Comparison between CDC and WHO BMI z-score and their relation with metabolic risk markers in Northern Portuguese obese adolescents

Association Between Early-Life Exposure to Antibiotics and Development of Child Obesity: Population-Based Study in Italy

BACKGROUND

Childhood obesity is a significant public health problem representing the most severe challenge in the world. Antibiotic exposure in early life has been identified as a potential factor that can disrupt the development of the gut microbiome, which may have implications for obesity.

OBJECTIVE

This study aims to evaluate the risk of developing obesity among children exposed to antibiotics early in life.

METHODS

An Italian retrospective pediatric population-based cohort study of children born between 2004 and 2018 was adopted using the Pedianet database. Children were required to be born at term, with normal weight, and without genetic diseases or congenital anomalies. We assessed the timing of the first antibiotic prescription from birth to 6, 12, and 24 months of life and the dose-response relationship via the number of antibiotic prescriptions recorded in the first year of life (none, 1, 2, and ≥3 prescriptions). Obesity was defined as a BMI z score >3 for children aged ≤5 years and >2 for children aged >5 years, using the World Health Organization growth references. The obese incidence rate (IR) × 100 person-years and the relative 95% CI were computed using infant sex, area of residence, preschool and school age, and area deprivation index, which are the covariates of interest. A mixed-effect Cox proportional hazards model was used to estimate the hazard ratio and 95% CI for the association between antibiotic exposure in early life and child obesity between 24 months and 14 years of age, considering the family pediatricians as a random factor. Several subgroup and sensitivity analyses were performed to assess the robustness of our results.

RESULTS

Among 121,540 children identified, 54,698 were prescribed at least an antibiotic within the first year of life and 26,990 were classified as obese during follow-up with an incidence rate of 4.05 cases (95% CI 4.01-4.10) × 100 person-year. The risk of obesity remained consistent across different timings of antibiotic prescriptions at 6 months, 1 year, and 2 years (fully adjusted hazard ratio [aHR] 1.07, 95% CI 1.04-1.10; aHR 1.06, 95% CI 1.03-1.09; and aHR 1.07, 95% CI 1.04-1.10, respectively). Increasing the number of antibiotic exposures increases the risk of obesity significantly (P trend<.001). The individual-specific age analysis showed that starting antibiotic therapy very early (between 0 and 5 months) had the greatest impact (aHR 1.12, 95% CI 1.08-1.17) on childhood obesity with respect to what was observed among those who were first prescribed antibiotics after the fifth month of life. These results were consistent across subgroup and sensitivity analyses.

CONCLUSIONS

The results from this large population-based study support the association between early exposure to antibiotics and an increased risk of childhood obesity. This association becomes progressively stronger with both increasing numbers of antibiotic prescriptions and younger age at the time of the first prescription.

Comparison of Different Anthropometric Indicators for Assessment of Nutritional Status Among Adolescent Girls in an Urban Resettlement Colony in New Delhi: A Cross-Sectional Study

Background In India, 44.8% of adolescent girls are under-nourished, while about 8%-13% of girls are overweight. Though several studies have been done regarding the nutritional status of adolescent girls over the years, there have been no significant changes. Also, there are several different anthropometric indicators for nutritional status assessment, due to which there are huge variations in the prevalence of malnutrition across different studies. So the objectives of this study were to determine the prevalence of malnutrition using different anthropometric indicators and compare them. Methods A random sample of 426 girls was taken from Health Management Information Systems (HMIS) of the Centre for Community Medicine (CCM), All India Institute of Medical Sciences (AIIMS), and a semi-structured questionnaire was administered among 386 of them to determine associated factors. Height, weight, and mid-upper arm circumference (MUAC) were measured for 386 girls, and BMI for age and height for age z scores were calculated using WHO AnthroPlus. Mid-upper arm circumference for age z scores (MUAC for age) were calculated using Lambda-Mu-Sigma (LMS) charts by the CDC for girls aged one year to 20 years. Results It was found in this study that using BMI for age z scores (BAZ), 33.4% of the adolescent girls were malnourished; 18.9% (95% CI 15.1-23.2) being underweight, 10.6% (95% CI: 7.7-14.1) being overweight, and 3.9% (95% CI: 2.2-6.3) were obese. While using BMI solely as an indicator, the prevalence of thinness was 51.8% (95% CI: 46.9-56.9), while that of overweight and obesity was 10.6% (95% CI: 5.7-11.5) and 1.0% (95% CI: 0.2-2.6), respectively. The prevalence of under-nutrition by MUAC for age z scores was 53.4% (95% CI: 48.2-58.4), and that of over-nutrition was 1.8% (95% CI: 1.0-3.7). BMI for age z scores positively and strongly correlated with both MUAC and MUAC for age z scores and had a significant association with both on univariable linear regression. Though there was a negative correlation between BMI for age z scores and height-for-age z scores, it was not significant. Height-for-age z scores, even though positively correlated with MUAC for age z scores, the correlation was not that strong.

Adolescents' Self-Perceived Weight and Metabolic Syndrome

Background and Objective: The aim of this study was to assess the relationships of self-perceived weight with having more metabolic syndrome (MetS) components and the MetS score regardless of body mass index (BMI)-based weight category. Methods: Utilizing data from the Korea National Health and Nutrition Examination Survey 2014 to 2019, weight categories according to BMI and self-perception (underweight, normal weight, or overweight), MetS components defined by the International Diabetes Federation for adolescents, the MetS score, and confounding factors were evaluated in 1441 female adolescents and 1646 male adolescents aged 10 to 18 years. A complex samples general linear model and ordinal regression were used to analyze those relationships. Results: The odds of having more MetS components were 1.67 (95% confidence interval, CI: 1.38-2.03) in adolescents who self-perceived as overweight than in those who self-perceived as normal weight after controlling for sociodemographic and health-related factors and BMI-based weight categories. Compared with adolescents who accurately self-perceived as normal weight (reference group), the odds were 1.48 (95% CI: 1.19-1.84) in those with normal weight, but self-perceived as overweight; 2.90 (95% CI: 1.69-4.98) in those who were overweight, but self-perceived as normal weight; and 9.38 (95% CI: 7.52-11.71) in those who accurately self-perceived as overweight. In relation to the MetS score, similar findings were observed. The combined weight categories had significant interactions with sex and age groups (10-12 years vs. 13-18 years) in those relationships. Conclusions: Regardless of actual weight status, adolescents' self-perceived weight may be a crucial consideration when determining whether or not MetS components may be present.

Predicting metabolic syndrome by anthropometric measures among adults 35-65 years in the west of Iran; a cross sectional study from an Iranian RaNCD cohort data

AIMS

Anthropometric indices have been proposed for the early detection of metabolic syndrome (MetS) and its risk factors. The present study aimed to determine optimal cutoff points for the Body Mass Index (BMI), Waist Circumference (WC), and Waist Hip Ratio (WHR) in the prediction of MetS.

METHODS

This cross-sectional study was performed on 9746 adults 35-65 years, recruited in Ravansar Non-Communicable Diseases (RaNCD) cohort. The receiver operating characteristic (ROC) curve analysis was used to compare the predictive validity and determine optimal cutoff values.

RESULTS

The optimal cutoff points for BMI, WC and WHR were 27.3 kg/m² (AUC: 78.6; 95%CI 77.1, 80.1), 97 cm (AUC: 63.8; 95%CI 60.4, 67.2) and 0.95 (AUC: 75.5; 95% CI 73.9, 77.1), respectively in men for the prediction of MetS. But in women the optimal cutoff points for BMI, WC and WHR were 28.6 kg/m² (AUC: 65.7; 95%CI 62.1, 69.4), 98.1 cm (AUC: 65.6; 95%CI 62.4,68.8) and 0.95 (AUC:62.39; 95%CI 60.9,63.9). The risk of MetS in men and women with a BMI higher than the optimal cutoff point was respectively 2.23 and 2.30 times higher than that in those with a WC lower than the cutoff point.

CONCLUSIONS

BMI is a better predictor of MetS than WC and WHR in adults 35-65 years. We recommend that the optimal cut off point be set for men 27.3 kg/m² and for women 28.6 kg/m².

Comparison of International Growth Standards for Assessing Nutritional Status in Cystic Fibrosis: The GreeCF Study

OBJECTIVE

The aim of the study was to compare 3 international growth references and explore their differences in assessing growth in Greek school-aged patients with cystic fibrosis (CF).

METHODS

Sample included 114 patients (50 boys, age 11.5 ± 3.9 years), provided care at Aghia Sofia Children's Hospital, Greece. Anthropometrics and predicted forced expiratory volume in 1 second (FEV1%) were measured. Body mass index (BMI) and height z scores were computed according to the Centers for Disease Control and Prevention (CDC), World Health Organization (WHO), and International Obesity Task Force (IOTF) references. Agreement between methods was analyzed with kappa statistics, repeated-measures analysis of variance, and Bland-Altman analysis. The relationship between FEV1% and BMI was explored with linear regression.

RESULTS

Mean CDC BMI z score was the lowest (0.06 ± 1.08), followed by WHO (0.17 ± 1.14) and IOTF (0.35 ± 1.05) (P ≤ 0.001 for all). The CDC and WHO growth references highly agreed for most weight status strata and stunting; all other comparisons produced lower agreements. Except for CDC and IOTF BMI z scores, all other comparisons produced wide levels of agreement and proportional bias. CDC reference classified more children as attaining low or normal weight, against WHO or IOTF (P ≤ 0.001 for all). Lowest prevalence of ideal and excess weight was recorded by CDC, compared to all other standards (P ≤ 0.001 for all). All BMI z scores provided moderate associations with FEV1%.

CONCLUSION

Large variations across weight status classification were present when employing 3 growth standards in school-aged patients . Given than BMI z-scores from all references provided comparable associations with pulmonary function, our data indicate that no studied reference is better than others in assessing growth in CF.

Association Between the Brain-derived Neurotrophic Factor Val66Met Polymorphism and Overweight/Obesity in Pediatric Population

BACKGROUND

The brain-derived neurotrophic factor (BDNF) rs6265 (G196A; Val66Met) single nucleotide polymorphism has been associated with BMI and obesity in distinct populations, both adult and pediatric, with contradictory results involving either Val or Met as the risk variant.

AIM OF THE STUDY

To determine the association between the BDNF Val66Met polymorphism and BMI in Mexican children and adolescents.

METHODS

BDNF Val66Met genotyping by restriction fragment length polymorphism and nutritional status characterized by their BMI-for-age z-scores (BAZ) from pediatric volunteers (n = 498) were analyzed by Fisher's exact test association analysis. Standardized residuals (R) were used to determine which genotype/allele had the major influence on the significant Fisher's exact test statistic. Odds ratios were analyzed to measure the association between genotype and normal weight (≥-2 SD < + 1 SD) and overweight (≥ + 1 SD, including obesity, Ow + Ob) status with 95% confidence intervals to estimate the precision of the effect as well as 95% credible intervals to obtain the most probable estimate.

RESULTS

Comparisons between GG (Val/Val), GA (Val/Met) and AA (Met/Met) genotypes or Met homozygotes vs. Val carriers (combination of GG and GA genotypes) showed significant differences (p = 0.034 and p = 0.037, respectively) between normal weight and the combined overweight and obese pediatric subjects. Our data showed that children/adolescents homozygous for the A allele have increased risk of overweight compared to the Val carriers (Bayes OR = 4.2, 95% CI**[1.09-33.1]).

CONCLUSION

This is the first study showing the significant association between the BDNF rs6265 AA (Met/Met) genotype and overweight/obesity in Mexican pediatric population.

Defining a BMI Cut-Off Point for the Iranian Population: The Shiraz Heart Study

In this study we evaluated and redefined the optimum body mass index (BMI) cut-off point for the Iranian population based on metabolic syndrome (MeS) risk factors. We further evaluated BMI cut-off points with and without waist circumference (WC) as a cofactor of risk and compared the differences. This study is part of the largest surveillance programs conducted in Shiraz, Iran, termed the Shiraz Heart study. Our study sample included subjects between the ages of 20 to 65 years old. After excluding pregnant women, those with missing data and those with comorbid disease, a total of 12283 made up the study population. The participants underwent a series of tests and evaluations by trained professionals in accordance with WHO recommendations. Hypertension, abnormal fasting blood sugar (FBS), triglyceride (TG) and high density lipoprotein cholesterol (HDL) (in the context of the definition of metabolic syndrome) were prevalent among 32.4%, 27.6%, 42.1 and 44.2% of our participants, respectively. Women displayed higher rates of overall obesity compared to men (based on the definition by the WHO as higher than 30 kg/m²). Regarding MeS, 38.9% of our population had the all symptoms of MeS which was more prevalent among women (41.5% vs. 36%). When excluding WC in the definition of MeS, results showed that males tend to show a higher rate of metabolic risk factors (19.2% vs. 15.6%). Results of multivariate analysis showed that parallel to an increase in BMI, the odds ratio (OR) for acquiring each component of the metabolic syndrome increased (OR = 1.178; CI: 1.166–1.190). By excluding WC, the previous OR decreased (OR = 1.105; CI: 1.093–1.118). Receiver Operating Characteristic (ROC) curve analysis showed that the optimum BMI cut-off point for predicting metabolic syndrome was 26.1 kg/m² and 26.2 kg/m² [Accuracy (Acc) = 69% and 61%, respectively)] for males and females, respectively. The overall BMI cut-off for both sexes was 26.2 kg/m² (Acc = 65%) with sensitivity and specificity of 69% and 62%, respectively. This cut-off had a positive predictive value of 54% and a negative predictive value of 76%. When we excluded waist circumference, the optimum BMI cut-off for acquiring metabolic risk factors in males decreased to 25.7 kg/m² (Acc = 67%) and increased for women to 27.05 kg/m² (Acc = 66%). Iranians are at higher risks of morbidity related to metabolic factors at a lower BMI cut-off and prompt action and preventive health policy are required to prevent and educate Iranians regarding diseases associated with obesity.