OBJECTIVE: Systolic blood pressure (SBP) and diastolic blood pressure (DBP) increase significantly until around 55 years, when SBP increases, DBP decreases. Whether the rates of change of SBP and DBP with age exhibit a similar dissociation has never been investigated. DESIGN AND PARTICIPANTS: The Data from an Epidemiologic Study on the Insulin Resistance Syndrome Study (D.E.S.I.R.), a 9-year longitudinal study included 2278 men and 2314 women, 30-65 years and SBP, DBP, and other cardiometabolic risk factors were determined every 3 years. RESULTS: Both SBP and DBP increased with age, more rapidly in women than in men. SBP and DBP were higher in the presence of risk factors (except smoking) but the increases with age were similar. For the rates of change, whereas DeltaSBP increased linearly with age, DeltaDBP declined as early as 45 years. This finding was not influenced by sex, menopause or other risk factors but was significantly attenuated in the presence of hypertension at baseline, whether treated or not, and mainly in men. CONCLUSION: DBP increases with age between 30 and 60 years, DeltaDBP tends to be markedly reduced as early as 45 years, in contrast with DeltaSBP. Consequences for the understanding of vascular aging and antihypertensive therapy remain to be explored.