Metabolic Syndrome in Adolescents: Issues and Opportunities

Trends in Dietary Intake of Total Fat and Fatty Acids Among Korean Adolescents from 2007 to 2017

We analyzed the trends in dietary intake of total fat and fatty acids among Korean adolescents during 2007-2017. A total of 6406 adolescents from the 2007-2017 Korea National Health and Examination Surveys were selected. Total fat and fatty acids intakes were calculated based on single 24-hour recall data and presented as grams (g) and percentage of energy intake (% kcal) across the survey period. Linear trends in intake across the survey period were compared using the multiple regression model. Total fat intake increased during the 11-year period from 54.3 g (21.7% kcal) to 61.8 g (25.2% kcal). Saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) intakes changed from 17.8 g (7.1% kcal) and 17.2 g (6.8% kcal) to 20.6 g (8.4% kcal) and 20.7 g (8.4% kcal) over time, respectively. For polyunsaturated fatty acids (PUFA), n-3 fatty acid intake did not change during the survey period. The proportions of individuals who had total fat and SFA above the recommendations increased across the survey period: 13.7% to 27.5% for total fat and 36.0% to 49.7% for SFA. Among Korean adolescents, dietary fat intake increased over time and the increases in SFA and MUFA intake were prominent. Monitoring dietary fat intake is helpful to suggest dietary guidelines and health policies.

Novel association of the R230C variant of the ABCA1 gene with high triglyceride levels and low high-density lipoprotein cholesterol levels in Mexican school-age children with high prevalence of obesity

BACKGROUND AND AIMS

Metabolic syndrome (MetS) is a disorder that includes a cluster of several risk factors for the development of type 2 diabetes and cardiovascular disease. The R230C variant of the ABCA1 gene has been associated with low HDL-cholesterol in several studies, but its association with MetS in children remains to be determined. The aim of this study was to analyze the association of the R230C variant with MetS and other metabolic traits in school-aged Mexican children.

METHODS

The study was performed in seven urban primary schools in the State of Mexico. Four hundred thirty-two Mexican school-age children 6-13 years old were recruited. MetS was identified using the International Diabetes Federation definition. The R230C variant of the ABCA1 gene was genotyped to seek associations with MetS and other metabolic traits.

RESULTS

The prevalence of MetS was 29% in children aged 10-13 years. The R230C variant was not associated with MetS (OR = 1.65; p = 0.139). Furthermore, in the whole population, the R230C variant was associated with low HDL-cholesterol levels (β coefficient = -3.28, p <0.001). Interestingly, in the total population we found a novel association of this variant with high triglyceride levels (β coefficient = 14.34; p = 0.027).

CONCLUSIONS

We found a new association of the R230C variant of the ABCA1 gene with high triglyceride levels. Our findings also replicate the association of this variant with low HDL-cholesterol levels in Mexican school-age children.

Metabolic syndrome risk factors are associated with white rice intake in Korean adolescent girls and boys

In the present study, we examined the associations of total carbohydrate intake, dietary glycaemic load (DGL) and white rice intake with metabolic syndrome risk factors by sex in Korean adolescents. For the present cross-sectional study, data from the Fourth Korea National Health and Nutrition Examination Survey (2007–9) were used. A total of 2209 adolescents (n 1164 boys and n 1045 girls) aged 10–18 years with complete anthropometric, biochemical and dietary intake data were included in the study. Dietary intake data were obtained using the 24 h recall method, and total carbohydrate intake, DGL and white rice intake were divided into quartiles by sex. The metabolic syndrome and its risk factors were defined using the International Diabetes Federation criteria for children and adolescents. Fasting insulin levels and insulin resistance were included as the metabolic syndrome risk factors. All statistical analyses considered the complex sampling design effect and appropriate sampling weights. Multivariate linear regression analysis was used to estimate means with their standard errors of the mean for the metabolic syndrome risk factors across the quartiles of total carbohydrate intake, DGL and white rice intake. While high DGL was significantly associated with increased fasting glucose levels in boys, high total carbohydrate intake, DGL and white rice intake were consistently associated with reduced HDL-cholesterol levels in girls. High white rice intake was significantly associated with an increased risk of insulin resistance and the metabolic syndrome in girls but not in boys. Optimising dietary carbohydrate intake with respect to the source or amount is fundamental to preventing and managing metabolic diseases in Asian adolescents.

Is dairy consumption associated with low cardiovascular disease risk in European adolescents? Results from the HELENA Study

OBJECTIVE

To identify those food groups best discriminating individuals at high/low cardiovascular disease (CVD) risk and to investigate the relationship between dairy consumption and CVD risk factors (individual and scores) in adolescents (12.5-17.5 years) from eight European cities participating in the cross-sectional (2006-2007) HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) project.

METHODS

Diet, waist circumference, skin-folds thickness, systolic blood pressure, insulin resistance, triglycerides, total cholesterol/high-density lipoprotein ratio and cardiorespiratory fitness (CRF) were assessed in 511 (49.9% boys) adolescents. Individual z-scores of CVD risk factors were summed to compute sex-specific clustered CVD risk scores.

RESULTS

Dairy emerged as the food group best discriminating adolescents at low/high CVD risk. In both genders, waist circumference and sum of skin-folds were inversely associated with consumption of milk and yogurt, and milk- and yogurt-based beverages, whereas a positive association was observed with CRF. Moreover, CVD risk score (β = -0.230, P = 0.001) was also inversely associated with overall dairy consumption only in girls.

DISCUSSION

Dairy consumption is associated with lower adiposity and higher CRF in these adolescents. An inverse association between CVD risk score and dairy consumption is also depicted in girls. The study adds further evidence to the scarce literature on the influence of milk and dairy products on adolescents' cardiovascular health.

Variations in the prevalence of metabolic syndrome in adolescents according to different criteria used for diagnosis: which definition should be chosen for this age group?

BACKGROUND

Despite the increasing prevalence of metabolic syndrome in adolescents, there is no consensus for its diagnosis.

METHODS

A cross-sectional study was conducted to compare the prevalence of metabolic syndrome in adolescents by different definitions, evaluate their concordance, and suggest which definition to apply in this population. A total of 851 adolescents between 10 and 18 years of age were evaluated. Anthropometric (weight, height, waist circumference), biochemical (glucose, lipid profile), and blood pressure data were taken. The prevalence of metabolic syndrome was determined by the definitions of the International Diabetes Federation (IDF) and four published studies by Cook et al., de Ferranti et al., Agudelo et al., and Ford et al. Concordance was determined according to the kappa index.

RESULTS

The prevalence of metabolic syndrome was 0.9%, 3.8%, 4.1%, 10.5%, and 11.4%, according to the IDF, Cook et al., Ford et al., Agudelo et al., and de Ferranti et al. definitions, respectively. The most prevalent components were hypertriglyceridemia and low high-density lipoprotein cholesterol, whereas the least prevalent components were abdominal obesity and hyperglycemia. The highest concordance was found between the definitions by Cook et al. and Ford et al. (kappa=0.92), whereas the greatest discordance was between the de Ferranti et al. and IDF definitions (kappa=0.14).

CONCLUSIONS

Metabolic syndrome and its components were conditions present in the adolescents of this study. In this population, with a high prevalence of dyslipidemia and a lower prevalence of abdominal obesity and hyperglycemia, the recommendation to diagnose metabolic syndrome would be that used by Ford et al.

n-3 fatty acids modulate adipose tissue inflammation and oxidative stress

PURPOSE OF REVIEW

Dietary n-3 polyunsaturated fatty acids (n-3 PUFAs) may be related to a number of chronic metabolic abnormalities, including metabolic syndrome. This review presents an update on the effects of n-3 PUFAs on risk factors of metabolic syndrome, especially adipose tissue inflammation, oxidative stress and underlying mechanisms of these effects.

RECENT FINDINGS

Anti-inflammatory actions of n-3 PUFAs are thought to be mediated by the formation of their active metabolites (eicosanoids and other lipid mediators) as well as their regulation of the production of inflammatory mediators (e.g., adipocytokines, cytokines) and immune cell infiltration into adipose tissue. n-3 PUFAs mediate these effects by modulating several pathways, such as those involving nuclear factor-κB, peroxisome proliferator-activated receptors and Toll-like receptors. The antioxidative effects of n-3 PUFAs in adipocytes appear to inhibit reactive oxygen species production and alter mitochondrial function.

SUMMARY

This review summarizes the evidence for beneficial effects of n-3 PUFAs on adipose tissue inflammation and oxidative stress. More studies are necessary to investigate the mechanisms underlying these effects and to relate this topic to human health.