Age-related differences of blood pressure profile in essential hypertension

The purpose was to assess age-related circadian changes of blood pressure profile (BPP) employing a truncated Fourier series with four harmonics (tFs) in patients with essential hypertension. The study was performed on 32 patients with essential hypertension divided in two groups: (A) 15 patients younger than 55 years and (B) 17 patients older than 60 years. Systolic blood pressure (SEP) and diastolic blood pressure (DBP) were monitored every 20 minutes for 24h with a noninvasive portable device (SpaceLabs 90202). To evaluate the existence of SEP and DBP circadian rhythms a one-sample runs-test was performed and the mesor, amplitude, and acrophase from the overall curve of each patient were obtained by tFs. In both groups, SEP and DBP profiles showed a first peak in the late morning and a second peak in the early evening around the same hours. The two peaks in the SEP profile were higher and the two peaks in the DBP profile were lower in older patients than in younger ones (p < .01, p < .05, p < .3, p <.05). The truncated Fourier series with four harmonics evidences different age-related BP profiles characterized by two peaks with higher SEP and lower DBP in elderly patients. These changes of BPP are in accordance with the reported higher risk of cardiovascular events observed around the same hours.