Adiposity and blood pressure have been associated with derangements in cardiac structure and the retinal microvascular architecture in both adults and children. These derangements in adults including left ventricular (LV) hypertrophy (a consequence of increased left ventricular mass) and retinal diameters are associated with an increased risk of myocardial infarction and cardiovascular disease (CDV) mortality. To further our understanding of these associations, the link between the microvasculature and cardiac structure and to tease out the separate and synergistic impact of CVD risk factors, studies need to be undertaken in children and young adults assessing both the microvasculature and cardiac structure, before the disease process is established.

The measures of cardiac structure (left atrial size (LA size), relative wall thickness (RWT) and posterior wall thickness (PWT)) and the retinal microvasculature, provide surrogate measures of CVD which can be assessed non-invasively, are highly reproducible and track through childhood and early adulthood. The identification of a strong link between the microvasculature and measures of cardiac structure could potentially allow further risk stratification to identify sub groups at increased risk of coronary heart disease (CHD), who would not normally be identified by assessment of traditional risk factors. To date these studies have only been undertaken in adults and the results have been varied, a likely consequence of assessing populations with advanced disease, where confounding is difficult to fully adjust for. The Avon Longitudinal Study of Parents and Children (ALSPAC) has followed a cohort of 14,541 children from birth to late adolescence, with measures of adiposity, blood pressure, retinal microvascular architecture and cardiac structure. The ALSPAC study provides the ideal setting to further our understanding of the link between the microvasculature and cardiac structure.

Hypothesis: We hypothesised that retinal microvascular measures (potential predictors) would be associated with derangements in cardiac structure (outcome), independent of cardiovascular risk factors and body mass index (BMI) in adolescence.

Variables: The current study would include all children with cardiac images and ambulatory blood pressure acquired at the 17 year clinic and retinal images acquired at the 11+ year clinic. Other measures to be included in the analsyis are: Gestation, age, mother smoking during pregnancy, mother drank during pregnancy, BMI 17 year clinic, systolic and diastolic BP at the 17 year clinic, sex, paternal SES, height 17 year clinic, pubertal stage at measurement. With the exeption on the ambulatory BP data at the 17 year clinic I have all of the data required for the analysis.

The associations between retinal diameters (potential predictors) and cardiac measures (outcomes) will be modelled using multiple linear regression. The associations between retinal diameters and cardiac measures will be presented unadjusted, a second model including retinal diameter (separately for each retinal vascular measure) gestation and sex, and potential confounding factors (paternal SES, maternal smoking during 1st three months pregnancy, pubertal stage at measurement outcome and height and height2). A third model will include potential mediating factors BMI and systolic BP at age 17 years.