Blood pressure is associated with abnormal arterial structure and function in a community-based cohort of 8-year old children

Introduction: The relationship between blood pressure (BP) and arterial structure and function is not well established, in the first decade of life. Furthermore, low birth weight has been implicated as a risk factor for both later life hypertension and coronary disease. Thus we aimed to describe the relationships between blood pressure, arterial structure and function and birthweight, in a community-based cohort of 8 year-old children.

Methods: We performed detailed anthropometric, metabolic and vascular testing in 290 children (145 boys) followed from birth (as part of an asthma study), during their 8-year follow-up visits. Weight, height, BMI z-score, waist, non-fasting LDL and HDL cholesterol, average supine resting systolic and diastolic BP and prior passive smoke exposure were recorded. These parameters were included in a model to determine correlates of the outcome variables: Mean left and right common carotid intimamedia thickness (IMT), assessed by high-resolution ultrasound as a measure of arterial structure, and carotid to radial pulse pressure ratio (CRPPR-a marker of pulse wave augmentation) and pulse wave velocity (PWV) assessed by arterial tonometry, as measures of arterial function.

Results: Birth weight was 3.48 ± 0.47 kg and weight at 8 years was 29 ± 6.7 kg (BMI z-score 0.49 ± 1.0). Carotid IMT was 0.58 ± 0.06 mm, mean CRPPR was 0.47 ± 0.12 and PWV 6.5 ± 1.0 m/sec. Carotid IMT was significantly associated with systolic BP (r=0.17,P=0.007) and diastolic BP (r=0.16,P=0.01). Similarly CRPPR was associated with systolic BP (r=- 0.35,P<0.0001) and diastolic BP (r=-0.36,P<0.0001). PWV was significantly related to diastolic BP alone (r=0.26,P=0.0009). Weight and BMI z-score at age 8 years were both significantly negatively related to PWV (r = -0.24 and -0.26 respectively, P<0.01). The relationship between IMT and BP remained significant (P<0.02) in a multivariate analysis with adjustment for height and weight. There was no significant relationship between birthweight and IMT, CRPPR, PWV or BP measured at 8 years.

Conclusions: At age 8 years, higher systolic and diastolic blood pressures are significantly and independently associated with markers of abnormal arterial structure and function, in a community-based cohort of children.