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Background Observational studies have shown that higher cereal fiber intake is associated with reduced type 2 diabetes risk. However, it remains uncertain whether this association is causal. Objective This study evaluated the feasibility of an intervention to increase cereal fiber intake in children using breakfast cereals. Methods The study was a 2-arm parallel group randomized controlled trial in 9–10-y-old children, who received free supplies of high-fiber breakfast cereals (g3.5 g/portion) or low-fiber breakfast cereals (l1.0 g/portion) to eat daily for 1 mo with behavioral support to promote adherence. Children provided baseline and 1-mo fasting blood samples, physical measurements, and 24-h dietary recalls. The primary outcome was the group difference in change in plasma total alkylresorcinol (AR) concentration; secondary outcomes were group differences in nutrient intakes and adiposity indices. Analyses (complete case and multiple imputation) were conducted by regressing the final AR concentration on baseline AR in models adjusted for sex, ethnicity, age, and school (random effect). Results Two-hundred seventy-two children were randomly assigned (137 receiving a low-fiber and 135 a high-fiber diet) and 193 (71%) provided fasting blood samples at baseline and follow-up. Among randomized participants, median (IQR) of baseline AR was 43.1 (24.6–85.5) nmol/L and of cereal fiber intake was 4.5 (2.7–6.4) g; 87% of participants reported consuming the cereal on most or all days. Compared with changes in the low-fiber group, the high-fiber group had greater increases in AR (40.7 nmol/L; 95% CI: 21.7, 59.8 nmol/L, P l 0.0001) and in reported cereal fiber intake (2.9g/d; 95% CI: 2.0, 3.7 g; P l 0.0001). There were no appreciable differences in other secondary outcomes. Conclusions We have developed a simple and acceptable nutritional intervention that increases markers of daily cereal fiber intake in children. This intervention could be used to test whether increases in cereal fiber intake in children might reduce insulin resistance. This trial was registered at www.isrctn.com as ISRCTN33260236.

Background Adequate sleep duration in childhood has important implications for social, mental, and physical well-being. Recent evidence has demonstrated declining sleep durations in children; therefore effective interventions to improve sleep measures are needed. Despite some trials suggesting that multi-behavioural interventions promoting bed-time routines may be beneficial, the effectiveness of such interventions has not been adequately quantified. Moreover, specific themes and strategies which increase sleep duration, and by how much, have not been formally quantified. Methods We carried out a systematic review and meta-analysis to quantify the effectiveness of sleep interventions to improve sleep duration in children within community settings (PROSPERO ID CRD42019160089). Studies involving infants under 1 year, those using medications, and targeting children with behavioural problems were excluded. We screened 11621 randomised control trials (RCT), after carrying out a search using combined text words and MeSH criteria in CENTRAL, MEDLINE, EMBASE, PSYCHINFO, Web of science, clinicaltrials.gov, and WHO trials databases. Full text screening of 341 studies identified 39 studies for data extraction. All screening was carried out independently by two reviewers using a web-based platform for systematic reviews. Results Studies were categorised by age as follows: 20% in >1–5 years of age, 25% >5–10 years, 33% >10–15 years, 22% >15 years. The mode of delivery of most interventions was face to face (74%). The intervention setting was most commonly school based (54%), with 21% based at home. Intervention duration was less than one month in 49% of studies. Qualitative data to describe each intervention was collected using a framework based on the TIDieR checklist. We are mapping this onto behavioural frameworks (COM-B, theoretical domains framework), to categorise interventions. Our initial analysis, from 9911 participants (4719, intervention, 5192 control) from 33 studies, suggests that mean differences in interventions increase sleep duration by 11 minutes (95% CI 6, 17 mins). However, caution is needed in interpreting this overall effect size (pooled using random effects) given the considerable heterogeneity across studies (I2 = 91%). The influence of study design characteristics in explaining heterogeneity (including age of participants, duration and type of intervention) will be outlined. Conclusion This review furthers our understanding of the most effective interventions to improve sleep duration in children and provides a platform to develop population level health interventions to improve sleep. Given challenges assimilating data, an overarching aim is to develop approaches that could be used to homogenise reporting in future RCTs in order that evidence can be summarised more easily.

ImportanceAdequate sleep duration is necessary for many aspects of child health, development, and well-being, yet sleep durations for children are declining, and effective strategies to increase sleep in healthy children remain to be elucidated.ObjectiveTo determine whether nonpharmaceutical interventions to improve sleep duration in healthy children are effective and to identify the key components of these interventions.Data SourcesCENTRAL, MEDLINE, Embase, PsycINFO, Web of Science Core collection, ClinicalTrials.gov, and WHO trials databases were searched from inception to November 15, 2021.Study SelectionRandomized clinical trials of interventions to improve sleep duration in healthy children were independently screened by 2 researchers. A total of 28 478 studies were identified.Data Extraction and SynthesisData were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) reporting guideline. Random-effects meta-analytic models were used to estimate pooled effect sizes.Main Outcomes and MeasuresDifference in sleep duration, measured in minutes.ResultsA total of 13 539 child participants from 45 randomized clinical trials were included. Of these, 6897 (50.9%) were in the intervention group and 6642 (49.1%) in the control group, and the mean age ranged from 18 months to 19 years. Pooled results indicate that sleep interventions were associated with 10.5 minutes (95% CI, 5.6-15.4) longer nocturnal sleep duration. There was substantial variation between trials. Sources of variation that were not associated with the study effect size included age group, whether the population was identified as having a sleep problem or being at a socioeconomic disadvantage (eg, coming from a low-income family or area), method of assessment of sleep duration (objective vs subjective), location of intervention delivery (home vs school), whether interventions were delivered in person or used parental involvement, whether behavioral theory was used, environmental change, or had greater or lower intensity. Interventions that included earlier bedtimes were associated with a 47-minute sleep extension (95% CI, 18.9-75.0; 3 trials) compared with remaining studies (7.4 minutes; 95% CI, 2.9-11.8; 42 trials) (P = .006 for group difference). Trials of shorter duration (6 months or less) had larger effects.Conclusions and RelevanceInterventions focused on earlier bedtimes may offer a simple, pragmatic, effective way to meaningfully increase sleep duration that could have important benefits for child health.

Body mass index (BMI) overweight/obesity thresholds in South Asian (SA) adults, at equivalent type 2 diabetes risk are lower than for white Europeans (WE). We aimed to define adjusted overweight/obesity thresholds for UK SA children based on equivalent insulin resistance (HOMA-IR) to WE children. In 1138 WE and 1292 SA children 9.0-10.9y, multi-level regression models quantified associations between BMI and HOMA-IR, by ethnic group. HOMA-IR levels for WE children were calculated at established overweight/obesity thresholds (9.5y,10.5y), based on UK90 BMI cut-offs. Quantified associations in SA children were then used to estimate adjusted SA weight status thresholds at the calculated HOMA-IR levels. At 9.5y, current WE BMI overweight and obesity thresholds were 19.2kg/m2, 21.3kg/m2 (boys) and 20.0kg/m2, 22.5kg/m2 (girls). At equivalent HOMA-IR, SA overweight and obesity thresholds were lower by 2.9kg/m2 (95%CI: 2.5–3.3kg/m2) and 3.2kg/m2 (95%CI: 2.7–3.6kg/m2) in boys and 3.0kg/m2 (95%CI: 2.6–3.4kg/m2) and 3.3kg/m2 (95%CI: 2.8–3.8kg/m2) in girls respectively. At these lower thresholds, overweight/obesity prevalences in SA children were approximately doubled (boys:61%,girls:56%). Patterns at 10.5y were similar. In conclusion, SA adjusted overweight/obesity thresholds based on equivalent IR, were markedly lower than BMI thresholds for WE children and defined more than half of SA children as overweight/obese.

Background The National Child Measurement Programme (NCMP) assesses patterns of overweight–obesity in English children. It uses body mass index (BMI), which overestimates body fatness in South Asian children and underestimates body fatness in black children of presumed African ethnicity. Using previously derived BMI adjustments, ensuring that adjusted BMI was similarly related to body fatness in South Asian, black, and white children, we reassessed population body fatness, overweight, and obesity patterns in these ethnic groups in the NCMP. Methods Analyses were based on 2012–13 NCMP data in 582 899 children aged 4–5 years and 485 362 children aged 10–11 years. Standard centile-based approaches defined weight status in each age-group before and after applying BMI adjustments, derived previously with the deuterium dilution method, for South Asian and black children. Findings Among white children, overweight–obesity prevalences were 23% (45 508/197 691) for boys and 21% (39 411/188 663) for girls in 4–5 year olds and 33% (52 635/160 278) and 30% (45 978/151 146), respectively, in 10–11 year olds. Before adjustment, South Asian children had lower overweight–obesity prevalences at 4–5 years (19% of boys [4485/23 191], 19% of girls [4176/22 109]; both p Interpretation Adjusted BMI data reveal a substantial excess of overweight–obesity among English South Asian children (at 4–5 years and especially at 10–11 years) and among black girls (aged 10–11 years), with important implications for prevention. These patterns are not apparent with the use of unadjusted BMI data, which systematically underestimated overweight–obesity prevalences in South Asian children and overestimated them in black children. Funding British Heart Foundation, National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care (South London & North Thames).

BACKGROUND: Associations between sleep duration and type 2 diabetes (T2D) risk markers in childhood have been little studied. We examined associations between self-reported sleep duration and T2D risk markers in children. METHODS: Cross-sectional study of 4525 multiethnic UK children aged 9 to 10 years. Sleep time was calculated from self-reported usual time of going to bed and getting up on a school day, validated in a subset using accelerometers. Fasting blood samples provided levels of serum lipids and insulin, plasma glucose, and HbA1c. Physical measures included height, weight, bioimpedance, and blood pressure. Multilevel linear regression models of anthropometric, T2D, and cardiovascular risk markers with sleep duration were adjusted for sex, age, month, ethnicity, socioeconomic position, observer (physical measures only), and random effect of school. RESULTS: On average, children slept 10.5 hours per night (95% range 8.0–12.0 hours). There were strong inverse graded relationships between sleep duration, adiposity, and diabetes risk markers. In adjusted models, a 1-hour-longer sleep duration was associated with 0.19 lower BMI (95% confidence interval [CI] 0.09 to 0.28), 0.03 kg/m5 lower fat mass index (95% CI 0.00 to 0.05 kg/m5), 2.9% lower homeostasis model assessment insulin resistance (95% CI 1.2% to 4.4%), and 0.24% lower fasting glucose (95% CI 0.03% to 0.44%); there was no association with HbA1c or cardiovascular risk. Associations with insulin and glucose remained after an additional adjustment for adiposity markers. CONCLUSIONS: The finding of an inverse association between sleep duration and T2D risk markers in childhood is novel. Intervention studies are needed to establish the causality of these associations, which could provide a simple strategy for early T2D prevention.

Background High body fat (BF) levels in UK children are a major problem, with particular concerns about children of South Asian and Black (presumed African) origin. However, available national data are based on body mass index (BMI), which underestimates BF in South Asian children and overestimates BF in Black children. We reassessed childhood BF patterns and time trends between 2007–08 and 2012–13 using ethnicity-specific BMI adjustments to derive adjusted BMI levels (aBMI) that were related to BF in an equivalent way across South Asian, Black and White children. Methods Analyses were based on National Child Measurement Programme (NCMP) data from 2007–08 to 2012–13 in 3,195,323 aged 4–5 years and 2,962,673 children aged 10–11 years. aBMI values were derived for South Asian and Black children in a separate study, using body composition measured by the deuterium dilution method. These aBMI values related to BF similarly in South Asians, Blacks and Whites. To examine time trends in mean aBMI and in overweight-obesity prevalence by ethnicity, multiple linear regression and logistic regression analyses were used respectively. Results In the first year (2007–08), mean aBMIs in 10–11 year-olds (boys, girls) compared with Whites (18.64, 18.98 kg/m 2 ) were higher in South Asians (20.08, 19.94 kg/m 2 ; both p 2 ; both p 2 ) were significantly higher in South Asians (0.16, 0.32 kg/m 2 ; both p 2 ; p=0.01, p=0.41*). Among South Asians, both means and mean changes were greater among Bangladeshis and Pakistanis than Indians. Ethnic differences in mean aBMI levels were similar in younger children, but time trends were not as pronounced. Analyses examining overweight-obesity prevalence showed similar findings to those using mean aBMI. Parallel analyses in unadjusted BMI (the usual NCMP data presentation) showed similar time trends but different mean BMI patterns; Black children had highest mean unadjusted BMI values while White boys and South Asian girls had the lowest. *P-Value for difference from Whites Conclusion These analyses using aBMI data emphasise the particularly high (and rising) burden of BF among UK South Asians, compared with both White and Black children. These patterns are not adequately described by unadjusted BMI data, which tend to overestimate the BF burden in Black children and underestimate that in South Asians.

Background The relationship between physical fitness and risk markers for type 2 diabetes (T2D) in children and the contribution to ethnic differences in these risk markers have been little studied. We examined associations between physical fitness and early risk markers for T2D and cardiovascular disease in 9‐ to 10‐year‐old UK children. Methods Cross‐sectional study of 1445 9‐ to 10‐year‐old UK children of South Asian, black African‐Caribbean and white European origin. A fasting blood sample was used for measurement of insulin, glucose (from which homeostasis model assessment [HOMA]‐insulin resistance [IR] was derived), glycated hemoglobin (HbA1c), urate, C‐reactive protein (CRP), and lipids. Measurements of blood pressure (BP) and fat mass index (FMI) were made; physical activity was measured by accelerometry. Estimated VO2 max was derived from a submaximal fitness step test. Associations were estimated using multilevel linear regression. Results Higher VO2 max was associated with lower FMI, insulin, HOMA‐IR, HbA1c, glucose, urate, CRP, triglycerides, LDL‐cholesterol, BP and higher HDL‐cholesterol. Associations were reduced by adjustment for FMI, but those for insulin, HOMA‐IR, glucose, urate, CRP, triglycerides and BP remained statistically significant. Higher levels of insulin and HOMA‐IR in South Asian children were partially explained by lower levels of VO2max compared to white Europeans, accounting for 11% of the difference. Conclusions Physical fitness is associated with risk markers for T2D and CVD in children, which persist after adjustment for adiposity. Higher levels of IR in South Asians are partially explained by lower physical fitness levels compared to white Europeans. Improving physical fitness may provide scope for reducing risks of T2D.

BACKGROUND/OBJECTIVES: Body mass index (BMI) (weight per height(2)) is the most widely used marker of childhood obesity and total body fatness (BF). However, its validity is limited, especially in children of South Asian and Black African origins. We aimed to quantify BMI adjustments needed for UK children of Black African and South Asian origins so that adjusted BMI related to BF in the same way as for White European children. METHODS: We used data from four recent UK studies that made deuterium dilution BF measurements in UK children of White European, South Asian and Black African origins. A height-standardized fat mass index (FMI) was derived to represent BF. Linear regression models were then fitted, separately for boys and girls, to quantify ethnic differences in BMI-FMI relationships and to provide ethnic-specific BMI adjustments. RESULTS: We restricted analyses to 4-12 year olds, to whom a single consistent FMI (fat mass per height(5)) could be applied. BMI consistently underestimated BF in South Asians, requiring positive BMI adjustments of +1.12 kg m(-)(2) (95% confidence interval (CI): 0.83, 1.41 kg m(-)(2); P

Diet and nutrition are strongly implicated in the aetiology of type 2 diabetes; low dietary fibre intake could be an important factor. Evidence from prospective observational studies has suggested that it may be low cereal fibre intake, rather than low fruit and vegetable fibre intake, which is particularly important. In this issue of Diabetologia (DOI 10.1007/s00125-015-3585-9 ) Kuijsten et al report on the prospective associations between different dietary fibre sources and type 2 diabetes risk in the European Prospective Investigation of Cancer and Nutrition (EPIC)-Interact study and set their findings in context with a meta-analysis of relevant published prospective studies. The results presented strengthen the evidence implicating cereal fibre as an important determinant of type 2 diabetes risk and suggest that randomised controlled trials examining the effect of cereal fibre supplementation on type 2 diabetes risk are now needed.

OBJECTIVE Energy intake, energy density, and nutrient intakes are implicated in type 2 diabetes risk in adults, but little is known about their influence on emerging type 2 diabetes risk in childhood. We examined these associations in a multiethnic population of children. RESEARCH DESIGN AND METHODS This was a cross-sectional study of 2,017 children predominantly of white European, South Asian, and black African-Caribbean origin aged 9–10 years who had a detailed 24-h dietary recall and measurements of body composition and provided a fasting blood sample for measurements of plasma glucose, HbA1c, and serum insulin; homeostasis model assessment of insulin resistance was also derived. RESULTS Energy intake was positively associated with insulin resistance. After the removal of 176 participants with implausible energy intakes (unlikely to be representative of habitual intake), energy intake was more strongly associated with insulin resistance and was also associated with glucose and fat mass index. Energy density was also positively associated with insulin resistance and fat mass index. However, in mutually adjusted analyses, the associations for energy intake remained while those for energy density became nonsignificant. Individual nutrient intakes showed no associations with type 2 diabetes risk markers. CONCLUSIONS Higher total energy intake was strongly associated with high levels of insulin resistance and may help to explain emerging type 2 diabetes risk in childhood. Studies are needed to establish whether reducing energy intake produces sustained favorable changes in insulin resistance and circulating glucose levels.

Background Higher screen time is associated with type 2 diabetes (T2D) risk in adults, but the association with T2D risk markers in children is unclear. We examined associations between self-reported screen time and T2D risk markers in children. Methods Survey of 4495 children aged 9–10 years who had fasting cardiometabolic risk marker assessments, anthropometry measurements and reported daily screen time; objective physical activity was measured in a subset of 2031 children. Results Compared with an hour or less screen time daily, those reporting screen time over 3 hours had higher ponderal index (1.9%, 95% CI 0.5% to 3.4%), skinfold thickness (4.5%, 0.2% to 8.8%), fat mass index (3.3%, 0.0% to 6.7%), leptin (9.2%, 1.1% to 18.0%) and insulin resistance (10.5%, 4.9% to 16.4%); associations with glucose, HbA1c, physical activity and cardiovascular risk markers were weak or absent. Associations with insulin resistance remained after adjustment for adiposity, socioeconomic markers and physical activity. Conclusions Strong graded associations between screen time, adiposity and insulin resistance suggest that reducing screen time could facilitate early T2D prevention. While these observations are of considerable public health interest, evidence from randomised controlled trials is needed to suggest causality.

OBJECTIVE: Little is known about levels of physical fitness in children from different ethnic groups in the UK. We therefore studied physical fitness in UK children (aged 9-10 years) of South Asian, black African-Caribbean and white European origin. DESIGN: Cross-sectional study. SETTING: Primary schools in the UK. PARTICIPANTS: 1625 children (aged 9-10 years) of South Asian, black African-Caribbean and white European origin in the UK studied between 2006 and 2007. OUTCOME MEASURES: A step test assessed submaximal physical fitness from which estimated VO2 max was derived. Ethnic differences in estimated VO2 max were estimated using multilevel linear regression allowing for clustering at school level and adjusting for age, sex and month as fixed effects. RESULTS: The study response rate was 63%. In adjusted analyses, boys had higher levels of estimated VO2 max than girls (mean difference 3.06 mL O2/min/kg, 95% CI 2.66 to 3.47, p

In the UK, South Asian adults have increased risks of CHD, type 2 diabetes and central obesity. Black African-Caribbeans, in contrast, have increased risks of type 2 diabetes and general obesity but lower CHD risk. There is growing evidence that these risk differences emerge in early life and that nutritional factors may be important. We have therefore examined the variations in nutritional composition of the diets of South Asian, black African-Caribbean and white European children, using 24 h recalls of dietary intake collected during a cross-sectional survey of cardiovascular health in eighty-five primary schools in London, Birmingham and Leicester. In all, 2209 children aged 9–10 years took part, including 558 of South Asian, 560 of black African-Caribbean and 543 of white European ethnicity. Compared with white Europeans, South Asian children reported higher mean total energy intake; their intakes of total fat, polyunsaturated fat and protein (both absolute and as proportions of total energy intake) were higher and their intakes of carbohydrate as a proportion of energy (particularly sugars), vitamin C and D, Ca and haem Fe were lower. These differences were especially marked for Bangladeshi children. Black African-Caribbean children had lower intakes of total and saturated fat (both absolute and as proportions of energy intake), NSP, vitamin D and Ca. The lower total and saturated fat intakes were particularly marked among black African children. Appreciable ethnic differences exist in the nutritional composition of children's diets, which may contribute to future differences in chronic disease risk.

Aim To examine whether low circulating vitamin C concentrations and low fruit and vegetable intakes were associated with insulin resistance and other Type 2 diabetes risk markers in childhood. Methods We conducted a cross‐sectional, school‐based study in 2025 UK children aged 9–10 years, predominantly of white European, South‐Asian and black African origin. A 24‐h dietary recall was used to assess fruit, vegetable and vitamin C intakes. Height, weight and fat mass were measured and a fasting blood sample collected to measure plasma vitamin C concentrations and Type 2 diabetes risk markers. Results In analyses adjusting for confounding variables (including socio‐economic status), a one interquartile range higher plasma vitamin C concentration (30.9 μmol/l) was associated with a 9.6% (95% CI 6.5, 12.6%) lower homeostatic model assessment of insulin resistance value, 0.8% (95% CI 0.4, 1.2%) lower fasting glucose, 4.5% (95% CI 3.2, 5.9%) lower urate and 2.2% (95% CI 0.9, 3.4%) higher HDL cholesterol. HbA1c concentration was 0.6% (95% CI 0.2, 1.0%) higher. Dietary fruit, vegetable and total vitamin C intakes were not associated with any Type 2 diabetes risk markers. Lower plasma vitamin C concentrations in South‐Asian and black African‐Caribbean children could partly explain their higher insulin resistance. Conclusions Lower plasma vitamin C concentrations are associated with insulin resistance and could partly explain ethnic differences in insulin resistance. Experimental studies are needed to establish whether increasing plasma vitamin C can help prevent Type 2 diabetes at an early stage., What's new? We examined the cross‐sectional associations between intakes of fruit, vegetables and vitamin C, circulating vitamin C concentrations and insulin resistance in UK children.Circulating vitamin C concentration was inversely associated with insulin resistance, while intakes of fruit, vegetable and vitamin C were unrelated to insulin resistance.Low levels of circulating vitamin C concentrations in UK South‐Asian children could contribute to their higher insulin resistance.Further studies (including trials) are needed to examine the association of vitamin C with insulin resistance and its potential implications for Type 2 diabetes prevention.

Background Excess childhood body fatness, overweightness, and obesity are a major public health challenge in the UK. Accurate assessments, usually based on body-mass index (BMI), are crucial. However, recent studies have demonstrated that BMI underestimates body fatness in South Asian children and overestimates it in black African children. These errors are a concern in these ethnic minority populations, particularly UK South Asians, who are at high risk of obesity, type 2 diabetes, and cardiovascular disease. We aimed to develop BMI adjustments for these children to ensure that BMI relates to body fatness in the same way as for white European children. Methods Four recent UK population-based studies, which used deuterium dilution assessments of fat mass as a reference method, were pooled to include 1725 children (52% girls) aged 4–12 years (mean 9·3, SD 1·6) of white European, South Asian, and black African origins. A height-standardised fat-mass index (FMI) was derived to represent body fatness. Linear regression models were fitted, separately by sex, to quantify ethnic differences in BMI–FMI associations and to provide ethnic-specific BMI adjustments. Findings The FMI derived for this study population and used in analyses was fat mass/height 5 , which was independent of height for the 4–12-year age-group. BMI consistently underestimated body fatness in South Asians, requiring a BMI adjustment of +1·12 kg/m 2 (95% CI 0·83–1·41) for boys and +1·07 (0·74–1·39) for girls, irrespective of age and FMI. BMI overestimated body fatness in black Africans. However, adjustments for black African children were more complex, with statistically significant interactions between black African ethnicity and FMI (p=0·004 boys, p=0·003 girls) and between FMI and age-group (p 2 for boys and between −0·22 and −2·86 kg/m 2 for girls for unadjusted BMI values of 13 kg/m 2 in 10–12 year-olds and 25 kg/m 2 in 4–6 year-olds, respectively. Interpretation BMI underestimated body fatness in South Asians and overestimated it in black Africans. Ethnic-specific adjustments—increasing BMI in South Asians and reducing BMI in black Africans—can improve the accuracy of body fatness assessment in these children. Funding This work was supported by the British Heart Foundation (grant ref PG/15/19/31336) and National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care (South London) (grant ref CLAHRC-2013-10022). Primary data collection was funded by the British Heart Foundation (PG/11/42/28895), BUPA Foundation (TBF-S09-019), Child Growth Foundation (GR 10/03), and Wellcome Trust (WT094129MA). MF is supported by Great Ormond Street Hospital Childrens' Charity.

Background and Purpose— UK black African-Caribbean adults have higher risks of stroke than white Europeans and have been shown to have increased carotid intima-media thickness (cIMT). We examined whether corresponding ethnic differences in cIMT were apparent in childhood and, if so, whether these could be explained by ethnic differences in cardiovascular risk markers. Methods— We conducted a 2-stage survey of 939 children (208 white European, 240 black African-Caribbean, 258 South Asian, 63 other Asian, 170 other ethnicity), who had a cardiovascular risk assessment and measurements of cIMT at mean ages of 9.8 and 10.8 years, respectively. Results— Black African-Caribbean children had a higher cIMT than white Europeans (mean difference, 0.014 mm; 95% CI, 0.008–0.021 mm; P Conclusions— UK black African-Caribbean children have higher cIMT levels in childhood; the difference is not explained by conventional cardiovascular risk markers. There may be important opportunities for early cardiovascular prevention, particularly in black African-Caribbean children.

BACKGROUND: Ischemic heart disease (IHD) rates are lower in UK black Africans and black Caribbeans and higher in South Asians when compared with white Europeans. Ethnic differences in lipid concentrations may play a part in these differences. OBJECTIVE: The objective was to investigate blood lipid and dietary patterns in UK children from different ethnic groups. DESIGN: This was a cross-sectional study in 2026 UK children (including 285 black Africans, 188 black Caribbeans, 534 South Asians, and 512 white Europeans) attending primary schools in London, Birmingham, and Leicester. We measured fasting blood lipid concentrations and collected 24-h dietary recalls. RESULTS: In comparison with white Europeans, black African children had lower total cholesterol (−0.14 mmol/L; 95% CI: −0.25, −0.04 mmol/L), LDL-cholesterol (−0.10 mmol/L; 95% CI: −0.20, −0.01 mmol/L), and triglyceride concentrations (proportional difference: −0.11 mmol/L; 95% CI: −0.16, −0.06 mmol/L); HDL-cholesterol concentrations were similar. Lower saturated fat intakes (−1.4%; 95% CI: −1.9%, −0.9%) explained the differences between total and LDL cholesterol. Black Caribbean children had total, LDL-cholesterol, HDL-cholesterol, and triglyceride concentrations similar to those for white Europeans, with slightly lower saturated fat intakes. South Asian children had total and LDL-cholesterol concentrations similar to those for white Europeans, lower HDL-cholesterol concentrations (−0.7 mmol/L; 95% CI: −0.11, −0.03 mmol/L), and elevated triglyceride concentrations (proportional difference: 0.14 mmol/L; 95% CI: 0.09, 0.20 mmol/L); higher polyunsaturated and monounsaturated fat intakes did not explain these lipid differences. CONCLUSIONS: Only black African children had a blood lipid profile and associated dietary pattern likely to protect against future IHD. The loss of historically lower LDL-cholesterol concentrations among UK black Caribbeans and South Asians may have important adverse consequences for future IHD risk in these groups. Am J Clin Nutr 2010;92:776–83.

Background The accurate assessment of overweight–obesity prevalence in UK children of South Asian and black African origin (in whom its consequences are especially adverse) is an important challenge. However, body-mass index (BMI), the marker of body fatness used in most national surveys, differs in its association to body fatness between ethnic groups, which biases ethnic comparisons of body fatness based on BMI. We recalibrated BMI values for ethnicity to assess overweight–obesity prevalence more accurately in UK South Asian and black African children in recent survey data from the National Child Measurement Programme (NCMP), an inclusive assessment programme in English primary schools. Methods Deuterium dilution measurements of body fat and BMI were collated from four recent UK population-based studies (three in schools selected to provide balanced ethnic representation) in 873 children of South Asian, black African, and white European origin aged 9−11 years. Data were analysed with linear regression models to determine the age-adjusted and sex-adjusted BMI differences in South Asian and black African children compared with white Europeans at an equivalent level of body fatness (denoted by fat mass index [kg/m 5 ], which is uncorrelated with height). These BMI adjustments were applied to NCMP 2012–13 survey data in 489 146 children aged 10–11 years to determine ethnic-specific overweight–obesity prevalences; standard NCMP overweight–obesity definitions were used. Findings BMI adjustments for equivalent body fatness were +1·11 kg/m 2 and +0·98 kg/m 2 for South Asian boys and girls, respectively, and −1·20 kg/m 2 and −1·66 kg/m 2 for black African boys and girls, respectively; these adjustments were applied to NCMP data for South Asian and black African children. Overweight–obesity was recorded in 14 538 of 38 201 South Asian children (38·1%, 95% CI 37·6–38·5) and 9839 of 22 672 black African children (43·4%, 42·8–44·0) before BMI adjustment and in 18 145 of 38 201 (47·5%, 47·0–48·0) and 7065 of 22 672 (31·2%, 30·6–31·8), respectively, after adjustment; overweight–obesity was recorded in 92 002 of 292 467 white European children (31·5%, 95%CI 31·3–31·6). Interpretation Use of ethnic-specific BMI adjustments to obtain comparable assessments of body fatness substantially changed observed overweight–obesity prevalences in ethnic minority groups. Adjusted BMI particularly emphasised the substantial overweight–obesity burden in South Asian children, an important priority for prevention. Funding This research was supported by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South London and by grants from the British Heart Foundation (PG/11/42/28895), the Child Growth Foundation (GR 10/03), and the Wellcome Trust (WT094129MA).

Background Shorter sleep duration has been associated with obesity, increased cardiovascular morbidity, and mortality in adults and with obesity in children. However, effects on childhood risk markers for cardiometabolic disease have been little studied. We examined associations between self-reported sleep duration and cardiometabolic risk markers in children and whether sleep duration might explain ethnic differences in insulin resistance. Methods This was a cross-sectional study of 4560 children aged 9–10 years, predominantly of white European, South Asian, and black African origin, from 200 UK primary schools. Children were asked to recall usual time of going to sleep and awakening on a school day. Fasting blood samples provided concentrations of serum insulin, plasma glucose, HbA 1c , and serum lipids. Physical measures included height, weight, bioimpedance, and blood pressures. Multilevel linear regression models examined the association of sleep duration (in hours) with blood markers and anthropometric measures, adjusted for sex, age quartiles, month, ethnicity, socioeconomic status, observer (physical measures only), and random effect for school; percentange changes are given for log transformed outcomes. Informed consent was obtained from parents or children, and ethics approval was given by the Multicentre Research Ethics Committee (Wales). Findings Median sleep duration was 10·5 h (95% central range 8–12). On average, white European children slept longer than South Asian and black African children (10·4 h/night, 10·2, and 10·1, respectively). There were strong inverse graded associations between sleep duration, adiposity, and diabetes risk markers. Per hour increase in sleep duration was associated with 0·8 kg/m 3 lower ponderal index (95% CI 1·2–0·3), 0·03 kg/m 5 lower fat-mass index (0·05–0·0), 1·73% lower HOMA (homoeostatis model assessment) insulin resistance (0·50–3·91), 2·43% lower fasting glucose (0·86–3·97), and 0·19% lower HbA 1c (0·0–0·39) after adjustment. Associations with diabetes risk markers remained after adjustment for adiposity and objective measures of physical activity. Sleep duration did not account for ethnic differences in insulin resistance, and was unrelated to blood pressure and serum lipids. Interpretation The inverse association between type 2 diabetes risk markers and sleep duration in childhood is novel. Intervention studies are needed to establish causal associations, especially since increased sleep duration might offer a strategy for early prevention of type 2 diabetes. Funding This research was supported by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care (South London) and by grants from Diabetes UK and the Wellcome Trust.

Background Frequent takeaway meal consumption has been associated with increased risks of coronary heart disease (CHD), type 2 diabetes (T2D) and obesity in adults. However, the associations between takeaway meal consumption and risk markers for CHD, T2D and obesity have been little studied in children. We set out to examine these associations in a study of 9–0 year-old children. Methods A cross-sectional study of UK primary school children aged 9–10 years from a sample of 85 primary schools in London, Birmingham and Leicester provided balanced numbers of white European, South Asian and black African origin. Children reported their frequency of takeaway meal consumption (never/hardly ever, 1/ week), completed a 24 h dietary recall, had physical measurements including bioelectrical impedance assessment of fat mass and provided a fasting blood sample for measurement of insulin, HbA1c and blood lipids. Standard multilevel linear regression models were used to examine associations between takeaway meal frequency and risk markers. Results 2529 children (response 69%) participated in the study, of whom 1948 had complete data; participants with and without complete data were similar. Among participants, 499 (26%) never/rarely ate a takeaway meal, 894 (46%) did so less than weekly and 545 (28%) did so at least weekly. In models adjusted for age, sex, month, school (random effect), ethnic group and socioeconomic status, higher reported takeaway meal frequency had graded positive associations with fat mass index, serum total and LDL-cholesterol (p trend = 0.03, 0.04, 0.01 respectively). Compared with children who never/hardly ever ate a takeaway meal, children who ate one at least weekly had a higher fat mass index (% difference 10.6% [95% CI 1.00, 20.9%]), a higher total cholesterol (mean difference 0.09 mmol/L [95% CI 0.01, 0.17 mmol/L]) and a higher LDL-cholesterol (mean difference 0.10mmol/L [95% CI 0.02, 0.18 mmol/L]); insulin resistance, HbA1c and blood pressure did not differ. Children with higher takeaway meal frequency had higher total energy, energy density, fat% energy (particularly saturated fat% energy) intakes (all p Conclusion More frequent takeaway meal consumption was associated with higher body fatness, total and LDL-cholesterol levels and with higher energy and fat intakes (particularly saturated fat). Frequent takeaway meal consumption may have adverse cardiometabolic effects but the takeaway effects need to be distinguished from those of other dietary differences in takeaway meal consumers.

Background Although high fruit and vegetable intakes and high vitamin C intake may protect against type 2 diabetes risk, recent evidence in adults has suggested that circulating vitamin C levels, rather than fruit and vegetable intake, could be particularly important. However, the influence of these factors on emerging type 2 diabetes risk in childhood (particularly insulin resistance) has not been reported. We therefore examined these associations in children, including their contributions to emerging ethnic differences in insulin resistance. Methods This investigation is based on a cross-sectional, school-based survey in UK children aged 9–10 years, predominantly of white European, South Asian and black African origin from London, Birmingham and Leicester. Children provided a detailed 24-hour dietary recall (collected by a trained nutritionist) providing intakes of fruit, vegetables and vitamin C, had detailed measurements of body composition and provided a fasting blood sample for measurements of plasma vitamin C, serum insulin, plasma glucose, HbA1c and other metabolic markers; homeostasis model assessment (HOMA) insulin resistance was also derived. Multilevel linear regression models were fitted to provide adjusted means and differences in risk factors. Results Among 2025 participants (68% response rate), intakes of fruit, vegetables and vitamin C showed no associations with markers of insulin resistance, though plasma vitamin C showed an inverse association. In age, gender, month, adiposity and school adjusted analyses, a 1 interquartile range increase in plasma vitamin C level was associated with 9.22% (95% CI 6.25, 12.11%) lower HOMA insulin resistance, 0.75% (95% CI 0.32, 1.18%) lower fasting glucose, a 4.11% (95% CI 2.78, 5.42%) lower urate and 2.26% (95% CI 1.03, 3.51%) higher HDL-cholesterol and (less consistently) a 0.62% (95% CI 0.24, 1.0%) higher HbA1c. Further adjustments for socio-economic status and physical activity did not substantially alter the results. Plasma vitamin C levels were markedly lower among South Asian children; higher levels of HOMA insulin resistance in South Asian children (particularly in Bangladeshis) could be at least partly accounted for (˜20%) by lower plasma vitamin C levels. Conclusion Plasma vitamin C levels (but not fruit, vegetable or vitamin C intakes) are independently associated with insulin resistance in childhood, a consistent pattern to what has been shown in adult studies. Further studies are needed to establish whether this association is causal and can provide a basis for type 2 diabetes prevention.

Background Compared to UK white European adults, UK black African-Caribbean adults have higher mean systolic (SBP) and diastolic (DBP) blood pressure; UK South Asian adults have higher mean DBP but lower SBP. However, information on blood pressure in UK children from different ethnic groups is limited. The aim of this study was to compare blood pressure levels in UK children of black African-Caribbean, South Asian and white European origin. Methods A cross sectional study of 5,666 UK primary school children of South Asian, black African Caribbean, and white European origin aged 9 to 10 years was undertaken. Ethnic and socioeconomic differences in SDP and DBP (as means and differences with their 95% confidence intervals) were obtained from multilevel linear regression models fitting school as a random effect in order to take account of the natural clustering of children within school. All analyses were adjusted for sex, age, month of assessment, blood pressure observer, room temperature and time of day of measurement fitted as fixed effects. The effects of adjustment for height, adiposity (fat mass index, sum of skinfolds) fitted as continuous variables, and socioeconomic circumstances on ethnic differences in blood pressure were then explored. Results After adjustment for height and adiposity, black African-Caribbean children had a lower mean SBP than white Europeans (mean difference 1.62 mmHg, 95% CI 0.86, 2.38 mmHg), while mean DBP was similar (mean difference 0.58 mmHg, 95%CI –0.12, 1.28 mmHg). The mean SBP difference was particularly marked in black African children. In similar analyses, South Asian children had a lower mean SBP (mean difference 1.10 mmHg, 95%CI 0.34, 1.86 mmHg) than white Europeans and a higher mean DBP (mean difference 1.07 mmHg, 95%CI 0.37, 1.76 mmHg). The mean DBP difference was particularly marked among Indian and Bangladeshi, rather than Pakistani, children. Blood pressure was largely unrelated to socioeconomic circumstances; the ethnic differences in blood pressure were not affected by socioeconomic adjustment. Conclusion A blood pressure pattern similar to that in adults is present in UK South Asian but not in UK black African-Caribbean children at 9–10 years. This suggests that key determinants of ethnic differences in blood pressure operate at different stages of the life course in these different ethnic groups. Understanding the reasons for the early emergence of ethnic differences in blood pressure (particularly among South Asians) is an important research priority.

Background There are marked ethnic differences in cardiovascular risk in UK adults; South Asians have high coronary heart disease (CHD) and stroke risks while black African-Caribbeans have high stroke risks and low CHD risks when compared with white Europeans. Ethnic differences in cardiovascular risk factors are apparent in childhood, but ethnic differences in vascular structure and function during childhood have been little studied. We measured common carotid intima-media thickness (cIMT) and carotid-femoral pulse wave velocity (PWV) in UK children from different ethnic groups. Methods School-based study examining the cardiovascular risk profiles of 9–10 year-old UK children, including similar numbers of South Asian, black African-Caribbean and white European participants. Following a baseline cardiovascular risk survey with measurements of body build, blood pressure, fasting blood lipids, insulin and glycated haemoglobin (HbA1c), 1400 children were invited to have ultrasound measurements of cIMT. A subgroup of these children (n = 900) was invited for PWV measurements. All analyses were adjusted for age, gender and allowed for clustering at school level. Results In all, 939 children (67% response) had cIMT measurements and 631 children (70% response) had PWV measurements. Mean cIMT was 0.475 mm (SD 0.035 mm); mean PWV was 5.2 m/s (SD 0.7 m/s). Compared with white European children, black African-Caribbeans had higher cIMT (mean difference 0.014 mm, 95% CI 0.008 to 0.021 mm) and PWV (% difference 3.3, 95% CI 0.4 to 6.2); South Asian children had similar cIMT to white Europeans but slightly higher PWV (% difference 2.7, 95% CI −0.1 to 5.5%). cIMT was positively associated with systolic and diastolic blood pressure but not with other cardiovascular risk markers. In contrast, PWV was positively associated with adiposity, diastolic blood pressure and insulin resistance. Black African-Caribbean children had lower LDL-cholesterol levels and higher insulin and HbA1c levels than white Europeans; South Asian children had higher insulin, HbA1c and triglyceride levels. However, adjustment for these risk factors had little effect on the observed ethnic differences in cIMT and PWV. Conclusions Ethnic differences in cIMT and PWV, adult predictors of cardiovascular risk, are apparent in childhood. These differences are not fully explained by the ethnic differences in established cardiovascular risk markers observed. There may be important opportunities for prevention of cardiovascular disease before adult life in ethnic minority groups at high risk of adult cardiovascular disease.

Introduction UK South Asian adults have high risks of coronary heart disease, stroke and type 2 diabetes (T2D) when compared with Europeans; UK African-Caribbeans have high risks of stroke and T2D and low coronary heart disease risks. With growing evidence that cardiovascular disease risks begin before adulthood, we compared risk factor patterns and vascular disease markers in UK children from these ethnic groups. Methods We conducted a school-based study of cardiovascular risk profiles in 4796 9–10 year-old UK children of South Asian, African-Caribbean and European origin, with substudies of carotid intimal-medial thickness (cIMT) and carotid-femoral pulse wave velocity (cfPWV) in 939 and 631 children respectively. Results Compared with Europeans, UK South Asian children had higher adiposity, diastolic BP, insulin resistance, HbA1c and triglyceride levels; their HDL-cholesterol was low. cfPWV was slightly higher in South Asians and cIMT similar. In contrast, African-Caribbean children had lower adiposity, LDL-cholesterol and triglyceride levels and higher diastolic BP, insulin resistance, HbA1c and HDL-cholesterol; both cfPWV and cIMT were higher in African-Caribbeans. cIMT was positively associated with systolic and diastolic BP, while cfPWV was positively associated with adiposity, diastolic BP and insulin resistance. However, adjustment for these risk factors had little effect on the ethnic differences in cfPWV and cIMT observed. Conclusion Appreciable ethnic differences both in cardiovascular risk factors and vascular disease markers are apparent in children before puberty, which are substantially consistent with adult cardiovascular disease patterns. There may be important opportunities for cardiovascular disease prevention before adult life in high-risk ethnic minority groups.

Introduction There are marked ethnic differences in cardiovascular disease risks in UK adults; South Asians have high risks of coronary heart disease and stroke while black African-Caribbeans have high risks of stroke and slightly low risks of coronary heart disease when compared with white Europeans. Ethnic differences in cardiovascular risk factors are apparent in childhood, but little is known abut ethnic differences in vascular structure and function during childhood. We set out to measure two vascular markers of cardiovascular risk, common carotid intimal-medial thickness (cIMT) and carotid-femoral pulse wave velocity (PWV) in UK children from different ethnic groups. Methods We conducted a school-based study examining the cardiovascular risk profiles of 9–10 year-old UK children, including similar numbers of South Asian, black African-Caribbean and white European participants. Following a baseline cardiovascular risk survey with measurements of body build, blood pressure, fasting blood lipids, insulin and HbA1c, 1400 children were invited to have measurements of cIMT (bilateral measurements were made with a Zonare ultrasound scanner). A subgroup of these children (n=900) was also invited for PWV measurements, made with a Vicorder device. All analyses were adjusted for age, gender and allowed for clustering at school level. Results In all, 939 children (67% response) had measurements of cIMT and 631 children (70% response) had measurements of PWV. Mean cIMT was 0.475 mm (SD 0.035 mm); mean PWV was 5.2 m/s (SD 0.7 m/s). Compared with white European children, black African-Caribbeans had higher cIMT (mean difference 0.014 mm, 95%CI 0.008 to 0.021 mm) and PWV (% difference 3.3, 95%CI 0.4 to 6.2); South Asian children had similar cIMT to white Europeans but slightly higher PWV (% difference 2.7, 95%CI −0.1 to 5.5%). cIMT was positively associated with systolic and diastolic blood pressure but not with other cardiovascular risk markers. In contrast, PWV was positively associated with adiposity, diastolic blood pressure and insulin resistance. Black African-Caribbean children had lower LDL-cholesterol levels and higher insulin and HbA1c levels than white Europeans; South Asian children had higher insulin, HbA1c and triglyceride levels. However, adjustment for these risk factors had little effect on the ethnic differences in cIMT and PWV observed. Conclusions Ethnic differences in cIMT and PWV, markers of long-term cardiovascular risk, are apparent in childhood. These differences are not fully explained by the ethnic differences in established cardiovascular risk markers observed. The results suggest that there may be important opportunities for prevention of cardiovascular disease before adult life, particularly in high-risk ethnic minority groups.

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. Electronic supplementary material The online version of this article (doi:10.1007/s00125-014-3474-7) contains peer-reviewed but unedited supplementary material, which is available to authorised users.