The association of birthweight and contemporary size with insulin resistance among children from Estonia and Denmark: findings from the European Youth Heart Study

Hyperglycemia and Adverse Pregnancy Outcome Follow-Up Study: newborn anthropometrics and childhood glucose metabolism

AIMS/HYPOTHESIS

We aimed to examine associations of newborn anthropometric measures with childhood glucose metabolism with the hypothesis that greater newborn birthweight, adiposity and cord C-peptide are associated with higher childhood glucose levels and lower insulin sensitivity.

METHODS

Data from the international, multi-ethnic, population-based Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study and the HAPO Follow-Up Study were used. The analytic cohort included 4155 children (mean age [SD], 11.4 [1.2] years; 51.0% male). Multiple linear regression was used to examine associations of primary predictors, birthweight, newborn sum of skinfolds (SSF) and cord C-peptide, from HAPO with continuous child glucose outcomes from the HAPO Follow-Up Study.

RESULTS

In an initial model that included family history of diabetes and maternal BMI during pregnancy, birthweight and SSF demonstrated a significant, inverse association with 30 min and 1 h plasma glucose levels. In the primary model, which included further adjustment for maternal sum of glucose z scores from an oral glucose tolerance test during pregnancy, the associations were strengthened, and birthweight and SSF were inversely associated with fasting, 30 min, 1 h and 2 h plasma glucose levels. Birthweight and SSF were also associated with higher insulin sensitivity (Matsuda index) (β = 1.388; 95% CI 0.870, 1.906; p < 0.001; β = 0.792; 95% CI 0.340, 1.244; p < 0.001, for birthweight and SSF higher by 1 SD, respectively) in the primary model, while SSF, but not birthweight, was positively associated with the disposition index, a measure of beta cell compensation for insulin resistance (β = 0.034; 95% CI 0.012, 0.056; p = 0.002). Cord C-peptide levels were inversely associated with Matsuda index (β = -0.746; 95% CI -1.188, -0.304; p < 0.001 for cord C-peptide higher by 1 SD) in the primary model.

CONCLUSIONS/INTERPRETATION

This study demonstrates that higher birthweight and SSF are associated with greater childhood insulin sensitivity and lower glucose levels following a glucose load, associations that were further strengthened after adjustment for maternal glucose levels during pregnancy. Graphical abstract.

Evaluation of anthropometric measures for assessment of cardiometabolic risk in early childhood

OBJECTIVE

Waist-to-height ratio has been shown to be an important indicator of cardiometabolic risk. There are few studies evaluating this measure against existing measures of adiposity and cardiometabolic markers in early childhood. The objectives were: (i) to determine in young children the ability of waist-to-height ratio, BMI z-score, weight for length, and sum of skin fold thickness to predict cardiometabolic risk and (ii) to examine this association at ages 1, 3 and 5 years.

DESIGN

Prospective cohort study.

SETTING

A university hospital in Toronto, Ontario.

PARTICIPANTS

Infants at 1 (n 406), 3 (n 112) and 5 years of age (n 94) born to mothers with and without gestational diabetes mellitus.

RESULTS

Weight for length and BMI z-score demonstrated the strongest correlations with biochemical measures compared to waist-to-height ratio, including leptin (at 5 years, weight for length z-score: ρ = 0·65, P < 0·001; BMI z-score: ρ = 0·67, P < 0·001) and measures of insulin resistance (at 3 years, weight for length z-score: ρ = 0·25, P = 0·02; BMI z-score: ρ = 0·24, P = 0·02). The magnitude of associations between anthropometric measures and biochemical measures strengthened over time. Weight for length and BMI z-scores were moderately correlated with overall measures of fat mass as measured by dual-energy X-ray absorptiometry (ρ = 0·65, P = 0·00; ρ = 0·61, P = 0·01).

CONCLUSIONS

Waist-to-height ratio was not superior to existing measures in predicting cardiometabolic risk in young children. BMI z-score is a preferred measure of adiposity between birth and 5 years of age.

Obesity and abnormal glucose tolerance in the offspring of mothers with diabetes

PURPOSE OF REVIEW

Type 2 diabetes and obesity during childhood, puberty, and adulthood have become more common. This trend presents a global problem in terms of public health and health economics. Associations between intrauterine exposure to hyperglycemia, obesity, and abnormal glucose tolerance (AGT) in offspring have been reported in populations at high risk of diabetes such as Pima Indians, but these associations have not been established in other groups. In this review, we summarize the evidence on obesity and AGT in the offspring of mothers with diabetes.

RECENT FINDINGS

Although there are many reports indicating that the incidence of obesity or overweight is higher in the offspring of mothers with gestational diabetes, there is no consensus on whether maternal prepregnancy obesity has a larger impact than intrauterine exposure to hyperglycemia. While the risk of AGT or type 2 diabetes in the offspring of mothers with gestational diabetes is thought to increase after puberty, the incidence of AGT is elevated by the age of 7 years in the offspring of mothers with untreated gestational diabetes. Maternal gestational diabetes is a risk factor for AGT or type 2 diabetes independent of maternal prepregnancy BMI. When the offspring of women who had gestational diabetes and received therapeutic intervention in two randomized controlled studies were followed, the prevalence of obesity and impaired fasting glucose was lower in some 7-year-old girls, but the effect of maternal intervention was limited. The risk of obesity or overweight is higher in the offspring of mothers with type 1 diabetes, even after adjustment for maternal prepregnancy BMI. The risk of type 2 diabetes in such offspring is also higher. Although the offspring of mothers with type 2 diabetes are likely to be at high risk for type 2 diabetes, there are only limited reports supporting this hypothesis.

SUMMARY

Intrauterine exposure to hyperglycemia is associated with obesity and AGT among offspring. The present review suggests that these associations might depend on the type of maternal diabetes, that is, the timing and degree of exposure to hyperglycemia. There are only a small number of studies on the effect of therapeutic interventions for maternal diabetes on metabolism in the offspring.

Pathways Linking Birth Weight and Insulin Sensitivity in Early Adolescence: A Double Mediation Analysis

PURPOSE

We examined pathways linking birth weight, weight gain from 0 to 2 years, and adiposity during childhood with insulin sensitivity in early adolescence.

METHODS

Data were from a longitudinal cohort of 630 Quebec white children with a parental history of obesity (Quebec Adipose and Lifestyle Investigation in Youth study). In a subsample of children born at term (n = 395), weight-for-length z score (zWFL) from 0 to 2 years were computed. At 8 to 10 years, the percentage of body fat was assessed using dual energy X-ray absorptiometry. At 10 to 12 years, the Matsuda insulin sensitivity index (ISI) and the homeostasis model assessment for insulin resistance were determined. A linear regression-based approach for mediation analysis was used to estimate the distinct pathways linking zWFL at 0 to 2 years to insulin sensitivity.

RESULTS

Every additional unit in zWFL at birth was associated with a 10% (95% CI, 5.26% to 14.85%) increase in the Matsuda ISI in early adolescence, independently of the weight at 0 to 2 years and in childhood. An indirect effect of zWFL at birth on the Matsuda ISI was also observed but in the opposite direction (-4.44; 95% CI, -7.91 to -1.05). This relation was mediated by childhood adiposity but not by weight gain from 0 to 2 years. The indirect effect of weight gain from 0 to 2 years, via childhood adiposity, also led to lower insulin sensitivity (-4.83%, 95% CI, -7.34 to -2.53). The findings were similar for the homeostasis model assessment for insulin resistance or when restricted to children with appropriate-for-gestational-age birth weights.

CONCLUSIONS

A greater birth weight-for-length resulted in improved insulin sensitivity in early adolescence. However, in the presence of excess childhood adiposity, both a greater birth weight and a faster rate of weight gain from 0 to 2 years resulted in lower insulin sensitivity.

Birth Weight, Postnatal Weight Gain, and Childhood Adiposity in Relation to Lipid Profile and Blood Pressure During Early Adolescence

Background

Different pathways likely underlie the association between early weight gain and cardiovascular disease risk. We examined whether birth weight for length relationship and weight gain up to 2 years of age are associated with lipid profiles and blood pressure (BP) in early adolescence and determined whether childhood adiposity mediates these associations.

Methods and Results

Data from QUALITY (Quebec Adipose and Lifestyle Investigation in Youth), a cohort of white children with parental history of obesity, were analyzed (n=395). Sex‐specific weight for length z scores from birth to 2 years were computed. Rate of postnatal weight gain was estimated using individual slopes of weight for length z‐score measurements. Percentage of body fat was measured at 8 to 10 years. Fasting lipids and BP were measured at 10 to 12 years. Using path analysis, we found indirect effects of postnatal weight gain, through childhood adiposity, on all outcomes: Rate of postnatal weight for length gain was positively associated with childhood adiposity, which in turn was associated with unfavorable lipid and BP levels in early adolescence. In contrast, small beneficial direct effects on diastolic BP z scores, independent of weight at other time points, were found for birth weight for length (β=−0.05, 95% CI, −0.09 to −0.002) and for postnatal weight gain (β=−0.02, 95% CI, −0.03 to −0.002).

Conclusions

Among children with at least 1 obese parent, faster postnatal weight gain leads to cardiovascular risk factors in early adolescence through its effect on childhood adiposity. Although heavier newborns may have lower BP in early adolescence, this protective direct effect could be offset by a deleterious indirect effect linking birth weight to later adiposity.

Lessons from a peer-led obesity prevention programme in English schools

Obesity in young people is a major public health concern. Energy balance, the interrelationship between diet and physical activity, is known to be a key determinant. Evidence supports the development of school-based approaches to obesity prevention. ASSIST (A Stop Smoking in Schools Trial) is an effective school-based, peer-led smoking prevention programme for 12-13-year-old students, based on diffusion of innovations theory. The AHEAD (Activity and Healthy Eating in ADolescence) study tested the feasibility of adapting ASSIST to an obesity prevention intervention. The AHEAD intervention was tested and refined during a pilot study in one school, followed by an exploratory trial in six schools. Quantitative (self-report behavioural questionnaires and evaluation forms) and qualitative (structured observations, focus groups and interviews) research methods were used to examine the implementation and acceptability of the intervention. The potential effectiveness of the intervention in increasing healthy eating was measured using self-report behavioural questionnaires. Activity monitors (accelerometers) were used to measure physical activity. Results show it was feasible to implement the AHEAD intervention, which was well received. However, implementation was resource and labour intensive and relatively expensive. Furthermore, there was no evidence of promise that the intervention would increase physical activity or healthy eating in adolescents. Although diet and physical activity are both relevant for obesity prevention, the focus on two behaviours appeared too complex for informal diffusion through peer networks. This identifies a tension, particularly for adolescent peer-led health promotion, between the desire not to isolate or oversimplify health behaviours and the need to present clear, succinct health promotion messages.

Birth weight was longitudinally associated with cardiometabolic risk markers in mid-adulthood

PURPOSE

Birth weight (BW) is associated with risk of cardiovascular (CV) disease. The findings from studies examined the association of BW with metabolic markers of CV risk were inconsistent and controversial. We examined the association of BW with insulin resistance and blood lipids using repeated measures up to mid-adulthood.

METHODS

Data from seven screenings of the Bogalusa Heart Study-a longitudinal study of cardiovascular risk factors in Bogalusa, LA-are analyzed using generalized estimation equations method. Participants with birth data and at least one measurement of study outcomes between 18 and 44 years (n = 2,034) were included.

RESULTS

BW is inversely associated with insulin resistance, triglycerides, and total cholesterol (P < .01 for all). For 1-kg decrease in BW, insulin resistance increased by 2.3 units, 95% confidence interval (CI) = 0.7-3.9; triglycerides by 8.7 mg per dL, 95% CI = 4.9-12.4, and total cholesterol by 5.4 mg per dL, 95% CI = 1.8-9.1. The association of body mass with adult blood lipids levels is weaker in persons with low versus normal BW.

CONCLUSIONS

The study provides strong evidence of an inverse relationship of BW with adulthood cardiometabolic risk profile. Persons born with low BW are maybe less responsive to preventive interventions aiming at weight reduction.

Birthweight and risk markers for type 2 diabetes and cardiovascular disease in childhood: the Child Heart and Health Study in England (CHASE)

AIMS/HYPOTHESIS

Lower birthweight (a marker of fetal undernutrition) is associated with higher risks of type 2 diabetes and cardiovascular disease (CVD) and could explain ethnic differences in these diseases. We examined associations between birthweight and risk markers for diabetes and CVD in UK-resident white European, South Asian and black African-Caribbean children.

METHODS

In a cross-sectional study of risk markers for diabetes and CVD in 9- to 10-year-old children of different ethnic origins, birthweight was obtained from health records and/or parental recall. Associations between birthweight and risk markers were estimated using multilevel linear regression to account for clustering in children from the same school.

RESULTS

Key data were available for 3,744 (66%) singleton study participants. In analyses adjusted for age, sex and ethnicity, birthweight was inversely associated with serum urate and positively associated with systolic BP. After additional height adjustment, lower birthweight (per 100 g) was associated with higher serum urate (0.52%; 95% CI 0.38, 0.66), fasting serum insulin (0.41%; 95% CI 0.08, 0.74), HbA1c (0.04%; 95% CI 0.00, 0.08), plasma glucose (0.06%; 95% CI 0.02, 0.10) and serum triacylglycerol (0.30%; 95% CI 0.09, 0.51) but not with BP or blood cholesterol. Birthweight was lower among children of South Asian (231 g lower; 95% CI 183, 280) and black African-Caribbean origin (81 g lower; 95% CI 30, 132). However, adjustment for birthweight had no effect on ethnic differences in risk markers.

CONCLUSIONS/INTERPRETATION

Birthweight was inversely associated with urate and with insulin and glycaemia after adjustment for current height. Lower birthweight does not appear to explain emerging ethnic difference in risk markers for diabetes.

"Leaner and less fit" children have a better cardiometabolic profile than their "heavier and more fit" peers: the Healthy Growth Study

BACKGROUND AND AIMS

To examine differences in cardiometabolic risk factors between children of different BMI and fitness levels.

METHODS AND RESULTS

From a representative sample of 1222 boys and 1188 girls, aged 9-13 years, anthropometric, body composition, physical activity, cardiorespiratory fitness, biochemical and blood pressure data was collected. The prevalence of overweight and obesity was 29.9% and 11.8% respectively. In both genders, plasma HDL cholesterol concentration was higher in the 'leaner and less fit' group (lowest quartile of BMI and lowest quartile of fitness) compared to the 'heavier and more fit' (highest quartile of BMI and highest quartile of fitness) and intermediate (all other children) groups (p < 0.05). Furthermore, the 'leaner and less fit' groups in both genders had lower triacylglycerol concentration, total-to-HDL cholesterol ratio, HOMA-IR, insulin and systolic blood pressure levels compared to the 'heavier and more fit' and/or intermediate groups. Similar trends were observed for hypertension in boys and insulin resistance for both genders. Finally, the effect size of being 'leaner and less fit' on serum levels of cardiometabolic risk indices was mainly small to medium (i.e. Cohen's d 0.2-0.5).

CONCLUSION

Leaner and less fit boys and girls had better cardiometabolic risk profiles than their heavier and more fit peers, probably suggesting a higher importance of leanness over fitness in children from a cardiometabolic health benefit perspective.

Childhood Obesity and the Metabolic Syndrome

There have been dramatic increases over the past several decades in the prevalence of childhood obesity and childhood metabolic syndrome in the United States and other industrialized nations. Since the 2 conditions carry negative health implications, both during childhood and later in life, it is important for health care professionals to stay abreast of the current literature relative to both conditions. This review will examine definitional issues, prevalence rates, causative factors, and health consequences associated with childhood obesity and the metabolic syndrome, as well as current thinking regarding prevention and treatment efforts. The review will conclude with recommendations relative to future research needs.

Effects of birth size, post-natal growth and current size on insulin resistance in 9-year-old children: a prospective cohort study

The influence of pre-natal conditions on later type 2 diabetes risk factors such as insulin resistance (IR) may be mediated by post-natal growth trajectory. We aimed to investigate the association of body size at birth and 9 years with IR at 9 years. Using data from a prospective Australian cohort study, we examined the influence of body size from birth to 9 years [z-score for weight or body mass index (BMI)] on IR at 9 years (estimated by homeostasis model assessment). At age 9 years, 151 children provided a fasting blood sample. z-BMI at age 9 was positively associated with IR. Birth z-BMI was inversely associated with IR only after adjustment for z-BMI at age 9 years. This may be interpreted as an effect of accelerated growth between birth and 9 years on IR. There was a statistically significant interaction between birth and 9-year z-BMI. Results from regression models including z-BMI at all available time points (birth, 6 and 12 months, and 2, 3.5 and 9 years) indicate a possible inverse association between body size at 3.5 years and HOMA-IR at 9 years. Results were similar when the analyses were repeated with z-weight substituted for z-BMI. These results add to the body of evidence concerning the importance of growth in early life for later IR, and highlight a possible interaction between pre- and post-natal growth. The potential influence of growth at around 3.5 years for HOMA-IR at 9 years warrants further investigation.

Birth weight, current body mass index, and insulin sensitivity and secretion in young adults in two Latin American populations

BACKGROUND AND AIMS

Although studies have shown association of birth weight (BW) and adult body mass index (BMI) with insulin sensitivity in adults, there is limited evidence that BW is associated with insulin secretion. We assessed the associations between BW and current BMI with insulin sensitivity and secretion in young Latin American adults.

METHODS AND RESULTS

Two birth cohorts, one from Ribeirao Preto, Brazil, based on 1984 participants aged 23-25 years, and another from Limache, Chile, based on 965 participants aged 22-28 years were studied. Weight and height at birth, and current fasting plasma glucose and insulin levels were measured. Insulin sensitivity (HOMA%S) and secretion (HOMA%β) were estimated using the Homeostatic Model Assessment (HOMA2). Multiple linear regression analyses were carried out to test the associations between BW and adult BMI z-scores on log HOMA%S and log HOMA%β. BW z-score was associated with HOMA%S in the two populations and HOMA%β in Ribeirao Preto when adult BMI z-score was included in the model. BW z-score was associated with decreasing insulin secretion even without adjusting for adult BMI, but only in Ribeirao Preto. BMI z-score was associated with low HOMA%S and high HOMA%β. No interactions between BW and BMI z-scores on insulin sensitivity were shown.

CONCLUSIONS

This study supports the finding that BW may affect insulin sensitivity and secretion in young adults. The effect size of BW on insulin status is small in comparison to current BMI.

Physical activity attenuates the effect of low birth weight on insulin resistance in adolescents: findings from two observational studies

OBJECTIVE

To examine whether physical activity influences the association between birth weight and insulin resistance in adolescents.

RESEARCH DESIGN AND METHODS

The study comprised adolescents who participated in two cross-sectional studies: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study (n = 520, mean age = 14.6 years) and the Swedish part of the European Youth Heart Study (EYHS) (n = 269, mean age = 15.6 years). Participants had valid data on birth weight (parental recall), BMI, sexual maturation, maternal education, breastfeeding, physical activity (accelerometry, counts/minute), fasting glucose, and insulin. Insulin resistance was assessed by homeostasis model assessment-insulin resistance (HOMA-IR). Maternal education level and breastfeeding duration were reported by the mothers.

RESULTS

There was a significant interaction of physical activity in the association between birth weight and HOMA-IR (logarithmically transformed) in both the HELENA study and the EYHS (P = 0.05 and P = 0.03, respectively), after adjusting for sex, age, sexual maturation, BMI, maternal education level, and breastfeeding duration. Stratified analyses by physical activity levels (below/above median) showed a borderline inverse association between birth weight and HOMA-IR in the low-active group (standardized β = -0.094, P = 0.09, and standardized β = -0.156, P = 0.06, for HELENA and EYHS, respectively), whereas no evidence of association was found in the high-active group (standardized β = -0.031, P = 0.62, and standardized β = 0.053, P = 0.55, for HELENA and EYHS, respectively).

CONCLUSIONS

Higher levels of physical activity may attenuate the adverse effects of low birth weight on insulin sensitivity in adolescents. More observational data, from larger and more powerful studies, are required to test these findings.

Thin newborns are more insulin resistant at 10 years of age

AIMS

To investigate the relation between ponderal index or birth weight and insulin resistance in late childhood.

METHODS

An observational study of 92-term appropriate-for-gestational age infants was carried out. Weight and length were measured at birth and at 9 months and duration of breast feeding was noted at 9 months. Follow-up examinations at 10 years of age included measurement of weight, height, pubertal status, fasting insulin and glucose concentrations.

RESULTS

Ponderal index at birth was negatively (B±SE=-0.05±0.02; p=0.025) and current BMI was positively (B±SE=0.14±0.02; p<0.001) associated with insulin resistance measured as homeostasis model assessment (HOMA) at 10 years of age adjusted for gender and pubertal stage. Current BMI and ponderal index at birth were still significant after adjusting for weight at 9 months. Birth weight and weight at 9 months was not correlated with HOMA (p=0.58) adjusted for current BMI, gender and pubertal stage. HOMA was higher in the tertile with the lowest ponderal index than in the two remaining tertiles (p=0.024).

CONCLUSION

Relative thinness at birth, but neither birth weight nor weight gain from 0-9 months, was associated with higher insulin resistance at 10 years of age in this cohort with a low prevalence of overweight at 10 years of age and normal birth weight.

Obesity-susceptibility loci have a limited influence on birth weight: a meta-analysis of up to 28,219 individuals

BACKGROUND

High birth weight is associated with adult body mass index (BMI). We hypothesized that birth weight and BMI may partly share a common genetic background.

OBJECTIVE

The objective was to examine the associations of 12 established BMI variants in or near the NEGR1, SEC16B, TMEM18, ETV5, GNPDA2, BDNF, MTCH2, BCDIN3D, SH2B1, FTO, MC4R, and KCTD15 genes and their additive score with birth weight.

DESIGN

A meta-analysis was conducted with the use of 1) the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk, Hertfordshire, Fenland, and European Youth Heart Study cohorts (n(max) = 14,060); 2) data extracted from the Early Growth Genetics Consortium meta-analysis of 6 genome-wide association studies for birth weight (n(max) = 10,623); and 3) all published data (n(max) = 14,837).

RESULTS

Only the MTCH2 and FTO loci showed a nominally significant association with birth weight. The BMI-increasing allele of the MTCH2 variant (rs10838738) was associated with a lower birth weight (β ± SE: -13 ± 5 g/allele; P = 0.012; n = 23,680), and the BMI-increasing allele of the FTO variant (rs1121980) was associated with a higher birth weight (β ± SE: 11 ± 4 g/allele; P = 0.013; n = 28,219). These results were not significant after correction for multiple testing.

CONCLUSIONS

Obesity-susceptibility loci have a small or no effect on weight at birth. Some evidence of an association was found for the MTCH2 and FTO loci, ie, lower and higher birth weight, respectively. These findings may provide new insights into the underlying mechanisms by which these loci confer an increased risk of obesity.

Do physical activity and aerobic fitness moderate the association between birth weight and metabolic risk in youth?: the European Youth Heart Study

OBJECTIVE

Lower birth weight has been associated with a greater risk of metabolic diseases. The aim of this study was examine whether physical activity and aerobic fitness may modify associations between birth weigh and metabolic risk.

RESEARCH DESIGN AND METHODS

The European Youth Heart Study is a population-based study of 9 and 15 year olds (n = 1,254). Birth weight was maternally reported. Skin fold measures were used to calculate body fat and fat mass index (FMI = fat mass [kilograms]/height²). Insulin was measured using fasting blood samples. Physical activity was measured using a hip-worn accelerometer (MTI Actigraph) for >600 min/day for ≥3 days and is expressed as "average activity" (counts per minute) and time spent in above moderate intensity activity (>2000 cpm). Aerobic fitness was assessed using a maximal cycle ergometry test (watts per kilogram fat-free mass).

RESULTS

Higher birth weight was associated with higher FMI (β = 0.49 [95% CI 0.21-0.80]; P = 0.001) and greater waist circumference (0.90 [0.32-1.47]; P < 0.001), adjusted for sex, age-group, sexual maturity, height, and socioeconomic status. Lower birth weight was associated with higher fasting insulin only after further adjustment for adolescent waist circumference and height (-0.059 [-0.107 to -0.011]; P = 0.016). There was no evidence for any modification of the associations after adjustment for physical activity or aerobic fitness.

CONCLUSIONS

The present study did not find any evidence that physical activity or aerobic fitness can moderate the associations among higher birth weight and increased fat mass and greater waist circumference or between lower birth weight and insulin resistance in healthy children and adolescents.

Determinants of blood glucose and insulin in healthy 9-month-old term Danish infants; the SKOT cohort

AIMS

Insulin secretion is important for early regulation of growth, but high insulin concentration is also a risk factor for insulin resistance later in life. It is therefore important to better understand how insulin and glucose are associated with early diet and growth. The aim of this study was to examine blood glucose and insulin concentration in relation to anthropometric measurements, growth, breastfeeding practice and complementary feeding in 9-month-old infants.

METHODS

This was a cross-sectional study (SKOT cohort), examining 312 healthy term infants from the age of 9 months. Of these, 265 infants had data on insulin and glucose and were included in this study. Measurements include weight, length, skinfold thickness, waist circumference, 7-day food records, 2-h fasting venous glucose and insulin analysis, and questionnaire.

RESULTS

At 9 months of age there was a strong negative association between number of breastfeedings per day and insulin concentration (P=0.0015). Insulin concentration was positively associated to waist circumference (P=0.042) and change in Z-score for weight-for-age between 5 and 9 months (P=0.004). Glucose concentration was positively associated to subscapular skinfold (P=0.002) and sum of skinfolds thicknesses (P=0.006).

CONCLUSION

At 9 months, breastfeeding still had a strong negative effect on insulin concentrations, which were positively associated with weight gain and current waist circumference, while glucose concentrations were associated with subcutaneous fat. These results are of interest in disentangling the association between early growth and later risk of disease.

Adiposity, insulin resistance and cardiovascular risk factors in 9-10-year-old Indian children: relationships with birth size and postnatal growth

Lower birthweight, and rapid childhood weight gain predict elevated cardiovascular risk factors in children. We examined associations between serial, detailed, anthropometric measurements from birth to 9.5 years of age and cardiovascular risk markers in Indian children. Children (n = 663) born at the Holdsworth Memorial Hospital, Mysore, India were measured at birth and 6-12 monthly thereafter. At 9.5 years, 539 (255 boys) underwent a 2-h oral glucose tolerance test, and blood pressure (BP) and fasting lipid concentrations were measured. Insulin resistance was calculated using the HOMA equation. These outcomes were examined in relation to birth measurements and changes in measurements (growth) during infancy (0-2 years), 2-5 years and 5-9.5 years using conditional s.d. scores. Larger current weight, height and skinfold thickness were associated with higher risk markers at 9.5 years (P < 0.05). Lower weight, smaller length and mid-arm circumference at birth were associated with higher fasting glucose concentrations at 9.5 years (P ⩽ 0.01). After adjusting for current weight/height, there were inverse associations between birthweight and/or length and insulin concentrations, HOMA, systolic and diastolic BP and plasma triglycerides (P < 0.05). Increases in conditional weight and height between 0-2, 2-5 and 5-9.5 years were associated with higher insulin concentrations, HOMA and systolic BP. In conclusion, in 9-10-year-old Indian children, as in other studies, cardiovascular risk factors were highest in children who were light or short at birth but heavy or tall at 9 years. Greater infant and childhood weight and height gain were associated with higher risk markers.

Size at birth is associated with blood pressure but not insulin resistance in 6–8 year old children in rural Nepal

Earlier, we reported that antenatal micronutrient supplementation reduced the risk of metabolic syndrome and microalbuminuria among offspring at 6–8 years of age in rural Nepal. In the same birth cohort, we examined associations of size at birth (weight, length and ponderal index), and gestational age, with cardiometabolic risk factors in childhood across all antenatal micronutrient interventions. There was an inverse association between birth weight and systolic blood pressure (SBP,β= −1.20 mm Hg/kg; 95% confidence interval (CI): −1.93, −0.46) and diastolic blood pressure (DBP,β= −1.24 mm Hg/kg; 95% CI: −2.00, −0.49). Current child body mass index was positively associated with SBP but not with DBP. Birth weight was unassociated with insulin resistance, but each kilogram of increase was associated with a reduced risk of high triglycerides (odds ratio (OR) = 0.64/kg; 95% CI: 0.41, 0.97) and an increased risk of high waist circumference (OR = 3.16/kg; 95% CI: 2.47, 4.41). In this rural Nepalese population of children 6–8 years of age with a high prevalence of undernutrition, size at birth was inversely associated with blood pressure and triglycerides and positively associated with waist circumference.

Common genetic determinants of glucose homeostasis in healthy children: the European Youth Heart Study

OBJECTIVE

The goal of this study was to investigate whether the effects of common genetic variants associated with fasting glucose in adults are detectable in healthy children.

RESEARCH DESIGN AND METHODS

Single nucleotide polymorphisms in MTNR1B (rs10830963), G6PC2 (rs560887), and GCK (rs4607517) were genotyped in 2,025 healthy European children aged 9-11 and 14-16 years. Associations with fasting glucose, insulin, homeostasis model assessment (HOMA)-insulin resistance (IR) and HOMA-B were investigated along with those observed for type 2 diabetes variants available in this study (CDKN2A/B, IGF2BP2, CDKAL1, SLC30A8, HHEX-IDE, and Chr 11p12).

RESULTS

Strongest associations were observed for G6PC2 and MTNR1B, with mean fasting glucose levels (95% CI) being 0.084 (0.06-0.11) mmol/l, P = 7.9 x 10(-11) and 0.069 (0.04-0.09) mmol/l, P = 1.9 x 10(-7) higher per risk allele copy, respectively. A similar but weaker trend was observed for GCK (0.028 [-0.006 to 0.06] mmol/l, P = 0.11). All three variants were associated with lower beta-cell function (HOMA-B P = 9.38 x 10(-5), 0.004, and 0.04, respectively). SLC30A8 (rs13266634) was the only type 2 diabetes variant associated with higher fasting glucose (0.033 mmol/l [0.01-0.06], P = 0.01). Calculating a genetic predisposition score adding the number of risk alleles of G6PC2, MTNR1B, GCK, and SLC30A8 showed that glucose levels were successively higher in children carrying a greater number of risk alleles (P = 7.1 x 10(-17)), with mean levels of 5.34 versus 4.91 mmol/l comparing children with seven alleles (0.6% of all children) to those with none (0.5%). No associations were found for fasting insulin or HOMA-IR with any of the variants.

CONCLUSIONS

The effects of common polymorphisms influencing fasting glucose are apparent in healthy children, whereas the presence of multiple risk alleles amounts to a difference of >1 SD of fasting glucose.

Effect of growth on cardiometabolic status at 4 y of age

BACKGROUND

Cardiovascular disease (CVD) risks are increasingly being diagnosed in children and track into adulthood. Growth is associated with CVD risk in adulthood; however, its contribution to CVD risks in children facing the obesity epidemic is unclear.

OBJECTIVE

The objective was to assess relations between growth from age 0 to 4 y and CVD status at 4 y in 323 Chilean children with normal birth weight.

DESIGN

From health records we obtained weight and height every 6 mo from age 0 to 3 y and calculated body mass index (BMI; weight/height(2)). At age 4 y, we measured height, waist circumference, insulin, glucose, and plasma lipids; infant feeding information was provided by the mothers. Outcomes were metabolic score (waist-to-height ratio + glucose + insulin + triglycerides - HDL-cholesterol z scores/5), total cholesterol (TC):HDL cholesterol, and homeostasis model of assessment of insulin resistance.

RESULTS

At 4 y, the prevalence of obesity was 13%. Changes in BMI, particularly from 6 to 24 mo, predicted a higher metabolic score (standardized regression coefficient = 0.29; 95% CI: 0.16, 0.42) but were unrelated to homeostasis model of assessment of insulin resistance and TC:HDL cholesterol. Height changes were not associated with CVD risks at the age of 4 y. Mode of infant feeding was unrelated to CVD status at 4 y; however, in children who were exclusively breastfed at 4 mo, an increase in BMI from 0 to 6 mo was positively associated with TC:HDL cholesterol at 4 y (standardized regression coefficient = 0.24; 95% CI: -0.02, 0.50), whereas in children who were partially or nonbreastfed at 4 mo, it was negatively associated with TC:HDL cholesterol at 4 y (standardized regression coefficient = -0.30; 95% CI: -0.52, -0.08).

CONCLUSION

In children with normal birth weight and a high prevalence of obesity at 4 y, changes in BMI after 6 mo predicted a higher overall CVD risk at 4 y.

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.

METHOD

Two hundred thirty-three children (134 boys, 99 girls) with a gestational age of >37 weeks were assessed at birth, 5 years of age, and 9 years of age. Measures included weight SD scores at each time point and excess weight gained (Delta weight SD score) between them. The outcome measure included composite metabolic score (sum of internally derived z scores of insulin resistance, mean blood pressure, triglyceride level, and total cholesterol/high-density lipoprotein cholesterol ratio).

RESULTS

Weight SD score increased by 0.29 SD score in girls and 0.26 SD score in boys from 0 to 5 years of age and by 0.03 SD score in girls and 0.11 SD score in boys from 5 to 9 years of age. Weight SD score correlated poorly to moderately before 5 years of age but strongly after 5 years of age. Birth weight SD score predicted (girls/boys) 2.4%/0% of the variability in composite metabolic score at 9 years of age. Adding Delta weight SD score (0-5 years old) contributed (girls/boys) 11.2%/7.0% to the score, and adding Delta weight SD score (5-9 years old) additionally contributed (girls/boys) 26.4%/16.5%. Importantly, once weight SD score at 9 years of age was known, predictive strength was changed little by adding Delta weight SD score.

CONCLUSIONS

Most excess weight before puberty is gained before 5 years of age. Weight at 5 years of age bears little relation to birth weight but closely predicts weight at 9 years of age. Single measures of current weight are predictive of metabolic health, whereas weight gain within a specific period adds little. A single measure of weight at 5 years of age provides a pointer to future health for the individual. If metabolic status at 9 years of age means future risk, diabetes/cardiovascular prevention strategies might better focus on preschool-aged children, because the die seems to be largely cast by 5 years of age, and a healthy weight early in childhood may be maintained at least into puberty.

Relation of birth weight, body mass index, and change in size from birth to adulthood to insulin resistance in a female twin cohort

CONTEXT AND OBJECTIVES

Because an adverse intrauterine environment is thought to induce insulin resistance, our objective was to investigate the relationships between birth weight, BMI, and change in body size over the life course and insulin resistance. SETTING, DESIGN, AND PARTICIPANTS: We conducted a cross-sectional study in a cohort of 1194 female twins aged 18-74 yr. The relationship between birth weight and insulin resistance was analyzed using a regression method allowing for a simultaneous estimation of within- and between-pair influences. The approach allows the influence of individual fetal nutrition on adult insulin resistance to be distinguished from effects that are mediated by confounding factors in the maternal environment.

MAIN OUTCOME MEASURES

Insulin resistance was measured by the homeostasis model assessment.

RESULTS

Individual level regression analyses showed no significant relationship between birth weight and insulin resistance. There was a significant positive relationship between insulin resistance and current body mass index (BMI) (a 26% increase in insulin resistance per sd increase in BMI; confidence interval, 22.6-29.5%). This significant relationship was accounted for in equal parts by individual-specific effects and by confounding factors in the shared environment of the twins. The relationship with birth weight became significant only after adjustment for BMI and was mediated only through between-pair differences.

CONCLUSIONS

These results suggest that insulin resistance is influenced more by current body size than birth weight and that postnatal growth is potentially more important than fetal growth in the subsequent development of insulin resistance.

Prevalence and independent predictors of insulin resistance in children from Crete, Greece: the Children Study

BACKGROUND

It has been proposed that insulin resistance (IR) is associated with the development of Type 2 diabetes mellitus and cardiovascular disease. The aim of this study is to determine the prevalence of IR in Greek schoolchildren and to investigate factors associated with IR.

METHODS

Between October 2005 and March 2006, 522 children were recruited from Crete. Physical activity and dietary habits, anthropometric and biochemical characteristics, as well as medical history of pupils' parents were recorded. IR was estimated using the homeostasis model assessment (HOMA-IR), fasting glucose-to-insulin ratio (FGIR) and quantitative insulin sensitivity check index (QUICKI). Multiple linear regression was used to determine independent predictors for IR.

RESULTS

Fasting insulin levels and HOMA-IR scores were higher in obese children and girls compared with their normal-weight peers (P < 0.001). Moreover, the former had lower values in FGIR and QUICKI indices compared with the latter, indicating that obese children and girls are more insulin resistant compared with their counterparts (P < 0.001). The prevalence of IR was 9.2% (2.9% in normal-weight, 10.5% in overweight and 31.0% in obese children), using as a threshold HOMA-IR > 2.10 97.5th percentile of normal-weight participants). Multiple linear regression revealed that central adiposity, female gender and intake of simple carbohydrates is associated positively with HOMA-IR values, even after controlling for many other factors.

CONCLUSION

These findings demonstrate that girls and obese children, particularly those with central adiposity, are at high risk of developing IR. Therefore, these groups should be targets of Type 2 diabetes mellitus and cardiovascular disease preventive interventions.

Maternal size in pregnancy and body composition in children

CONTEXT

Evidence suggests that babies' fat mass at birth is greater if their mothers were themselves fatter during pregnancy, but it is unclear whether this association persists into childhood.

OBJECTIVE

Our objective was to examine the relation between maternal size in pregnancy, early growth and body composition in children.

DESIGN AND SETTING

We conducted a prospective cohort study in Southampton, United Kingdom.

PARTICIPANTS

Participants included 216 9-yr-old children whose mothers had participated in a study of nutrition during pregnancy.

MAIN OUTCOME MEASURES

Fat mass and lean mass were measured by dual-energy x-ray absorptiometry and adjusted for height (fat mass index and lean mass index).

RESULTS

Fat mass index at age 9 yr was greater in children whose mothers had a larger mid-upper arm circumference in late pregnancy or a higher prepregnant body mass index. For 1 sd increase in maternal mid-upper arm circumference in late pregnancy, fat mass index rose by 0.26 [95% confidence interval (CI) 0.06-0.46] sd in boys and by 0.44 (95% CI 0.31-0.57) sd in girls. For 1 sd increase in maternal prepregnant BMI, fat mass index rose by 0.26 (95% CI 0.04-0.48) sd in boys and by 0.42 (95% CI 0.29-0.56) sd in girls.

CONCLUSIONS

Mothers with a higher prepregnant body mass index or a larger mid-upper arm circumference during pregnancy tend to have children with greater adiposity at age 9. The extent to which this is attributable to genetic factors, the influence of maternal lifestyle on that of her child, or maternal adiposity acting specifically during pregnancy on the child's fat mass cannot be determined in this study.

Trends in body mass index, blood pressure and parental smoking habits in middle socio-economic level Turkish adolescents

Patterns of cardiovascular risk factors in populations are not static over time. We examined trends in body mass index (BMI), parental smoking and blood pressure over a 15-year period in Turkish children aged 15-17 years. Two cross-sectional studies were performed in secondary schools in Turkey in 1989-1990 and 2004-2005. Study participants were 673 children in 1989-1990 and 640 adolescents in 2004-2005. Main outcome measures were weight, height, BMI, presence and amount of parental smoking, systolic and diastolic blood pressure. Age and sex matched comparisons were performed to assess temporal trends in these measures. Children in 2004-2005 had increased weight, height, BMI and decreased systolic and diastolic blood pressure in all age groups compared with children in 1989-1990. According to the international criteria, 3.4% of children were obese and 15.8% were overweight in 2005, compared to 0.7% obese and 4.2% overweight in 1990 (P<0.001). However, a decrease was noted in blood pressure; 16% were classified as hypertensive in 1989-1990 versus 8% in 2004-2005 (P<0.001). The prevalence and amount of parental smoking also decreased over the last 15 years. We observed significant changes in BMI and blood pressure in Turkish children over the last 15 years. Temporal trends in these parameters may indicate a change in the pattern of cardiovascular disease in this population.

Little evidence for early programming of weight and insulin resistance for contemporary children: EarlyBird Diabetes Study report 19

OBJECTIVE

The aim of this study was to evaluate whether adaptive responses made to the uterine or very early infant environment are affecting the current metabolic health of young children in the United Kingdom.

METHODS

Participants were 300 healthy children and their parents from the EarlyBird Diabetes Study cohort. Children were recruited from randomly selected schools at 5 years of age. Retrospective measures were maternal prepregnancy weight (n = 230), maternal fasting glucose levels at 28 weeks of pregnancy (n = 27), birth weight, and infant weight at ages 3 and 6 weeks. Prospective measures were insulin resistance, height, weight, and percentage of body fat (sum of 5 skinfold measurements) at ages 5, 6, 7, and 8 years.

RESULTS

Maternal third-trimester fasting glucose levels were associated positively with birth weight but were not associated with either weight or insulin resistance for the same children at 8 years. Birth weight was unrelated to insulin resistance at 8 years. There were no relationships between weight change in the first weeks of life and weight, percentage of fat, or insulin resistance at 8 years. Longer breastfeeding correlated inversely, although weakly, with percentage of body fat for boys only. Current weight was correlated with insulin resistance at 8 years.

CONCLUSIONS

For these contemporary children, neither the gestational environment nor early postnatal growth predicted insulin resistance, which was best predicted by current weight. There was no evidence that predictive adaptive responses made by the fetus or infant affected the child's weight or insulin resistance later in childhood.

Association of socioeconomic position with insulin resistance among children from Denmark, Estonia, and Portugal: cross sectional study

OBJECTIVES

To examine the association between socioeconomic position and insulin resistance in children from three countries in northern Europe (Denmark), eastern Europe (Estonia), and southern Europe (Portugal) that have different physical, economic, and cultural environments.

DESIGN

Cross sectional study.

PARTICIPANTS

3189 randomly selected schoolchildren aged 9 and 15 years from Denmark (n = 933), Estonia (n = 1103), and Portugal (n = 1153).

MAIN OUTCOME MEASURE

Insulin resistance (homoeostasis model assessment).

RESULTS

Family income and parental education were inversely associated with insulin resistance in Danish children but were positively associated with insulin resistance in Estonian and Portuguese children. Among Danish children, insulin resistance was 24% lower (95% confidence interval -38% to -10%) in those whose fathers had the most education compared with those with the least education. The equivalent results were 15% (2% to 28%) higher for Estonia and 19% (2% to 36%) higher for Portugal. These associations remained after adjustment for a range of covariates: -20% (-36% to -5%) for Denmark, 10% (-4% to 24%) for Estonia, and 18% (-1% to 31%) for Portugal. Strong statistical evidence supported differences between the associations in Denmark and those in the other two countries in both unadjusted and adjusted models (all P < 0.03).

CONCLUSIONS

Among Danish children, those with the most educated and highest earning parents had least insulin resistance, whereas the opposite was true for children from Estonia and Portugal.