It's About Timing: Contrasting the Metabolic Effects of Early vs. Late Time-Restricted Eating in Humans

PURPOSE OF REVIEW

Time-restricted eating (TRE), a form of intermittent fasting, restricts feeding time across the day, imposing a daily 'eating window'. The time of day when the eating window occurs could result in differential metabolic effects. Here, we describe recent intervention studies in humans assessing the metabolic consequences of an early- (i.e., eating window starting in the early morning) vs. late (i.e., eating window starting after midday)-TRE protocol.

RECENT FINDINGS

Well-controlled studies indicate that both TRE protocols effectively reduce body weight and improve altered glucose metabolism, lipid profile, inflammation, or blood pressure levels. An early-TRE (e-TRE) might have a further positive impact on improving blood glucose, insulin levels, and insulin resistance. However, the studies directly assessing the metabolic consequences of an early- vs. late-TRE have shown dissimilar findings, and more well-controlled clinical trials are needed on the metabolic benefits of these two types of TRE. Evidence suggests that an e-TRE might have enhanced metabolic results, particularly regarding glucose homeostasis. More long-term studies, including larger sample sizes, are needed to assess the metabolic, circadian, and adherence benefits, together with socio-cultural acceptance of both TRE approaches.

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 (β = -1.22 kg/m2, 95% CI: -2.02, -0.42), waist circumference (β = -2.39 cm, 95% CI: -4.03, -0.75), and WHtR (β = -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.

Breastfeeding Duration and Timing of Bottle Supplementation: Associations with Body Mass Index from Childhood to Young-Adulthood

Evidence for the association between breastfeeding (BF) duration and later body mass index (BMI) is inconsistent. We explored how BF duration and BF type (exclusive or partial) related to BMI from childhood to young adulthood in a Chilean cohort. Infants were recruited at 6 months between 1994 and 1996 in Santiago, Chile (n = 821). Mothers reported date of first bottle and last BF; anthropometry was measured at 1, 5, 10, 16, and 23 years. We tested whether: (1) type of BF at 6 months (none, partial, exclusive) and (2) duration of exclusive BF (<1 month, 1 to <3 months, 3 to <6 months, and ≥6 months) related to BMI. At 6 months, 35% received both breastmilk and formula ("partial BF") and 38% were exclusively breastfed. We found some evidence of an association between longer BF and lower BMI z-scores at young ages but observed null effects for later BMI. Specifically, BF for 3 to <6 months compared to <1 month related to lower BMI z-scores at 1 and 5 years (both p < 0.05). Our results are in partial accordance with others who have not found a protective effect of longer BF for lower BMI.

Socioeconomic position and executive functioning from childhood to young adulthood: Evidence from Santiago, Chile

BACKGROUND

Optimizing cognitive development through early adulthood has implications for population health. This study aims to understand how socioeconomic position (SEP) across development relates to executive functioning. We evaluate three frameworks in life-course epidemiology - the sensitive period, accumulation, and social mobility hypotheses.

METHODS

Participants were young adults from Santiago, Chile who were studied from 6 months to 21 years. Family SEP was measured at ages 1 y, 10 y, and 16 y with the modified Graffar Index. Executive functioning was assessed at ages 16 y and 21 y by the Trail Making Test Part B (Trails B). Analyses estimating 16 y and 21 y executive function involved 581 and 469 participants, respectively. Trails B scores were modeled as a function of SEP at 1 y, 10 y, and 16 y, as the total accumulation of disadvantage, and as change in SEP between 1 y and 10 y and between 10 y and 16 y.

RESULTS

Participants were low- to middle-income in infancy and, on average, experienced upwards mobility across childhood. Half of participants (58%) improved Trails B scores from 16 y and 21 y. Most (68%) experienced upward social mobility between infancy and 16 y. When examined independently, worse SEP measured at 10 y and 16 y related to worse (longer time to complete) Trails B scores at Age 21 but did not relate to the other outcomes. After mutual adjustment as a test of the sensitivity hypothesis, no SEP measure was independently related to any outcome. Testing the accumulation hypothesis, cumulative low SEP was associated with worse cognitive performance at 21 y (β = 3.6, p = 0.04). Results for the social mobility hypothesis showed no relation to cognitive scores or to change in cognitive scores. Comparing all hypotheses, SEP at 16 y explained the most variability in executive functioning at 21 y, providing support for the sensitive period hypothesis.

CONCLUSIONS

Results indicate that experiencing cumulatively low socioeconomic position from infancy to adolescence can have a negative impact on cognitive functioning in young adulthood. Findings also provide evidence in support of adolescence as a key developmental period during which SEP can most strongly impact cognitive functioning.

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.

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.

A Single-Point Insulin Sensitivity Estimator (SPISE) of 5.4 is a good predictor of both metabolic syndrome and insulin resistance in adolescents with obesity

BACKGROUND

The Single-Point Insulin Sensitivity Estimator (SPISE) is a biomarker of insulin sensitivity estimated using BMI and triglycerides and high-density lipoprotein cholesterol. We assessed the accuracy of SPISE to screen obesity-related cardiometabolic risk in children and adolescents.

METHOD

Cross-sectional validation study for a screening test in a sample of n=725 children and adolescents from an obesity clinic. Weight, height, waist circumference, blood arterial pressure, lipid profile, glucose, insulin and Tanner stage were measured. BMI, BMI for-age-and sex (BAZ), and HOMA-IR were estimated. HOMA-IR values ≥2.1 and ≥3.3 were considered IR in Tanner I-II, ≥3.3 for Tanner III-IV and ≥2.6 for Tanner V, respectively. Metabolic Syndrome (MetS) was diagnosed with the Cook phenotype. SPISE was estimated according to the following algorithm: [600* HDL^0.185/(TG^0.2* BMI^1.338)]. The optimal SPISE cut points for IR and MetS prediction were determined by ROC curve analysis.

RESULTS

In prepubertal obese patients (9.2 ± 2.1y; 18.4% males), the prevalence of IR and MetS was 28.2% y 46.9%, respectively; 58% had severe obesity (BAZ ≥4 SD). In pubertal obese patients (12.6 ± 1.8y; 57% males), the prevalence of IR and MetS was 34.1% and 55.3%, respectively; 34% had severe obesity. In prepubertal children, a SPISE of 6.3 showed the highest sensitivity (73.2%) and specificity (80%) to screen individuals with IR (AUC: 0.80; LR +: 3.3). Likewise, a SPISE of 5.7 got the highest sensitivity (82.6%) and specificity (86.1%) to screen patients with MetS (AUC: 0.87; LR +: 5.4). In pubertal patients, a SPISE of 5.4 showed the highest sensitivity and specificity to screen children and adolescents with both IR (Sn: 76.1%; Sp: 77.5%; AUC: 0.8; LR +: 3.1) and MetS (Sn: 90.4%; Sp: 76.1%; AUC: 0.90; LR +: 3.5).

CONCLUSION

In children and adolescents with obesity, SPISE has good or very good performance in predicting IR and MetS. SPISE may be considered a relatively simple and low-cost diagnosis tool that can be helpful to identify patients with greater biological risk. In adolescents with obesity, the same cut point allows identification of those at higher risk of both IR and MetS.

Associations between Adolescent Alcohol Use and Neurocognitive Functioning in Young Adulthood

This study examined the associations between excessive alcohol intake during adolescence and neurocognitive functioning in young adulthood and whether these relations varied by sex. Participants were working-class Chilean adolescents (N = 692; Mage 16.0 years; 54.5% female) who provided frequency of past 30-day bingeing and past-year intoxication. Neurocognitive measures were completed in young adulthood (Mage 21.2 years). Illicit substance users were excluded a priori and other substance use was controlled. When males and females were considered simultaneously, no main effects of intoxication or bingeing were found. However, several sex-specific effects emerged for intoxication, such that more frequent intoxication was associated with poorer visual memory, attention, processing speed, response inhibition, and cognitive flexibility in females, while frequent intoxication related to better attention and processing speed in males. In general, effect sizes were small. No relations emerged for verbal memory, working memory, or spatial learning. Possible factors that contribute to divergent sex effects are discussed.

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.

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.

Multiple events case-control study in a prospective cohort to identify systemic, cellular, and molecular biomarkers of obesity-induced accelerated aging in 30-years-olds: the ObAGE study protocol

Background

Aging is characterized by a progressive loss of capacities linked to fundamental alterations/damage in multiple cellular and molecular pathways. It is the most significant risk factor for all non-communicable diseases (NCDs). Another contributing factor to the rise in NCDs is obesity. It has been suggested that obesity not only accelerates the onset of metabolic imbalances but also decreases lifespan and impacts cellular and molecular processes in a manner similar to aging. Obesity might accelerate the pace of aging. Guided by a lifecourse approach, we will explore how exposure to obesity in critical developmental stages disrupt homeostatic resilience mechanisms that preserve physiological integrity, inducing an early expression of aging phenotypes. Also, we will determine whether exposure to early psychosocial adversity influences vulnerability to obesity as a risk factor for accelerated aging.

Methods

Multiple events case–control study embedded in a prospective cohort of Chileans at 30-31y, 50% females, of low- to-middle socioeconomic status, who participated in nutrition research since birth. At 23y, 25% had obesity and cardiometabolic risk was high. We will use a multi-layer approach including: anthropometric assessment; DXA scan for body composition; abdominal ultrasound of the liver; stool samples collection and sequencing of the ribosomal RNA 16S gene to characterize the gut microbiome; determination of age-related pro-inflammatory cytokynes and anti-inflammatory miokynes. For the first time in Chile, we will address age-related epigenetic changes using the Horvath´s epigenetic clock. In a subset we will conduct a controlled physical challenge to characterize physical resilience (autophagy).

Discussion

ObAGE is in an excellent position to: approach aging as a process whose expression involves multiple factors from the early stages of a person's life; understand how longitudinal changes in health trajectories impact the biological mechanisms of aging; identify potential resilience mechanisms that help prevent unhealthy aging. Because SLS participants are still young, our research setting combined with advanced scientific techniques may identify individuals or groups at risk of early onset health issues. Results from ObAGE may pave the way to address the contribution of obesity to aging through lifespan from cells to systems and might be instrumental to developing interventions to improve health span in the Chilean population.

Trial registration

The proposed study does not consider any health care intervention on human participants.

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 (β (SE): 0.58 (0.06) for females; 0.53 (0.05) for males), between 16 y PTF and 22 y adiponectin levels (β (SE): -0.31 (0.06) for females; -0.18 (0.06) for males) and between 16 y adiponectin levels and 22 y BF% (β (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.

Association of fasting orexin-A levels with energy intake at breakfast and subsequent snack in Chilean adolescents

Orexin-A, a hormone secreted by orexin neurons, is involved in caloric-intake regulation. Current understanding is based primarily on animal studies. Studies of orexin in humans are scarce, and to our knowledge there are no prior studies in adolescents. We studied fasting Orexin-A levels related to energy intake at breakfast and a subsequent snack in adolescents (n = 668) from a longitudinal study in Chile. Body-Mass Index (BMI), components of the metabolic syndrome and fasting blood levels of leptin, insulin, ghrelin, and orexin-A were measured. Energy intake was calculated based on food weights before and after the standardized breakfast and subsequent snack. High energy intake was defined as ≥ 75th percentile. We assessed the relationship between orexin-A and high energy intake, adjusting for confounders. Higher orexin levels were associated with high breakfast energy intake (OR: 1.21; 95%CI: 0.98-1.49). Conversely, those with higher orexin levels showed a non-significant trend for lower odds of high energy intake for the snack (OR: 0.87; 95%CI: 0.70-1.07). There was a significant interaction between high breakfast energy intake and orexin levels. Those who ate more calories at breakfast displayed a lower inhibitory effect of orexin on eating at the snack (p < 0.05). There was no significant interaction between weight status and orexin. In conclusion, orexin-A levels were associated with breakfast energy intake and inversely related with subsequent snack energy intake in participants whose caloric intake at breakfast was within the normal range. Based on these findings, it appears that the association of orexin-A with energy intake depends on eating behavior.

Associations between adverse home environments and appetite hormones, adipokines, and adiposity among Chilean adolescents

Little is known regarding the relationship between adverse home environments and hormones important in regulation of appetite and their impact on obesity in children and adolescents. In this study, we examined the impact of socioeconomic economic status, family stress and maternal depressive symptoms on appetite hormones, adipokines and adiposity. To determine whether adverse home environments in childhood and adolescence relate to adiposity in adolescence and disruptions in appetite hormones and adipokines, specifically lower levels of adiponectin and ghrelin and elevated levels of leptin and orexin. Adversity in the home (maternal depressive symptoms, family stress, socioeconomic disadvantage) was measured in the households of 593 Chilean youth at age 10 years (52.3% male) and in 606 youth at 16 years. At 16 years, participants provided fasting blood samples for assessment of adipokines and appetite hormones. Waist-to-height ratio was used to assess central adiposity. Correlational analyses examined associations between continuous levels of adversity in childhood and adolescence and appetite hormones and adiposity in adolescence. Multinomial logistic regressions compared hormone levels by tertiles of adversity. Participants were 52% male, with average age at the 16 years hormone assessment being 16.8 (n = 606, SD = 0.26). Those with highest maternal depression at age 10 had lower adiponectin OR = 0.95 [95% CI: 0.91, 0.99], p = 0.005) and ghrelin levels (OR = 0.98 [95% CI: 0.98, 1.00), p = 0.022) than those in the lowest maternal depression group at age 16. Those with the highest family stress at 16 years had lower adiponectin levels (OR = 0.93 [95% CI: 0.89, 0.98), p = 0.004) and higher central adiposity (OR = 1.05 [1.01, 1.08], p = 0.009) than the lowest family stress group. There were no significant associations found between socioeconomic status at either 10 or 16 years and appetite hormones. Results add new evidence regarding the relationship between household adversity to appetite hormones and adipokines, with the most consistent results for adiponectin. Current findings suggest that the relationship between home environment and adipokines and appetite hormones may play a role in altered adiposity in children and adolescents.

Resolving early obesity leads to a cardiometabolic profile within normal ranges at 23 years old in a two-decade prospective follow-up study

Obesity is the most important predisposing factor for cardiovascular disease and type-2 diabetes. We explored the relationship between the age at onset of obesity and selected cardiometabolic parameters in young adults. Longitudinal study of n = 1,039 participants (48% males) in their early twenties. BMI was measured at birth, 1–5–10–12–14–16–23 years. BMI trajectories were interpolated. Five groups were identified: never obese (never-OB); early childhood obesity transitioning to non-obesity before adolescence (former-OB); obesity starting in preadolescence transitioning to non-obesity as adolescents (transient-OB); obesity from adolescence into early adulthood (recent-onset-OB); participants who were obese in early childhood and remained obese into adulthood (persistent-OB). Waist circumference (WC), blood pressure, lipids, glucose, and insulin were measured at 23 years. HOMA-IR and the Metabolic Syndrome Risk Z-Score were estimated. In the sample, 47% were obese during at least one time-point. Mean obesity duration was 20.7 years, 8.5 years, 6.2 years, and 3.3 years in persistent-OBs, recent-onset-OBs, former-OBs, and transient-OBs, respectively. The cardiometabolic profile was more adverse in recent-onset-OBs (12%) and persistent-OBs (15%) compared to never-OB participants (53%). Although former-OBs (15%) and transient-OBs (4%) had higher WC values than never-OBs, no differences were seen in other biomarkers. Both persistent and recent-onset obesity led to a cardiometabolic profile of risk in early adulthood, as suggested by values of WC, HOMA-IR, and hs-CRP above normal limits and HDL-chol values below normal limits. Participants who had obesity in early childhood or preadolescence but transitioned to a non-obesity status had a cardiometabolic profile similar to participants who were never obese and within normal limits. Obesity leads to risky values in a number of cardiometabolic biomarkers in young adulthood independent of age at obesity onset. Likewise, overcoming obesity during the pediatric age leads to a cardiometabolic profile within normal ranges at 23 years of age.

Genome-wide association study identifying novel variant for fasting insulin and allelic heterogeneity in known glycemic loci in Chilean adolescents: The Santiago Longitudinal Study

BACKGROUND

The genetic underpinnings of glycemic traits have been understudied in adolescent and Hispanic/Latino (H/L) populations in comparison to adults and populations of European ancestry.

OBJECTIVE

To identify genetic factors underlying glycemic traits in an adolescent H/L population.

METHODS

We conducted a genome-wide association study (GWAS) of fasting glucose (FG) and fasting insulin (FI) in H/L adolescents from the Santiago Longitudinal Study.

RESULTS

We identified one novel variant positioned in the CSMD1 gene on chromosome 8 (rs77465890, effect allele frequency = 0.10) that was associated with FI (β = -0.299, SE = 0.054, p = 2.72×10-8 ) and was only slightly attenuated after adjusting for body mass index z-scores (β = -0.252, SE = 0.047, p = 1.03×10-7 ). We demonstrated directionally consistent, but not statistically significant results in African and Hispanic adults of the Population Architecture Using Genomics and Epidemiology Consortium. We also identified secondary signals for two FG loci after conditioning on known variants, which demonstrate allelic heterogeneity in well-known glucose loci.

CONCLUSION

Our results exemplify the importance of including populations with diverse ancestral origin and adolescent participants in GWAS of glycemic traits to uncover novel risk loci and expand our understanding of disease aetiology.

Iron deficiency in infancy and neurocognitive and educational outcomes in young adulthood

This study examines the extent to which iron deficiency in infancy contributes to adverse neurocognitive and educational outcomes in young adulthood directly and indirectly, through its influence on verbal cognition and attention problems in childhood. Young adults (N = 1,000, M age = 21.3 years, 52% female; of Spanish or indigenous descent) from working-class families in Santiago, Chile, completed instruments assessing memory, processing speed, mental flexibility, and educational attainment. Iron status was assessed at ages 6, 12, and 18 months, and verbal intelligence, inattention, and sluggish cognitive tempo (SCT) symptoms were assessed at age 10. Results indicated that young adults who had iron-deficiency in infancy had poor executive control at age 21. Severity of iron deficiency during infancy was associated with lower verbal IQ and more frequent inattention and SCT symptoms in childhood, and with lower educational attainment in young adulthood through its effect on inattention. No additional indirect effects were found. Interventions directed toward improving cognitive and attention deficits linked to early-life iron deficiency appear warranted and could alter the course to adult functioning. Further research on the impact of such interventions would be helpful. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Mother-Adolescent Discrepancies in Ratings of Adolescents' Adjustment: Associations with Maternal Mental Health and Family Factors

OBJECTIVE

Many children and adolescents are assessed for potential psychological and behavioral problems through the parent-completed Child Behavior Checklist (CBCL) and Youth Self-Report (YSR) questionnaires. However, because these assessments are based on individual reports, they are subject to disagreement. This study considered multiple family factors and aspects of mothers' mental health in discrepancies between mothers' and youths' ratings on the CBCL and YSR.

METHOD

This study involved 926 mothers and their adolescent children (48.7% female children, mean age = 14.4 years) who completed the CBCL and YSR questionnaires, respectively.

RESULTS

Mothers who experienced more severe mental health problems reported more internalizing symptoms of their adolescent relative to the adolescent's ratings.

CONCLUSION

Findings indicate that mothers' poor mental health is related to their reports of more frequent psychological problems in their adolescents. To verify the accuracy of maternal reports, additional raters and additional methods, such as behavioral observation and clinical interview, would be helpful.

Obesity and impairment of pancreatic β-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 β-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-β, 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-β, 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 β-cell functionality of NOBs, TOBs and FOBs.

CONCLUSIONS

Persistent and recent obesity are both related to IR, NAFL and a decline of β-cell function in emerging adulthood. Defeating obesity in childhood or adolescence allows reaching emerging adulthood with β-cell functioning similar to that of subjects who were NOB.

Vitamin D status in infancy and cardiometabolic health in adolescence

BACKGROUND

Vitamin D deficiency is associated with obesity-related conditions, but the role of early life vitamin D status on the development of obesity is poorly understood.

OBJECTIVES

We assessed whether serum 25-hydroxyvitamin D [25(OH)D] at age 1 y was related to metabolic health through adolescence.

METHODS

We quantified serum 25(OH)D in samples obtained at age 1 y from 306 participants in a cohort study in Santiago, Chile. Anthropometry was performed at ages 5, 10, and 16/17 y. At 16/17 y, we determined body composition using DXA and quantified metabolic parameters in a blood sample. We examined the associations of infancy 25(OH)D with BMI-for-age z-score (BMIZ) at ages 5, 10, and 16/17 y; with percentage fat and percentage lean body mass at age 16/17 y; and with a metabolic syndrome (MetS) score and its components at age 16/17 y.

RESULTS

Infancy 25(OH)D was inversely associated with BMIZ in childhood. Every 25-nmol/L difference in 25(OH)D was related to an adjusted 0.11 units lower BMIZ at age 5 y (95% CI: -0.20, -0.03; P = 0.01) and a 0.09 unit lower BMIZ change from ages 1 to 5 y (95% CI: -0.17, -0.01; P = 0.02). Also, every 25-nmol/L 25(OH)D in infancy was associated with an adjusted 1.3 points lower percentage body fat mass (95% CI: -2.2, -0.4; P = 0.005) and an adjusted 0.03 units lower MetS score (95% CI: -0.05, -0.01; P = 0.01) at age 16/17 y, through inverse associations with waist circumference and the HOMA-IR.

CONCLUSIONS

Serum 25(OH)D at age 1 y is inversely associated with childhood BMIZ, percentage body fat at age 16/17 y, and a MetS score at age 16/17 y. Intervention studies are warranted to examine the effects of vitamin D supplementation in early life on long-term cardiometabolic outcomes.

Serum polyunsaturated fatty acids in infancy are associated with body composition in adolescence

BACKGROUND

Polyunsaturated fatty acids (PUFA) have been related to the development of adiposity. N-3 PUFA appears to be protective against obesity risk, while n-6 PUFA may be associated with greater adiposity. However, most studies have been conducted among adults. The role of PUFA in infancy is unknown.

OBJECTIVE

To examine associations of serum PUFA at age 1 year with age- and sex-adjusted body mass index Z score (BMIZ) change through age 16 years and body composition at 16 years.

METHODS

We quantified serum PUFA in 636 Chilean infants aged 1 year. We measured BMIZ at ages 1, 5, 10 and 16 years, and body composition by dual energy X-ray absorptiometry at 16 years. We estimated differences in 1- to 16-years BMIZ change between PUFA quartiles from multivariable linear mixed models with restricted cubic splines. At 16 years, we estimated differences in total fat mass (ToFM), truncal fat mass (TrFM), total lean mass (TLM), percent total fat mass (%ToFM) and percent truncal fat mass (%TrFM) between PUFA quartiles using linear regression.

RESULTS

PUFA were not associated with BMIZ change. Alpha-linolenic acid (ALA) was positively associated with TrFM (P = .03) and %TrFM (P < .0001) at 16 years while eicosapentaenoic acid (EPA) was inversely associated with %TrFM (P = .001). Docosapentaenoic acid (DPA) was positively associated with ToFM (P = .01), TrFM (P = .009), %ToFM (P = .02) and %TrFM (P = .02). Gamma-linolenic acid (GLA) and the Δ6-desaturase (D6D) activity index were each positively, linearly associated with ToFM, TrFM and %ToFM. The Δ5-desaturase (D5D) activity index was inversely associated with %TrFM (P = .04).

CONCLUSIONS

ALA, DPA, GLA and the D6D index at 1 year of age were positively associated with adiposity at age 16 years, while EPA and the D5D index were inversely associated with central adiposity. Our results related to EPA and desaturase indices are in agreement with limited prior studies.

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.

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.

Eating in the Absence of Hunger and Obesity Among Adolescents in Santiago, Chile

In reports among mostly, US, white, preschool and young school-age children eating in the absence of hunger (EAH) has been positively related to adiposity, with some support for a sex-specific relationship. There is considerable interest in EAH and obesity in populations at risk for obesity-like populations of countries that have undergone rapid development. We assessed adolescents (n = 679) after an overnight fast with anthropometry and an EAH paradigm beginning with an ad lib pre-load meal. Participants reported satisfaction and perceived ability to eat more food, and then proceeded to a room with freely available snacks where they were permitted to eat ad lib for 20 min. Adolescents were 16.8 years old, 52% male, and 14% with obesity. Median preload meal kcal consumption was 602 (IQR 474-746). Additional calories were consumed at the EAH snack by 47.6%. Among those who ate snack, 155 additional calories were consumed (IQR 78-283). Adolescents with obesity had 0.61 (95% CI 0.37-0.99) reduced odds of eating at the EAH snack adolescents without obesity. Adolescents with obesity were also less likely to eat above the median total calories compared to adolescents without obesity (OR = 0.59, 95% CI 0.36-0.96). A sex by obesity interaction term was not significant in any model. Obesity was related to eating behavior in our sample of Chilean adolescents, however not in the direction we hypothesized. Adolescents with obesity were less likely to eat additional calories in the EAH paradigm and ate fewer total calories compared to adolescents without obesity.

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.

Vitamin D Status in Infancy and Cardiometabolic Health in Adolescence

Objectives

Vitamin D deficiency has been associated with obesity-related conditions, but the role of early life vitamin D status is not clear. We assessed whether serum 25-hydroxy vitamin D [25(OH)D] at age 1 y was related to metabolic health through adolescence.

Methods

We quantified serum 25(OH)D in samples obtained at age 1 y from 307 participants in a cohort study in Santiago, Chile. Anthropometry was performed at ages 5, 10, and 16 y. At the 16 y assessment we determined body composition using dual-energy X-ray absorptiometry and quantified metabolic parameters in a blood sample. Using linear regression, we examined the associations of infancy 25(OH)D with body mass index-for-age Z (BMIZ) at ages 5, 10, and 16 y; with % fat and % lean body mass at age 16 y; and with a metabolic syndrome (MetS) score at age 16 y. The MetS score was calculated from sex- and age-standardized values of waist circumference (WC), mean arterial pressure, the homeostatic model assessment for insulin resistance (HOMA-IR), and serum triglyceride and high-density lipoprotein concentrations. Results were adjusted for sex, maternal education, breastfeeding, socioeconomic status, and BMIZ at age 1 y.

Results

Mean ± SD 25(OH)D concentration was 80.6 ± 33.0 nmol/L. The prevalence of 25(OH)D &lt;50 nmol/L was 11.1%. 25(OH)D was inversely, significantly associated with BMIZ at age 5 y; every 25 nmol/L 25(OH)D was related to an adjusted 0.11 units (95% CI: 0.02, 0.20; P = 0.01) lower BMIZ. At age 16 y, every 25 nmol/L 25(OH)D was associated with a mean 1.3 points (95% CI: 0.4, 2.2; P = 0.005) lower % body fat, and a mean 1.4 points (95% CI: 0.4, 2.3; P = 0.005) higher % lean body mass. Also, every 25 nmol/L 25(OH)D in infancy was related to an adjusted 0.03 units (95% CI: 0.01, 0.05; P = 0.01) lower MetS score at age 16 y, through inverse associations with WC (−0.02 units per 25 nmol/L; 95% CI: −0.03, −0.00; P = 0.02) and HOMA-IR (−0.06 units per 25 nmol/L; 95% CI: −0.12, −0.00; P = 0.05).

Conclusions

Serum 25(OH)D at age 1 y is inversely associated with childhood BMIZ, % body fat at age 16 y, and a MetS score at age 16 y. Intervention studies are warranted to examine the effect of early-life vitamin D supplementation on later cardiometabolic outcomes.

Funding Sources

This study was funded by grants from the National Institutes of Health and the University of Michigan.

Childhood socioeconomic hardship, family conflict, and young adult hypertension: The Santiago Longitudinal Study

OBJECTIVE

Stress derived from socioeconomic disadvantage can be damaging to mental and physical health. This study uses longitudinal data on a large prospectively studied cohort to examine how socioeconomic hardship during childhood leads to hypertension in young adulthood by its effects on family conflict, anxiety-depression, and body mass.

METHOD

Data are from 1,039 participants of the Santiago Longitudinal Study who were studied in childhood (M age 10 years), adolescence (14-17 years), and young adulthood (21-26 years). As young adults, 26% had elevated blood pressure or hypertension.

RESULTS

Children from more economically disadvantaged families experienced higher levels of family conflict, which related to significant increases in anxiety-depression and body mass over time, both of which were directly linked to hypertension in young adulthood.

CONCLUSIONS

Findings provide an understanding of how early-life adversity associated with socioeconomic hardship manifests as stress-related health problems in adulthood. Intervention efforts that target overweight/obesity and anxiety and depression that stem from childhood poverty might be useful for reducing the socioeconomic disparities in adult health.

BMI Trajectories from Birth to 23 Years by Cardiometabolic Risks in Young Adulthood

OBJECTIVE

The aim of this study was to investigate whether the level, rate, and acceleration of BMI growth differ according to the presence or absence of adult cardiometabolic (CM) risks.

METHODS

BMI was measured in 1,000 Chileans at nine time points from birth to 23 years, and metabolic syndrome and its components were assessed at young adulthood. BMI growth was analyzed in the following three developmental periods: birth to 6 months, 6 months to 5 years, and 5 to 23 years.

RESULTS

Individuals with CM risks had a specific constellation of early-life growth (faster growth after infancy, lower BMI decline approaching age 5, absence of a definitive BMI nadir in early childhood, higher 5-year BMI) and distinct young adult growth (larger BMI increases from childhood to young adulthood and lower levels of expected growth deceleration approaching young adulthood). Those with CM risks also attained BMI ≥ 25 at significantly younger ages than those absent risks (metabolic syndrome: 12.3 years vs. 20.1 years; hyperglycemia: 13.1 years vs. 18.9 years; hypertension: 13.2 years vs. 19.4 years; hypertriglyceridemia: 14.3 years vs. 19.5 years; inflammation: 15.9 years vs. 20.6 years).

CONCLUSIONS

Larger and faster increases in BMI and a failure of BMI growth to decline or decelerate at specific developmental periods distinguished individuals who would and would not have adult CM risks.

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.

Cardiometabolic health in adolescence and its association with educational outcomes

Aim

To explore the association of selected cardiometabolic biomarkers and metabolic syndrome (MetS) with educational outcomes in adolescents from Chile.

Methods

Of 678 participants, 632 (52% males) met criteria for the study. At 16 years, waist circumference (WC), systolic blood pressure, triglycerides (TG), high-density lipoprotein and glucose were measured. A continuous cardiometabolic risk score (zMetS) using indicators of obesity, lipids, glucose and blood pressure was computed, with lower values denoting a healthier cardiometabolic profile. MetS was diagnosed with the International Diabetes Federation/American Heart Association/National Heart, Lung, and Blood Institute joint criteria. Data on high school (HS) graduation, grade point average (GPA), college examination rates and college test scores were collected. Data were analysed controlling for sociodemographic, lifestyle and educational confounders.

Result

zMetS, WC, TG and homeostatic model assessment of insulin resistance at 16 years were negatively and significantly associated with the odds of completing HS and taking college exams. Notably, for a one-unit increase in zMetS, we found 52% (OR: 0.48, 95% CI 0.227 to 0.98) and 39% (OR: 0.61, 95% CI 0.28 to 0.93) reduction in the odds of HS completion and taking college exams, respectively. The odds of HS completion and taking college exams in participants with MetS were 37% (95% CI 0.14 to 0.98) and 33% (95% CI 0.15 to 0.79) that of participants with no cardiometabolic risk factors. Compared with adolescents with no risk factors, those with MetS had lower GPA (515 vs 461 points; p=0.002; Cohen’s d=0.55). Adolescents having the MetS had significantly lower odds of passing the mathematics exam for college compared with peers with no cardiometabolic risk factors (OR: 0.49; 95% CI 0.16 to 0.95).

Conclusion

In Chilean adolescents, cardiometabolic health was associated with educational outcomes.

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 (β = 0.10, 95% CI = 0.00-0.19) and in adolescence (β = 0.15, 95% CI = 0.06-0.24) but not at 5 years. A poorer infant psychosocial environment was associated with higher blood pressure (β = 0.15, 95% CI = 0.05-0.24), greater anthropometric risk (β = 0.13, 95% CI = 0.03-0.22), greater biomarker (triglycerides, homeostatic model assessment of insulin resistance, total cholesterol) risk (β = 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.

Marijuana use associated with worse verbal learning and delayed recall in a sample of young adults

BACKGROUND

There is concern about the cognitive consequences of marijuana consumption.

AIM

To assess the influence of current and past marijuana use and frequency on verbal learning and memory in a sample of adults aged 21 years old.

MATERIAL AND METHODS

Marijuana use was assessed using a clinician administered interview in 654 participants (56% females), who reported frequency of use, age of first use and whether its use led to problems in their lives. The CogState International Shopping List was administered to assess learning and memory.

RESULTS

Seventy percent reported ever using marijuana, 46% consuming during the past year and 27% during the past 30 days. The latter scored significantly lower on delayed recall. Current and frequent use were significantly associated with lower accuracy in verbal learning and memory.

CONCLUSIONS

In this cohort of adults aged 21 years old, marijuana use was prevalent and related to worse verbal memory.

Home and Family Environment Related to Development of Obesity: A 21-Year Longitudinal Study

BACKGROUND

Early-life conditions are important for the development of obesity. We hypothesized that home and family characteristics reflective of less supportive environments during childhood will be associated with higher adult BMI and faster BMI growth between ages 5 and 21 years. We also examined the timing and acceleration of BMI increase by adult weight status (normal weight, overweight, obese, and extremely obese) to discern how BMI increase differs across group and across time.

METHODS

BMI was assessed in 1000 Chilean youth (52% female) at ages 5, 10, 15, and 21 years. Latent growth curve analysis modeled BMI trajectories from 5 to 21 years. Observer and maternal ratings assessed children's home and family environments and parenting at 1 and 10 years.

RESULTS

The four weight groups differed in acceleration of BMI increase starting at age 5, with bigger children getting bigger faster. Higher 21-year BMI related to family stress, father absence, maternal depression, frequent child confinement (in playpen), an unclean home environment at 1 year, and low provision for active stimulation and few stimulating experiences at 10 years. Accelerated BMI increase related to lower learning stimulation in the home at 1 year and less parental warmth and acceptance at child age 10.

CONCLUSIONS

Home and family characteristics that reflect an absence of support for children's development were associated with overweight/obesity in young adulthood and accelerated BMI growth. Findings identify several home and family characteristics that can serve as preventive or intervention targets.

Light smoking is associated with metabolic syndrome risk factors in Chilean young adults

AIMS

Metabolic syndrome (MetS) is a cluster of risk factors for cardiometabolic diseases. While cigarette smoking is associated with MetS in adults, young adulthood is an under-studied, susceptible period for developing long-term morbidity from MetS. We examined associations between cigarette smoking and MetS risk factors.

METHODS

We studied 430 participants in Santiago, Chile who have been followed in a longitudinal cohort since infancy and assessed in adolescence for MetS. Participants were evaluated at 22 years from May 2015 to July 2017. Adiposity, blood pressure, and blood samples were measured. MetS was defined using International Diabetes Federation criteria. A continuous MetS score was calculated using z-scores. Participants self-reported cigarette and alcohol consumption using standardized questionnaires. We used multivariate regressions to examine associations between smoking and MetS risk factors, adjusting for sex, MetS in adolescence, alcohol consumption, and socioeconomic status.

RESULTS

Thirteen percent of participants had MetS and 50% were current smokers. Among smokers, mean age of initiation was 14.9 years and consumption was 29 cigarettes weekly. Smokers had larger waist circumferences, higher BMIs, and lower high-density lipoprotein (HDL) cholesterol compared to non-smokers. Being a current smoker was significantly associated with higher waist circumference (β = 2.82; 95% CI 0.63, 5.02), lower HDL (β = - 3.62; 95% CI - 6.19, - 1.04), higher BMI (β = 1.22; 95% CI 0.16, 2.28), and higher MetS score (β = 0.13, 95% CI 0.02, 0.24).

CONCLUSIONS

Cigarette smoking at light levels (mean < 30 cigarettes weekly) was associated with MetS risk factors in a sample of Chilean young adults.

Ferritin levels throughout childhood and metabolic syndrome in adolescent stage

BACKGROUND AND AIM

Increased ferritin levels have been widely associated with cardiovascular risk in adults. Whether ferritin levels and their changes during childhood are related to metabolic syndrome (MetS) at adolescence is unknown. We aimed to evaluate these associations using levels of ferritin at 5, 10 and 16 years and their linear increases and patterns of sustained increased levels across childhood.

METHODS AND RESULTS

There were four samples evaluated according to non-missing values for study variables at each stage (5 years: 562; 10 years: 381; and 16 years: 567 children; non-missing values at any stage: 379). MetS risk was evaluated as a continuous Z score. Patterns of sustained increased ferritin (highest tertile) and slope of the change of ferritin per year across the follow-up were calculated. Ferritin levels in the highest versus lowest tertile at five and 16 years were significantly positively associated with MetS risk Z score at adolescence in boys and these associations were unaffected by adjustment for covariates. Having high, compared to low/moderate ferritin level at 2 or more time periods between 5 and 16 years was related to higher Mets Z-score in boys only [e.g. 5-10 years adjusted-beta (95 %CI):0.26 (0.05-0.48),P < 0.05]. In girls, ferritin Z score at 10 and 16 years was positively and independently associated with HOMA-IR Z score. In girls, the slope of ferritin per year in the highest tertile was positively associated with MetS risk Z-score [adjusted-beta (95 %CI):0.21 (0.05-0.38),P < 0.05].

CONCLUSIONS

Ferritin levels throughout childhood are positively related to cardiometabolic risk in adolescence, with associations varying by sex.

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.

Heparin Effect on Bone Density

In order to provide estimates of the risks of symptomatic osteoporosis and reduced bone density in premenopausal women treated with long-term (greater than 1 month) heparin therapy, we evaluated a cohort of 61 consecutive premenopausal women previously treated with long-term heparin (cases) and a group of controls matched for age, parity and duration between the last pregnancy and evaluation. All patients underwent dual photon absorptiometry of the lumbar spine and single photon absorptiometry of the wrist and most cases underwent plain lateral radiography of the thoracolumbar spine in order to exclude silent fractures. Although none of the cases suffered symptomatic fractures (0 of 61, 95% confidence intervals 0.0 to 5.9%), there was a significantly greater proportion of cases than controls with bone density below our pre-defined levels. The long-term implications of our findings are uncertain but because it is possible that the reduction in bone density predisposes women to fractures, this potential risk should be considered when treating women with long-term heparin.

Greater early weight gain and shorter breastfeeding are associated with low adolescent adiponectin levels

BACKGROUND

Early life factors can programme future risk for cardiovascular disease.

OBJECTIVES

We explored associations between adolescent adiponectin levels and concomitant metabolic alteration and also looked at the association between early life factors and adolescent adiponectin levels.

METHODS

We studied a longitudinal cohort of low-income to middle-income Chilean adolescents who were enroled in an infancy iron-deficiency anaemia preventive trial and follow-up studies at the Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile. In the 577 adolescents who were assessed as part of the 16-year follow-up, we evaluated independent associations between adiponectin levels and metabolic disturbances during adolescence. We also assessed the association between early life factors [short breastfeeding {<6 months} and infancy weight gain] and adolescent adiponectin levels.

RESULTS

Participants were 16.8 years old (16.4-18.1), 48% female and 38% overweight/obese. Adolescent adiponectin levels were inversely associated with metabolic disturbances: altered homeostatic model assessment of insulin resistance and high-density lipoprotein cholesterol [odds ratios {95% confidence interval} = 0.87 {0.79-0.95}, p-value = 0.002, and 0.90 {0.87-0.94}, p-value < 0.001, respectively], adjusting for sex and fat mass index. Early life factors were independently associated with adolescent adiponectin levels, which decreased 0.88 ug mL^-1 per each unit increase in weight-for-age z-score between 0 and 6 months and was 1.58 ug mL^-1 lower among participants with short breastfeeding.

CONCLUSIONS

Higher adolescent adiponectin levels were independently associated with lower odds of metabolic disturbances. Greater weight gain during infancy and shorter breastfeeding were associated with lower adolescent adiponectin levels, supporting research indicating early life as a window of opportunity for prevention of later cardiovascular alterations. © 2017 World Obesity Federation.

Low muscle mass is associated with cardiometabolic risk regardless of nutritional status in adolescents: A cross-sectional study in a Chilean birth cohort

BACKGROUND

Increased cardiometabolic risk (CMR) is documented in obese and non-obese adolescents with low muscular fitness. However, the association of low muscle mass (LMM) with CMR, independent of weight status, has not been examined. We analyzed the relationship of LMM with CMR in adolescents, regardless of their weight status.

MATERIALS AND METHODS

Observational study in 660 adolescents. BMI, waist circumference (WC), arterial blood pressures (ABP) were measured. Total fat mass (TFM), total lean tissue (TLT), and appendicular skeletal muscle mass (ASM) were estimated (DXA). Fasting lipid profile, glucose, and insulin were measured. HOMA-IR was estimated. Metabolic Syndrome (MetS) was diagnosed (AHA/NHLBI/IDF). ROC analysis was performed to find the optimal cutoffs of TLT percentage for MetS diagnosis. Values below these cutoffs defined LMM. ANCOVA examined the association of LMM with selected cardiometabolic biomarkers.

RESULTS

In both sexes, TLT showed better sensitivity and specificity than ASM for MetS diagnosis. In males and females, TLT of 66.1% and 56.3%, respectively, were the optimal cutoff for MetS diagnosis. In the sample, 17.3% of males and 23.7% of females had LMM. In both sexes, adolescents with LMM had significantly higher values of WC, ABP, TG, TC/HDL, HOMA-IR, and MetS z-score than non-LMM participants. Adolescents with LMM, regardless nutritional status, had significantly increased values of MetS z-score, ABP, TG, TC/HDL-chol, and HOMA-IR than non-obese non-LMM adolescents. Adolescents having both obesity and LMM had the unhealthiest CMR profile.

CONCLUSION

In adolescents, LMM was associated with higher CMR, regardless of nutritional status. In obese adolescents, LMM increased obesity-associated CMR.

Physically active Chilean school kids perform better in language and mathematics

We examined the association between the engagement in regular physical activity (PA) and the academic performance (AP) of school-age children from Santiago Metropolitan Region. In a random sample of 1271 students (13.3 ± 2.3 years old) we measured regular PA, accounting for hours of weekly scheduled exercise, and AP, using national standardized tests scores in Language and Mathematics. Bivariate and multivariate regression analyses were used to model the relation between academic and health-related behaviors. Two outcomes were considered: (i) sufficiency according to the Ministry of Education and (ii) discretionary sufficiency (tests z-scores ≥50th percentile). About 80% of students were poorly engaged in scheduled exercise (<2 h per week). Devoting more than 4 h per week to scheduled exercise significantly increased the odds of reaching the official and discretionary sufficiency in both Language and Mathematics. Moderate engagement (2-4 h per week) just improved the odds of reaching the discretionary sufficiency standard. These results confirm the poor engagement in regular exercise at the school level. School kids with the highest allocation of time to scheduled exercise have better AP in Language and Mathematics. Our findings support the notion that academic and health-related behaviors are linked and, similarly, that school health programs may have positive effects on educational outcomes.

Early Onset Obesity and Risk of Metabolic Syndrome Among Chilean Adolescents

INTRODUCTION

Obesity and metabolic syndrome (MetS) indicators have increased globally among the pediatric population. MetS indicators in the young elevate their risk of cardiovascular disease and metabolic disorders later in life. This study examined early onset obesity as a risk factor for MetS risk in adolescence.

METHODS

A cohort of Chilean participants (N = 673) followed from infancy was assessed at age 5 years and in adolescence (mean age, 16.8 y). Adiposity was measured at both time points; blood pressure and fasting blood samples were assessed in adolescence only. Early onset obesity was defined as a World Health Organization z score of 2 standard deviations (SDs) or more for body mass index (BMI) at age 5 years. We used linear regression to examine the association between early onset obesity and adolescent MetS risk z score, adjusting for covariates.

RESULTS

Eighteen percent of participants had early onset obesity, and 50% of these remained obese in adolescence. Mean MetS risk z score in adolescence was significantly higher among those with early onset obesity than among those without (1.0; SD, 0.8 vs 0.2; SD, 0.8 [P < .001]). In the multivariable model, early onset obesity independently contributed to a higher MetS risk score in adolescence (β = 0.27, P < .001), controlling for obesity status at adolescence and sex, and explained 39% of the variance in MetS risk.

CONCLUSION

Early onset obesity as young as age 5 years relates to higher MetS risk.

Breastfeeding as the sole source of milk for 6 months and adolescent bone mineral density

Little is known regarding the relationship between early life factors and bone mineral density (BMD). We found a positive association between breastfeeding for at least 6 months, without formula supplementation, and whole body adolescent BMD z-score.

INTRODUCTION

The aim of the study is to assess the role of breastfeeding BF on adolescent bone mineral density (BMD) in a cohort prospectively followed since infancy.

METHODS

We studied 679 participants from an infancy iron deficiency anemia preventive trial in Santiago, Chile, followed to adolescence. Breast and bottle feeding were ascertained weekly from 4 to 12 months. At 16 years, whole body BMD was assessed by DEXA. Using linear regression, we evaluated associations between BF duration and BF as the sole source of milk and adolescent BMD z-score, adjusting for possible infancy, adolescent, and background confounders.

RESULTS

Mean birth weight and length were 3.5 (0.3) kg and 50.7 (1.6) cm. For at least 6 months, BF was the sole source of milk for 26.3% and with supplementation for 36.7%. For 37%, BF was provided for less than 6 months. Mean 16-year BMD z-score was 0.25 (1.0). Covariates included male sex, birth length, and gestational age. BF as the sole source of milk ≥6 months, compared to BF < 6 months, was associated with higher adolescent BMD z-score adjusting for covariates (β = 0.29, p < 0.05). Mixed BF was not significantly related to adolescent BMD z-score (β = 0.06, p = 0.47). For every 30 days of BF as the sole source of milk, adolescent BMD z-score increased by 0.03 (p = 0.01).

CONCLUSION

BF without formula supplementation for at least 6 months was associated with higher adolescent BMD z-score and a suggestive trend in the same direction for BMD suggests that exclusivity and duration of BF may play a role in adolescent bone health.

Snacking Quality Is Associated with Secondary School Academic Achievement and the Intention to Enroll in Higher Education: A Cross-Sectional Study in Adolescents from Santiago, Chile

Although numerous studies have approached the effects of exposure to a Western diet (WD) on academic outcomes, very few have focused on foods consumed during snack times. We explored whether there is a link between nutritious snacking habits and academic achievement in high school (HS) students from Santiago, Chile. We conducted a cross-sectional study with 678 adolescents. The nutritional quality of snacks consumed by 16-year-old was assessed using a validated food frequency questionnaire. The academic outcomes measured were HS grade point average (GPA), the likelihood of HS completion, and the likelihood of taking college entrance exams. A multivariate analysis was performed to determine the independent associations of nutritious snacking with having completed HS and having taken college entrance exams. An analysis of covariance (ANCOVA) estimated the differences in GPA by the quality of snacks. Compared to students with healthy in-home snacking behaviors, adolescents having unhealthy in-home snacks had significantly lower GPAs (M difference: -40.1 points, 95% confidence interval (CI): -59.2, -16.9, d = 0.41), significantly lower odds of HS completion (adjusted odds ratio (aOR): 0.47; 95% CI: 0.25-0.88), and significantly lower odds of taking college entrance exams (aOR: 0.53; 95% CI: 0.31-0.88). Unhealthy at-school snacking showed similar associations with the outcome variables. Poor nutritional quality snacking at school and at home was associated with poor secondary school academic achievement and the intention to enroll in higher education.

Weight Status and Physical Activity: Combined Influence on Cardiometabolic Risk Factors Among Adolescents, Santiago, Chile

We tested the independent and combined influence of overweight/obesity and meeting moderate to vigorous physical activity (MVPA) guidelines (≥60 minutes per day) on cardiometabolic risk factors among healthy adolescents. We measured anthropometry, blood pressure, fasting lipids, and activity by accelerometer in 223 adolescents. They were categorized as overweight/obese versus normal weight and meeting the World Health Organization guidelines for MVPA per day. Adolescents were 16.8 years, 41% overweight/obese, 30% met MVPA guidelines, 50% low high-density lipoprotein, 22% high triglycerides, 12% high blood pressure, and 6% high fasting glucose. Controlling for sex, overweight/obese adolescents who did not meet MVPA guidelines had 4.0 and 11.9 increased odds for elevated triglycerides and systolic blood pressure, respectively, compared to normal weight adolescents who met MVPA guidelines. Overweight/obese and normal weight adolescents who met MVPA guidelines did not differ in cardiometabolic risk factors. Among overweight/obese adolescents, being physically active attenuated the likelihood of high triglycerides and systolic blood pressure.

Leptin status in adolescence is associated with academic performance in high school: a cross-sectional study in a Chilean birth cohort

OBJECTIVE

Leptin is a pleiotropic hormone associated with learning and memory via brain receptors. However, elevated plasma leptin levels may impair cognitive and memory functions. Since individual differences in memory performance affect students' ability to learn, we aimed to study the relation between leptin status in adolescence and school performance.

DESIGN AND SETTING

We studied 568 adolescents aged 16-17 years from Santiago. A cross-sectional analysis was carried out on a birth cohort conducted in Santiago (Chile).

PRIMARY AND SECONDARY OUTCOME MEASURES

We measured serum leptin concentration using an enzyme-linked immunosorbent assay. Cut-offs from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study for 16-year-olds were used to define abnormally high leptin levels (hyperleptinaemia). Academic performance was measured using high-school grades and grade point average (GPA). Data were collected in 2009-2012; data analysis was performed in 2014.

RESULTS

15% of participants had hyperleptinaemia. They had significantly lower school grades and GPA compared with participants with normal leptin levels (eg, GPA mean difference=33.8 points). Leptin levels were negative and significantly correlated with school grades in 9th, 10th and 12th. Similarly, it was negatively correlated with high-school GPA. After controlling for health, sociodemographic and education confounders, the chances of having a performance ≥75th centile in students having hyperleptinaemia were 32% (95% CI 0.19% to 0.89%) that of students having normal serum leptin concentration.

CONCLUSIONS

In high school students, abnormally high levels of leptin were associated with poorer academic performance. These findings support the idea of a relationship between leptin and cognition. Further research is needed on the cognitive effects of leptin in younger populations.

Nutritional quality of diet and academic performance in Chilean students

Objective

To explore associations between the nutritional quality of diet at age 16 years and academic performance in students from Santiago, Chile.

Methods

We assessed the nutritional quality of diet, using a validated food frequency questionnaire, in 395 students aged 16.8 ± 0.5 years. Depending on the amount of saturated fat, fibre, sugar and salt in the foods, diet was categorized as unhealthy, fair or healthy. Academic performance was assessed using high school grade-point average (GPA) and tests for college admission in language and mathematics. Academic results on or above the 75th percentile in our sample were considered good academic performance. We tested associations between nutritional quality of diet and good academic performance using logistic regression models. We considered sociodemographic, educational and body-mass index (BMI) factors as potential confounders.

Findings

After controlling for potential confounding factors, an unhealthy diet at age 16 years was associated with reduced academic performance. Compared to participants with healthy diets, those with unhealthy diets were significantly less likely to perform well based on language tests (odds ratio, OR: 0.42; 95% confidence interval, CI: 0.18–0.98) mathematics tests (OR: 0.35; 95% CI: 0.15–0.82) or GPA (OR: 0.22; 95% CI: 0.09–0.56).

Conclusion

In our sample, excessive consumption of energy-dense, low-fibre, high-fat foods at age 16 years was associated with reduced academic performance.

Obesity is associated with acute inflammation in a sample of adolescents

BACKGROUND

Obesity is associated with a mild chronic inflammatory response, which has been suggested to be pivotal in the development of cardiometabolic alterations of obesity. However, little is known about the involvement of acute inflammation.

OBJECTIVE

To evaluate whether circulating neutrophils, markers of acute inflammation, are associated (quantitatively and qualitatively) with adolescent obesity and whether leptin modulates these associations.

SUBJECTS AND METHODS

We assessed 528 adolescents (16.8 yr old, 47% females), without chronic/acute illness. We measured anthropometry and dual energy X-ray absorptiometry and calculated fat mass percentage (FM%). Fasting serum glucose, high-density lipoprotein (HDL)-cholesterol, and triglycerides were used with blood pressure and waist circumference to compute a metabolic z-score. Leukocyte and neutrophil counts were obtained, together with levels of serum leptin. In a subsample of 23 males, flow cytometry was used to assess degranulation (CD66b expression) of neutrophils.

RESULTS

Female sex and obesity were positively related to mean neutrophil counts (p < 0.05). When accounting for sex and weight status, leptin was associated with neutrophil counts (p < 0.05), partially explaining the association between obesity and neutrophil counts. Neutrophil counts were related to metabolic risk z-scores, controlling for fat mass. Participants with elevated FM% showed more neutrophil degranulation than controls (p < 0.05).

CONCLUSIONS

Participants with increased adiposity had higher circulating neutrophil counts, suggesting acute inflammation. Furthermore, the neutrophils showed more degranulation, indicating inflammation. Obesity-induced alteration of the adipose secretory pattern (i.e., changes in leptin levels) could be involved in acute inflammation.