Influence of seasonal variation on blood pressure measurements in children, adolescents and young adults

Seasonal fluctuations in outdoor temperature have been shown to affect blood pressure in adults. The aim of our study was to determine whether blood pressure measurements in children and adolescents in Central Europe undergo seasonal variation or are influenced by outdoor temperature. The blood pressure of 6,714 subjects (3,497 boys, 3,237 girls) aged 3 to 21 (median age 10.6) years was routinely measured. The study cohort comprised both healthy and sick children and adolescents visiting outpatient clinics and during hospitalisation. Cross-sectional analysis showed a significant seasonal variation in blood pressure measurements. The mean increase of systolic/diastolic blood pressure was 4.45/2.42 mmHg during the winter. A significant correlation between average outdoor temperature and systolic blood pressure was found (rho = -0.074 p < 0.001). However, the effect was only detectable at an average temperature below 0 A degrees C/32 A degrees F and above 10 A degrees C/50 A degrees F. For each 1 A degrees C increase in average outdoor temperature, the systolic blood pressure fell by 0.12 mmHg. Blood pressure measurements in children and adolescents, even in a temperate climate, are influenced by temperature and subject to seasonal variation. Considering seasonal variations in blood pressure could be of clinical interest.