Objectives: Arterial stiffness increases with age, diabetes and hypertension, and is linked to the occurrence of cardiovascular complications, independently of traditional risk factors. The important influence of age and blood pressure on arterial stiffness and cardiovascular risk complicates analysis of factors involved in increased arterial stiffness. Study of the PROOF cohort supplied further information by analysis of subjects of identical age using a method that eliminates the immediate influence of blood pressure on pulse wave velocity.
Methods: The PROOF cohort comprised 1011 subjects, aged 65 years, from the city of Saint-Etienne (France). All benefited from 24-h ambulatory blood pressure monitoring coupled with measurement of QKD interval. Ambulatory Arterial Stiffness Index and QKD(100-60), were calculated for each recording. Measurements were performed again 2 years later.
Results: Height-predicted QKD(100-60) was correlated with pulse pressure and the presence of diabetes. We found no significant influence of sex, current smoking or total serum cholesterol. Ambulatory Arterial Stiffness Index, whether it was height predicted or not, only had a significant relationship with blood pressure. Two years later, although the QKD(100-60) remained stable for the overall population, it was reduced in the normotensive subjects. Over the whole population, there was a correlation between the changes in 24-h systolic blood pressure and QKD(100-60).
Conclusion: QKD(100-60), an isobaric index of arterial stiffness, is significantly linked to blood pressure and blood sugar levels in a population of 65-year-old subjects. Two years later, the arterial stiffness increased significantly in the normotensive subjects, whereas it remained stable in the hypertensive subjects.