The association between changes in blood pressure components and incident cardiovascular diseases

PURPOSE: To determine the association of changes in blood pressure (BP) components between baseline examination (1999-2001) and a second visit (2002-2005) with incident cardiovascular diseases (CVD). METHODS: In 3569 (2048 female) Iranian subjects ≥30 y, systolic BP, diastolic BP, mean arterial pressure (MAP) and pulse pressure (PP) were evaluated in two consecutive visits. Subjects were then followed for cardiovascular events. Multivariate sex-adjusted Cox Proportional-Hazards models were built for each BP component's change, and further adjusted for baseline BP values, traditional cardiovascular risk factors, and their changes. RESULTS: During a median follow-up of 6.09 years after the second examination, 303 CVD cases occurred. A 1 SD increase in systolic BP, diastolic BP and MAP were significantly associated with 21%, 22%, and 95% increased CVD risk after adjustments for baseline values of BP components and other common risk factors (all p-values <0.05). Importantly, diastolic BP change resisted after further adjustment with systolic BP change (hazard ratio 1.21, CI 95% 1.05-1.39). PP change showed no significant association with CVD. CONCLUSIONS: In a middle-aged population, three-year rises in systolic BP, diastolic BP, MAP, but not PP were associated with increased incident CVD. The significant association between diastolic BP change and CVD was shown independent of systolic BP change.