Abstract:

Objective To explore the characteristics of ambulatory blood pressure of old patients with hypertension and the relationship of cardiovascular risk factors (such as the serum uric acid), parameters of ambulatory blood pressure, and target organ damage. Methods A total of 243 old inpatients with hypertension (the average age was 76.2 years and 84.0% of them were male) who were hospitalized from January 2009 to July 2013 were selected after patients with secondary hypertension, severe infections, or other severe diseases were excluded. Patients underwent the ambulatory blood pressure monitoring (ABPM), biochemical tests of blood, and ultrasound examinations of the heart and carotid arteries. Patients were divided into groups according to their patterns of blood pressure fluctuation. The clinical and ambulatory blood pressure characteristics of each group were analyzed. The relationship of cardiovascular risk factors (such as left ventricular hypertrophy, intima-media thickening of carotid artery, and serum uric acid) and ambulatory blood pressure was also analyzed. Results The elderly hypertension was characterized by nocturnal hypertension and marked morning blood pressure surge. The serum uric acid level was positively correlated to the rhythm of blood pressure (β＜0.001, P=0.008) and morning blood pressure surge (β=0.025, P=0.003). Average nocturnal systolic blood pressure level was independently correlated to left ventricular hypertrophy (χ2=5.435, P=0.020). Age, serum uric acid, and ambulatory pulse pressure were independently correlated to intima-media thickening of carotid artery (χ2=36.578, P<0.001). Conclusion Age and serum uric acid level are important factors that influence the circadian fluctuations of blood pressure of old patients with hypertension. Serum uric acid is closely correlated to intima-media thickening of carotid artery, but not correlated to left ventricular hypertrophy. Increased nocturnal systolic blood pressure is an independent risk factor of left ventricular hypertrophy.

Key words: elderly hypertension, ambulatory blood pressure monitoring, serum uric acid, target organ damage