Hypertension represents a major cause of cardiovascular morbidity and mortality, affecting one in three adults worldwide[1]. Intergenerational transmission of blood pressure characteristics has long been demonstrated[2, 3] and may be attributed to a variable combination of genetic and environmental factors[4-8].

Despite some studies demonstrating age-specific effects[9], tracking of cardiovascular traits, including blood pressure, has been shown to persist into adulthood[10]. There has been a suggestion that a stronger maternal-offspring association exists for some cardiovascular risk factors, including hypertension[11-13], although this has not been replicated in other studies[14-16], which has led to speculation that intrauterine influences may contribute to development of risk factors for adult diseases in the offspring[17].

Adolescent blood pressure increases with ageing and the rate of change has been shown to track into later adult life, being associated with higher systolic pressures and thus a greater risk of cardiovascular events[18, 19]. It has been postulated that adolescence provides a critical window for mediating the transition to adult hypertension[20], with the familial aggregation potentially increasing throughout this time[21]. However, there has been limited evidence to support screening and interventions in childhood to prevent later cardiovascular disease[22, 23]. Recent analysis of serial measurements in longitudinal studies have allowed calculation of adolescent blood pressure trajectories, which may facilitate a more accurate depiction of the associations between childhood blood pressure changes and later cardiovascular disease[24], allowing for better stratification of cardiovascular risk and interventions that are targeted[25] rather than population-based[26].

Arterial stiffness, measured non-invasively through pulse wave velocity[27] is independently associated with several cardiovascular risk factors in adults, including systolic hypertension[28, 29]. The main contributors to arterial stiffness are known to be time (age), heart rate and blood pressure[30] - pulse pressure is correlated with arterial stiffness and reflects age-related changes in systolic (increase) and diastolic (decrease) that occur with ageing. Such changes result from the reduced ability to repair damage to collagen and elastin fibres caused by constant expansion and relaxation and may be a reflection of age repair mechanisms more generally[31]. Arterial stiffness is related to ageing in other domains including cognition[32, 33] and thus parental vascular ageing may provide an indicator of an individual offspring's propensity to age across more than just cardiovascular traits, allowing for early interventions that minimise these effects.

The ALSPAC study provides an excellent resource to explore these issues further. In addition to investigating the relationships between blood pressure trajectories and vascular ageing in this study, the project will enable us to clean the existing PWV data. Due to occasional field worker errors and a software upgrade that changed the output fields, it will be first necessary to produce a clean research ready dataset with the arterial stiffness exposures that can subsequently be used by others.