Adolescent sedentary behavior and body composition in early adulthood: results from a cohort study.

BACKGROUND: This study investigates the cross-sectional and prospective associations between accelerometer-measured sedentary behavior and body composition from adolescence to early adulthood. METHODS: Data from the Santiago Longitudinal Study were analyzed (n = 212). Sedentary time was measured at age 16 years, and body composition (body mass index [BMI], waist circumference, waist-to-height ratio [WHtR], fat mass percentage, and lean mass percentage) was examined at both age 16 and 23 years. Adjusted linear regression models estimated associations between sedentary time, sedentary bout duration, and body composition, overall and by sex. RESULTS: In all analyses, mean sedentary bout duration was not associated with body composition. In cross-sectional analyses, more sedentary time during adolescence was significantly associated with lower BMI, waist circumference, WHtR, fat mass percentage, and higher lean mass percentage (p < 0.05). One standard deviation increase in daily sedentary time was prospectively associated with lower body mass index (ß = -1.22 kg/m2, 95% CI: -2.02, -0.42), waist circumference (ß = -2.39 cm, 95% CI: -4.03, -0.75), and WHtR (ß = -0.014, 95% CI: -0.024, -0.004). Sedentary time at 16 years was not associated with changes in body composition from 16 to 23 years. CONCLUSIONS: Sedentary behavior in adolescence is not adversely associated with body composition profiles in early adulthood. IMPACT: Little is known about the effect of device-measured sedentary behavior on body composition during the transition from adolescence to early adulthood. Among participants in the Santiago Longitudinal Study, more accelerometer-measured sedentary time during adolescence was associated with lower BMI, waist circumference, and waist-to-height ratio in early adulthood though point estimates were generally small in magnitude. Sedentary behavior in adolescence was not detrimentally associated with healthy body composition profiles in early adulthood. Public health interventions aimed at reducing obesity rates could consider other behaviors, such as physical activity and healthy diet, instead of sitting time.

Iron supplementation given to nonanemic infants: neurocognitive functioning at 16 years.

OBJECTIVE: There is concern that high iron uptake during the critical period of early brain development carries potential risks, especially for nonanemic infants. This study examined the neurocognitive functioning of 16-year-olds who were nonanemic as infants and received iron supplementation. METHODS: We studied 562 Chilean adolescents (M 16.2 years; 52.7% female) who participated in a randomized controlled iron supplementation trial in infancy. Between 6 and 12 months, 346 consumed an iron-fortified formula (12.7 Fe mg/L) or, if primarily breastfed, liquid vitamins with 15 mg elemental iron as ferrous sulfate, and 216 consumed unmodified cow milk without iron or liquid vitamins without iron if primarily breastfed. RESULTS: Compared to adolescents in the no-added iron condition in infancy, those in the iron-supplemented condition had poorer visual-motor integration, quantitative reasoning skills, and incurred more errors on neurocognitive tasks. Consuming larger amounts of iron-fortified formula in infancy was associated with lower arithmetic achievement. Of adolescents who had high hemoglobin at 6 months (Hb ≥ 125 g/L), those in the iron supplemented condition had poorer performance on arithmetic, quantitative reasoning, and response inhibition tests than those in the no-added iron condition. Of adolescents who had marginally low 6-month hemoglobin (Hb > 100 and < 110 g/L), those who received no-added iron incurred more errors on a visual searching task than those in the iron-supplemented condition. CONCLUSION: The physiologic need for iron during the period of rapid and critical brain development in young infants should be considered vis-à-vis the risks associated with supplementing nonanemic infants with high levels of iron.Clinical Trials number: NCT01166451.

Early-life adversity is associated with poor iron status in infancy.

Exposure to early-life adversity (ELA) and iron deficiency early in life are known risk factors for suboptimal brain and socioemotional development. Iron deficiency may arise from and co-occur with ELA, which could negatively affect development. In the present study, we investigated whether ELA is associated with iron deficiency in infants receiving no iron supplementation. This study is a secondary analysis of extant data collected in the 1990s; participants were healthy infants from working-class communities in Santiago, Chile (N = 534, 45.5% female). We measured stressful life events, maternal depression, and low home support for child development during infancy and assessed iron status when the infant was 12 months old. Slightly more than half of the infants were iron-deficient (51%), and 25.8% were iron-deficient anemic at 12 months. Results indicated that ELA was associated with lower iron levels and iron deficiency at 12 months. The findings are consistent with animal and human prenatal models of stress and iron status and provide evidence of the association between postnatal ELA and iron status in humans. The findings also highlight a nutritional pathway by which ELA may impact development and present a nutritionally-focused avenue for future research on ELA and psychopathology.

Iron Deficiency in Infancy and Sluggish Cognitive Tempo and ADHD Symptoms in Childhood and Adolescence.

OBJECTIVE: To determine whether iron deficiency in infancy is associated with sluggish cognitive tempo (SCT) or attention-deficit/hyperactive-impulsive (AD-HI) symptoms in childhood and adolescence, and whether such behaviors contribute concurrently and predictively to lower verbal and mathematical abilities. METHOD: Chilean children (N = 959; 50% male, of Spanish or indigenous descent from working-class backgrounds) were rated by mothers for SCT or AD-HI symptoms at ages 5, 10, and 16 years. Children completed standardized tests assessing verbal and mathematical abilities at ages 5, 10, and 16. At ages 12 and 18 months, children were assessed for iron deficiency. RESULTS: Adjusting for a comprehensive panel of covariates, greater severity of iron deficiency in infancy was associated with more frequent SCT and AD-HI symptoms at all ages studied. Most effects of iron deficiency on children's verbal and math skills were indirect, mediated through AD-HI behaviors. Children's AD-HI symptoms related to lower verbal and math test scores within age and across age. CONCLUSIONS: The long-term associations found between infant iron deficiency and SCT and AD-HI behaviors suggest that the neurodevelopmental alterations that stem from postnatal iron deficiency might play an etiological role in the development of ADHD. Screening for early-life nutritional deficiencies among children with SCT or ADHD symptoms might prove useful, and behavioral screening of children with a history of iron deficiency seems warranted. Interventions that support brain development after early nutritional deprivation also would be beneficial.

Infant Growth Trajectories and Lipid Levels in Adolescence: Evidence From a Chilean Infancy Cohort.

Growth in early infancy is hypothesized to affect chronic disease risk factors later in life. To date, most reports draw on European-ancestry cohorts with few repeated observations in early infancy. We investigated the association between infant growth before 6 months and lipid levels in adolescents in a Hispanic/Latino cohort. We characterized infant growth from birth to 5 months in male (n = 311) and female (n = 285) infants from the Santiago Longitudinal Study (1991-1996) using 3 metrics: weight (kg), length (cm), and weight-for-length (g/cm). Superimposition by translation and rotation (SITAR) and latent growth mixture models (LGMMs) were used to estimate the association between infant growth characteristics and lipid levels at age 17 years. We found a positive relationship between the SITAR length velocity parameter before 6 months of age and high-density lipoprotein cholesterol levels in adolescence (11.5, 95% confidence interval; 3.4, 19.5), indicating higher high-density lipoprotein cholesterol levels occurring with faster length growth. The strongest associations from the LGMMs were between higher low-density lipoprotein cholesterol and slower weight-for-length growth, following a pattern of associations between slower growth and adverse lipid profiles. Further research in this window of time can confirm the association between early infant growth as an exposure and adolescent cardiovascular disease risk factors.

Adjusting Ferritin Concentrations for Nonclinical Inflammation in Adolescents with Overweight or Obesity.

OBJECTIVE: To compare approaches for adjusting serum ferritin concentrations for inflammation in Chilean adolescents with overweight and obesity. STUDY DESIGN: Cross-sectional data from 518 adolescents (aged 16-17 years; 48% females) from Santiago, Chile were analyzed. Several approaches were compared for estimating the prevalence of depleted iron stores (defined as serum ferritin <15 µg/L), including unadjusted prevalence and higher cutoffs for various subgroups (excluding participants with inflammation), correction factors, and regression corrections. A "reference" prevalence estimate was calculated as the prevalence of serum ferritin <15 µg/L in normal weight individuals without inflammation. Each adjustment approach was compared with this reference prevalence. RESULTS: The sample comprised 61.2% normal weight, 23.7% overweight, and 15.1% obese individuals. The prevalence of inflammation (marked by C-reactive protein level >5.0 mg/L) was 6.3%, 8.1%, and 14.1% in the 3 groups, respectively. The correction factor approaches produced adjusted estimates closest to the reference estimate (24.1%-24.7% vs 22.9%), followed by the regression corrections (24.7%-25.1% vs 22.9%). Applying a higher serum ferritin cutoff (30 µg/L) to all participants or to participants with overweight/obesity produced adjusted estimates farthest from the reference (59.5% and 35.3%, respectively). CONCLUSIONS: Adjusting serum ferritin concentration may be necessary when assessing iron status in populations with high rates of overweight/obesity. After reviewing 6 approaches for adjusting for the influence of inflammation, this study suggests that using correction factors may be the most appropriate approach for adjusting serum ferritin in Chilean adolescents. Further research is needed to determine the optimal approach for adjusting serum ferritin concentrations for weight-related inflammation in broader populations.

Genetic determinants of metabolic biomarkers and their associations with cardiometabolic traits in Hispanic/Latino adolescents.

BACKGROUND: Metabolic regulation plays a significant role in energy homeostasis, and adolescence is a crucial life stage for the development of cardiometabolic disease (CMD). This study aims to investigate the genetic determinants of metabolic biomarkers-adiponectin, leptin, ghrelin, and orexin-and their associations with CMD risk factors. METHODS: We characterized the genetic determinants of the biomarkers among Hispanic/Latino adolescents of the Santiago Longitudinal Study (SLS) and identified the cumulative effects of genetic variants on adiponectin and leptin using biomarker polygenic risk scores (PRS). We further investigated the direct and indirect effect of the biomarker PRS on downstream body fat percent (BF%) and glycemic traits using structural equation modeling. RESULTS: We identified putatively novel genetic variants associated with the metabolic biomarkers. A substantial amount of biomarker variance was explained by SLS-specific PRS, and the prediction was improved by including the putatively novel loci. Fasting blood insulin and insulin resistance were associated with PRS for adiponectin, leptin, and ghrelin, and BF% was associated with PRS for adiponectin and leptin. We found evidence of substantial mediation of these associations by the biomarker levels. CONCLUSIONS: The genetic underpinnings of metabolic biomarkers can affect the early development of CMD, partly mediated by the biomarkers. IMPACT: This study characterized the genetic underpinnings of four metabolic hormones and investigated their potential influence on adiposity and insulin biology among Hispanic/Latino adolescents. Fasting blood insulin and insulin resistance were associated with polygenic risk score (PRS) for adiponectin, leptin, and ghrelin, with evidence of some degree of mediation by the biomarker levels. Body fat percent (BF%) was also associated with PRS for adiponectin and leptin. This provides important insight on biological mechanisms underlying early metabolic dysfunction and reveals candidates for prevention efforts. Our findings also highlight the importance of ancestrally diverse populations to facilitate valid studies of the genetic architecture of metabolic biomarker levels.

Young adult outcomes associated with lower cognitive functioning in childhood related to iron-fortified formula in infancy.

Objective: This study examined how the lower cognitive skills in children who consumed iron-fortified formula in infancy relate to outcomes in young adulthood.Methods: Participants were 443 Chilean young adults (M age = 21.2y, 55% female) who took part in a randomized controlled iron-deficiency anemia preventive trial during infancy (6-12 m). Slightly over half of participants (n = 237) received iron-fortified formula (12.7 mg/L) and 206 received a low-iron formula (2.3 mg/L). Spatial memory, IQ, and visual-motor integration were measured at age 10, and neurocognition, emotion regulation, educational level, and attainment of adult developmental milestones were assessed at age 21.Results: Consumption of iron-fortified formula in infancy was associated with poorer performance on neurocognitive tests in childhood, and these effects related to poorer neurocognitive, emotional, and educational outcomes in young adulthood. Dosage effects associated with consumption of iron-fortified formula were found for lower educational attainment and, marginally, slower mental processing. Those who received iron-fortified formula and had low age 10 cognitive abilities performed most poorly on neurocognitive tests at age 21.Conclusion: Findings suggest that the long-term development of infants who consume iron-fortified formula may be adversely affected.Clinical Trials number: NCT01166451.

Dynamic relationships between body fat and circulating adipokine levels from adolescence to young adulthood: The Santiago Longitudinal Study.

BACKGROUND AND AIMS: Adipose tissue secretes adipokines such as adiponectin and leptin, playing important roles in energy metabolism. The longitudinal associations between such adipokines and body fat accumulation have not been established, especially during adolescence and young adulthood and in diverse populations. The study aims to assess the longitudinal association between body fat measured with dual X-ray absorptiometry and plasma adipokines from adolescence to young adulthood. METHODS AND RESULTS: Among Hispanic/Latino participants (N = 537) aged 16.8 (SD: 0.3) years of the Santiago Longitudinal Study, we implemented structural equation modeling to estimate the sex-specific associations between adiposity (body fat percent (BF%) and proportion of trunk fat (PTF)) and adipokines (adiponectin and leptin levels) during adolescence (16 y) and these values after 6 years of follow-up (22 y). In addition, we further investigated whether the associations differed by baseline insulin resistance (IR) status. We found evidence for associations between 16 y BF% and 22 y leptin levels (ß (SE): 0.58 (0.06) for females; 0.53 (0.05) for males), between 16 y PTF and 22 y adiponectin levels (ß (SE): -0.31 (0.06) for females; -0.18 (0.06) for males) and between 16 y adiponectin levels and 22 y BF% (ß (SE): 0.12 (0.04) for both females and males). CONCLUSION: We observed dynamic relationships between adiposity and adipokines levels from late adolescence to young adulthood in a Hispanic/Latino population further demonstrating the importance of this period of the life course in the development of obesity.

Fasting levels of appetite regulating hormones predict caloric intake at breakfast in a group of Chilean adolescents.

BACKGROUND: Appetite regulation is integral to food intake and is modulated by complex interactions between internal and external stimuli. Hormonal mechanisms which stimulate or inhibit intake have been characterized, but the physiologic effects of serum levels of such hormones in short-term appetite regulation have received little attention. AIM: To evaluate whether fasting levels of orexigenic/anorexigenic hormones were associated with energy intake at breakfast, served soon after drawing a fasting blood sample, in a group of adolescents. MATERIAL AND METHODS: Anthropometry, body composition and fasting blood levels of leptin, insulin, ghrelin, and orexin-A were measured in 655 Chilean adolescents aged 16.8 ± 0.3 years (52% males). Energy intake was measured at a semi-standardized breakfast. Associations between hormone levels and energy intake were studied using multivariate linear models. RESULTS: Thirty nine percent of participants were overweight/ obese. After an overnight fast, median values for leptin, insulin, ghrelin and orexin-A were 7.3 ng/mL, 6.7 IU/dL, 200.8 pg/mL, and 16.1 pg/mL, respectively. Participants ate on average 637 ± 239 calories at breakfast. In multivariable models, insulin levels were inversely and independently associated with caloric intake at breakfast (ß = -18.65; p < 0.05), whereas leptin, ghrelin and orexin-A levels were positively and independently associated with intake: ß= 5.56, ß = 0.34 and ß = 8.40, respectively, p < 0.05. CONCLUSIONS: Fasting leptin, ghrelin and orexin-A were positively associated with energy intake during breakfast provided soon after the blood draw. Insulin was negatively associated with energy intake. Modifiable factors influencing levels of appetite regulating hormones could be a potential target for influencing food intake.

Obesity and impairment of pancreatic ß-cell function in early adulthood, independent of obesity age of onset: The Santiago Longitudinal Study.

AIM: We investigated the relation of time of onset and length of obesity with biomarkers of ß-cell function in early adulthood in an infancy cohort. MATERIAL AND METHODS: In 1039 23-year-olds, body-mass index (BMI) was measured at multiple time-points from enrollment. BMI trajectories were interpolated with cubic polynomials. Fasting glucose, insulin and adiponectin were measured at 23 years. Homeostatic model assessment-insulin resistance (HOMA-IR), HOMA-S, HOMA-ß, HOMA-adiponectin (AD) and disposition index (DI) were estimated. IR and non-alcoholic fatty liver (NAFL) were diagnosed. According to the BMI trajectory, five groups were defined: participants who were never obese (NOB); participants with obesity starting in adolescence and remained obese into adulthood (recent-onset obesity, ROB); participants who were obese in early childhood but transitioned to non-obesity as preadolescents (former obesity, FOB); participants who were obese in early childhood and remained obese into adulthood (persistent obesity, POB); participants with obesity starting in preadolescence and transitioned to non-obesity as adolescents (transient obesity; TOB). RESULTS: Obesity was present in 47% of participants during at least one time-point. ROBs and POBs had higher insulin, HOMA-IR and HOMA-ß, lower HOMA-S and DI, and higher prevalence of IR and NAFL at 23 years than NOBs, TOBs and FOBs. No differences were found in the ß-cell functionality of NOBs, TOBs and FOBs. CONCLUSIONS: Persistent and recent obesity are both related to IR, NAFL and a decline of ß-cell function in emerging adulthood. Defeating obesity in childhood or adolescence allows reaching emerging adulthood with ß-cell functioning similar to that of subjects who were NOB.

Eating behavior and body composition in Chilean young adults.

BACKGROUND: Notable weight gain is observed during young adulthood, compared to other adult age groups, yet the relation between eating behavior and body composition at this stage remains poorly understood. OBJECTIVE: The aim of this cross-sectional study was to assess the association between eating behavior scores (cognitive restraint, uncontrolled eating, and emotional eating), and body composition in a sample of Chilean young adults. METHODS: Logistic and linear regression models assessed the independent associations between cognitive restraint, uncontrolled eating, and emotional eating, derived from the Three Factor Eating Questionnaire-R18, and body mass index (BMI), percent body fat by dual-energy X-ray absorptiometry, and central obesity, accounting for demographic covariates, stratified by sex, in a sample of 555 participants of the Santiago Longitudinal Study (mean age 22.6 years [SD 0.4]). RESULTS: Cognitive restraint was positively associated with obesity, defined by BMI, % body fat, and central obesity. Emotional eating was related to obesity, defined by % body fat and central obesity in men and women and to obesity, defined by BMI, in women. Cognitive restraint was related to BMI in men and % body fat in women. Uncontrolled eating was not associated with adiposity in men or women. CONCLUSIONS: In Chilean young adults, cognitive restraint and emotional eating scores were associated with higher BMI, elevated percent body fat, and greater central obesity.

Mechanisms linking childhood weight status to metabolic risk in adolescence.

BACKGROUND: Obesity is a risk factor for insulin resistance (IR) and metabolic disease. OBJECTIVE: To examine potential metabolic pathways linking childhood weight status to adolescent IR and metabolic risk. METHODS: Participants were 600 low- to middle-income Chilean adolescents from a cohort studied since infancy as part of an iron deficiency anemia preventive trial and follow-up study. We examined body mass index z-score at 10 y (BMIz-10y) and blood pressure, total fat, and fasting glucose, adiponectin to leptin ratio (A:L), ghrelin, and HOMA-IR at 16 y. A total count for metabolic risk factors (MRF) was calculated using the International Diabetes Federation criteria. We used path analysis to estimate pathways and model indirect effects from BMIz-10y, controlling for child age and sex and maternal body mass index (BMI). RESULTS: Participants were 54% male; mean BMIz-10y of 0.53 (SD = 1.02); mean MRF of 1.3 (SD = 0.9); mean HOMA-IR of 1.8 (SD = 1.3). Path analysis showed that BMIz-10y directly and indirectly related to increased MRF via A:L and HOMA-IR. Ghrelin was not in the metabolic pathway from BMIz-10y to MRF but was related to MRF via HOMA-IR. CONCLUSION: These results elucidate metabolic pathways involving child weight status, IR and metabolic risk in adolescents. Childhood BMI was an indirect risk factor for adolescent cardiometabolic risk via several pathways that involved BMI, appetite hormones, markers of inflammation, and insulin resistance during adolescence. Findings illustrate the adverse effect that childhood obesity has on adolescent health outcomes, which sets precedence for health outcomes over the life course.

Sensitive periods for psychosocial risk in childhood and adolescence and cardiometabolic outcomes in young adulthood.

Greater psychosocial risk in childhood and adolescence predicts poorer cardiometabolic outcomes in adulthood. We assessed whether the timing of psychosocial risk from infancy through adolescence predicts cardiometabolic outcomes in young adulthood. Young adults and their mothers participated in a longitudinal study beginning in infancy in Santiago, Chile (N = 1040). At infancy, 5 years, 10 years, and adolescence, mothers reported on depressive symptoms, stressful experiences, support for child development in the home, father absence, parental education, and socioeconomic status (SES) to create a psychosocial risk composite at each time point. Young adults (52.1% female; 21-27 years) provided fasting serum samples and participated in anthropometric and blood pressure (BP) assessments, including a dual-energy X-ray absorptiometry (DXA) scan for measuring body fat. Greater infant psychosocial risk was associated with a greater young adult metabolic syndrome score (ß = 0.07, 95% confidence intervals (CI): 0.01 to 0.13, p = 0.02), a higher body mass index and waist circumference composite (ß = 0.08, 95% CI: 0.03 to 0.13, p = 0.002), and a higher body fat (DXA) composite (ß = 0.07, 95% CI: 0.01 to 0.12, p = 0.02). No psychosocial risk measure from any time point was associated with BP. Infant psychosocial risk predicted cardiometabolic outcomes in young adulthood better than psychosocial risk at 5 years, 10 years, or adolescence, mean of psychosocial risk from infancy through adolescence, and maximum of psychosocial risk at any one time. Consistent with the Developmental Origins of Health and Disease model, findings suggest that infancy is a sensitive period for psychosocial risk leading to poorer cardiometabolic outcomes in young adulthood.

Risk taking, sensation seeking and personality as related to changes in substance use from adolescence to young adulthood.

INTRODUCTION: This study examined changes in substance use from adolescence to young adulthood as related to adolescents' risk taking, sensation seeking, antisocial activities, and personality traits. METHODS: Chilean youth (N = 890, 52% female) were studied in adolescence (14.5 and 16.2 years) and young adulthood (M age 21.3 years). Risk taking was assessed via a laboratory-based performance task (Balloon Analogue Risk Task), and self-administered questionnaires assessed sensation seeking, antisocial behaviors, personality and substance use. RESULTS: Frequent involvement in sensation seeking and antisocial activities were associated with increased odds of continued marijuana use from adolescence to young adulthood and of illicit substance use at young adulthood. High risk taking was associated with a reduced likelihood of discontinuing marijuana use at young adulthood, and high agreeableness and conscientiousness were associated with reduced likelihood of new onset marijuana use and illicit substance use at young adulthood. CONCLUSIONS: Results highlight specific risk-taking tendencies and personality characteristics that relate to initiating, continuing, or discontinuing substance use at entry into adulthood. Sensation seeking and involvement in antisocial activities were the two foremost risk factors for continued use, which is a forecaster of drug dependence. Findings suggest potential prevention and intervention targets for abstaining from or discontinuing substance use as youth transition to adulthood.

Randomized Controlled Trial of Iron-Fortified versus Low-Iron Infant Formula: Developmental Outcomes at 16 Years.

OBJECTIVES: To test differences in cognitive outcomes among adolescents randomly assigned previously as infants to iron-fortified formula or low-iron formula as part of an iron deficiency anemia prevention trial. STUDY DESIGN: Infants were recruited from community clinics in low- to middle-income neighborhoods in Santiago, Chile. Entrance criteria included term, singleton infants; birth weight of ≥3.0 kg; and no major congenital anomalies, perinatal complications, phototherapy, hospitalization >5 days, chronic illness, or iron deficiency anemia at 6 months. Six-month-old infants were randomized to iron-fortified (12 mg/L) or low-iron (2.3 mg/L) formula for 6 months. At 16 years of age, cognitive ability, visual perceptual ability, visual memory, and achievement in math, vocabulary, and comprehension were assessed, using standardized measures. We compared differences in developmental test scores according to randomization group. RESULTS: At the follow-up assessment, the 405 participants averaged 16.2 years of age and 46% were male. Those randomized to iron-fortified formula had lower scores than those randomized to low-iron formula for visual memory, arithmetic achievement, and reading comprehension achievement. For visual motor integration, there was an interaction with baseline infancy hemoglobin, such that the iron-fortified group outperformed the low-iron group when 6-month hemoglobin was low and underperformed when 6-month hemoglobin was high. CONCLUSIONS: Adolescents who received iron-fortified formula as infants from 6 to 12 months of age at levels recommended in the US had poorer cognitive outcomes compared with those who received a low-iron formula. The prevention of iron deficiency anemia in infancy is important for brain development. However, the optimal level of iron supplementation in infancy is unclear. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01166451.

Infant Psychosocial Environment Predicts Adolescent Cardiometabolic Risk: A Prospective Study.

OBJECTIVE: To prospectively assess whether the infant psychosocial environment was associated with cardiometabolic risk as early as adolescence. STUDY DESIGN: Participants were recruited in Santiago, Chile, and have been followed from infancy. Inclusion criteria included healthy infants with birth weight ≥3 kg and a stable caregiver. The psychosocial environment, including depressive symptoms, stressful life events, poor support for child development, father absence, and socioeconomic status, was reported by mothers at 6-12 months. Body mass index (BMI) z score was assessed at 5 and 10 years. BMI z score, waist-to-hip ratio, systolic and diastolic blood pressure, fat mass and body fat percentage, fasting glucose, total and high-density lipoprotein cholesterol, and homeostatic model of insulin resistance were tested in adolescence. RESULTS: Adolescents ranged from 16 to 18 years of age (n = 588; 48.1% female). A poorer infant psychosocial environment was associated with BMI z score at 10 years (ß = 0.10, 95% CI = 0.00-0.19) and in adolescence (ß = 0.15, 95% CI = 0.06-0.24) but not at 5 years. A poorer infant psychosocial environment was associated with higher blood pressure (ß = 0.15, 95% CI = 0.05-0.24), greater anthropometric risk (ß = 0.13, 95% CI = 0.03-0.22), greater biomarker (triglycerides, homeostatic model assessment of insulin resistance, total cholesterol) risk (ß = 0.12, 95% CI = 0.02-0.22), and a higher likelihood of metabolic syndrome in adolescence (aOR = 1.50; 95% CI = 1.06-2.12). CONCLUSIONS: These findings demonstrate that a poorer infant psychosocial environment was associated with greater adolescent cardiometabolic risk. The results support screening for infants' psychosocial environments and further research into causality, mechanisms, prevention, and intervention.

A waist-to-height ratio of 0.54 is a good predictor of metabolic syndrome in 16-year-old male and female adolescents.

BACKGROUND: We aimed to determine the sensitivity and specificity of selected anthropometric indicators as predictors of cardiovascular risk in adolescents. METHODS: Cross-sectional study in 678 adolescents (16.8 y ± 0.3) from an infancy cohort. Weight, height, waist circumference (WC), and hip circumference were measured. Body mass index (BMI), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were estimated. MetS was diagnosed with IDF/AHA/NHLBI. Optimal cutoffs of BMI, WC, WHR, and WHtR for diagnosing MetS were determined using ROC analysis. RESULTS: In males, WHtR (0.96) had the greatest area under the ROC curve, followed by WC (0.95) and BMI (0.93). In females, BMI (0.84) had the greatest area under the ROC curve (0.84), followed by WHtR (0.83) and WC (0.83). In both sexes, the optimal WHtR cutoff for MetS diagnosis was 0.54. A BMI of 26.9 in males and 26.3 in females were the optimal cutoffs for diagnosing MetS. Finally, WC values of 92 and 81.6 cm in males and females, respectively, were the optimal cutoffs for MetS diagnosis. CONCLUSIONS: In both sexes, a WHtR value of 0.54 was a good predictor of MetS. In males and females, the optimal cutoff of BMI for Mets diagnosis was below the values for diagnosing obesity.

Long-term vs. recent-onset obesity: their contribution to cardiometabolic risk in adolescence.

BACKGROUND: The contribution of long-term vs. recent-onset obesity to cardiometabolic risk in adolescence remains controversial. Here, we aimed to investigate the association of time of onset and length of obesity with the cardiometabolic profile of adolescence. METHODS: Prospective study in 678 16-year-olds. BMI was measured at birth-1-5-10-16 years and BMI trajectories were interpolated using cubic splines. BMI > 2 SD at <6 years was defined as early obesity. Waist circumference (WC), blood pressure, lipid and glucose profiles were measured at 16 years. A cardiometabolic risk score was computed (MetS_score). According to the BMI trajectory, four groups were defined: participants who were never obese (NOB), participants with obesity during adolescence (recent-onset obese (ROB)), participants who were obese in early childhood but transitioned to normal/overweight as preadolescents (formerly obese (FOB)), and participants who were obese in early childhood and remained obese (persistently obese (POB)). RESULTS: ROBs and POBs had significantly unhealthier cardiometabolic profile than NOBs. No differences were observed in the cardiometabolic profile of ROBs compared to POBs. Although FOBs had higher WC and MetS_score than NOBs, no differences were found in other biomarkers. FOBs were in healthier cardiometabolic condition than ROBs and POBs. CONCLUSIONS: Both long-term and recent-onset obesity increase the cardiometabolic risk in adolescents.

Changes in socio-economic status and lipoproteins in Chilean adolescents: a 16-year longitudinal study.

OBJECTIVE: The present longitudinal study assessed whether changes in socio-economic status (SES) from infancy to adolescence were associated with plasma lipoprotein concentrations in adolescence, of which low HDL-cholesterol (HDL-C) and high LDL-cholesterol (LDL-C), TAG and total cholesterol (TC) concentrations are associated with higher cardiovascular risk. DESIGN: SES, assessed using the modified Graffar Index, was calculated at 1, 5, 10 and 16 years. Principal components factor analysis with varimax rotation extracted two orthogonal SES factors, termed 'environmental capital' and 'social capital'. Generalized linear models were used to analyse associations between environmental and social capital at 1 and 16 years and outcomes (HDL-C, LDL-C, TAG, TC) at 16 years, as well as changes in environmental and social capital from 1-5, 5-10, 10-16 and 1-16 years, and outcomes at 16 years. SETTING: Santiago, Chile.ParticipantsWe evaluated 665 participants from the Santiago Longitudinal Study enrolled at infancy in Fe-deficiency anaemia studies and examined every 5 years to age 16 years. RESULTS: Social capital in infancy was associated with higher HDL-C in adolescence. Environmental capital in adolescence was associated with higher LDL-C and TC during adolescence. Changing environmental capital from 1-16 years was associated with higher LDL-C. Changing environmental capital from 1-5 and 1-16 years was associated with higher TC. CONCLUSIONS: Improvements in environmental capital throughout childhood were associated with less healthy LDL-C and TC concentrations in adolescence. We found no evidence of associations between changing environmental capital and HDL-C or TAG, or changing social capital and HDL-C, LDL-C, TAG or TC.