Natividad Castro-Alarcón

Body Fat Distribution and Its Association With Hypertension in a Sample of Mexican Children

Background The association between elevated blood pressure and childhood overweight and obesity has been documented in several studies. However, the linkage of blood pressure with body fat distribution in children is not well established. We investigated the relationship between both central and subcutaneous adiposity with BP in the 95th percentile or higher in Mexican children. Methods and Results Our study, using a sample of children from the State of Guerrero, Mexico was comprised of 252 children, 124 girls and 128 boys, with an age range of 6 to 13 years. Resting blood pressure was measured in duplicate with an aneroid sphygmomanometer. Hypertension was classified as systolic or diastolic BP in the 95th percentile or higher. Additional measures included weight, height, body mass index, body circumferences, and skinfold thickness. The prevalence of obesity (26.5%) was higher than overweight (15.8%), but the prevalence of hypertension was moderate (4.7%). Both systolic and diastolic blood pressures correlated strongly with age, weight, height, and all measurements of central and subcutaneous adiposity. Interestingly, after being adjusted by age, sex, and body mass index, the BP in the 95th percentile or higher was associated with suprailiac skinfold, third tertile (OR = 11.83, P = 0.023); triceps skinfold, third tertile (OR = 6.02; P = 0.034); and biceps skinfold, third tertile (OR = 4.71; P = 0.038). Conclusions Our data indicate that the prevalence of hypertension in children is moderate. In addition, the skinfold thickness was a better predictor of hypertension than central adiposity in the sample of children studied.

Gut Microbiota and Metabolic Endotoxemia in Young Obese Mexican Subjects.

Background: The gut microbiota plays an important role in human metabolism; previous studies suggest that the imbalance can cause a metabolic endotoxemia that may be linked to weight gain and insulin resistance. The purpose of this study was to investigate the relationship between the gut microbiota composition, the lipopolysaccharide levels and the metabolic profile in obese and normal-weight young subjects. Methods: We studied 32 obese (BMI ≥ 30 kg/m2) and 32 normal-weight subjects (BMI = 18.5-24.9 kg/m2), aged 18-25 years. Quantification of intestinal bacteria was performed by real-time PCR. Endotoxin units were determined with the test QCL-1000, and biochemical profile was performed under a standard protocol of Spinreact. Results: Obese individuals had a BMI of 34.5 (32.9-36.45) kg/m2, increased triglycerides (123 vs. 70 mg/dl), total cholesterol (168 vs. 142 mg/dl), and LDL-cholesterol (114 vs. 96.5 mg/dl). In obese subjects body temperature was higher than in normal-weight subjects. We found a greater number of Clostridum leptum and Lactobacillus (p < 0.001) and lower numbers of Prevotella and Escherichia coli (p < 0.001) in the obese group. A decrease of E. coli was associated with an increased risk of lipopolysaccharide levels ranging from 1 to 1.3 EU/ml. A positive correlation was found between serum lipopolysaccharides and BMI (r = 0.46, p = 0.008), triglyceride levels (r = 0.44, p = 0.011) as well as waist circumference (r = 0.34, p = 0.040), being more evident in young obese females. Conclusion: Subclinical metabolic endotoxemia determined by serum concentration of lipopolysaccharides was related to the smallest amount of E. coli, high triglyceride levels, and central adiposity in obese young persons.

Molecular typing and characterization of macrolide, lincosamide and streptogramin resistance in Staphylococcus epidermidis strains isolated in a Mexican hospital

Staphylococcus epidermidis is a normal commensal of skin that has become a serious clinical problem because of the combination of increased use of intravascular devices and an increasing number of hospitalized immunocompromised patients. In addition, there is a lack of information pertaining to resistance to macrolide, lincosamide and streptogramin type B (MLS(B)) in developing countries, including Mexico. The aim of this study was to investigate the incidence of resistance to MLS(B) antibiotics in isolates of S. epidermidis obtained in the General Hospital of Acapulco in Mexico. Susceptibility to erythromycin, clindamycin and quinupristin-dalfopristin was tested by a diffusion test, and MICs to oxacillin, erythromycin and lincomycin were determined. Differentiation between MLS(B) phenotypes was performed by a double disc diffusion test. A total of 38 of the 47 strains of S. epidermidis isolated from nosocomial infections were resistant to oxacillin [meticillin-resistant S. epidermidis (MRSE)]. The phenotypes obtained were: 18 constitutive MLS(B), 3 inducible MLS(B), 6 macrolide streptogramin and 4 lincosamide; 7 strains were susceptible to MLS(B) antibiotics. The genes associated with resistance were detected by PCR. Genotyping showed a predominance of the ermA gene followed by genes ermC and msrA. The frequency of the genes detected varied slightly from results that have been reported in isolates from other countries. Clonal types were identified by PFGE and revealed the dissemination of two major clones of MRSE in the Mexican hospital. This is believed to be the first report in Mexico on the genes associated with the MLS(B) resistance phenotype in S. epidermidis, in addition to observing a wide distribution of clonal types in the General Hospital of Acapulco, Mexico.

Body adiposity but not insulin resistance is associated with -675 4G/5G polymorphism in the PAI-1 gene in a sample of Mexican children

OBJECTIVE To assess whether the -675 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene is associated with obesity and insulin resistance in Mexican children. METHODS A cross-sectional study was performed in 174 children, 89 with normal-weight and 85 with obesity, aged from 6 to 13 years. All children were from state of Guerrero, and recruited from three primary schools in the city of Chilpancingo, state of Guerrero, Mexico. Insulin levels were determined by immunoenzymatic assay. The homeostasis model assessment was used to determine insulin resistance. The -675 4G/5G polymorphism in PAI-1 gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS The prevalence of insulin resistance in the obese group was higher (49.41%) than in the normal-weight group (16.85%). The 4G/5G PAI-1 polymorphism was found in Hardy Weinberg equilibrium. The 4G/5G genotype contributed to a significant increase in waist-hip ratio (β=0.02, p=0.006), waist circumference (β=4.42, p=0.009), and subscapular skinfold thickness (β=1.79, p=0.04); however, it was not related with insulin resistance. CONCLUSION The -675 4G/5G genotype of PAI-1 gene was associated with increase of body adiposity in Mexican children.

Original articleBody adiposity but not insulin resistance is associated with -675 4G/5G polymorphism in the PAI-1 gene in a sample of Mexican childrenAdiposidade corporal, mas não resistência insulínica, associa-se ao polimorfismo -675 4G/5G no gene PAI-1 em uma amostra de crianças mexicanas☆

OBJECTIVE To assess whether the -675 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene is associated with obesity and insulin resistance in Mexican children. METHODS A cross-sectional study was performed in 174 children, 89 with normal-weight and 85 with obesity, aged from 6 to 13 years. All children were from state of Guerrero, and recruited from three primary schools in the city of Chilpancingo, state of Guerrero, Mexico. Insulin levels were determined by immunoenzymatic assay. The homeostasis model assessment was used to determine insulin resistance. The -675 4G/5G polymorphism in PAI-1 gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS The prevalence of insulin resistance in the obese group was higher (49.41%) than in the normal-weight group (16.85%). The 4G/5G PAI-1 polymorphism was found in Hardy Weinberg equilibrium. The 4G/5G genotype contributed to a significant increase in waist-hip ratio (β=0.02, p=0.006), waist circumference (β=4.42, p=0.009), and subscapular skinfold thickness (β=1.79, p=0.04); however, it was not related with insulin resistance. CONCLUSION The -675 4G/5G genotype of PAI-1 gene was associated with increase of body adiposity in Mexican children.

Concentraciones circulantes de MCP-1, VEGF-A, sICAM-1, sVCAM-1, sE-selectina y sVE-cadherina: su relación con componentes del síndrome metabólico en población joven

INTRODUCTION Inflammation and endothelial dysfunction are considered the primary manifestations of the cardiovascular disease. Studies have established a relationship among components of metabolic syndrome (MetS) with inflammatory markers and the loss of permeability, vasoconstriction and vasodilatation endothelial. OBJECTIVE To determine the relationship among the concentrations of soluble endothelial dysfunction molecules and inflammation cytokines and components of the metabolic syndrome in young population. MATERIAL AND METHODS A study was performed in 240 young adult students ages 18-28 years. To define the presence of clinical and metabolic alterations and MetS the modified ATP-III criteria was considered. In all subjects were determined sociodemographic characteristics, anthropometric measures and the metabolic profile. Circulating levels of MCP-1, VEGF-A, sICAM-1, sVCAM-1, sE-selectin and sVE-cadherin were determined by ELISA immunoassay (Bioscience). Statistical analysis was performed using STATA statistical software v. 9.2. RESULTS From all the participants, 44.6% had obesity, 59.9% had abdominal obesity, 49.6% low HDL-c and 16.7% high levels triglycerids. The 16.25% of the population showed 3 or more components of the MetS. Elevated MCP-1, sICAM-1 and sE-selectin levels were linked to the presence of obesity. In a model adjusted by age-gender, high soluble levels of MCP-1 and VEGF-A were linked with abdominal obesity (OR=1.83; 1.02-3.28 and OR=2.03; 1.15-3.56, respectively), as well as to the presence of the 2 components of MetS. sVCAM-1 levels were associated with impaired glucose (OR=4.74; 1.32-17.0); sE-selectin with low HDL-c (OR=1.99; 1.05-3.75), although sICAM-1 and sVE-cadherin were associated with impaired systolic blood pressure (OR=4.04; 1.24-13.1 and OR=6.28; 1.90-20.7, respectively). CONCLUSION Levels of circulating MCP-1 and VEGF-A were associated with adiposity, levels of sVCAM-1 with the presence of impaired glucose, sE-selectin with low HDL-c, while the levels of sICAM-1 and sVE-cadherin were associated with impaired systolic blood pressure in young adults independently of other traditional risk factors.

Association between TLR4 polymorphisms (896 A>G, 1196 C>T, − 2570 A>G, − 2081 G>A) and virulence factors in uropathogenic Escherichia coli

Escherichia coli is the main etiological agent of urinary tract infections. Its virulence factors are important during the initial interaction stage with the host as they enable colonization of urinary tract tissues. The genetic markers evidencing susceptibility to develop recurrent infections have been previously described. Toll-like receptors are critical sensors of microbial attacks, and they are also effectors of the individual’s innate defense for elimination of pathogens. The aim of this study was to evaluate the association between functional polymorphisms (896 A>G, 1196 C>T, − 2570 A>G, − 2081 G>A) and susceptibility to develop urinary tract infections as well as E. coli virulence factors. This study includes 100 samples from patients diagnosed with UTI and 100 samples from uninfected subjects. A conventional urine culture was performed and the isolates were identified by using the Vitek automated system. TLR4 gene polymorphisms were identified by the PCR–RFLP technique. The hlyA, fimH, papC, iutA and cnf1 virulence factors as well as the E. coli phylogenetic group were assessed by PCR. In this study, it was observed that the presence of the − 2570 polymorphism represents a risk of UTI (p < 0.01), whereas − 2081 confers protection (p < 0.01). The 896A>G and 1196C>T polymorphisms were associated with the E. coli virulence factors fimH and hlyA, respectively (p < 0.05). The B2 group was the most frequent in clinical isolates (51%), and it displayed more virulence factors regarding other phylogenetic groups (p ≤ 0.05). An interesting finding was that strains considered as commensals, belonging to groups A and B1, can cause UTI and present virulence factors. Polymorphisms occurring in the TLR4 promoter region are correlated with susceptibility or risk of UTI, whereas structural polymorphisms are associated with the recognition of virulence factors displayed by E. coli.