Cardiovascular Journal of Africa: Vol 31 No 6 (November/December 2020)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 31, No 6, November/December 2020

298

AFRICA

The contribution of plasma uric acid to the risk of stroke

in hypertensive populations

Jing Shi, Guanyun Yan, Liming Cao, Xue Li, Yiwei Zhang, Suhua Zhao, Changyi Wang, Jianping Ma,

Xiaolin Peng, Hongen Chen, Fulan Hu, Ran Wang

Abstract

Background:

There is limited available evidence of a relation-

ship between uric acid (UA) level and stroke in hypertensive

populations worldwide. We aimed to estimate the relationship

between UA level and stroke in Chinese hypertensive popula-

tions.

Methods:

A total of 4 710 essentially hypertensive Chinese

patients, including 307 with stroke, were recruited consecu-

tively by cluster sampling from 60 communities in Shenzhen

from April 2010 to September 2011. Demographic character-

istics, UA level and stroke diagnosis were collected from every

participant. Logistic regression analysis was used to estimate

the association between UA level and stroke.

Results:

The study population comprised 2 361 females and

2 349 males, with a mean age of 58

11.75 years. There

were significant associations between UA level and stroke

and ischaemic stroke (IS) risk for females in the crude model

(M0), model 1 (M1) and model 2 (M2), with increasing odds

ratios (OR) as the quartiles (Q) increased. The odds of stroke

risk was highest in Q4 in M2 (UA

396

mol/l, OR: 3.05,

95% CI: 1.74–5.36 and OR: 3.19, 95% CI: 1.74–5.85), but not

for males in M0, M1 and M2. A significant dose–response

relationship existed between UA level and stroke, and between

UA level and IS for females but not for males. Hyperuricaemia

(HU) was also significantly associated with stroke and IS

for females but not for males. Taking negative uric acid,

homocysteine, triglycerides, total cholesterol and low-density

lipoprotein cholesterol (UA-Hcy-TG-TC-LDL-C-) as the

reference, the combinations of UA

Hcy

TG-TC-LDL-,

Hcy

LDL-C- and UA

Hcy

LDL-C

were significantly associated with the risk of stroke for

females (OR

2.48, 7.85 and 3.04).

Conclusion:

High UA level could significantly increase stroke

risk in female hypertensive patients. Female hypertensive

patients may benefit from managing UA at normal levels for

stroke prevention.

Keywords:

hypertension, stroke, uric acid, hyperuricaemia, haem-

orrhagic stroke, ischaemic stroke

Submitted 16/10/19, accepted 23/6/20

Published online 12/8/20

Cardiovasc J Afr

2020;

: 298–303

www.cvja.co.za

DOI: 10.5830/CVJA-2020-023

Stroke is the second commonest cause of death and a major

cause of long-term disability worldwide.

1,2

In China, the burden

of stroke is increasing,

with an increasing annual incidence rate

of 8.7%. Stroke has now become the leading cause of death,

4,5

moreover, stroke mortality is projected to double in the next two

decades from two to four million deaths.

Ischaemic stroke (IS) is the most common type of stroke,

accounting for 63 to 84% of all strokes worldwide.

In China, IS

has increased by 43.3% from 1990 to 2013,

with a 28-day fatality

rate of 20%, whereas, haemorrhagic stroke (HS) accounts for

17.1 to 39.4% of all strokes, with the highest 28-day mortality

rate of 49.4%.

The goal of stroke prevention is to identify high-

risk populations and to target the modifiable risk factors.

In a study by Rapsomanik

et al.

, hypertensive patients had a

higher lifetime risk of overall cardiovascular disease compared

with normotensive patients.

From the index age of 30 years,

hypertensive populations had higher lifetime risks of IS and HS

than normotensive populations. Hypertension was also found to

be closely related to uric acid (UA) level.

11-13

Hypertension often accompanies a UA metabolic disorder,

thereby leading to hyperuricaemia (HU). A systematic review

from five countries from North America, Asia and Europe

showed a significant association between HU and increased

risk of hypertension, particularly in young individuals and

women.

Moreover, a systematic review and meta-analysis

indicated that HU may modestly increase the risks of both

stroke incidence and mortality.

While many studies have shown

significant associations between UA level and stroke in the

general population,

15-18

few focused on hypertensive populations.

We therefore conducted this cross-sectional study to estimate

the association between plasma UA level and the risk of stroke,

Department of Epidemiology, School of Public Health,

Harbin Medical University, Harbin, PR China

Jing Shi, MD

Liming Cao, MD

Xue Li, MD

Yiwei Zhang, MD

Suhua Zhao, MD

Fulan Hu, PhD,

hufu1525@163.com

School of Humanities and Social Sciences, Harbin Medical

University, Harbin; Health Culture Research Center of

Shaanxi, PR China

Guanyun Yan, MD

Department of Chronic Disease Prevention and Control,

Shenzhen Nanshan Center for Chronic Disease Control,

Shenzhen, PR China.

Changyi Wang, MD

Jianping Ma, MD

Xiaolin Peng, MD

Hongen Chen, MD

Department of Physiology, School of Basic Medicine,

Harbin Medical University, Harbin, PR China

Ran Wang, MD,

wangranharbin@163.com