Age-differential association between serum uric acid and incident hypertension

Abstract

Introduction: Increasing evidence suggests that elevated serum uric acid level is associated with an increased risk of hypertension. Although the positive association between serum uric acid and incident hypertension has been reported in many previous studies, this association is inconsistent according to age, sex, lipid profiles and adiposity level. Additionally, data on interaction of serum uric acid and other risk factors on incident hypertension in general Korean population are limited. Thus, we aimed to investigate whether there is an independent association between serum uric acid and the risk of hypertension in Korean population, and to assess the interaction between serum uric acid and other risk factors on the risk of developing hypertension.

Methods: This prospective cohort study included 808 participants aged 40-79 years from the Korean Genome Epidemiology Study (KoGES), which is an ongoing rural community-based cohort study. They were free of hypertension and major cardiovascular disease at baseline. Hypertension was defined as systolic blood pressure ≥ 140 mmHg, diastolic blood pressure ≥ 90 mmHg, or using antihypertensive medication. Serial multivariable linear regression models were used to investigate cross-sectional association between serum uric acid and blood pressure. Covariates were sex, age, body mass index, high-density lipoprotein cholesterol and creatinine. A generalized linear model was used to estimate the relative risks for incident hypertension according to serum uric acid level at baseline. In addition to, to examine the consistency of the observed association between serum uric acid and hypertension, we performed subgroup analyses of participants according to sex, age (< 55, ≥ 55 years), body mass index (< 25, ≥ 25 kg/m2), triglycerides (< 150, ≥ 150 mg/dL), high-density lipoprotein cholesterol (40 ≤, > 40 mg/dL), low-density lipoprotein cholesterol (130 ≤, > 130 mg/dL) and fasting glucose (100 ≤, > 100 mg/dL) levels. The p value for interactions between serum uric acid and other risk factors for incident hypertension were calculated using a Z-test.

Results: In this study, 314 male and 494 female which is middle-aged adults were included. During the mean follow-up of 3.3 years, cases of incident hypertension were 36 (11.5%) in men and 53 (10.7%) in women. In a cross-sectional analysis, serum uric acid level was positively associated with diastolic blood pressure when adjusting for sex, age, body mass index, high-density lipoprotein cholesterol and creatinine only in men. In a longitudinal analysis, the association between serum uric acid and incident hypertension was different by participant’s age (p for interaction=0.009). There was no significant association between serum uric acid and incident hypertension in participants of age ≥ 55 years, but we found a significant association between serum uric acid and incident hypertension in participants of age < 55 years (relative risk 1.74 per 1.0 mg/dL increase in serum uric acid, p=0.002). However, BMI, triglycerides, fasting glucose, high-density lipoprotein and low-density lipoprotein cholesterol did not affect the association between serum uric acid and incident hypertension.

Conclusion: We observed that age-differential association between serum uric acid level and incident hypertension among community-dwelling healthy Korean population. Among people who aged < 55 years, increased serum uric acid level was associated with increased risk of developing hypertension. It is recommended to measure and control serum uric acid level for middle-aged population to identify high-risk individuals and prevent future hypertension.

서론: 여러 선행연구들에서 높은 혈중 요산 수치가 고혈압 발생 위험 증가와 관련이 있었다. 그러나 혈중 요산 농도와 고혈압 발생의 관련성은 연령이나 성별, 혈중 지질, 비만도 등에 따라 달라지기도 하였다. 본 연구에서는 건강한 한국인을 대상으로 고혈압 발생에 대한 혈중 요산 농도의 관련성을 조사하고, 잘 알려진 고혈압 관련 위험요인에 의해 그 관련성이 달라지는지 알아보고자 하였다.

방법: 이 연구는 지역사회에 기반한 전향적 코호트 연구인 Korean Genome Epidemiology Study (KoGES-Kangwha)에 참여한 사람들...