Association of serum uric acid, morning home blood pressure and cardiovascular risk factors in a population with previous prehypertension: a cross-sectional study

Abstract

Objective: To observe the changes in blood pressure (BP) over 10 years and to investigate current BP association to serum uric acid (SUA) levels and cardiovascular risk factors in the epidemiological data of a target group of patients with prehypertension in 2007.

Design: Cross-sectional study.

Setting: Mlati Subdistrict, Sleman District, Yogyakarta Province, Indonesia.

Participants: A total of 733 patients from 'Mlati Study Database' in 2007 were selected by simple random sampling using statistical software. Subjects had both physical and laboratory examinations.

Outcome measures: Morning home BP and laboratory examination of urine (uric acid excretion and creatinine) and blood samples (SUA, blood urea nitrogen, creatinine, a lipid profile and fasting blood glucose levels).

Results: About 31.1% of 733 subjects with prehypertension became hypertensive after 10 years, 24.6% returned to normal tension and the rest of it remained in prehypertensive state. Mean (SD) of SUA levels in 2017 was significantly higher in men than in women (5.78 (1.25) mg/dL vs 4.52 (1.10) mg/dL, p<0.001). Furthermore, men tended to have high-normal (5-7 mg/dL) or high SUA levels (≥7 mg/dL) compared with women (p<0.001, Relative Risk (RR)=2.60). High-normal and high SUA levels in population with a history of prehypertension were significantly associated with current prehypertension and hypertension only in women (p=0.001, RR=1.21). Age and body mass index was found to be significantly associated with both systolic and diastolic BP in men, but only with systolic BP in women. Fasting blood glucose and SUA levels were significantly associated with systolic and diastolic BP only in women.

Conclusion: We concluded that after 10 years, of 733 subjects with prehypertension, 31.1% became hypertensive. The SUA levels in men are significantly higher than those in women. Moreover, high-normal and high SUA levels were significantly associated with prehypertension and hypertension in women but not in men.

Keywords: epidemiology; hypertension; public health.

Figure 1

Study flow chart. Data collection was conducted two times in 2007 (resulting in a collection of prehypertensive population of 4190 patients) and 2017 (to collect the study sample of 733 and obtain physical and laboratory examinations data). BP, blood pressure; DBP, diastolic blood pressure; HDL, high-density lipoprotein; LDL, low-density lipoprotein; SBP, systolic blood pressure.

Figure 2

Mean of cardiovascular risk factors in different serum uric acid (SUA) levels. The SUA levels were significantly associated with total cholesterol (p=0.001), LDL/low-density lipoprotein (p=0.002), HDL/high- density lipoprotein (p<0.001), triglycerides (p<0.001) and fasting blood glucose (p=0.030). The SUA category: normal (<5 mg/dL), high-normal (5–7 mg/dL) and high (≥7 mg/dL).

Figure 3

A - F) Mean of cardiovascular risk factors in men and women between normal and high-normal/high SUA levels. A and E) Significant differences were found in BMI (p<0.001) and triglycerides (p=0.002) between subjects with normal SUA levels and those with high-normal and high SUA levels in men. B, C, D, F) There were not significant differences (p>0.05) between subjects with normal SUA levels and those with high-normal and high SUA levels in men and women. The SUA category: normal (<5 mg/dL), high-normal (5–7 mg/dL) and high (≥7 mg/dL). BMI, body mass index; LDL, low-density lipoprotein; HDL, high-density lipoprotein; SUA, serum uric acid.