Prevalence of IgG antibodies induced by the SARS-COV-2 virus in asymptomatic adults in Nuevo Leon, Mexico.

Population-based immunoglobulin G (IgG) seroprevalence studies in asymptomatic individuals in Latin America are scarce. The objective of the study was to estimate the prevalence and geographic distribution of IgG antibodies induced by natural SARS-CoV-2 infection in asymptomatic adults, 5-8 months after the first case was reported in a northeastern state of Mexico. This was a population-based cross-sectional study carried out in Nuevo Leon during August-November 2020. Individuals ≥18 years with no previous diagnosis or symptoms suggestive of COVID-19 were consecutively screened in one of the busiest subway stations. Also, a search for eligible individuals was done from house-to-house, after selecting densely populated geographic sectors of each of the municipalities of the metropolitan area (n = 4495). The IgG antibodies to SARS-CoV-2 nucleocapsid protein were analyzed. The IgG antibody positivity rate was 27.1% (95% confidence interval [CI]: 25.8, 28.4); there were no differences by sex or age (p > 0.05). Analysis by month showed a gradual increase from 11.9% (August) to 31.9% (November); Week 39 had the highest positivity rate (42.2%, 95% CI: 34.2, 50.7). Most people did not have evidence of previous SARS-CoV-2 infection. Preventive measures and promotion of the COVID-19 vaccine should be strengthened.

Prevalence of liver fibrosis in an unselected general population with high prevalence of obesity and diabetes mellitus. Time for screening?

INTRODUCTION: Cirrhosis and liver cancer are currently common causes of death worldwide. The global epidemic of obesity has increased the incidence of nonalcoholic fatty liver disease (NAFLD) and cirrhosis in recent years. Advanced fibrosis increases the morbimortality rate in NAFLD. The Mexican population has one of the highest prevalence of obesity and diabetes mellitus (DM) worldwide. AIM: To determine the prevalence of advanced liver fibrosis in Mexican general population. METHODS: Adult individuals, without a history of liver disease nor heavy alcohol consumption were randomly sampled from 20,919 participants of a health and nutrition survey applied to the general population. Clinical and laboratory evaluations were performed to calculate the NAFLD fibrosis score (NFS) (an extensively validated non-invasive method). Two cut-off points were used. Advanced fibrosis was defined as a result >0.676. RESULTS: In total 695 individuals were included. The mean age was 47.8±16.4. The majority were between 20 and 50 years (59%), 70.2% were female, 35.5% showed obesity and 15.8% DM. The 93% had normal serum ALT. Based on the NFS results, 56 individuals (8.1%) had a high probability of fibrosis. Most patients from this subgroup showed normal serum ALT (92.9%), 89.3% were >45yr. old, 52% were obese and 27% suffered from DM. CONCLUSIONS: Based on these results, 8.1% of Mexican general population without a history of liver disease is at high risk of having advanced liver fibrosis and complications and death derived from cardiovascular disease and cirrhosis. Most of them showed normal ALT serum levels.

Vitamin D deficiency in Mexican mothers and their newborns. / Deficiencia de vitamina D en madres y neonatos mexicanos.

Objective: The purpose of this study is to establish the prevalence of vitamin D deficiency and their newborns and analyze the risk factors related to this deficiency. Methods: This is an observational, transversal, and prospective study. It included 191 puerperal women and their full-term newborns. Serum 25 hydroxyvitamin D values were analyzes by enzyme immunoassay. Results: 61% of the puerperal presented deficiency and 26% insufficiency of vitamin D. In the newborn group 98% showed deficiency and 66% of them presented severe deficiency. There is a positive correlation between the values of vitamin D in mothers and their newborns (r2 = 0.173 ng/ml; p = 0.017). The lowest levels were in autumn. (15.75 ng/mL mothers, 6 ng/mL newborns). There was no correlation between vitamin D levels in mothers and their dietary intake, maternal skin type, sun time exposure and prenatal body mass index. Conclusions: This is the first study that shows the existence of a high deficiency of vitamin D in Mexican mothers and their newborns.

Measurement of Leptin by RIA Versus MIA in a Population of Healthy Newborns.

BACKGROUND: Assays based on multiplex immunoassay (MIA) technology have demonstrated advantages over enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA). Its acceptance depends on how well it performs in comparison to older techniques. The aim is to compare the results of leptin using RIA versus MIA. METHODS: We analyzed 81 samples of umbilical cord blood of healthy term newborns by RIA and MIA. RESULTS: The concordance correlation coefficient was 0.158 (95% CI 0.10-0.21). Pearson's correlation coefficient was 0.6651 (95% CI 0.52-0.77; P < 0.0001). In the Bland-Altman plot, concordance is acceptable because most of the measurements are within a mean of ±1.96 SD. CONCLUSIONS: As shown by the Bland-Altman plot, there is concordance by both methods, but with a weak correlation.

Leptin, IL-6 and TNF-α levels in umbilical cord blood of healthy term newborns in relation to mode of delivery.

In the development of the foetal immune system, cytokines play an important role in its function. Therefore, we sought to determine whether the mode of delivery affects the expression of leptin, IL-6 and TNF-α in umbilical cord blood in healthy term newborns. We collected 125 samples of umbilical cord blood to analyse leptin, IL-6 y TNF-α levels with multiplex immunoassay (MIA). The samples were classified according to mode of delivery: vaginal delivery (VD) and caesarean section (CS). Leptin and IL-6 had higher concentrations in umbilical cord blood in VD than in CS: 42.55 ng/ml (11.92-104.28) versus 35.20 ng/ml (3.26-9326.76), p = 0.039; 9.32 pg/ml (1.13-2020.31) versus 3.81 pg/ml (0.52-834.69) p < 0.001, respectively. Also, a weak correlation between TNF-α and IL-6 was found (r = 0.238, p = 0.007). The most important finding in our study was the differential concentrations of leptin and IL-6 according to mode of delivery.

[Evaluation of strategies aimed at reducing the level of noise in different areas of neonatal care in a tertiary hospital]. / Evaluación de las estrategias enfocadas a disminuir el nivel de ruido en las diferentes áreas de atención neonatal en un hospital de tercer nivel.

OBJECTIVE: To determine the noise levels of different areas responsible for newborn care, develop intervention strategies to decrease the noise, and evaluate its effectiveness. METHODS: Prospective, observational and longitudinal study carried out using a sonometer, measuring sound levels for three weeks in the neonatal intensive care unit (NICU), neonatal intermediate care unit (UCIREN), delivery (TOCO QX) and nursery (CUNERO) units. We implemented an intervention program and subsequent measurements were performed under the same initial conditions. RESULTS: When comparing the decibel levels in different areas during the three weeks, pre- and post-intervention, we found at the neonatal intensive care unit 59.9±4.8 vs. 56.4±4.7 dB (p<0.001), neonatal intermediate care unit 55.3±3.9 vs. 51.3±4.4 dB (p<0.001), delivery unit 57.3±4.6 vs. 57.3±5.5 dB (NS), and nursery unit 57.6±5.8 vs. 53.9±5.8 dB (p<0.001). CONCLUSIONS: There was a significant reduction in noise levels of 3.5 dB at the NICU, 4 dB at UCIREN and 3.7 dB at TOCO QX, so the intervention program was effective in these areas; however, the decibel levels registered continue above those recommended by international standards.

A new positive-pressure device for nasal foreign body removal.

OBJECTIVES: Nasal foreign bodies (FBs) are common causes of pediatric emergency consultations. The different methods for removing nasal FBs have varying levels of efficacy. The aim of this study was to evaluate the safety and efficacy of a new device for nasal FB removal in children. METHODS: A nasal occlusion device that uses modulated positive pressure to remove FBs was evaluated in a series of 18 patients ranging in age from 1 to 8 years diagnosed with a nasal FB during a period of 7 months. RESULTS: The device successfully removed FBs in 17 (94.4%) of the 18 patients. In 12 of the cases (66.7%), the FB was removed during the first attempt. None of the patients had complications or sequelae at the time of removal or at the follow-up visit. CONCLUSIONS: The nasal occlusion device used in this study was found to be a promising, safe, effective, and easy to use tool for FB removal in a pediatric emergency room setting.

Immunogenicity and safety of an inactivated quadrivalent influenza vaccine candidate: a phase III randomized controlled trial in children.

BACKGROUND: Mismatch between circulating influenza B viruses (Yamagata and Victoria lineages) and vaccine strains occurs frequently. METHODS: In a randomized controlled trial, immunogenicity and safety of an inactivated quadrivalent influenza vaccine candidate (QIV) versus trivalent inactivated influenza vaccine (TIV)-Victoria(Vic) and TIV-Yamagata(Yam) in children 3-17 years of age was evaluated. In an open-label study arm, QIV only was assessed in children 6-35 months of age. RESULTS: A total of 3094 children (932 QIV, 929 TIV-Vic, 932 TIV-Yam, and 301 QIV only) were vaccinated. QIV was noninferior to the TIVs for shared strains (A/H3N2 and A/H1N1) based on hemagglutination-inhibition (HI) antibodies 28 days after last vaccination, and superior for the unique B strains Victoria and Yamagata (geometric mean titer ratios 2.61, 3.78; seroconversion rate differences 33.96%, 44.63%). Among children in the randomized trial, adverse event rates were similar except for injection site pain (dose 1: 65.4% QIV, 54.6% TIV-Vic, 55.7% TIV-Yam). CONCLUSION: QIV elicited superior HI responses to the added B strains compared to TIV controls, potentially improving its effectiveness against influenza B. HI responses were similar between QIV and TIV controls for the shared strains. QIV had an acceptable safety profile relative to TIVs. CLINICAL TRIALS REGISTRATION: NCT01198756.

Gut microbiota in preterm infants receiving breast milk or mixed feeding.

BACKGROUND: Preterm birth is the leading cause of mortality in newborns, with very-low-birth-weight infants usually experiencing several complications. Breast milk is considered the gold standard of nutrition, especially for preterm infants with delayed gut colonization, because it contains beneficial microorganisms, such as Lactobacilli and Bifidobacteria. AIM: To analyze the gut microbiota of breastfed preterm infants with a birth weight of 1500 g or less. METHODS: An observational study was performed on preterm infants with up to 36.6 wk of gestation and a birth weight of 1500 g or less, born at the University Hospital Dr. José Eleuterio González at Monterrey, Mexico. A total of 40 preterm neonates were classified into breast milk feeding (BM) and mixed feeding (MF) groups (21 in the BM group and 19 in the MF group), from October 2017 to June 2019. Fecal samples were collected before they were introduced to any feeding type. After full enteral feeding was achieved, the composition of the gut microbiota was analyzed using 16S rRNA gene sequencing. Numerical variables were compared using Student's t-test or using the Mann-Whitney U test for nonparametric variables. Dominance, evenness, equitability, Margalef's index, Fisher's alpha, Chao-1 index, and Shannon's diversity index were also calculated. RESULTS: No significant differences were observed at the genus level between the groups. Class comparison indicated higher counts of Alphaproteobacteria and Betaproteobacteria in the initial compared to the final sample of the BM group (P < 0.011). In addition, higher counts of Gammaproteobacteria were detected in the final than in the initial sample (P = 0.040). According to the Margalef index, Fisher's alpha, and Chao-1 index, a decrease in species richness from the initial to the final sample, regardless of the feeding type, was observed (P < 0.050). The four predominant phyla were Bacteroidetes, Actinobacteria, Firmicutes, and Proteobacteria, with Proteobacteria being the most abundant. However, no significant differences were observed between the initial and final samples at the phylum level. CONCLUSION: Breastfeeding is associated with a decrease in Alphaproteobacteria and Betaproteobacteria and an increase of Gammaproteobacteria, contributing to the literature of the gut microbiota structure of very low-birth-weight, preterm.

Genome Sequences of Bordetella pertussis Isolates from Outbreaks in Northeastern Mexico.

Here, we report the draft genome sequences of 4 Bordetella pertussis isolates which correspond to major clones isolated between 2008 and 2014 from two outbreaks in northeastern Mexico. The B. pertussis clinical isolates belong to the ptxP3 lineage, and they are grouped into two major clusters, defined by the fimH allele.

Association between umbilical cord leptin and weight gain according to feeding type in the early postnatal period, a brief report.

BACKGROUND: Weight gain in infancy depends on in utero nutritional status, with postnatal growth also dependent on feeding practices, culture, food accessibility and parents' education. OBJECTIVE: To evaluate the relationship between umbilical cord blood leptin levels and feeding mode (breast-fed vs. formula) on weight gain at three months of life. MATERIAL AND METHODS: Ninety-nine full-term newborns (male, n = 48; female, n = 51) were included in two groups according to feeding type: breast-fed (n = 49) and formula-fed (n = 50). Leptin was measured in blood obtained from the umbilical cord vein. RESULTS: Umbilical cord leptin levels and weight gain at three months had a significant inverse correlation in formula-fed infants (r = -0.294, P = 0.038). This finding was not reflected in breast-fed infants (r = -0.212, P = 0.144). CONCLUSIONS: In our Mexican breastfeeding cohort, umbilical cord leptin levels were a significant predictor of weight gain in formula-fed infants.

Severe COVID-19 patients have severe vitamin D deficiency in Northeast Mexico.

Introduction: Objective: the association between vitamin D and COVID-19 severity is not consistent. We compared prevalences and analyzed the association between vitamin D deficiency and COVID-19 severity in Northeast Mexico. Methods: this was a cross-sectional study with individuals consecutively included at a referral diagnostic center during March-September 2020 (n = 181). Concurrently, every patient admitted to intensive care was also consecutively included (n = 116). Serum 25(OH)D < 20 ng/mL was considered vitamin D deficiency. Descriptive, ANOVA, and multivariate ordinal regression analyses were performed. Results: vitamin D deficiency prevalence was 63.8 % (95 % CI, 54.7, 72.0) in severe COVID-19; 25.6 % (95 % CI, 17.4, 36.0) in mild COVID-19; and 42.4 % (95 % CI, 33.2, 52.3) in non-diseased individuals. Vitamin D deficiency increased 5 times the odds of severe COVID-19 (95 % CI, 1.1, 24.3), independently of sex, age, body mass index, and inflammatory markers. Conclusions: this study is the first report of vitamin D deficiency in Northeast Mexico. Vitamin D deficiency was associated with COVID-19 severity.

Introducción: Objetivo: la asociación entre la vitamina D y la gravedad de la COVID-19 no es consistente. Se comparó la prevalencia y se analizó la asociación de la deficiencia de vitamina D con la gravedad de los pacientes con COVID-19 en el noreste de México. Métodos: este fue un estudio transversal. Se incluyó consecutivamente a individuos de un centro de diagnóstico de referencia durante marzo-septiembre de 2020 (n = 181). Paralelamente, se reclutó a todos los pacientes que ingresaron a cuidados intensivos en ese mismo periodo (n = 116). Se consideró que había deficiencia de vitamina D ante cifras de 25(OH)D sérica < 20 ng/ml. Se realizaron un análisis descriptivo, un ANOVA y una regresión ordinal multivariante. Resultados: la prevalencia de la deficiencia de vitamina D fue del 63,8 % (IC del 95 %: 54,7; 72,0) en la COVID-19 grave, del 25,6 % (IC del 95 %: 17,4; 36,0) en la COVID-19 leve y del 42,4 % (IC del 95 %: 33,2; 52,3) sin COVID-19. La deficiencia aumentó 5 veces las probabilidades de una COVID-19 grave (IC del 95 %: 1,1; 23,9) independientemente del sexo, la edad, el índice de masa corporal y los marcadores inflamatorios. Conclusiones: este estudio es el primer informe de la deficiencia de vitamina D en el noreste de México. La deficiencia de vitamina D se asoció con la gravedad de la COVID-19.

Decline in influenza cases in Mexico after the implementation of public health measures for COVID-19.

Mexico took swift action and has strictly followed mitigation measures to prevent the spread of coronavirus disease, COVID-19. In this study we compared influenza activity indicators in our country after the implementation of public health measures for COVID-19. We compared indicators of influenza activity in 2020 before and after public health measures were taken to reduce COVID-19 with the corresponding indicators from three preceding years and the immediate one, and the potential decrease in seasonal influenza cases/deaths. Nationwide surveillance data revealed a drastic decline in influenza diagnosis in outpatient clinics and public hospitals, influenza positivity rates of clinical specimens, and confirmed severe cases during the following 10 weeks of 2020 as lockdown activities and control measures were established compared with the same period of 2019. Our results suggest that the measures taken for COVID-19 were effective in reducing the spread of other viral respiratory diseases as influenza in our country.

Seroprevalence of Anti-SARS-CoV-2 Antibodies in Blood Donors from Nuevo Leon State, Mexico, during 2020: A Retrospective Cross-Sectional Evaluation.

The progression and distribution of the SARS-CoV-2 pandemic are continuously changing over time and can be traced by blood donors' serological survey. Here, we investigated the seroprevalence of anti-SARS-CoV-2 antibodies in blood donors in Nuevo Leon, Mexico during 2020 as a strategy for the rapid evaluation of the spread of SARS-CoV-2 and asymptomatic case detection. We collected residual plasma samples from blood donors who attended two regional donation centers from January to December of 2020 to identify changes in anti-SARS-CoV-2 IgG prevalence. Plasma samples were analyzed on the Abbott Architect instrument using the commercial Abbott SARS-CoV-2 IgG chemiluminescent assay. We found a total of 99 reactive samples from 2068 analyzed plasma samples, resulting in a raw prevalence of 4.87%. Donors aged 18-49 years were more likely to be seropositive compared to those aged >50 years (p < 0.001). Weekly seroprevalence increased from 1.8% during the early pandemic stage to 27.59% by the end of the year. Prevalence was 1.46-fold higher in females compared to males. Case geographical mapping showed that Monterrey city recorded the majority of SARS-CoV-2 cases. These results show that there is a growing trend of seroprevalence over time associated with asymptomatic infection that is unnoticed under the current epidemiological surveillance protocols.

Predicting the optimal depth of ultrasound-guided right internal jugular vein central venous catheters in neonates.

BACKGROUND: Poor positioning of a central venous catheter (CVC) can cause severe complications. The objective is to create a formula that predicts the optimal insertion depth of a real time ultrasound-guided CVC in the right internal jugular vein (RIJV) in newborns. METHODS: Between 2015 and 2017, 91 newborns that required a CVC were included in a prospective observational study. Variables such as gestational age, gender, weight, height, and neck length were studied. On the chest x-ray, the distance between the insertion site on the skin and the catheter tip was measured. RESULTS: Of the patients included, 50 (54.9%) were males and 40 (44.4%) females; 64 (70.3%) were preterm. Mean gestational age was 33.44 (25 to 41) weeks, weight 2020 (580 to 3980) g, and height 43.04 (26 to 53) cm. Variables were correlated with catheter length and an algorithm was modeled for the introduction method, in which the highest corrected determination coefficient was obtained for weight (R2 = 0.723). CONCLUSION: This study demonstrated that the weight of the newborn was the most significant individual predictor of optimal insertion depth of a CVC in the RIJV. The formula Y = 2.6 + 0.7 (weight in kg) that we suggest is practical and reproducible. LEVEL OF EVIDENCE: Level IV.

Are cord blood visfatin concentrations different depending on birth weight category?

BACKGROUND AND OBJECTIVE: Increased visceral adipose tissue mass is strongly associated to metabolic disorders. Visfatin is a visceral fat adipocytokine. There is epidemiological evidence of a link between a suboptimal gestational environment and a greater propensity to develop metabolic disease in adult life. The objective of this study was to establish whether visfatin concentrations in umbilical cord blood are different in newborns small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA). SUBJECTS AND METHODS: Term newborns from an university medical center were included in the study. A blood sample was taken from the umbilical cord vein of each baby immediately after birth. Visfatin was measured using an enzyme immunoassay in the study population, consisting of 35 subjects in the SGA group, 58 in the AGA group, and 35 in the LGA group. RESULTS: Cord blood visfatin concentrations were not different in the three groups, with respective values of 2.78 (1.86-4.49) ng/mL, 3.28 (1.98-4.97) ng/mL, and 3.46 (2.48-5.38) ng/mL in the SGA, AGA and LGA groups (p=0.141). Gestational weight gain (GWG) (14.09±6.37kg) was negatively associated to visfatin levels (r=-0.218, p=0.036). GWG is an independent predictor of visfatin concentrations (r2=-0.067, p=0.027). CONCLUSIONS: There were no differences in cord blood visfatin concentrations depending on birth weight. GWG is an independent predictor of visfatin levels in the cord blood of term newborns.

Differences in omentin-1 levels in term newborns according to birth weight.

BACKGROUND: Adipokines are produced by adipose tissue and are involved in metabolic processes. Omentin-1 is an adipokine that has been shown in vitro to possibly be involved in insulin sensitivity modulation. The prenatal stage is a crucial period for development of metabolic diseases in the long term, therefore, small (SGA) and large (LGA) for gestational age newborns have an increased risk of type 2 diabetes and metabolic syndrome later in life. AIMS: To evaluate the differences in omentin-1 concentrations in umbilical cord blood from healthy term newborns according to birth weight and explore the association between omentin-1 and anthropometry, glucose, insulin and insulin sensitivity. STUDY DESIGN: This was a secondary analysis of stored umbilical cord blood of term newborns. SUBJECTS: Newborns classified according to birth weight as SGA (n = 30), adequate for gestational age (AGA) (n = 12) and LGA (n = 34). OUTCOME MEASURES: An analysis of omentin-1, glucose and insulin were performed. RESULTS: Differences were found in serum omentin-1 levels (ng/mL) between SGA 328.17 ±â€¯108.04, AGA 253.05 ±â€¯98.25 and LGA 250.91 ±â€¯100.48 (p = 0.009). In the linear regression analysis, the independent variables HOMA-IR, QUICK-I and FGIR were predictors of serum omentin-1 levels (r = 0.175, p = 0.003). CONCLUSIONS: Omentin-1 cord blood levels have a differentiated behavior according to weight for gestational age with LGA newborns having lower levels and SGA newborns higher levels. HOMA-IR, QUICK-I and FGIR weakly predicted omentin-1 in cord blood, suggesting that omentin-1 possibly has an implication in insulin sensitivity since birth.

Vaspin, a Compensatory Mechanism Against High Glucose Levels Since Birth?

Objective: Hormones produced by fat tissue, adipokines, produced during intrauterine life have recently been implicated in fetal growth. Vaspin is an adipokine expressed in visceral adipose tissue and has insulin-sensitizing effects. Elevated serum vaspin concentrations are associated with alterations in insulin sensitivity. We aimed to determine if vaspin concentrations in cord blood from healthy, term newborns differ among those born small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA). A secondary objective was to determine whether an association existed between vaspin and anthropometric measurements, glucose and insulin levels in the newborn. Methods: The study population included healthy term newborns, 30 subjects in the SGA, 12 in the AGA, and 34 in the LGA group. Anthropometry was documented in all subjects. Blood was taken from the umbilical cord vein from each child for later analysis for vaspin, insulin and glucose concentrations. Results: Cord blood vaspin, insulin and glucose concentrations were not different between the three study groups. A negative correlation between vaspin and glucose concentrations was demonstrated in the whole cohort (r=-0.364, p=0.001). This correlation was also observed in the LGA group (r=-0.482, p=0.004). Glucose concentrations significantly predicted vaspin concentrations (r2=0.132, p=0.001). Conclusion: We found a negative association between glucose and vaspin concentrations in umbilical cord blood. In addition there was a predictive association between blood glucose and resulting vaspin concentration, suggesting that vaspin can be used as a predictor of alterations in the insulin-glucose metabolism from birth.

Comparison of an increased waist circumference with a positive hydrogen breath test as a clinical predictor of lactose intolerance. / Comparación del incremento del perímetro abdominal con la prueba de hidrógeno espirado como predictor clínico de intolerancia a la lactosa.

INTRODUCTION: Lactose intolerance is a common disease in pediatrics, and its wrong diagnosis will lead to morbidity. The primary objective of this study was to assess the usefulness of an increased waist circumference during the hydrogen breath test as a predictor of lactose intolerance. The secondary objective was to analyze the impact of body mass index, waist circumference measurement, and age on the abdominal distension of patients with lactose intolerance. POPULATION AND METHODS: A total of 138 subjects aged 3 to 15 years were included. They underwent serial measurements of the waist circumference and hydrogen levels in the breath every 30 minutes over 3 hours during the hydrogen breath test. RESULTS: Out of the entire sample, 35 (25.4%) patients had lactose intolerance. An increase of 0.85 cm in waist circumference compared to the baseline waist circumference results in a sensitivity of 88% and a specificity of 85% to predict lactose intolerance (odds ratio: 42.14, 95% confidence interval: 13.08-135.75, p ≤ 0.001). The body mass index and waist circumference measurement did not affect abdominal distension (p= not significant); however, age modified the time of distension. CONCLUSIONS: A 0.85 cm increase in waist circumference compared to the baseline waist circumference during the hydrogen breath test is a useful parameter for the diagnosis of lactose intolerance in pediatrics. Variations in relation to body mass index and waist circumference did not affect the usefulness of an increased waist circumference, unlike age.

La intolerancia a la lactosa es una afección frecuente en pediatría, cuyo diagnóstico erróneo conlleva morbilidad. El objetivo primario del estudio fue evaluar la utilidad del incremento del perímetro abdominal durante la prueba de hidrógeno espirado como predictor de intolerancia a la lactosa. El objetivo secundario fue analizar la influencia del índice de masa corporal, de la medida de la cintura y de la edad en la distensión abdominal de pacientes intolerantes a la lactosa.