Influences of abnormal circadian rhythm of blood pressure on carotid artery intima-media thickness and left ventricular hypertrophy

Objective To investigate the influences of abnormal circadian rhythm of blood pressure(BP) on carotid artery intima-media thickness(CA-IMT) and left ventricular hypertrophy(LVH) in the elderly patients with primary hypertension. Methods The elderly patients(n=280) were chosen and their data were collected by using 24-h ambulatory blood pressure monitoring(ABPM), carotid ultrasound and echocardiography. All patients were divided, according to circadian rhythm of BP and percentage of systolic BP(ΔSBP%), into dipper group(n=125, ΔSBP%≥10% but 20%), non-dipper group(n=92, ΔSBP%≥0% but 10%), reverse-dipper group(n=41, ΔSBP%0%) and extreme-dipper group(n=22, ΔSBP%≥20%). The incidence rates of bilateral CA-IMT thickening and LVH were compared and analyzed in 4 groups. Results The incidence rate of CA-IMT thickening was 44.0% in dipper group, 58.7% in non-dipper group, 77.3% in extreme-dipper group and 80.5% in reversedipper group(P0.01). The incidence rate of LVH was 30.4% in dipper group, 44.6% in non-dipper group, 50.0% in extreme-dipper group and 61.0% in reverse-dipper group(P0.01). The incidence rate of CA-IMT thickening complicating LVH was 20.8% in dipper group, 34.8% in non-dipper group, 40.9% in extreme-dipper group and 48.8% in reverse-dipper group(P0.01). The multifactor logistic regression analysis showed that low-density lipoprotein-cholesterol(LDL-C) and fasting plasma glucose had independent predictive effects to the morphological features of BP circadian rhythm(P0.05). Conclusion The incidence rates of CA-IMT thickening and LVH will significantly increase as the severity of abnormal BP circadian rhythm exacerbates in the elderly patients with hypertension.