The metabolic inter-relationships between changes in waist circumference, triglycerides, insulin sensitivity and small, dense low-density lipoprotein particles with acute weight loss in clinically obese children and adolescents

Relationship of Apolipoproteins with Subclinical Cardiovascular Risk in Youth

OBJECTIVE

To examine the association of apolipoproteins with arterial stiffness and carotid artery structure in children and adolescents.

STUDY DESIGN

A total of 338 children and adolescents (178 female) with a mean age 13.0 ± 2.8 years were examined. Apolipoproteins (AI, AII, B₁₀₀, CII, CIII, and E) were measured via human apolipoprotein magnetic bead panel. Applanation tonometry determined pulse wave velocity and ultrasound imaging measured carotid intima-media thickness. Dual X-ray absorptiometry measured total body fat percent. Linear regression models were adjusted for Tanner stage, sex, and race with further adjustments for body fat percent. Linear regression models also examined the interaction between Tanner stage and apolipoproteins.

RESULTS

There was a significant positive association between pulse wave velocity and apolipoproteins: AI (0.015 m/s/10 μg/mL [CI 0.005-0.026], P = .003), AII (0.036 m/s/10 μg/mL [0.017-0.056], P < .001), B₁₀₀ (0.009 m/s/10 μg/mL [0.002-0.016], P = .012), E (0.158 m/s/10 μg/mL [0.080-0.235], P < .001), and CIII:CII (0.033/μg/mL [0.014-0.052], P < .001). After we added body fat percent to the models, pulse wave velocity (PWV) remained positively associated with greater levels of apolipoproteins: AI, AII, B₁₀₀, E, and CIII:CII. Both with and without the adjustment for body fat percent, there were no significant associations between any apolipoprotein and carotid intima-media thickness. There were no significant interactions between Tanner stage and apolipoproteins.

CONCLUSIONS

These findings suggest that greater levels of apolipoprotein AII, E, and CIII:CII are associated with increased arterial stiffness in children and adolescents, both with and without adjusting for percent body fat. These specific apolipoproteins may be useful as biomarkers of cardiovascular risk.

Resolution of fatty liver and weight loss: Independent associations with changes in serum lipids and apolipoproteins

BACKGROUND AND AIMS

It is uncertain whether resolution of fatty liver can improve cardiovascular disease risk factors, independently of changes in body mass index (BMI). Our aim was to test whether resolution of fatty liver is associated with improvements in components of the lipid profile, independently of changes in BMI, and to quantify and compare the magnitude of benefit of resolution of liver fat, and decreases in BMI on the lipid profile.

METHODS

36,195 subjects with fatty liver were studied. Persistence/resolution of fatty liver was determined by ultrasound at follow up (mean = 4.93 years). Total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and apolipoproteins were measured at baseline and follow up. Regression modelling was undertaken to test the independence of associations between change in fatty liver status or change in BMI, with any change in lipid profile concentrations between baseline and follow up.

RESULTS

Mean (SD) age was 36.3 ± 6.6 and 39.8 ± 8.7 years (men and women, respectively). Resolution of fatty liver occurred in 7,086, and persisted in 29,109 subjects. Mean ± SD weight change was -3.2 ± 4.3 (∼1 kg/m² decrease in BMI) with resolution of, and +0.5 ± 3.5 kg with persistence of fatty liver, respectively. Both resolution of fatty liver and decrease in BMI were independently associated with improvements in all components of the lipid profile and there was a similar magnitude of benefit associated with resolution of fatty liver, or 1 kg/m² decrease in BMI.

CONCLUSIONS

Resolution of fatty liver improves the lipid profile, independently of weight loss.

The CHANGE! Project: Changes in Body Composition and Cardiorespiratory Fitness in 10- to 11-Year-Old Children After Completing the CHANGE! Intervention

PURPOSE

To assess the effects of the Children's Health, Activity and Nutrition: Get Educated! intervention on body size, body composition, and peak oxygen uptake in a subsample of 10- to 11-year-old children.

METHODS

Sixty children were recruited from 12 schools (N = 6 intervention) to take part in the CHANGE! subsample study. Baseline, postintervention, and follow-up measures were completed in October 2010, March-April 2011, and June-July 2011, respectively. Outcome measures were body mass index z score, waist circumference, body composition assessed using dual-energy X-ray absorptiometry (baseline and follow-up only), and peak oxygen uptake.

RESULTS

Significant differences in mean trunk fat mass (control = 4.72 kg, intervention = 3.11 kg, P = .041) and trunk fat % (control = 23.08%, intervention = 17.75%, P = .022) between groups were observed at follow-up. Significant differences in waist circumference change scores from baseline to follow-up were observed between groups (control = 1.3 cm, intervention = -0.2 cm, P = .023). Favorable changes in body composition were observed in the intervention group; however, none of these changes reached statistical significance. No significant differences in peak oxygen uptake were observed.

CONCLUSIONS

The results of the present study suggest the multicomponent curriculum intervention had small to medium beneficial effects on body size and composition health outcomes.

Changes in pediatric waist circumference percentiles despite reported pediatric weight stabilization in the United States

BACKGROUND

Obesity is a global health concern but the United States has reported a leveling in obesity rates in the pediatric population.

OBJECTIVE

To provide updated waist circumference (WC) percentile values, identify differences across time and discuss differences within the context of reported weight stabilization in a nationally representative sample of American children.

METHODS

Percentiles for WC in self-identified African Americans (AA), European Americans (EA) and Mexican Americans (MA) were obtained from 2009-2014 National Health and Nutrition Examination Survey data (NHANES2014). Descriptive trends across time in 10th, 25th, 50th, 75th and 90th percentile WC distributions were identified by comparing NHANES2012 with previously reported NHANESIII (1988-1994).

RESULTS

WC increased in a monotonic fashion in AA, EA and MA boys and girls. When compared with NHANESIII data, a clear left shift of percentile categories was observed such that values that used to be in the 90th percentile are now in the 85th percentile. Differences in WC were observed in EA and MA boys during a reported period of weight stabilization.

CONCLUSION AND RELEVANCE

WC has changed in the US pediatric population across time, even during times of reported weight stabilization, particularly among children of diverse racial/ethnic backgrounds.

APOA5 and APOA1 polymorphisms are associated with triglyceride levels in Mexican children

BACKGROUND

Dyslipidemia is an important risk factor for the development of several diseases. The genetic component of hypertriglyceridemia has been studied in adults, but little is known in children.

OBJECTIVE

The objective is to evaluate the association of two variants in APOA5 (rs662799) and APOA1 (rs5072) with triglyceride (TG) levels in Mexican children.

METHODS

Anthropometric parameters were measured in 1559 Mexican children 5-14 years of age. DNA was isolated from blood samples. Lipid profiles and glucose concentrations were determined from serum and genotyping of rs662799, and rs5072 was performed using TaqMan® technology. Additive and dominant models adjusted for age, gender and body mass index were used to evaluate the association of these single nucleotide polymorphisms with TG levels.

RESULTS

Children with high TG levels were found to have a higher body mass index and waist circumference as well as a worse lipids profile and glucose levels (p < 0.001). Additive and dominant models demonstrated a significant association between the rs662799 and rs5072 with TG. The dominant model showed the strongest significant association (OR = 1.81; 95% CI 1.46-2.24; p = 5.40 × 10^-08 for rs662799 and OR = 1.54; 95% CI 1.05-2.25; p = 2.60 × 10^-02 for rs5072).

CONCLUSION

The minor alleles of rs662799 (APOA5) and rs5072 (APOA1) modulate TG levels in Mexican children.

Short-term isocaloric fructose restriction lowers apoC-III levels and yields less atherogenic lipoprotein profiles in children with obesity and metabolic syndrome

BACKGROUND AND AIMS

Dietary fructose may play a role in the pathogenesis of metabolic syndrome (MetS). In a recently published study of obese children with MetS, we showed that isocaloric fructose restriction reduced fasting triglyceride (TG) and LDL-cholesterol (LDL-C). In these ancillary analyses, we tested the hypothesis that these effects were also accompanied by improved quantitative and qualitative changes in LDL and HDL subclasses and their apolipoproteins; as well as change in VLDL, particularly apoC-III.

METHODS

Obese children with MetS (n = 37) consumed a diet that matched self-reported macronutrient composition for nine days, with the exception that dietary fructose was reduced from 11.7 ± 4.0% to 3.8 ± 0.5% of daily calories and substituted with glucose (in starch). Participants underwent fasting biochemical analyses on Days 0 and 10. HDL and LDL subclasses were analyzed using the Lipoprint HDL and LDL subfraction analysis systems from Quantimetrix.

RESULTS

Significant reductions in apoB (78 ± 24 vs. 66 ± 24 mg/dl) apoC-III (8.7 ± 3.5 vs. 6.5 ± 2.6 mg/dl) and apoE (4.6 ± 2.3 vs. 3.6 ± 1.1 mg/dl), all p < 0.001) were observed. LDL size increased by 0.87 Å (p = 0.008). Small dense LDL was present in 25% of our cohort and decreased by 68% (p = 0.04). Small HDL decreased by 2.7% (p < 0.001) and large HDL increased by 2.4% (p = 0.04). The TG/HDL-C ratio decreased from 3.1 ± 2.5 to 2.4 ± 1.4 (p = 0.02). These changes in fasting lipid profiles correlated with changes in insulin sensitivity.

CONCLUSIONS

Isocaloric fructose restriction for 9 days improved lipoprotein markers of CVD risk in children with obesity and MetS. The most dramatic reduction was seen for apoC-III, which has been associated with atherogenic hypertriglyceridemia.