What accounts for ethnic differences in newborn skinfold thickness comparing South Asians and White Caucasians? Findings from the START and FAMILY Birth Cohorts.

OBJECTIVE: South Asians are a high-risk group for type 2 diabetes and coronary heart disease. We sought to determine ethnic differences in newborn adiposity comparing South Asians (SA) to White Caucasians (Whites). METHODS: Seven hundred ninety pregnant women (401 SA, 389 Whites) and their full-term offspring from two birth cohorts in Canada were analyzed. Pregnant women completed a health assessment including a 75-g oral glucose tolerance test to assess for dysglycemia. Birthweight, length, waist and hip circumference, and triceps and subscapular skinfold thickness (a surrogate measure of body adiposity) were measured in all newborns. Multivariate regression was used to identify maternal factors associated with newborn skinfold measurements. RESULTS: South Asian women were younger (30.1 vs 31.8 years, P<0.001), their prepregnancy body mass index was lower (23.7 vs 26.2, P<0.0001) and gestational diabetes was substantially higher (21% vs 13%, P=0.005) compared with Whites. Among full-term newborns, South Asians had lower birthweight (3283 vs 3517 g, P=0.0001), had greater skinfold thickness (11.7 vs 10.6 mm; P=0.0001) and higher waist circumference (31.1 vs 29.9 cm, P=0.0001) compared with Whites. Risk factors for newborn skinfold thickness included South Asian ethnicity (standardized estimate (s.e.): 0.24; P<0.0001), maternal glucose (s.e.: 0.079; P=0.04) and maternal body fat (s.e.: 0.14; P=0.0002). CONCLUSIONS: South Asian newborns are lower birthweight and have greater skinfold thickness, compared with White newborns, and this is influenced by maternal body fat and glucose. Interventions aimed at reducing body fat prior to pregnancy and gestational diabetes during pregnancy in South Asians may favorably alter newborn body composition and require evaluation.

The influence of maternal and infant nutrition on cardiometabolic traits: novel findings and future research directions from four Canadian birth cohort studies.

A mother's nutritional choices while pregnant may have a great influence on her baby's development in the womb and during infancy. There is evidence that what a mother eats during pregnancy interacts with her genes to affect her child's susceptibility to poor health outcomes including childhood obesity, pre-diabetes, allergy and asthma. Furthermore, after what an infant eats can change his or her intestinal bacteria, which can further influence the development of these poor outcomes. In the present paper, we review the importance of birth cohorts, the formation and early findings from a multi-ethnic birth cohort alliance in Canada and summarise our future research directions for this birth cohort alliance. We summarise a method for harmonising collection and analysis of self-reported dietary data across multiple cohorts and provide examples of how this birth cohort alliance has contributed to our understanding of gestational diabetes risk; ethnic and diet-influences differences in the healthy infant microbiome; and the interplay between diet, ethnicity and birth weight. Ongoing work in this birth cohort alliance will focus on the use of metabolomic profiling to measure dietary intake, discovery of unique diet-gene and diet-epigenome interactions, and qualitative interviews with families of children at risk of metabolic syndrome. Our findings to-date and future areas of research will advance the evidence base that informs dietary guidelines in pregnancy, infancy and childhood, and will be relevant to diverse and high-risk populations of Canada and other high-income countries.

Continuous cardiometabolic risk score definitions in early childhood: a scoping review.

BACKGROUND: Cardiometabolic risk (CMR) in young children has been measured using various approaches, including a continuous summary score that incorporates components such as adiposity, lipids, metabolic factors and blood pressure. OBJECTIVES: The objective of this study was to comprehensively review definitions of continuous CMR scores in children <10 years of age. METHODS: A scoping review was conducted using a systematic search of four scientific databases up to June 2016. Inclusion criteria were children <10 years of age and report of a continuous CMR score. RESULTS: Ninety-one articles were included. Most studies were published from 2007 to 2016 (96%). Nearly all continuous CMR scores (90%) were calculated using the sum or the mean of z-scores, and many articles age-standardized and sex-standardized components within their own population. The mean number of variables included in the risk scores was 5 with a range of 3-11. The most commonly included score components were waist circumference (52%), triglycerides (87%), high-density lipoprotein cholesterol (67%), glucose (43%) and systolic blood pressure (52%). IMPORTANCE: Continuous CMR scores are emerging frequently in the child health literature and are calculated using numerous methods with diverse components. This heterogeneity limits comparability across studies. A harmonized definition of CMR in childhood is needed.