Factors Associating with Non-Dipping Pattern of Nocturnal Blood Pressure in Patients with Essential Hypertension

Background: In patients with essential hypertension, a non-dipping blood pressure pattern is a strong risk factor for cardiovascular diseases. However, background factors associating with such a blood pressure pattern remain unknown. Methods: Untreated essential hypertensive patients without chronic kidney diseases who were admitted to our outpatient clinic were included. Blood sampling and 24 h ambulatory blood pressure monitoring were mandatorily performed. Non-dipper status was defined as a maximum decrease in nocturnal systolic blood pressure within 10%. Clinical factors associating with non-dipper status were investigated. Results: A total of 154 patients (56 +/- 12 years old, 86 men) were included. Among baseline characteristics, a higher serum uric acid level was independently associated with non-dipper status (odds ratio 1.03, 95% confidence interval 1.00-1.05, p < 0.05). Among those with non-dipper status, a higher high-sensitivity C-reactive protein level tended to be associated with incremental nighttime systolic blood pressure levels (p = 0.065). Conclusions: Hyperuricemia and micro-inflammation might be associated with attenuated nocturnal blood pressure dipping and incremental nighttime systolic blood pressure levels.