Early infant growth is associated with the risk of islet autoimmunity in genetically susceptible children

Early-childhood body mass index and its association with the COVID-19 pandemic, containment measures and islet autoimmunity in children with increased risk for type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to determine whether BMI in early childhood was affected by the COVID-19 pandemic and containment measures, and whether it was associated with the risk for islet autoimmunity.

METHODS

Between February 2018 and May 2023, data on BMI and islet autoimmunity were collected from 1050 children enrolled in the Primary Oral Insulin Trial, aged from 4.0 months to 5.5 years of age. The start of the COVID-19 pandemic was defined as 18 March 2020, and a stringency index was used to assess the stringency of containment measures. Islet autoimmunity was defined as either the development of persistent confirmed multiple islet autoantibodies, or the development of one or more islet autoantibodies and type 1 diabetes. Multivariate linear mixed-effect, linear and logistic regression methods were applied to assess the effect of the COVID-19 pandemic and the stringency index on early-childhood BMI measurements (BMI as a time-varying variable, BMI at 9 months of age and overweight risk at 9 months of age), and Cox proportional hazard models were used to assess the effect of BMI measurements on islet autoimmunity risk.

RESULTS

The COVID-19 pandemic was associated with increased time-varying BMI (β = 0.39; 95% CI 0.30, 0.47) and overweight risk at 9 months (β = 0.44; 95% CI 0.03, 0.84). During the COVID-19 pandemic, a higher stringency index was positively associated with time-varying BMI (β = 0.02; 95% CI 0.00, 0.04 per 10 units increase), BMI at 9 months (β = 0.13; 95% CI 0.01, 0.25) and overweight risk at 9 months (β = 0.23; 95% CI 0.03, 0.43). A higher age-corrected BMI and overweight risk at 9 months were associated with increased risk for developing islet autoimmunity up to 5.5 years of age (HR 1.16; 95% CI 1.01, 1.32 and HR 1.68, 95% CI 1.00, 2.82, respectively).

CONCLUSIONS/INTERPRETATION

Early-childhood BMI increased during the COVID-19 pandemic, and was influenced by the level of restrictions during the pandemic. Controlling for the COVID-19 pandemic, elevated BMI during early childhood was associated with increased risk for childhood islet autoimmunity in children with genetic susceptibility to type 1 diabetes.

Low-Protein Infant Formula Enriched with Alpha-Lactalbumin during Early Infancy May Reduce Insulin Resistance at 12 Months: A Follow-Up of a Randomized Controlled Trial

High protein intake during infancy results in accelerated early weight gain and potentially later obesity. The aim of this follow-up study at 12 months was to evaluate if modified low-protein formulas fed during early infancy have long-term effects on growth and metabolism. In a double-blinded RCT, the ALFoNS study, 245 healthy-term infants received low-protein formulas with either alpha-lactalbumin-enriched whey (α-lac-EW; 1.75 g protein/100 kcal), casein glycomacropeptide-reduced whey (CGMP-RW; 1.76 g protein/100 kcal), or standard infant formula (SF; 2.2 g protein/100 kcal) between 2 and 6 months of age. Breastfed (BF) infants served as a reference. At 12 months, anthropometrics and dietary intake were assessed, and serum was analyzed for insulin, C-peptide, and insulin-like growth factor 1 (IGF-1). Weight gain between 6 and 12 months and BMI at 12 months were higher in the SF than in the BF infants (p = 0.019; p < 0.001, respectively), but were not significantly different between the low-protein formula groups and the BF group. S-insulin and C-peptide were higher in the SF than in the BF group (p < 0.001; p = 0.003, respectively), but more alike in the low-protein formula groups and the BF group. Serum IGF-1 at 12 months was similar in all study groups. Conclusion: Feeding modified low-protein formula during early infancy seems to reduce insulin resistance, resulting in more similar growth, serum insulin, and C-peptide concentrations to BF infants at 6-months post intervention. Feeding modified low-protein formula during early infancy results in more similar growth, serum insulin, and C-peptide concentrations to BF infants 6-months post intervention, probably due to reduced insulin resistance in the low-protein groups.

Effects of Type 1 Diabetes Mellitus on Linear Growth: A Comprehensive Review

Type 1 diabetes mellitus (T1DM) has a significant effect on the growth of children. The disease has a negative effect on growth when considered in relation to the time period and metabolic control. Studies in this review have suggested debilitated growth in children with T1DM and have a few anomalies in the growth hormone (GH)-insulin-like growth factor-1 (IGF-1) axis when compared to fit children. Some studies show that children with T1DM were taller before the onset of the disease and during early diagnosis. Moreover, the linear growth depends on the interaction between the gonadotropin hormone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and sex steroid hormones axis and GH-IGF-1; there's a rise in GH during puberty, which has an effect on the estrogen and testosterone, which leads to the pulsatile secretion of GH, this increment leads to insulin resistance. These studies suggest short stature in girls, and some suggest in both. The final height in boys was unchanged, but a slight decline was observed in girls. This review aims to provide the latest understanding of impaired height in children with T1DM. The most accepted and effective treatment of impaired growth is the administration of long-acting insulin or continuous rapid-acting insulin. However, height was affected by the administration of good basal insulin at puberty and was unaffected by the continuous subcutaneous insulin injection. Hence, new technologies are the therapeutic regimen in children, especially the prepubertal age group; it will be interesting to see their effects on growth patterns in these children with T1DM.

Dietary Intake and Body Mass Index Influence the Risk of Islet Autoimmunity in Genetically At-Risk Children: A Mediation Analysis Using the TEDDY Cohort

Background/Objective

Growth and obesity have been associated with increased risk of islet autoimmunity (IA) and progression to type 1 diabetes. We aimed to estimate the effect of energy-yielding macronutrient intake on the development of IA through BMI.

Research Design and Methods

Genetically at-risk children (n = 5,084) in Finland, Germany, Sweden, and the USA, who were autoantibody negative at 2 years of age, were followed to the age of 8 years, with anthropometric measurements and 3-day food records collected biannually. Of these, 495 (9.7%) children developed IA. Mediation analysis for time-varying covariates (BMI z-score) and exposure (energy intake) was conducted. Cox proportional hazard method was used in sensitivity analysis.

Results

We found an indirect effect of total energy intake (estimates: indirect effect 0.13 [0.05, 0.21]) and energy from protein (estimates: indirect effect 0.06 [0.02, 0.11]), fat (estimates: indirect effect 0.03 [0.01, 0.05]), and carbohydrates (estimates: indirect effect 0.02 [0.00, 0.04]) (kcal/day) on the development of IA. A direct effect was found for protein, expressed both as kcal/day (estimates: direct effect 1.09 [0.35, 1.56]) and energy percentage (estimates: direct effect 72.8 [3.0, 98.0]) and the development of GAD autoantibodies (GADA). In the sensitivity analysis, energy from protein (kcal/day) was associated with increased risk for GADA, hazard ratio 1.24 (95% CI: 1.09, 1.53), p = 0.042.

Conclusions

This study confirms that higher total energy intake is associated with higher BMI, which leads to higher risk of the development of IA. A diet with larger proportion of energy from protein has a direct effect on the development of GADA.

Effects of vitamin D supplementation on glycemic control of children and adolescents with type 1 diabetes mellitus: a systematic review

OBJECTIVES

To evaluate the effect of vitamin D supplementation on glycemic control in children and adolescents with T1DM.

CONTENT

A systematic search was conducted of the Medline/PubMed, Web of Science, Embase, BVS/Lilacs, Cochrane Library, Scopus, Cinahl, Food Science, and FSTA databases. Two reviewers independently extracted article data and assessed quality.

SUMMARY

A total of 1,613 eligible articles were retrieved, ten of which met the selection criteria: eight clinical trials, one retrospective cohort study, and one cross-sectional study. Regarding the cutoff points used to classify vitamin D status, most of the studies set deficiency at 25-hydroxyvitamin D <20 ng/mL, sufficiency at ≥30 ng/mL, and insufficiency as the interval between these values. Regarding intervention strategies, most used cholecalciferol for supplementation, but there was great variation in the dose and supplementation time. When evaluating the effect of vitamin D supplementation on HbA1c, a significant improvement in glycemic control was observed in 50% of the studies. However, only one of these studies was classified as being of positive methodological quality, with three having their quality classified as neutral and one as negative.

OUTLOOK

There is yet no consistent evidence on the effect of vitamin D supplementation on glycemic control as an adjuvant in the treatment of children and adolescents with T1DM.

Childhood Height Growth Rate Association With the Risk of Islet Autoimmunity and Development of Type 1 Diabetes

CONTEXT

Rapid growth has been suggested to promote islet autoimmunity and progression to type 1 diabetes (T1D). Childhood growth has not been analyzed separately from the infant growth period in most previous studies, but it may have distinct features due to differences between the stages of development.

OBJECTIVE

We aimed to analyze the association of childhood growth with development of islet autoimmunity and progression to T1D diagnosis in children 1 to 8 years of age.

METHODS

Longitudinal data of childhood growth and development of islet autoimmunity and T1D were analyzed in a prospective cohort study including 10 145 children from Finland, Germany, Sweden, and the United States, 1-8 years of age with at least 3 height and weight measurements and at least 1 measurement of islet autoantibodies. The primary outcome was the appearance of islet autoimmunity and progression from islet autoimmunity to T1D.

RESULTS

Rapid increase in height (cm/year) was associated with increased risk of seroconversion to glutamic acid decarboxylase autoantibody, insulin autoantibody, or insulinoma-like antigen-2 autoantibody (hazard ratio [HR] = 1.26 [95% CI = 1.05, 1.51] for 1-3 years of age and HR = 1.48 [95% CI = 1.28, 1.73] for >3 years of age). Furthermore, height rate was positively associated with development of T1D (HR = 1.80 [95% CI = 1.15, 2.81]) in the analyses from seroconversion with insulin autoantibody to diabetes.

CONCLUSION

Rapid height growth rate in childhood is associated with increased risk of islet autoimmunity and progression to T1D. Further work is needed to investigate the biological mechanism that may explain this association.

Growth and development in type 1 diabetes

PURPOSE OF REVIEW

The purpose of this review is to summarize the current literature on the subject of linear growth in children and adolescents with or at risk for type 1 diabetes mellitus (T1DM).

RECENT FINDINGS

Poor glycemic control in T1DM is associated with growth hormone resistance, and improving glycemic control can improve linear growth. Newer reports suggest that the increasingly popular very low carbohydrate diets, may reduce linear growth velocity.

SUMMARY

Linear growth during childhood is a complex process regulated influenced by genetic, hormonal, nutritional and environmental factors. Linear growth may be impaired in children with T1DM, correlating with poor metabolic control; an extreme example is Mauriac syndrome. This decrement in linear growth appears to be driven in part by a reduction in growth hormone responsiveness, leading to low insulin-like growth factor-1 (IGF-1) levels. Improving glycemic control can lead to improved IGF-1 levels and linear growth. Other factors associated with poor linear growth in T1DM include celiac disease and dietary alterations, with early reports suggesting that very low carbohydrate diets, if not carefully managed, may increase risk of attenuated linear growth. This review examines the latest data regarding the associations between T1DM and linear growth in children.

Growth and development of islet autoimmunity and type 1 diabetes in children genetically at risk

AIMS/HYPOTHESIS

We aimed to evaluate the relationship between childhood growth measures and risk of developing islet autoimmunity (IA) and type 1 diabetes in children with an affected first-degree relative and increased HLA-conferred risk. We hypothesised that being overweight or obese during childhood is associated with a greater risk of IA and type 1 diabetes.

METHODS

Participants in a randomised infant feeding trial (N = 2149) were measured at 12 month intervals for weight and length/height and followed for IA (at least one positive out of insulin autoantibodies, islet antigen-2 autoantibody, GAD autoantibody and zinc transporter 8 autoantibody) and development of type 1 diabetes from birth to 10-14 years. In this secondary analysis, Cox proportional hazard regression models were adjusted for birthweight and length z score, sex, HLA risk, maternal type 1 diabetes, mode of delivery and breastfeeding duration, and stratified by residence region (Australia, Canada, Northern Europe, Southern Europe, Central Europe and the USA). Longitudinal exposures were studied both by time-varying Cox proportional hazard regression and by joint modelling. Multiple testing was considered using family-wise error rate at 0.05.

RESULTS

In the Trial to Reduce IDDM in the Genetically at Risk (TRIGR) population, 305 (14.2%) developed IA and 172 (8%) developed type 1 diabetes. The proportions of children overweight (including obese) and obese only were 28% and 9% at 10 years, respectively. Annual growth measures were not associated with IA, but being overweight at 2-10 years of life was associated with a twofold increase in the development of type 1 diabetes (HR 2.39; 95% CI 1.46, 3.92; p < 0.001 in time-varying Cox regression), and similarly with joint modelling.

CONCLUSIONS/INTERPRETATION

In children at genetic risk of type 1 diabetes, being overweight at 2-10 years of age is associated with increased risk of progression from multiple IA to type 1 diabetes and with development of type 1 diabetes, but not with development of IA. Future studies should assess the impact of weight management strategies on these outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00179777.

Nutrition and Obesity in the Pathogenesis of Youth-Onset Type 1 Diabetes and Its Complications

Since the 1980s, there has been a dramatic rise in the prevalence of overweight and obesity in pediatric populations, in large part driven by sedentary lifestyles and changing dietary patterns with more processed foods. In parallel with the rise in pediatric obesity in the general population, the prevalence of overweight and obesity has increased among children and adolescents with type 1 diabetes. Adiposity has been implicated in a variety of mechanisms both potentiating the risk for type 1 diabetes as well as exacerbating long-term complications, particularly cardiovascular disease. Treatment options targeting the unique needs of obese pediatric patients, both before and after diagnosis of type 1 diabetes, are limited. In this review, we discuss the history of the epidemiology of the obesity epidemic in the context of pediatric type 1 diabetes, highlight the possible role of obesity in type 1 diabetes pathogenesis and review the concept of "double diabetes". The impact of obesity at and after diagnosis will be discussed, including noted differences in clinical and biochemical markers, lipid abnormalities, and long-term cardiovascular complications. Finally, we will review the existing literature on pharmacologic and nutritional interventions as potential treatment strategies for youth with coexisting type 1 diabetes and obesity.

Distinct Growth Phases in Early Life Associated With the Risk of Type 1 Diabetes: The TEDDY Study

OBJECTIVE

This study investigates two-phase growth patterns in early life and their association with development of islet autoimmunity (IA) and type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

The Environmental Determinants of Diabetes in the Young (TEDDY) study followed 7,522 genetically high-risk children in Sweden, Finland, Germany, and the U.S. from birth for a median of 9.0 years (interquartile range 5.7-10.6) with available growth data. Of these, 761 (10.1%) children developed IA and 290 (3.9%) children were diagnosed with T1D. Bayesian two-phase piecewise linear mixed models with a random change point were used to estimate children's individual growth trajectories. Cox proportional hazards models were used to assess the effects of associated growth parameters on the risks of IA and progression to T1D.

RESULTS

A higher rate of weight gain in infancy was associated with increased IA risk (hazard ratio [HR] 1.09 [95% CI 1.02, 1.17] per 1 kg/year). A height growth pattern with a lower rate in infancy (HR 0.79 [95% CI 0.70, 0.90] per 1 cm/year), higher rate in early childhood (HR 1.48 [95% CI 1.22, 1.79] per 1 cm/year), and younger age at the phase transition (HR 0.76 [95% CI 0.58, 0.99] per 1 month) was associated with increased risk of progression from IA to T1D. A higher rate of weight gain in early childhood was associated with increased risk of progression from IA to T1D (HR 2.57 [95% CI 1.34, 4.91] per 1 kg/year) in children with first-appearing GAD autoantibody only.

CONCLUSIONS

Growth patterns in early life better clarify how specific growth phases are associated with the development of T1D.

Linear Growth in Children and Adolescents with Type 1 Diabetes Mellitus

Ensuring normal linear growth is one of the major therapeutic aims in the management of type one diabetes mellitus (T1DM) in children and adolescents. Many studies in the literature have shown that pediatric patients with T1DM frequently present some abnormalities in their growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis compared to their healthy peers. Data on the growth of T1DM children and adolescents are still discordant: Some studies have reported that T1DM populations, especially those whose diabetes began in early childhood, are taller than healthy pediatric populations at diagnosis, while other studies have not found any difference. Moreover, many reports have highlighted a growth impairment in T1DM patients of prepubertal and pubertal age, and this impairment seems to be influenced by suboptimal glycemic control and disease duration. However, the most recent data showed that children treated with modern intensive insulin therapies reach a normal final adult height. This narrative review aims to provide current knowledge regarding linear growth in children and adolescents with T1DM. Currently, the choice of the most appropriate therapeutic regimen to achieve a good insulin level and the best metabolic control for each patient, together with the regular measurement of growth parameters, remains the most important available tool for a pediatric diabetologist. Nevertheless, since new technologies are the therapy of choice in young children, especially those of pre-school age, it would be of great interest to evaluate their effects on the growth pattern of children with T1DM.

Could the high consumption of high glycaemic index carbohydrates and sugars, associated with the nutritional transition to the Western type of diet, be the common cause of the obesity epidemic and the worldwide increasing incidences of Type 1 and Type 2 diabetes?

The globally increasing incidences of Type 1 diabetes (T1DM) and Type 2 diabetes (T2DM) can have a common background. If challenged by the contemporary high level of nutritional glucose stimulation, the β-cells in genetically predisposed individuals are at risk for damage which can lead to the diseases. The fat to carbohydrate dietary shift can also contribute to the associated obesity epidemic.

Associations of maternal type 1 diabetes with childhood adiposity and metabolic health in the offspring: a prospective cohort study

AIMS/HYPOTHESIS

Exposure to an intrauterine hyperglycaemic environment has been suggested to increase the offspring's later risk for being overweight or having metabolic abnormalities, but conclusive evidence for pregnancies affected by maternal type 1 diabetes is still lacking. This study aims to analyse the relationship between maternal type 1 diabetes and the offspring's metabolic health and investigate whether birthweight and/or changes in the offspring's metabolome are in the potential pathway.

METHODS

We analysed data from 610 and 2169 offspring having a first-degree relative with type 1 diabetes from the TEENDIAB and BABYDIAB/BABYDIET cohorts, respectively. Anthropometric and metabolic outcomes, assessed longitudinally at 0.3-18 years of age, were compared between offspring of mothers with type 1 diabetes and offspring of non-diabetic mothers but with fathers or siblings with type 1 diabetes using mixed regression models. Non-targeted metabolomic measurements were carried out in 500 individuals from TEENDIAB and analysed with maternal type 1 diabetes and offspring overweight status.

RESULTS

The offspring of mothers with type 1 diabetes had a higher BMI SD score (SDS) and an increased risk for being overweight than the offspring of non-diabetic mothers (e.g. OR for overweight status in TEENDIAB 2.40 [95% CI 1.41, 4.06]). Further, waist circumference SDS, fasting levels of glucose, insulin and C-peptide, and insulin resistance and abdominal obesity were significantly increased in the offspring of mothers with type 1 diabetes, even when adjusted for potential confounders and birthweight. Metabolite patterns related to androgenic steroids and branched-chain amino acids were found to be associated with offspring's overweight status, but no significant associations were observed between maternal type 1 diabetes and metabolite concentrations in the offspring.

CONCLUSIONS/INTERPRETATION

Maternal type 1 diabetes is associated with offspring's overweight status and metabolic health in later life, but this is unlikely to be caused by alterations in the offspring's metabolome.

Undernutrition in childhood resulted in bad dietary behaviors and the increased risk of hypertension in a middle-aged Chinese population

This study was designed to explore the association between undernutrition in the growth period and cardiovascular risk factors in a middle-aged Chinese population. A total of 1756 subjects, aged 45-60 years, were invited to participate in the Hefei Nutrition and Health Study and divided into three groups according to their self-reported animal food intake in the growth period. Group 1, Group 2 and Group 3 were defined as undernutrition, nutritional improvement and the good nutrition group, respectively. In the three groups, the subjects in Groups 1 and 2 had more oil and salt intake (P<0.001), and less eggs and milk intake (P<0.001), when compared with the subjects in Group 3. After adjusting for age, education, smoking status and other confounding factors, it was found that male participants who experienced nutritional improvement before age 18 had higher risk of hypertension [odds ratio (OR)=1.68; 95% confidence intervals (CI): 1.05, 2.69] than those with good nutrition, and female participants with undernutrition (OR=1.52; 95% CI: 1.01, 2.29) and nutritional improvement (OR=1.68; 95% CI: 1.04, 2.69) before age 18 had a higher risk of hypertension than those with good nutrition. For diabetes, obesity, hypercholesterolemia and hypertriglyceridemia, our results did not found difference among the three groups both in male and female. Our findings indicated that nutritional deficiency in childhood was associated with bad dietary behaviors and a significantly increased risk of hypertension in middle age. Therefore, early adequate nutrition is very important for the prevention of non-communicable diseases later.

Associations of growth patterns and islet autoimmunity in children with increased risk for type 1 diabetes: a functional analysis approach

BACKGROUND

Several studies indicate associations between early growth and type 1 diabetes (T1D). However, it remains an open question whether these findings can be translated to typical growth patterns associated with increased risk for T1D-associated islet autoimmunity.

METHODS

We analyzed pooled data from 2236 children followed up in two large prospective German birth cohorts with a genetically increased risk for T1D including 18 564 measurements of height and weight, which were transformed to sex- and age-specific standard deviation scores (SDS). A total of 191 children developed any islet autoantibodies, 101 multiple islet autoantibodies. We applied a model-based clustering technique to derive typical height and body mass index (BMI) growth patterns, stratified for maternal T1D status. These patterns were used to predict islet autoimmunity in logistic regression models, adjusted for potential confounders.

RESULTS

Growth patterns were not associated with islet autoimmunity in the whole dataset and in children of diabetic mothers, respectively. In children of non-diabetic mothers ,however, islet autoimmunity was associated with rapidly increasing BMI SDS values until the age of 3 yr [adjusted odds ratio (95% confidence interval): 2.02 (1.03, 3.73) for development of any islet autoantibodies) and with consistently above average height SDS values [odds ratio: 2.21 (1.15, 4.17)]. In contrast, a pattern of high height SDS values at birth followed by a decrease to average values after 3 yr was associated with a reduced rate of islet autoimmunity [odds ratio: 0.16 (0.01, 0.62)].

CONCLUSION

Early growth patterns may be associated with T1D-related islet autoimmunity risk in children of non-diabetic mothers.

Growth in patients with type 1 diabetes

PURPOSE OF REVIEW

As the incidence of type 1 diabetes (T1DM) continues to rise, complications including impairment of childhood growth remain a major concern. This review provides an overview of alterations in growth patterns before and after the onset of T1DM.

RECENT FINDINGS

Recent advances in this field include several prospective investigations of height and weight trajectories in children leading up to the development of islet autoimmunity and T1DM as well as evaluations of larger cohorts of T1DM patients to better assess predictors of altered growth. In addition, genetic and metabolic investigations have improved our understanding of the more rare severe growth impairment of Mauriac Syndrome.

SUMMARY

Despite advances in medical care of children with T1DM, growth remains suboptimal in this population and likely reflects ongoing metabolic derangement linked with classic microvascular diabetic complications.

Growth and Risk for Islet Autoimmunity and Progression to Type 1 Diabetes in Early Childhood: The Environmental Determinants of Diabetes in the Young Study

Increased growth in early childhood has been suggested to increase the risk of type 1 diabetes. This study explored the relationship between weight or height and development of persistent islet autoimmunity and progression to type 1 diabetes during the first 4 years of life in 7,468 children at genetic risk for type 1 diabetes followed in Finland, Germany, Sweden, and the U.S. Growth data collected every third month were used to estimate individual growth curves by mixed models. Cox proportional hazards models were used to evaluate body size and risk of islet autoimmunity and type 1 diabetes. In the overall cohort, development of islet autoimmunity (n = 575) was related to weight z scores at 12 months (hazard ratio [HR] 1.16 per 1.14 kg in males or per 1.02 kg in females, 95% CI 1.06-1.27, P < 0.001, false discovery rate [FDR] = 0.008) but not at 24 or 36 months. A similar relationship was seen between weight z scores and development of multiple islet autoantibodies (1 year: HR 1.21, 95% CI 1.08-1.35, P = 0.001, FDR = 0.008; 2 years: HR 1.18, 95% CI 1.06-1.32, P = 0.004, FDR = 0.02). No association was found between weight or height and type 1 diabetes (n = 169). In conclusion, greater weight in the first years of life was associated with an increased risk of islet autoimmunity.

Circulating IGF1 and IGFBP3 in relation to the development of β-cell autoimmunity in young children

OBJECTIVE

This study aimed at investigating the role of IGF1 and IGF binding protein 3 (IGFBP3) in the development of β-cell autoimmunity.

METHODS

Five hundred and sixty-three subjects with HLA-conferred susceptibility to type 1 diabetes (T1D) were monitored for signs of seroconversion to positivity for insulin and/or GAD, IA2, and zinc transporter 8 autoantibodies by the age of 3 years. In 40 subjects who developed at least one autoantibody, IGF1 and IGFBP3 plasma concentrations were measured and compared with 80 control subjects who remained negative for autoantibodies, and were matched for age, sex, country of origin, and HLA genotype. The increments of IGF1, IGFBP3, and IGF1/IGFBP3 molar ratio before and after seroconverison were compared with corresponding time intervals in controls.

RESULTS

The IGF1 concentrations at the age of 12 months and the IGF1/IGFBP3 ratio at the age of 24 months were lower in the autoantibody-positive children (P<0.05). The increase in circulating IGFBP3 was significantly higher in the autoantibody-positive children before seroconversion than in the corresponding time intervals in controls (0.43 mg/l; 95% CI 0.29-0.56 vs 0.22 mg/l; 95% CI 0.10-0.34 mg/l; P<0.01). Children carrying the high-risk HLA genotype had lower plasma IGF1 and IGFBP3 concentrations at the age of 24 months than those with low-risk genotypes (P<0.05 and < 0.01 respectively).

CONCLUSIONS

Circulating IGF1 and IGFBP3 appear to have a role in early development of β-cell autoimmunity. The decreased IGF1 concentrations in children with the high-risk HLA genotype may contribute to the reduced growth previously described in such children.

Baseline heterogeneity in glucose metabolism marks the risk for type 1 diabetes and complicates secondary prevention

AIMS

Non-diabetic children with multiple islet autoantibodies were recruited to a secondary prevention trial. The objective was to determine the predictive value of baseline (1) HbA1c and metabolic variables derived from intravenous (IvGTT) and oral glucose tolerance tests (OGTT), (2) insulin resistance and (3) number, type and levels of islet autoantibodies, for progression to type 1 diabetes.

METHODS

Children [n = 50, median 5.1 (4-17.9) years] with autoantibodies to glutamate decarboxylase (GAD65A) and at least one of insulinoma-associated protein 2 (IA-2A), insulin or ZnT8 transporter (ZnT8RA, ZnT8WA, ZnT8QA) were screened with IvGTT and OGTT and followed for a minimum of 2 years.

RESULTS

Baseline first phase insulin response (sum of serum-insulin at 1 and 3 min during IvGTT; FPIR) ≤3 μU/mL [HR 4.42 (CI 1.40-14.0) p = 0.011] and maximal plasma glucose ≥11.1 mmol/L measured at 30, 60 and/or 90 min during OGTT [HR 6.13 (CI 1.79-21.0) p = 0.0039] were predictors for progression to diabetes. The combination of FPIR from IvGTT and maximal plasma glucose during OGTT predicted diabetes in 10/12 children [HR 9.17 (CI 2.0-42.0) p = 0.0043]. High-level IA-2A, but not number of autoantibodies, correlated to dysglycemia during OGTT (p = 0.008) and to progression to type 1 diabetes [HR 4.98 (CI 1.09-22.0) p = 0.039].

CONCLUSIONS

Baseline FPIR, maximal plasma glucose ≥11.1 at 30, 60 or 90 min during OGTT and high-level IA-2A need to be taken into account when randomizing islet autoantibody positive non-diabetic children to secondary prevention.

Body mass index (BMI) trajectories in infancy differ by population ancestry and may presage disparities in early childhood obesity

CONTEXT

No consensus definition exists for excess adiposity during infancy. After age 2 years, high body mass index (BMI) is related to adverse cardiometabolic outcomes. Before age 2 years, the utility of BMI as a metric of excess adiposity is unknown.

OBJECTIVES

The objective of the study was to characterize infant BMI trajectories in a diverse, longitudinal cohort and investigate the relationship between the infancy BMI trajectory and childhood obesity.

SUBJECTS

Healthy, nonpreterm infants (n = 2114) in the Genetic Causes for Complex Pediatric Disorders study (The Children's Hospital of Philadelphia) with six or more BMI measurements in the first 13.5 months participated in the study.

DESIGN

For each infant, the BMI trajectory was modeled using polynomial regression. Independent effects of clinical factors on magnitude and timing of peak BMI were assessed. The relationship between infancy BMI and early childhood BMI (age 4 y) was examined (n = 1075).

RESULTS

The cohort was 53% male and 61% African-American. Peak BMI was 18.6 ± 1.7 kg/m(2) and occurred at 8.6 ± 1.4 months. In multivariate analysis, boys had a higher (0.50 kg/m(2), P < .001) peak BMI than girls. The peak was higher (0.53 kg/m(2), P ≤ .001) and occurred earlier (by 12 d, P < .001) in African-American vs white children. The odds of obesity at age 4 years increased among children with higher (odds ratio 2.02; P < .001) and later (odds ratio 1.26; P = .02) infancy peak BMI.

CONCLUSIONS

We demonstrate sex- and ancestry-specific differences in infancy BMI and an association of infancy peak BMI with childhood BMI. These findings support the potential utility of infancy BMI to identify children younger than age 2 years with increased risk for later obesity.