Association between breastfeeding and anthropometry and cardiovascular disease risk factor status in adolescence and young adulthood: the Young Hearts Project, Northern Ireland.

Objective: To examine the association between breastfeeding and blood pressure, anthropometry, and plasma lipid profile in both adolescence and young adulthood. Design: Longitudinal study of biological and behavioural risk factors for cardiovascular disease. Setting: The Young Hearts Project, Northern Ireland Subjects: School children aged 12 years and 15 years who participated in a cross-sectional study of lifestyle and health, and who were followed up as young adults aged 20 – 25 years. Results: There was no significant difference in height, weight, BMI, skin-fold thickness measurements, blood pressure or plasma lipid profile in adolescents who had been breastfed when compared to those who had not been breastfed. However, by the time these adolescents had reached adulthood, those who had been breastfed were significantly taller when compared to those who had not been breastfed (standing height, P=0.013; leg length (P=0.035)). Specifically, the breastfed group were on average taller by 1.7cm (95% CI 0.4, 3.0) and had longer legs by 1cm (95% CI 0.1, 1.9). There was no significant difference in other anthropometric measures, blood pressure or plasma lipid profile in adults who had been breastfed when compared to those who had not been breastfed. Conclusions: Compared with those who had not been breastfed, individuals who had been breastfed were taller in adulthood. Given the known association of increased adult height with improved life expectancy the results from this study support a beneficial effect of breastfeeding.

Dietary patterns and cardiovascular risk factors in adolescents and young adults: the Northern Ireland Young Hearts Project

Dietary pattern (DP) analysis allows examination of the combined effects of nutrients and foods on the markers of CVD. Very few studies have examined these relationships during adolescence or young adulthood. Traditional CVD risk biomarkers were analysed in 12-15-year-olds (n 487; Young Hearts (YH)1) and again in the same individuals at 20-25 years of age (n 487; YH3). Based on 7 d diet histories, in the present study, DP analysis was performed using a posteriori principal component analysis for the YH3 cohort and the a priori Mediterranean Diet Score (MDS) was calculated for both YH1 and YH3 cohorts. In the a posteriori DP analysis, YH3 participants adhering most closely to the 'healthy' DP were found to have lower pulse wave velocity (PWV) and homocysteine concentrations, the 'sweet tooth' DP were found to have increased LDL concentrations, systolic blood pressure, and diastolic blood pressure and decreased HDL concentrations, the 'drinker/social' DP were found to have lower LDL and homocysteine concentrations, but exhibited a trend towards a higher TAG concentration, and finally the 'Western' DP were found to have elevated homocysteine and HDL concentrations. In the a priori dietary score analysis, YH3 participants adhering most closely to the Mediterranean diet were found to exhibit a trend towards a lower PWV. MDS did not track between YH1 and YH3, and nor was there a longitudinal relationship between the change in the MDS and the change in CVD risk biomarkers. In conclusion, cross-sectional analysis revealed that some associations between DP and CVD risk biomarkers were already evident in the young adult population, namely the association between the healthy DP (and the MDS) and PWV; however, no longitudinal associations were observed between these relatively short time periods.

Cognitive maturation in preterm and term born adolescents

Background: Adolescence is a critical period of brain structural reorganisation and maturation of cognitive abilities. This relatively late developmental reorganisation may be altered in individuals who were born preterm.

Methods: We carried out longitudinal neuropsychological testing in 94 very preterm individuals (VPT; before 33 weeks' gestation) and 44 term born individuals at mean ages of 15.3 years ( adolescence) and 19.5 years (young adulthood).

Results: Full scale, verbal and performance IQ and phonological verbal fluency were significantly lower in the VPT group than the term group at both ages. Repeated measures ANOVA showed only one group by time point interaction for semantic verbal fluency (F= 10.25; df = 107; p = 0.002). Paired- sample t tests showed that semantic verbal fluency increased significantly in the term group over adolescence (t = -5.10; df = 42; p < 0.001), but did not increase in the VPT group (t = 0.141; df = 69; p = 0.889). For verbal IQ, there was a significant interaction between time point and sex (F = 4.48; df = 1; p = 0.036) with paired- sample t tests showing that verbal IQ decreased in males between adolescence and adulthood (t = 3.35; df = 71; p = 0.001), but did not change significantly in females (t = 0.20; df = 52; p = 0.845).

Conclusion: Decrements of intellectual functioning in VPT individuals persist into adulthood. Additionally, there is a deficit in the adolescent maturation of semantic verbal fluency in individuals born VPT.