Insulin resistance is higher in prepubertal girls but switches to become higher in boys at age 16: A Cohort Study (EarlyBird 57).

Background: The risk of type 2 diabetes is increasing in teenage girls, and is associated with their greater insulin resistance (IR).

Hypothesis: We hypothesized that the adverse metabolic profile of girls (compared with boys) would persist from childhood through adolescence.

Patients And Methods: Community-based longitudinal cohort of 292 children (147 boys) studied annually from 9 to 16 years.

Physical activity attenuates the mid-adolescent peak in insulin resistance but by late adolescence the effect is lost: a longitudinal study with annual measures from 9-16 years (EarlyBird 66).

Aims/hypothesis: The aim of this work was to test whether the mid-adolescent peak in insulin resistance (IR) and trends in other metabolic markers are influenced by long-term exposure to physical activity.

Methods: Physical activity (7 day ActiGraph accelerometry), HOMA-IR and other metabolic markers (glucose, fasting insulin, HbA1c, lipids and BP) were measured annually from age 9 years to 16 years in 300 children (151 boys) from the EarlyBird study in Plymouth, UK. The activity level of each child was characterised, with 95% reliability, by averaging their eight annual physical activity measures.

Anti-Müllerian hormone in children: a ten-year prospective longitudinal study (EarlyBird 39).

Background: Anti-Müllerian hormone (AMH) is produced by Sertoli cells of the testes and granulosa cells of the ovary. There are limited prospective longitudinal data assessing AMH concentrations throughout childhood in both sexes.

Objective: This study aimed to examine AMH throughout childhood with particular reference to the relationship of AMH to pubertal development in both sexes.

Exploring the Adolescent Fall in Physical Activity: A 10-yr Cohort Study (EarlyBird 41).

Introduction: Contemporary adolescents are deemed inactive, especially girls, but whether for biological reasons associated with their maturation, changes in their behavior or because of environmental constraints, is uncertain. We examined the trends in physical activity (PA) in relation to both biological and environmental factors in an attempt to establish what drives activity patterns from childhood through adolescence.

Methods: Physical activity (7-d Actigraph accelerometry) was measured annually from 5 to 15 yr in a single cohort of some 300 UK children.

Divergence between HbA1c and fasting glucose through childhood: implications for diagnosis of impaired fasting glucose (Early Bird 52).

Objective: An HbA1c threshold of ≥ 6.5% has recently been adopted for the diagnosis of diabetes in adults, and of ≥ 5.7% to identify adults at risk.

Metabolic risk in contemporary children is unrelated to socio-economic status: longitudinal study of a UK urban population (EarlyBird 42).

Lifestyle interventions to improve health in young children tend to target areas of relative deprivation, but the evidence for so doing is largely historical. Accordingly, we have re-examined the link between deprivation, obesity and metabolic risk in contemporary UK children. Using a postcode-based index of multiple deprivation (IMD), we assessed 269 children from the community-based EarlyBird Study, attending 53 schools representing a wide socio-economic range.

PGC1α promoter methylation in blood at 5-7 years predicts adiposity from 9 to 14 years (EarlyBird 50).

The early environment, acting via epigenetic processes, is associated with differential risk of cardiometabolic disease (CMD), which can be predicted by epigenetic marks in proxy tissues. However, such measurements at time points disparate from the health outcome or the environmental exposure may be confounded by intervening stochastic and environmental variation. To address this, we analyzed DNA methylation in the peroxisome proliferator-activated receptor γ coactivator 1α promoter in blood from 40 children (20 boys) collected annually between 5 and 14 years of age by pyrosequencing.

A biological, latent variable model of health (EarlyBird 68).

Objective: To determine whether factor analysis of a set of health-related biomarkers provides evidence of an underlying common dimension of variation, and to explore the relationship between this dimension of variation with positive and negative affect.

Method: Twelve health-related metabolic, immune and body-composition biomarkers at ages 5, 7, 9, 11, 14 and 16years were obtained from the EarlyBird longitudinal cohort of 347 children and supplemented by positive affect (PA) and negative affect (NA) measured at age 16years.

Results: At each age, principal factor analysis revealed that nine of the 12 biomarkers consistently loaded on the first extracted factor, accounting for 25% of the variance at age 5, and 37-44% of the variance at 7-16years.

Mood and its association with metabolic health in adolescents: a longitudinal study, EarlyBird 65.

Background: Mood comprises two main traits - positive and negative affect, both associated with depression and anxiety. Studies in children have linked depression with obesity, but the association with metabolic health is unclear.

Objective: To explore the relationship between mood and metabolic health in adolescents.

Is autoimmunity or insulin resistance the primary driver of type 1 diabetes?

Diabetes is usually classified as autoimmune or metabolic but, as difficulties have arisen with the taxonomy of diabetes, it may help to forego the conventional classification for a more inclusive model. Thus, all diabetes can be ascribed to beta cell insufficiency-hyperglycemia occurs only when the insulin supply fails to meet demand. Humans enter the world with a reserve of beta cells, which is eroded variably by apoptosis over the course of a lifetime.

Evidence of early beta-cell deficiency among children who show impaired fasting glucose: 10-yr cohort study (EarlyBird 56).

Objective: Impaired fasting glucose (IFG) is a predictor of future diabetes and is increasingly common in children, but the extent to which it results from excess insulin demand or failure of supply is unclear. Our aim was to compare the behaviour of insulin sensitivity and beta-cell function in children who developed IFG with those whose glucose levels remained within the normal range.

Methods: We examined trends in fasting glucose, insulin sensitivity (HOMA-S) and beta-cell function (HOMA-B) in 327 healthy children annually from 5 to 15 yr, and the parents at baseline.

Age before stage: insulin resistance rises before the onset of puberty: a 9-year longitudinal study (EarlyBird 26).

Objective: Insulin resistance (IR) is associated with diabetes. IR is higher during puberty in both sexes, with some studies showing the increase to be independent of changes in adiposity. Few longitudinal studies have reported on children, and it remains unclear when the rise in IR that is often attributed to puberty really begins.

Direction of causality between body fat and insulin resistance in children--a longitudinal study (EarlyBird 51).

Objective: To investigate the direction of causality in the association between adiposity and insulin resistance in children.

Methods: Body composition by DEXA, and insulin resistance by HOMA-2 IR were measured annually in 238 children aged from 7-13 years. Longitudinal modelling was used to establish whether baseline and/or trends in adiposity were associated with change in IR or whether, conversely, baseline and/or trends in IR were associated with change in adiposity.

Consistency of children's dietary choices: annual repeat measures from 5 to 13 years (EarlyBird 49).

The objective of the present study was to explore the consistency of dietary choices made by children as they grow up. The dietary habits of 342 healthy children were reported annually from 5 to 13 years on a forty-five-item FFQ and analysed by factor analysis. The same two principal dietary patterns--'Healthy' and 'Unhealthy'--emerged each year, and their consistency was assessed using Tucker's congruence coefficient (φ).

The relationship of height and body fat to gender-assortative weight gain in children. A longitudinal cohort study (EarlyBird 44).

Objective: Height, body fat and body mass index (BMI) are correlated in children, so we hypothesized that the gender-assortative associations in BMI recently reported in contemporary children might extend to their height and body fat.

Design: Prospective longitudinal cohort study.

Subjects: A total of 226 healthy trios (mother, father and child) from a 1995?1996 birth cohort randomly recruited in the city of Plymouth, UK.

Little impact of resting energy expenditure on childhood weight and body composition: a longitudinal study (EarlyBird 47).

The role of resting energy expenditure (REE) in the development of obesity in children is controversial. Our aim was to test the hypothesis that REE has a meaningful impact on change in weight or body composition in healthy children. Resting energy expenditure by indirect calorimetry and body composition by dual-energy x-ray absorptiometry were measured in 236 children (131 boys) on 7 annual occasions (7-13 years).

Changes in resting energy expenditure and their relationship to insulin resistance and weight gain: a longitudinal study in pre-pubertal children (EarlyBird 17).

Background & Aims: In adults, adjustments in resting energy expenditure (REE) are used to defend energy balance against disturbance caused by over-and under-nutrition, and may be linked to changes in insulin resistance and leptin. Little is known of these associations in children. Our aim was to test the hypothesis that long-term weight gain in children is met with adaptive changes in resting energy expenditure, mediated by insulin resistance and/or leptin.

Chronic fatigue: is it endocrinology?

Fatigue and stress-related illnesses often become diagnoses of exclusion after extensive investigation. 'Tired all the time' is a frequent reason for referral to the endocrine clinic, the implicit question being--is there a subtle endocrine pathology contributing to the patient's symptoms? Often initial assessment suggests not but there are no clear data to address the question of whether overt pathology will develop in the future. This study observed outcomes after five years in 101 consecutive and unselected referrals to secondary care for 'fatigue?cause', where initial assessment did not suggest treatable endocrine pathology.

Contribution of early weight gain to childhood overweight and metabolic health: a longitudinal study (EarlyBird 36).

Background: Early weight gain (0-5 years) is thought to be an important contributor to childhood obesity and consequently metabolic risk. There is a scarcity of longitudinal studies in contemporary children reporting the impact of early weight gain on metabolic health.

Objective: We aimed to assess the impact of early weight gain on metabolic health at 9 years of age.

Adiponectin in childhood.

Adiponectin, a hormone produced and secreted by adipocytes, is present in circulation in high circulating concentrations, suggesting an important physiological role. An indirect regulator of glucose metabolism, adiponectin increases insulin sensitivity, improves glucose tolerance and inhibits inflammation. Plasma adiponectin relates inversely to adiposity and, importantly, reflects the sequelae of accumulation of excess adiposity.

Objectively measured physical activity and its association with adiponectin and other novel metabolic markers: a longitudinal study in children (EarlyBird 38).

Objective: Recent evidence suggests that, in children, traditional markers of metabolic disturbance are related only weakly to physical activity. We therefore sought to establish the corresponding relationships with newer metabolic markers.

Research Design And Methods: This was a nonintervention longitudinal study of 213 healthy children recruited from 54 schools in Plymouth, U.

Diabetes: 1 and 2, or one and the same? Progress with the accelerator hypothesis.

The accelerator hypothesis was published in 2001, and proposes that that type 1 and type 2 diabetes are the same disorder of insulin resistance set against different genetic backgrounds. The different genes modulate (variably accelerate) the tempo of beta cell loss and thereby determine the age at onset and incidence of the disease. Some of the predictions made by the hypothesis have been met by data not available when the hypothesis was first proposed.

Distribution of adiponectin, leptin, and metabolic correlates of insulin resistance: a longitudinal study in British children; 1: Prepuberty (EarlyBird 15).

Background: The emergence of type 2 diabetes in young populations has mirrored a rising prevalence of obesity and insulin resistance during childhood and adolescence. At the same time, the role of adipokines as links between obesity and insulin resistance is becoming more appreciated. We sought to establish age- and sex-specific distributions of metabolic correlates of insulin resistance in healthy prepubertal children.