Variance in the transaminase levels over the body mass index spectrum in 10- and 13-year-olds

Accuracy of Tri-ponderal Mass Index and Body Mass Index in Estimating Insulin Resistance, Hyperlipidemia, Impaired Liver Enzymes or Thyroid Hormone Function and Vitamin D Levels in Children and Adolescents

OBJECTIVE

Tri-ponderal mass index (TMI) has been reported to estimate body fat more accurately than body mass index (BMI). This study aimed to compare the efficacy of TMI and BMI in predicting insulin resistance (IR), hyperlipidemia, impaired liver enzymes or thyroid hormone function and vitamin D concentration.

METHODS

One hundred and forty-three overweight or obese children, based on BMI-standard deviation (SD) scoring (BMI-SDS) were studied retrospectively. TMI thresholds for overweight status were 16.0 kg/m³ for boys and 16.8 kg/m³ for girls and 18.8 kg/m³ for boys and 19.7 kg/m³ for girls for obese status.

RESULTS

Twenty-two overweight and eight obese children by BMI-SDS were classified as normal by TMI. Of the overweight children 22 (22.7%) had IR and IR was detected in 2 of 8 obese children with normal TMI. There was no increase in liver enzymes in any of the children with normal TMI. Forty-four obese children were overweight according to TMI and IR was detected in 40.9%. Thyroid stimulating hormone levels were significantly higher in BMI-based obese children. Vitamin D levels were similar in all groups of both classifications.

CONCLUSION

When TMI was used there may be a risk of overlooking IR. However, if it is assumed that liver enzymes are elevated as a result of visceral adiposity, TMI can be used as an auxiliary parameter to show visceral effects of adiposity. Normal TMI may indicate that visceral organ functions have not deteriorated yet. More studies are needed to evaluate TMI as a clinical tool.

Comparison of serum biochemical parameters between two broiler chicken lines divergently selected for abdominal fat content

In humans, obesity is associated with increased or decreased levels of serum biochemical indicators. However, the relationship is not as well understood in chickens. Due to long-term intense selection for fast growth rate, modern broilers have the problem of excessive fat deposition, exhibiting biochemical or metabolic changes. In the current study, the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) were used to identify differences in serum biochemical parameters between the 2 lines. A total of 18 serum biochemical indicators were investigated in the 16th, 17th, and 18th generation populations of NEAUHLF, and the genetic parameters of these serum biochemical indicators were estimated. After analyzing the data from these 3 generations together, the results showed that the levels of 16 of the tested serum biochemical parameters were significantly different between the lean and fat birds. In the fat birds, serum concentrations of high-density lipoprotein cholesterol (HDL-C), HDL-C:low-density lipoprotein cholesterol (LDL-C), total bile acid, total protein, albumin, globulin, aspartate transaminase (AST):alanine transaminase (ALT), γ-glutamyl transpeptidase (GGT), uric acid, and creatinine were very significantly higher (P < 0.01), whereas LDL-C, albumin:globulin, glucose, AST, ALT, and free fatty acids concentrations in serum were very significantly lower than those in the lean birds (P < 0.01). Of these 16 serum biochemical parameters, 5 (LDL-C, HDL-C:LDL-C, total bile acid, albumin, and albumin:globulin) had high heritabilities (0.58 ≤ h2 ≤ 0.89), 6 (HDL-C, total protein, globulin, AST:ALT, GGT, and creatinine) had moderate heritabilities (0.29 ≤ h2 ≤ 0.48), and the remaining 5 had low heritabilities (h2 < 0.20). Serum HDL-C, HDL-C:LDL-C, and glucose had higher positive genetic correlation coefficients (rg) with abdominal fat traits (0.30 ≤ rg ≤ 0.80), whereas serum globulin, AST, and uric acid showed higher negative genetic correlations with abdominal fat traits (–0.62 ≤ rg ≤ –0.30). The remaining 10 serum biochemical parameters had lower genetic correlations with abdominal fat traits (–0.30 < rg < 0.30). In conclusion, we identified serum HDL-C and HDL-C:LDL-C levels as potential biomarkers for selection of lean birds. These findings will also be useful in future studies for investigating obesity and lipid metabolism in humans as well as in other animal species.

Trends in underweight and overweight/obesity prevalence in Chinese youth, 2004-2009

BACKGROUND

There is a paucity of recent data on Chinese childhood overweight and underweight prevalence especially since 2004.

PURPOSE

The purpose of this study was to examine trends in underweight and overweight/obesity ("overweight" hereafter) prevalence and energy balance-related behaviors of Chinese youth from 2004 to 2009.

METHODS

Data from the China Health and Nutrition Survey, 2004-2009 (N = 4,061 students aged 6-18 years), were analyzed. Trained health workers took anthropometric measures at the participant's house or at a local clinic following a reference protocol recommended by the World Health Organization. The international age- and sex-specific body mass index reference standard proposed by the International Obesity Task Force was used to define underweight and overweight children in this study.

RESULTS

Among 6- to 11-year-old boys, underweight prevalence increased from 14.5% (2004) to 20.1% (2009, p = 0.068). Among 12- to 18-year-old boys, however, overweight prevalence increased from 7.5 to 12.6% (p = 0.034). From 2004 to 2009, after-school sedentary behavior increased from 2.3 to 3.4 h/day for 6- to 11-year-olds (p < 0.001) and from 2.2 to 3.1 h/day for 12- to 18-year-olds (p < 0.01). Meanwhile, the total energy intake decreased 7% for 6- to 11-year-olds (p < 0.05) and 10% for 12- to 18-year-olds (p < 0.01).

CONCLUSIONS

Both underweight and overweight Chinese students are increasing, with underweight increases more pronounced in 6- to 11-year-olds and overweight increases more pronounced in 12- to 18-year-olds. Nationwide efficacious interventions are needed that improve the diet, decrease sedentary behavior, and encourage a healthy and realistic body image in Chinese youth.

Psychosocial functioning and self-rated health in Japanese school-aged children: A cross-sectional study

Emotional and behavioral disorders in children are school-health concerns; however, Japanese screening tools for such disorders are not yet available. We examined the association between psychosocial functioning as measured by the Pediatric Symptom Checklist (PSC) and self-rated health within school settings. A cross-sectional study was conducted for 2513 fifth and eighth graders from all of the primary and secondary schools in Shunan City, Japan. The Japanese PSC had high internal consistency (Cronbach's α = 0.90) and a factor structure similar to that of the English PSC. When the cut-off values were set to ≥ 28 and ≥ 17, 4-9% and 20-39% of our respondents, respectively, reported high PSC scores. A multiple ordinal logistic regression analysis showed that the odds ratio of a positive PSC score (≥ 28) for poorer self-rated health among ratings of "very good," "good," "fair," and "poor" was 3.5 (95% confidence interval = 2.6-4.8). There was a clear association between psychosocial dysfunction identified by a PSC score ≥ 28 and poor self-rated health. We offer directions for further research on appropriate PSC cut-off values with Japanese samples.

Validity and reliability of physical activity questionnaire for Japanese students

BACKGROUND

Self-administered questionnaires about physical activity are useful for collecting data to develop public health policies. There is currently no validated physical activity questionnaire, however, for Japanese children and adolescents. The purpose of the present study was to evaluate the validity and reliability of self-administered, physical activity questionnaires for Japanese students.

METHODS

Fifth- and eighth-grade students were asked to complete two questionnaires that estimated the intensity and time of moderate-to-vigorous physical activities in which they participated, and the frequency and duration spent performing sports activities. Students also wore triaxial accelerometers to compare their actual activity levels to their estimates, to investigate the validity and reliability of the questionnaires.

RESULTS

The intensity and time spent performing moderate-to-vigorous physical activity that were estimated from the questionnaire were higher than those measured by accelerometry (9-161% of accelerometry). Questionnaire data were highly correlated with accelerometer data for eighth graders (Spearman correlation, 0.642-0.754), but the correlations were lower for fifth graders (≤ 0.331). Furthermore, there was higher repeatability in the data collected from eighth graders (intraclass correlation, 0.625-0.645) than from fifth graders (0.136-0.194).

CONCLUSIONS

Questionnaires may be useful in epidemiological studies for ranking physical activity levels of adolescents, such as a confounding factor for other lifestyle surveys, but these surveys are less accurate for younger children.

Iron load and liver enzymes in 10- and 13-year-olds

OBJECTIVES

Iron plays a pivotal role in adult steatosis, but its role in child and adolescent steatosis is unclear. We investigated the effect of dietary iron, serum iron, and ferritin on serum transaminases and γ-glutamyltransferase in 10- and 13-year-olds.

PATIENTS AND METHODS

The study included 4894 fifth and eighth graders enrolled between 2006 and 2009 in all schools in Shunan City, Japan. Multiple regression analyses were performed with adjustments for grade, sex, z score of the body mass index, serum lipids, plasma glucose, frequency of sports activities, having a single parent, number of siblings, tobacco smoking behavior, passive smoking at home, resident areas, and schools, using linear mixed models. In addition, we analyzed ferritin and insulin resistance in randomly selected subset of participants.

RESULTS

Dietary iron intake was positively associated with serum alanine aminotransferase levels (standardized coefficient β = 2.35, P = 0.019). Serum iron concentrations were associated with transaminase and γ-glutamyltransferase levels (β = 3.22, and 4.05, respectively, P < 0.01). In the subset of 421 subjects with further serum analysis, serum ferritin levels were significantly associated with serum enzyme levels (β = 2.43-3.35; P < 0.05) and showed significant odds ratio for the elevated alanine aminotransferase levels (1.05 for 1 SD with 95% confidence intervals 1.02-1.08). However, iron load did not show a positive association with insulin resistance.

CONCLUSIONS

Although an effect size for iron is small in regression analyses, iron is implicated in increased transaminase levels in prepubertal and pubertal children.