MASKED HYPERTENSION HAS HIGHER SERUM URIC ACID LEVEL AND PULSE WAVE VELOCITY THAN SUSTAINED NORMOTENSION, EVEN IN LOW RISK POPULATION

Abstract

Objective: Masked hypertension has been known to have higher cardiovascular risk than sustained normotension. However, little is known about the risk of masked hypertension in low risk population. We compared the cardiovascular risk factors of masked hypertension to other type of hypertension in low risk population. Design and method: Among 626 participants, data of 401 participants (43.7 ± 8.0 years, men = 97) with low risk (calculated SCORE = 0%) were analyzed. Hypertension by office blood pressure (BP) was defined as > = 140/90 mmHg. Hypertension by ambulatory BP was defined as 24-hour BP >=130/80 mmHg, and/or daytime BP >=135/85 mmHg, and/or nighttime BP >=120/70 mmHg. Participants were grouped as normotension and controlled hypertension (NT = 243), white-coat and white coat controlled hypertension (WH = 5), masked and masked uncontrolled hypertension (MH = 119), and sustained and uncontrolled hypertension (SH = 34). Serum uric acid level, 24-hour urine microalbumin, Cornell voltage of electrocardiography and brachial-ankle pulse wave velocity (baPWV) were compared between groups. Results: The serum uric acid level of SH (5.32 ± 1.75 mg/dL) was the highest, followed by that of MH (5.05 ± 1.36 mg/dL), which were significantly higher than that of NT (4.24 ± 1.14 mg/dL) (p < 0.001). The baPWV of SH (1472 ± 198 cm/sec) was the highest, followed by that of MH (1275 ± 164 cm/sec), which were significantly higher than that of NT (1149 ± 121 cm/sec) (p < 0.001). In a multivariate analysis controlled with age, gender, body mass index, estimated glomerular filtration rate, high density lipoprotein cholesterol level, fasting blood glucose level, serum creatinine level and use of antihypertensive medication, the serum uric acid level and baPWV of MH were higher than that of NT (p < 0.001 and p < 0.001, respectively). The level of 24-hour urine microalbumin and Cornell voltage were not different between the types of hypertension in unadjusted and adjusted analysis. Conclusions: Our study suggests that masked hypertension has higher cardiovascular risk than sustained normotension even in low risk population.