Biomarkers In Adolescents Research Articles

Prenatal pesticide exposure associated with glycated haemoglobin and markers of metabolic dysfunction in adolescents

BackgroundPesticide exposure has been associated with increased risk of diabetes mellitus in adults, but potential effects of prenatal exposure on glucose regulation have not been investigated.The aim of this study was to investigate if maternal occupational pesticide exposure in pregnancy was associated with glycated haemoglobin A1c (HbA1c) in adolescents and whether an association was modified by sex and paraoxonase-1 (PON1) Q192R polymorphism. MethodsA prospective cohort study of children whose mothers were either occupationally exposed or unexposed to pesticides in early pregnancy. At age 10-to-16 years, the children (n = 168) underwent clinical examinations including pubertal stage assessment (accepted by 141 children) and blood sampling. PON1 Q192R genotype was available for 139 children and 103 mothers.The main outcome measure was HbA1c but other relevant biomarkers were also included. ResultsPrenatal pesticide exposure was associated with a 5.0% (95% confidence interval: 1.8; 8.2) higher HbA1c compared to unexposed children after adjustment for confounders. After stratification, the association remained significant for girls (6.2% (1.6; 11.1)) and if the child or the mother had the PON1 192R-allele (6.1% (1.6; 10.8) and 7.1% (2.0; 12.6), respectively). Besides, an exposure-related increase was seen for the leptin-to-adiponectin ratio, for plasminogen activator inhibitor type-1 in girls, and for interleukin-6 in children whose mothers had the R-allele. ConclusionPrenatal pesticide exposure was associated with higher HbA1c and changes in related biomarkers in adolescents. Our results suggest an adverse effect on glucose homeostasis and support previous findings from this cohort of an exposure-associated metabolic risk profile with higher susceptibility related to female sex and the PON1 192R-allele.

Dietary inflammatory index and inflammatory biomarkers in adolescents from LabMed physical activity study.

The dietary inflammatory index (DII) is a tool to measure the diet's inflammatory potential and has been used with adults to predict low-grade inflammation. The present study aims to assess whether this dietary score predicts low-grade inflammation in adolescents. The sample comprises 329 adolescents (55.9% girls), aged 12-18 years, from LabMed Physical Activity Study. DII score was calculated based on a food-frequency questionnaire and categorized into tertiles. We collected blood samples to determine the follow inflammatory biomarkers: C-reactive protein (CRP), interleukin-6 (IL-6), complement component 3 (C3), and 4 (C4). In addition we calculated an overall inflammatory biomarker score. Odds ratios (OR) and 95% confidence intervals (95%CI) were computed from binary logistic regression models. DII score, comparing first with third tertile, was positively associated with IL-6 in crude model (OR = 1.88, 95%CI:1.09-3.24, p trend = 0.011) and in fully adjusted (for biological and lifestyle variables) (OR = 3.38, 95%CI:1.24-9.20, p trend = 0.023). Also, DII score was positively associated with C4, when fully adjusted (OR = 3.12, 95%CI:1.21-8.10, p trend = 0.016). DII score was negatively associated with C3 in crude model, comparing first with second but not with third tertile, and no significant associations in fully adjusted model were observed, although a trend was found (OR = 1.71, 95%CI:0.63-4.66, p trend = 0.044). No significant associations were observed between DII score and CRP. However, DII score was positively associated with the overall inflammatory biomarker score, when fully adjusted (OR = 5.61, 95%CI:2.00-15.78, p trend = 0.002). DII score can be useful to assess the diet's inflammatory potential and its association with low-grade inflammation in adolescents.

Muscular fitness and metabolic and inflammatory biomarkers in adolescents: Results from LabMed Physical Activity Study.

This study aimed to evaluate the associations between muscular fitness and inflammatory biomarkers and to investigate the relationship between muscular fitness and selected clustered inflammatory biomarkers in adolescents. This is a cross-sectional analysis with 529 adolescents (267 girls) aged 12-18years. Handgrip strength and standing long jump tests assessed MF. Continuous scores of clustered inflammatory biomarkers (sum of Z-scores of C-reactive protein [CRP], C3, C4, fibrinogen, and leptin); metabolic risk factor (MRF) score (sum of Z-scores of SBP, triglycerides, ratio total cholesterol [TC]/HDL, HOMA-IR, and waist circumference [WC]) were computed. Regression analyses showed an inverse association between muscular fitness score (β=-.204; P<.021) and clustered score of inflammatory biomarkers, adjusted for age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, cardiorespiratory fitness (CRF), MRF score, and body fat. Analysis of covariance showed that adolescents with an adverse inflammatory profile with low levels of muscular fitness exhibit the poorest MRF score (F3,525 =6.461; P<.001), adjusted for age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, CRF, and body fatness. The inflammatory state seems to explain a significant part of the highest MRF score and in adolescents with high inflammatory status and low muscular strength.

Foods contributing to vitamin B6, folate, and vitamin B12 intakes and biomarkers status in European adolescents: The HELENA study.

To examine the association between food groups consumption and vitamin B6, folate and B12 intakes and biomarkers in adolescents. In total 2189 individuals participating in the cross-sectional Healthy Lifestyle in Europe by Nutrition in Adolescence study met the eligibility criteria for analysis of dietary intakes (46% males) and 632 for biomarker analysis (47% males). Food intakes were assessed by two non-consecutive 24-h recalls. Biomarkers were measured by chromatography and immunoassay. Food groups which best discriminated participants in the extreme tertiles of the distribution of vitamins were identified by discriminant analyses. Food groups with standardised canonical coefficients higher or equal to 0.3 were selected as valid discriminators of vitamins intake and biomarkers extreme tertiles. Linear mixed model elucidated the association between food groups and vitamins intakes and biomarkers. Vitamin B6 intakes and biomarkers were best discriminated by meat (males and females), margarine and mixed origin lipids only in males and breakfast cereals (females). Breakfast cereals (males), and fruits, margarine and mixed origin lipids, vegetables excluding potatoes, breakfast cereals, and soups/bouillon (females) determined the most folate intakes and biomarkers. Considering vitamin B12 intakes and biomarkers, meat, and white and butter milk (males and females), snacks (males), and dairy products (females) best discriminated individual in the extremes of the distribution. Fewer associations were obtained with mixed model for biomarkers than for vitamins intakes with food groups. Whereas B-vitamin intakes were associated with their food sources, biomarkers did with overall food consumption. Low-nutrient-density foods may compromise adolescents' vitamin status.

Lipid peroxidation biomarkers in adolescents with or at high-risk for bipolar disorder

BackgroundPrior work suggests that adult bipolar disorder (BD) is associated with increased oxidative stress and inflammation. This exploratory study examined markers of lipid and protein oxidation and inflammation in adolescents with and at varying risk for BD type I (BD-I). MethodsBlood was obtained from four groups of adolescents (9–20 years of age): (1) healthy comparison subjects with no personal or family history of psychiatric disorders (n=13), (2) subjects with no psychiatric diagnosis and at least one parent with BD-I (‘high-risk’, n=15), (3) subjects with at least one parent with BD-I and a diagnosis of depressive disorder not-otherwise-specified (‘ultra-high-risk’, n=20), and (4) first-episode patients exhibiting mixed or manic symptoms that received a diagnosis of BD-I (n=16). Plasma levels of lipid peroxidation (LPH, 4-HNE, 8-ISO), protein carbonyl, and inflammation (IL-1α-β, IL-6, IL-10, IFNγ, TNFα) were assessed using analysis of variance and covariance models. ResultsLPH was lower in adolescents with fully syndromal BD than controls, while LPH levels in the at-risk groups were between healthy controls and fully syndromal BD. Post-hoc analysis showed a non-significant increase in the (4-HNE+8-ISO)/LPH ratio suggesting a potential conversion of LPH into late-stage markers of lipid peroxidation. There were no significant differences among protein carbonyl content and inflammatory markers. ConclusionsIn adolescents, fully syndromal BD is associated with significant reductions in LPH levels, and LPH levels decrease along the spectrum of risk for BD-I. Quantifying lipid peroxidation in longitudinal studies may help clarify the role of LPH in BD risk progression.

Breakfast and fast food consumption are associated with selected biomarkers in adolescents.

Objective: Skipping breakfast and consuming fast food are related to the risk of obesity and are common adolescent behaviors. The relationship between these behaviors and biomarkers related to diabetes and CVD is understudied in this population. Methods: Data are from a study of the etiologic factors related to obesity risk in adolescents. Breakfast and fast food consumption were assessed using a self-report survey. Anthropometrics, fasting lipids, glucose, insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) were assessed. Multivariate analyses were used to examine the relationship between dietary behaviors and selected biomarkers, controlling for calories consumed, body mass index (BMI), and demographic covariates. Results: 367 adolescents (11 to 18-years; mean 14.7 ± 1.8 years) were assessed at the University of Minnesota-Twin Cities from 2006–2008. Breakfast consumption was significantly associated with lower BMI, body fat, insulin, HOMA-IR, and metabolic syndrome (MetS) cluster score, while fast food consumption was associated with higher BMI, body fat, low-density lipoprotein cholesterol, triglycerides, glucose, insulin, HOMA-IR, and MetS cluster score. Some gender differences were observed. Conclusion: Breakfast and fast food consumption appear to be related to important metabolic syndrome biomarkers for chronic disease in a sample of healthy adolescents. The importance of this finding needs to be validated by examining the stability of this pattern over time and to assess the pattern in other populations.

Serum uric acid: relationships with biomarkers in adolescents and changes over 1 year

To (1) elucidate the range of serum uric acid (UA) levels in adolescent sample; (2) examine the relationships of serum UA and 1-year change with gender, anthropometric and cardiometabolic factors. Measurements (anthropometrics, fasting venipuncture and blood pressure) were performed at the beginning of the seventh and eighth grades. Descriptive data, differences according to weight, correlations and changes over time were examined. In 77 adolescents, BMI and serum UA had relationships with several cardiometabolic measures. Males had higher serum UA at follow-up compared to baseline; female change was minimal. Time-by-gender interaction was significant, as were the main effects of gender and BMI classification. Males had lower HDL-C at follow-up than at baseline; females had higher HDL-C at follow-up. Serum UA has importance in cardiometabolic examination of youth risk factors. It should be examined in youth with elevated BMI and/or hypertension. Early adolescence is the period when gender-related metabolic changes occur.

Muscular fitness, fatness and inflammatory biomarkers in adolescents

Muscular fitness, cardiorespiratory fitness (CRF) and fatness are mutually related with chronic inflammation. To examine the independent association of muscular fitness with inflammatory biomarkers in adolescents from nine European countries. A total of 639 adolescents (296 boys) aged from 12.5 to 17.5 year were included in this report. Data collection took place in 2006-2007 and analyses in 2012. A muscular fitness score was computed from handgrip strength and standing long jump. CRF was measured using the 20 m shuttle run test. Z-scores of C-reactive protein, complement factors C3 and C4, leptin and white blood cell counts were summed to create a cluster of inflammatory biomarkers. Sex, age, pubertal stage and centre were used as main confounders. Additional models were further adjusted for insulin resistance (HOMA-IR) and sum of four skinfolds. Muscular fitness was negatively associated with single and clustered inflammatory biomarkers (standardized β from -0.399 to -0.100, all P-values < 0.05). Additional adjustments for CRF and HOMA-IR weakened the associations, but they still remained significant. The association was no longer significant when adjusting for skinfolds. Decreasing values of inflammatory score were observed across incremental levels of muscular fitness in both non-overweight and overweight adolescents (P ≤ 0.05). Adolescents with higher levels of muscular fitness present a lower chronic inflammation, and this seems to be explained by lower levels of fatness. Yet, overweight and obese adolescents may exhibit a less adverse profile if they maintain appropriate levels of muscular fitness.

Validation of the Diet Quality Index for Adolescents by comparison with biomarkers, nutrient and food intakes: the HELENA study

Food-based dietary guidelines (FBDG) aim to address the nutritional requirements at population level in order to prevent diseases and promote a healthy lifestyle. Diet quality indices can be used to assess the compliance with these FBDG. The present study aimed to investigate whether the newly developed Diet Quality Index for Adolescents (DQI-A) is a good surrogate measure for adherence to FBDG, and whether adherence to these FBDG effectively leads to better nutrient intakes and nutritional biomarkers in adolescents. Participants included 1804 European adolescents who were recruited in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study. Dietary intake was assessed by two, non-consecutive 24 h recalls. A DQI-A score, considering the components' dietary quality, diversity and equilibrium, was calculated. Associations between the DQI-A and food and nutrient intakes and blood concentration biomarkers were investigated using multilevel regression analysis corrected for centre, age and sex. DQI-A scores were associated with food intake in the expected direction: positive associations with nutrient-dense food items, such as fruits and vegetables, and inverse associations with energy-dense and low-nutritious foods. On the nutrient level, the DQI-A was positively related to the intake of water, fibre and most minerals and vitamins. No association was found between the DQI-A and total fat intake. Furthermore, a positive association was observed with 25-hydroxyvitamin D, holo-transcobalamin and n-3 fatty acid serum levels. The present study has shown good validity of the DQI-A by confirming the expected associations with food and nutrient intakes and some biomarkers in blood.

Video game playing time and cardiometabolic risk in adolescents: The AFINOS study

Background and objectiveWe aimed to examine the association of video games playing time with cardiometabolic risk biomarkers in adolescents. Subjects and methodsThis study comprised 181 adolescents (88 girls), aged 13- to 17 years old. Moderate-to-vigorous physical activity (MVPA) was measured by accelerometry, and video game playing time in computer and console was self-reported. Waist circumference, systolic blood pressure (BP) and diastolic BP, mean arterial pressure, HDL-cholesterol, LDL-cholesterol, total cholesterol, triglycerides, glucose, insulin, and apolipoproteins A-1 and B-100 were measured. ResultsComputer games use was not significantly associated with any biomarker (P>0.1) but the time spent using console games was positively associated with diastolic BP, mean arterial pressure, triglycerides, and a clustered cardiometabolic risk score. These results were independent of age, sex, pubertal stage, MVPA, and WC. ConclusionThese results support some evidence regarding a plausible unfavorable role of playing (console) video games on cardiometabolic health in adolescence.

TV viewing, but not total sedentary behaviour, is associated with adverse cardiometabolic biomarkers in adolescents

Commentary on: D Martinez-Gomez, JC Eisenmann, GN Healy, et al.. Sedentary behaviors and emerging cardiometabolic biomarkers in adolescents.J Pediatr2012;160:104–10.e2.

Sedentary Behaviors and Emerging Cardiometabolic Biomarkers in Adolescents

To examine the associations of objectively measured sedentary time and television (TV) viewing time with emerging inflammatory and endothelial function markers in adolescents. This study comprised 183 adolescents (88 girls), aged 13 to 17 years. Sedentary time and moderate-to-vigorous physical activity was objectively measured with accelerometry, whereas TV viewing time was self-reported. White blood cell counts and levels of C-reactive protein, complement factors C3 and C4, interleukin-6, adiponectin, leptin, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, E-selectin, L-selectin, and plasminogen activator inhibitor-1 were measured in fasted blood samples. Sedentary time was not significantly associated with any of the examined cardiometabolic markers after controlling for potential confounders. However, TV viewing time was positively associated with soluble endothelial adhesion molecules intercellular adhesion molecule 1 (standardized β = 0.19, P = .008), vascular cell adhesion molecule 1 (β = 0.17, P = .020), L-selectin (β = 0.18, P = .013), and E-selectin (β = 0.16, P = .023) concentrations, after controlling for sex, age, pubertal status, moderate-to-vigorous physical activity, body mass index, and total sedentary time. High TV viewing time may play a key role in cardiovascular and metabolic diseases through the cell adhesion molecules in adolescence.

Smoking Affects Diagnostic Salivary Periodontal Disease Biomarker Levels in Adolescents

The effects of smoking on periodontal biomarkers in adolescents are unknown. This study investigates matrix metalloproteinase (MMP)-8 and polymorphonuclear leukocyte elastase levels in saliva together with periodontal health indices accounting for body mass index and smoking in a birth cohort from Finland. The oral health of boys (n = 258) and girls (n = 243) aged 15 to 16 years was examined clinically. Health habits were assessed by questionnaire. Saliva samples were collected and analyzed by immunofluorometric and peptide assays for MMP-8 levels and polymorphonuclear leukocyte elastase activities, and investigated statistically with the background factors. Median MMP-8 values of male smokers were 112.03 microg/l compared to 176.89 microg/l of non-smokers (P = 0.05). For female smokers corresponding values were 170.88 microg/l versus 177.92 microg/l in non-smokers (not statistically significant). Elastase values in male smokers were 5.88 x 10(-3) Delta OD(405)/h versus 11.0 x 10(-3) Delta OD(405)/h in non-smokers (P = 0.02), and in female smokers 9.16 x 10(-3) Delta OD(405)/h versus 10.88 x 10(-3) Delta OD(405)/h in non-smokers (P = 0.72). The effect was strengthened by high pack-years of smoking (MMP-8, P = 0.04; elastase, P = 0.01). Both biomarkers increased with gingival bleeding. However, statistically significant associations were observed with bleeding on probing and MMP-8 (P = 0.04); MMP-8 was suggestively associated with probing depth (P = 0.09) in non-smoking boys. In smokers with calculus, MMP-8 increased after adjusting with body mass index (P = 0.03). No corresponding differences were seen in girls. Smoking significantly decreased both biomarkers studied. Compared to girls, boys seem to have enhanced susceptibility for periodontitis as reflected in salivary MMP-8 values.

Abstract B2: Associations between self-reported versus objectively measured physical activity, biomarkers, and obesity in adolescents and adults

Abstract Epidemiological studies, based entirely on self-reported levels of physical activity (PA), indicate that PA reduces cancer risk at several sites. However, self reported PA is subject to the cognitive challenges of estimating its duration and intensity, and potential recall bias. Objective measurement of PA using accelerometers is an alternative to self report, even in large population studies of both children and adults Data for adults aged 20+ years (N=4417) with self-reported PA and 4 or more days of accelerometer data were obtained from the 2003–2006 National Health and Nutritional Examination Survey (NHANES). NHANES is a nationally representative sample of the US civilian, non-institutionalized population. Outcome measures were blood pressure, body mass index (BMI), waist circumference, triceps and subscapular skinfolds, cholesterol, triglyceride, c-reactive protein, homocysteine, and indices of insulin resistance and hyperinsulinaemia. Data for adolescents, (N = 723), were obtained from two cohorts in the Twin Cities, Minnesota. PA was measured using two self report instruments, the Modified Activity Questionnaire (MAQ) assessing past week moderate and vigorous PA (MVPA), the 3-Day Physical Activity Recall (3DPAR), and accelerometer data. Biomarkers included systolic and diastolic blood pressure (SBP, DBP), lipids (total cholesterol, LDL, HDL, % body fat (BF) and BMI. For both adolescents and adults, accelerometer data was summarized as total minutes of (MVPA). In adults, objectively-measured MVPA displayed stronger associations with most biomarkers compared with self-reported MVPA, even after adjusting for sociodemographic and health factors (Adj Wald F's = 5.1 to 55.4; p's &amp;lt; 0.05 to 0.0001). Adjustment for objectively measured PA eliminated some but not all associations between self-reported PA and biomarkers. Both measures of MVPA were independently associated with skinfold anthropometric measures, HDL, and c-reactive protein. In adolescents, after controlling for puberty, age and gender, all three PA measures had a strong, negative association with %BF (MAQ β = −1.77, p&amp;lt;0.001; 3DPAR β = −1.43, p&amp;lt;0.001; accelerometer β = −1.41, p&amp;lt;0.003). The MAQ and accelerometry were negatively associated with BMI (β = −3.17, p=0.003; β =−2.97, p =0.01), and the MAQ was negatively associated with DBP (β = −1.30, p=0.01). None of the PA measures were significantly associated with SBP or lipids. These results suggest that use of self-reported physical activity measures could attenuate associations between PA and several biomarkers related to energy balance in adults, but this was not observed for a few biomarkers in adolescents. Considerable care should be taken in the choice of PA measure for any study, but especially where the effects of PA are manifest all or in part via its impact on biological variables such as serum biomarkers or anthropometric characteristics. Citation Information: Cancer Prev Res 2010;3(1 Suppl):B2.

Renal function, cytogenetic measurements, and sexual development in adolescents in relation to environmental pollutants: a feasibility study of biomarkers

Human exposure to chemicals is normally monitored by measurement of environmental pollutants in external media. We investigated whether biomarkers in adolescents can show exposure to, and health effects of, common environmental pollutants. We recruited 200 17-year-old adolescents (120 girls) from a rural control area and from two suburbs polluted by a lead smelter and two waste incinerators. We measured biomarkers of exposure and of effect in blood and urine samples, and obtained questionnaire data. School doctors measured testicular volume and staged sexual maturation. Internal exposure was mostly within current standards. Concentrations of lead and cadmium in blood, PCBs (polychlorinated biphenyls) and dioxin-like compounds in serum samples, and metabolites of VOCs (volatile organic compounds) in urine were higher in one or both suburbs than in the control area. Children who lived near the waste incinerators matured sexually at an older age than others, and testicular volume was smaller in boys from the suburbs than in controls. Biomarkers of glomerular or tubular renal dysfunction in individuals were positively correlated with blood lead. Biomarkers of DNA damage were positively correlated with urinary metabolites of PAHs (polycyclic aromatic hydrocarbons) and VOCs. Interpretation Biomarkers can be used to detect environmental exposure to pollutants and measure their biological effects before overt disease develops. Our findings suggest that current environmental standards are insufficient to avoid measurable biological effects.

Serum Neopterin, β2-Microglobulin, Soluble Interleukin-2 Receptors, and Immunoglobulin Levels in Healthy Adolescents

Serum biomarkers, such as neopterin, β2-microglobulin (B2M), and soluble interleukin-2 receptors (sIL-2R), are elevated in viral infections, including HIV-1 infection, and in inflammatory conditions, autoimmune disease, and malignancies. For many of these conditions, serum levels correlate with disease activity. Application of these biomarkers in adolescents is limited by a lack of information on the range and determinants of variability (age, sex, race) for serum levels of these important molecules in this age group. To address this question, we analyzed serum samples from a well-characterized heterogeneous population of 111 healthy adolescents. White children had significantly higher serum levels of sIL-2R and IgM and lower levels of IgG (P≤ 0.001) than black children. Boys had higher sIL-2R and B2M levels (P< 0.005) and lower IgM levels (P< 0.05) than girls. No significant age effect on B2M or neopterin level was observed over the age range of 12–19 years included in this analysis. However, stratification by race showed that serum sIL-2R level was significantly associated with age among whites, but not among blacks. Values of these biomarkers in this population are compared with age-stratified values in the previously analyzed 20- to 69-year-old population from whose households the adolescent subjects were recruited.