The Relationship Between Ambulatory Blood Pressure Monitoring and Uric Acid Level in Hypertensive Patients

Abstract Introduction: Serum uric acid (SUA) is the end product of purine metabolism. Excessive SUA production or decreased renal excretion causes hyperuricemia. Elevated SUA is known to be a risk factor for cardiovascular diseases. It was reported that blood pressure (BP) was higher in patients with elevated uric acid and a decrease in BP was observed after the administration of uric acid-lowering drugs. Methods: We examined the relationship between SUA levels and hypertension in patients admitted to our hospital with hypertension (HT) and undergoing ambulatory blood pressure monitoring (ABPM). A total of 310 patients were included in the study. SUA levels were determined using an enzymatic colorimetric autoanalyzer. ABPM was performed using noninvasive multitasking CR recorders (TM2425; A&D, Tokyo, Japan). Results: Hyperuricemia was observed in 49.6% of the patients. Daytime, nocturnal, and 24-hour diastolic blood pressure (DBP) were significantly higher in patients with hyperuricemia (p=0.021, p=0.029, and p=0.005, respectively). Mean arterial pressure (MAP) and nocturnal MAP values were higher in patients with hyperuricemia (p=0.022 and p=0.003, respectively). The rate of patients with dipper HT was lower in patients with hyperuricemia than those without hyperuricemia (p=0.041). The rate of reverse-dipper HT was found to be higher in patients with hyperuricemia compared to those without hyperuricemia (p=0.022). Conclusion: Elevated uric acid was correlated with DBP, reverse HT, and MAP. Measurement of SUA could provide a valuable aid for the assessment and reduction of cardiovascular risk. Further studies are required to assess the effect of lowering uric acid on the reduction of nocturnal BP and DBP. Key words: Ambulatory blood pressure monitoring, uric acid, dipper hypertension, non-dipper hypertension, reverse-dipper hypertension