nivel celular, y conceptos actuales sobre las posibles consecuencias de un aporte materno elevado de AF sobre la descendencia.

Folate intake during pregnancy is essential for an adequate fetal and placental development and for the long time health of the individual. Its deficiency may induce fetal pathologies, including neural tube disease (NTD). Therefore, several countries implemented public policies to fortify foods with folic acid (FA). Chile started the fortification of wheat flour with FA in the year 2000, decreasing a 43% the prevalence of NTD. However, despite the high consumption of bread (the main fortified food with FA) by our population, a high number of pregnant women consume FA supplements, thus, over passing the maximal recommended FA intake. Additionally, if the diet is reduced in vitamin B12, the optimal ratio folates/vit B12 may be altered, thus inducing changes in the methylation of specific genes and other metabolic pathways, affecting fetal development and the long-term health of the neonates. We think that, after 16 years of the initiation of the fortification of wheat flour with FA, it is necessary to evaluate the possible side effects of a high intake of FA in the pregnant population and their offspring. This article shows antecedents about mechanisms of folates and vit B12 at cellular level, and their possible consequences of an elevated FA maternal intake on the offspring.

Evaluación de un programa ministerial para manejo del síndrome metabólico en adultos con sobrepeso y obesidad / Evaluation of a program for management of metabolic syndrome in adults with overweight and obesity

Background: The Chilean Ministry of Health developed a healthy lifestyles intervention directed to adults with overweight and cardiovascular risk factors, called "Program on Healthy Eating and Physical Activity" (PASAF). Aim: To evaluate the impact of PASAF on nutritional status and metabolic parameters. Patients and Methods: We analyzed databases from three primary care centers belonging to a municipality of Metropolitan Santiago. We selected adults enrolled in the PASAF during three years (2007-2009). The program lasted four months and included an assessment of anthropometric and metabolic parameters at baseline and at the end, eight workshops with a nutritionist, seven with a psychologist and 32 sessions of physical activity. Result: We evaluated 526 subjects aged ≥ 18 years (93% females), of whom 85.6% attended the last appointment for assessment. Analyzing available data, attendance to workshops was < 50% of the scheduled sessions. Weight, body mass index and waist circumference decreased significantly (median: -1.4 kg, -0.6 kg/m² and -3 cm, respectively). The median weight loss was 1.8% of initial weight and 17.1% of participants experienced a decrease ≥ 5% of their initial weight. There were significant improvements in lipid levels and blood pressure among participants with lower initial excess weight. A reduction in fasting blood glucose was observed only among subjects who lost ≥ 5% of their initial weight. Conclusions: The PASAF modestly reduced nutritional parameters. Correction of metabolic parameters was especially effective in less obese subjects. The attendance to workshops was low.

Sistema endocanabinoide y desarrollo de esteatosis hepática / A role for the endocannabinoid system in hepatic steatosis

The endocannabinoid system (SEC) is an important modulator of several metabolic functions. This system is composed by cannabinoid receptors type 1 and 2 (RCB1 and RCB2), their endogenous ligands, known as endocannabinoids, and the enzymes involved in their synthesis and degradation. A deregulated SEC originates metabolic alterations in several tissues, resulting in the typical manifestations of the metabolic syndrome. Liver steatosis of different origins constitutes a physiopathological condition where an altered hepatic SEC is observed. In this condition, there is an increased expression of RCB1 and/or higher endocannabinoid levels in different hepatic cells, which may exert an autocrine/paracrine hyperstimulation of RCB1/RCB2. Activation of RCB1 stimulate the expression of several hepatocyte lipogenic factors, thus leading to increased de novo fatty acids synthesis and consequently to an abnormal accumulation of triglycerides. The effect of RCB2 activity on hepatic function is still controversial because, on one side its stimulation has an interesting protective effect on alcoholic liver disease while, on the other, it may enhance the development of hepatic steatosis in experimental models of diet-induced obesity. In this review we discuss the proposed mechanisms by which SEC is involved in the etiology of hepatic steatosis, as well as the therapeutic possibilities involving peripheral RCB1/RCB2 antagonism/agonism, for the treatment of this condition.

Estudio piloto sobre entrenamiento físico durante hemodiálisis / A pilot study on physical training of patients in hemodialysis

Background: Exercise training during the dialytical procedure may have positive cardiovascular effects and prevent or revert muscle wasting in patients undergoing chronic hemodialysis. Aim: To evaluate the effects of an exercise training program in patients undergoing chronic hemodialysis. Material and Methods: Fifteen patients on chronic hemodialysis aged 21 to 69 years (three females) were included in the study. Nine of these were included in an exercise training program. During 16 weeks, exercise sessions were carried out during each dialytical procedure that included a warm-up period, aerobic exercises done using standing cycles, and resistance exercises, performed using Thera-Band® elastic bands and loops. Borg scale was used to control the intensity of training. At baseline and at the end of the study, a blood sample prior and after the dialytical procedure was obtained to measure C reactive protein, tumor necrosis factor α and interleukin 6. Quadriceps muscle strength, six minutes´ walk and quality of life using the SF-36 questionnaire, were also measured. Results: Four experimental subjects did not complete the study period, two that withdrew before starting, one due to problems with the venous access and one that decided to withdraw after 1 month of training. Among the five patients that finished the training period, significant improvements in the six minutes´ walk and quadriceps strength were observed in the experimental group. No significant changes were observed among controls. No changes were observed in either group in C reactive protein, tumor necrosis factor and interleukin 6 levels or quality of life. Conclusions: Among patients undergoing chronic hemodialysis exercise training improves endurance and muscle strength.

Calidad de vida en pacientes operadas de bypass gástrico hace más de un año: Influencia del nivel socioeconómico / Quality of life of patients subjected to gastric bypass more than one year ago: Influence of socioeconomic status

Background: The study of the effects of bariatric surgery on quality of life in patients of different socioeconomic levels (SEL) is worthwhile. Aim: To study quality of life (QoL), eating behavior, depressive symptoms and sexuality in patients subjected to a gastric bypass (GBP) more than 1 year before. Material and methods: The sample was composed of 33 GPB patients (19 high SEL and 14 low SEL), and 27 non-operated women (18 high SEL and 9 low SEL) of similar weight and age, as controls. Assessment included medical history anthropometry radiological densitometry. Eating behavior was assessed using the three factor eating questionnaire, quality of life using SF-36 and the Bariatric Analysis of Reporting Outcome System (BAROS) depressive symptoms were assessed using the Beck scale version II and sexual behavior using the female sexual function index (FSFI). Results: QoL was lower in operated patients from low SEL, especially when compared to high SEL control women. Operated patients had a predominantly restrictive pattern of eating behavior. Eating behavior disorders were detected in 5 of 33 operated patients versus 4 of 27 controls (p =ns). Sexual function was absent or dysfunctional in 22 operated versus 8 controls (p =0,02). No significant differences were observed for depressive symptoms, between operated patients and controls. Conclusions: In the long term, QoL of bariatric patients, especially those from low SEL, is inferior to control women and Chilean general population. Operated patients have restrictive eating patterns and lower sexual satisfaction indexes. Frequency of depressive symptoms was high both in bariatric and control women.

Evaluación a largo plazo del estado nutricional, composición corporal y densidad mineral ósea en mujeres operadas de bypass gástrico: impacto del nivel socioeconómico / Nutritional status, body composition and bone mineral density in gastric bypass females: impact of socioeconomic level

Background: Roux-en-Y gastric bypass (RYGBP) has had a positive impact on co-morbidities associated with obesity. However, in the long-term it can induce micronutrient deficiencies. Aim: To perform a complete nutritional assessment in a group of women previously operated of RYGBP, from different socioeconomic levéis (SEL). Patients and Methods: Thirty three women (19 high SEL and 14 low SEL), were assessed by dietary recalls, anthropometric measurements, muscle strength, bone mineral density, routine clinical laboratory, serum levéis of vitamin B12, 250H-vitamin D, Mate, calcium, ferritine, ceruloplasmin and indicators ofbone turnover (parathohormone, osteocalcin and urinary pyridinolines). Their valúes were compared to those of 30 control women (18 high SEL and 12 low SEL). Results: Low SEL operated women consumed fewer vitamin and mineral supplements compared with their high SEL pairs. No cases of vitamin B12, folie acid or copper deficiencies were detected. Frequency of iron deficieney was similar in patients and controls. Vitamin D insufficieney was higher amongpatients than in controls (p =0,04 7), regardless SEL. Patients had also a higher frequency of high serum PTH and osteocalcin and urinary pyridinoline levéis. However, no differences in bone mineral density were observed between operated women and controls. Conclusions: Vitamin and mineral deficiencies were lower than expected among operated women. However, problems associated with vitamin D deficieney were highly prevalent among patients operated of RYGBP, irrespective SEL. These alterations were only detectable through speciñe markers at this stage, because they did not transíate into lower bone mineral density (BMD) of surgicalpatients, probably due to the higher pre-operative BMD of these morbidobese patients.

Efecto del probiótico Saccharomyces boulardii en la prevención de la diarrea asociada con antibióticos en adultos ambulatorios en tratamiento con amoxicilina / Effect of probiotic Saccharomyces boulardii on prevention of antibiotic-associated diarrhea in adult outpatients with amoxicillin treatment

Background: Antibiotic-associated diarrhea is one of the most common adverse effects of antimicrobials. Any antimicrobial can potentially produce diarrhea but beta-lactamics have a higher risk. Among these, amoxicillin is widely indicated in ambulatory practice. One ofthe alternatives suggested to prevent antibiotic-associated diarrhea, is the use of the probiotic Saccharomyces boulardii. Aim: To evalúate whether the concomitant use of Saccharomyces boulardii and amoxicillin can prevent antibiotic associated diarrhea in ambulatory adults with acute infections diseases, without provoking other adverse effects. Material and Methods: Eighty six adults (aged 15 to 81 years) with acute infectious diseases, excluding those arising in the gastrointestinal tract, that received a prescription of oral amoxicillin for 5 to 10 days, were included. In a controlled randomized, double blind trial, 41 patients were assigned to receive lyophilized Saccharomyces boulardii (500 mg/day) duríng 12 days, and 45 patients were assigned to placebo for the same period. Results: Ten percent of patients (9/86) reported acute diarrhea, 9,8 percent (4/41) in the experimental group and 11.196 (5/45) in the control group (p = 100). No adverse effects were associated to the use of the probiotic. Conclusions: Saccharomyces boulardii (500 mg/day) did not prevent diarrhea related to amoxicillin.

Determinación de los índices glicémicos y de insulina en fórmulas para alimentación enteral en adultos sanos / Glycemic and insulin indices of tube feeding formulas in healthy adults

Background: In acute illnesses, plasma glucose levels are often increased and generally parallel the severity of stress. Hyperglycemia caused by reduced insulin sensitivity and reduced insulin secretion is associated with increased susceptibility to infections. Maintaining blood glucose levels at or below 110 mg/dl reduces morbidity and mortality in critically ill patients. Aim: To measure the glucose and insulin responses of four commercially available enteral formulas compared with a standard meal reference product. Material and Methods: The glycemic index (GI) and the insulin index (II) were determined in a randomized, cross over protocol in 38 healthy volunteers between 18 and 46 years of age. Each subject underwent five tests: three with the standard meal (bread) and two with the study products. The enteral formulas were Clinutren HPR (whole protein of high protein value), Crucial® (casein peptide based formula), Peptamen®, (whey peptide based formula), Glytrol® (formula for diabetics with whole protein with fiber). Each study product was evaluated 10 times. Results: The diabetic formula and the high protein energy dense formulas induced a significantly lower GI (p <0.02) compared with the standard meal. The GI response did not appear to be due to enhanced insulin secretion. The other tested formulas had lower GI than the standard meal, but in addition they exhibited increased II The whey based peptide formulation produced the highest insulin response (p <0.03). Conclusions: Both GI and II are related to the concentration, form and type of protein contained in the enteral formula. The whey peptide formulation produced a low GI with the highest insulin index. Based on the low GI of these enteral products, all can be useful to provide nutritional support during metabolic stress, without adding an additional challenge to blood glucose management.