Original Article

Association of Serum Uric Acid with Preeclampsia: A Case Control Study

Razia Sultana1, Selina Ahmed2, Nasima Sultana3, S.M. Fazlul Karim4, Farhana Atia5
Abstract
Background: Preeclampsia (PE) is still one of the important causes of maternal and fetal mortality in
Bangladesh. Many researches have been done to identify a unique screening test that would predict the risk of
developing PE before the classic symptoms appear. One of the most accessible and easiest screening tests is serum
uric acid measurement. Numerous studies have demonstrated a relation between elevated maternal serum uric
acid levels and adverse maternal and fetal outcome. Among several pathophysiologic factors the most commonly
accepted explanation for hyperuricemia in PE is increased reabsorption and decreased excretion of uric acid.
Objective: The aim of the present study was to assess the association of serum uric acid with preeclampsia.
Materials and method: A case control study was conducted in the department of Biochemistry, Dhaka Medical
College, Dhaka from July 2010 to June 2011. A total number of 100 pregnant women in third trimester of
pregnancy attending in Obstetrics and Gynaecology department of Dhaka Medical College Hospital were selected
purposively as study subjects. Among them 50 pregnant women with preeclampsia were selected as cases and 50
normal healthy pregnant women as controls. Results: Most of the study subjects were within 21 – 30 years of age
group and mean age in case and control was 24.06±3.71 and 24.66±3.22 years respectively, which was not
statistically different. Mean gestational age in case and control was 33.50±2.55 weeks and 33.60±2.95 weeks
respectively, which was also not statistically different. Among the study subjects majority was primi in both groups
(case 76%, contol 58%) showing no statistical significance. Majority of the subjects in both groups were irregular
in their antenatal checkup (case 52%, contol 40%). Uric acid concentration was measured in all the study
subjects. The mean serum uric acid concentration in cases and controls were 7.01±1.90 mg/dl and 4.55±1.63
mg/dl respectively. This difference was highly significant in statistical point of view. Conclusion: Hyperuricemia
is associated with preeclampsia.
Keywords: Preeclampsia; uric acid.
Delta Med Col J.Jul 2013;1(2):46-50

1. Assistant Professor, Dept of Biochemistry, Delta Medical College, Dhaka, Bangladesh.

2. Professor and Head, Dept of Biochemistry, Popular Medical College, Dhaka, Bangladesh.
3. Professor and Head, Dept of Biochemistry, Dhaka Medical College, Dhaka, Bangladesh.
4. Professor and Head, Dept of Biochemistry, Delta Medical College, Dhaka, Bangladesh.
5. Medical Officer, Adhunik Sadar Hospital, Nilphamari, Bangladesh.

Correspondence: Dr. Razia Sultana. e-mail:lipiarf@yahoo.com

Introduction
Preeclampsia (PE) is still one of the important causes dysfunction has been considered to play a central role
of maternal and fetal mortality.1 In Bangladesh, the in the pathophysiology of preeclampsia.3 Many
incidence of PE is alarmingly high, about 16% of researches have been done to identify a unique
maternal deaths are associated with it.2 PE is still screening test that would predict the risk of developing
regarded as a disease of theories and its etiology has PE before the classic symptoms appear. There is no
remained poorly understood. However, endothelial screening test for PE to be reliable and economic.

46 Delta Med Col J.Jul 2013;1(2)

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One of the most accessible and easiest screening tests prevent PE in near future.12 Therefore, the present
is serum uric acid measurement.4 Several studies have study was designed to assess the association of uric
demonstrated a correlation between elevated maternal acid level in PE.
serum uric acid levels and adverse maternal and fetal
outcome.5
Materials and method
Uric acid is a product of purine degradation catalyzed
by the enzyme xanthine oxidase. Uric acid A case control study was conducted in the department
concentrations are influenced by several factors like of Biochemistry, Dhaka Medical College, Dhaka from
high protein diet, alcohol consumption, increased cell July 2010 to June 2011. A total number of 100
turn over, enzyme defects in purine metabolism, pregnant women in third trimester of pregnancy
altered kidney function, etc. In normal pregnant attending in Obstetrics and Gynaecology department
women serum uric acid concentration initially falls of Dhaka Medical College Hospital were selected
25-35% due to elevation in renal clearance secondary purposively as study subjects. Among them 50
to increased GFR or reduced proximal tubular diagnosed cases of preeclampsia were selected as
reabsorption due to changes in its production rate.6 cases with age range of 18-35 years and 50 normal
Later in pregnancy the serum uric acid level increases healthy age matched pregnant women as controls with
possibly due to raised fetal production, decreased range of 18-32 years. Pregnant women with
binding to albumin and a decline in uric acid clearance pre-existing hypertension, diabetes mellitus and renal
until towards the end of pregnancy when they disease were excluded from the study by history,
approach non-pregnant value.7 There are several
clinical examination and relevant laboratory
potential origins for raised uric acid concentration in
investigations. After obtaining informed written
PE. It is usually secondary to altered renal function,
consent from all the study subjects relevant data were
increased tissue breakdown, increased oxidative stress
documented in a predefined data sheet and maintaining
and increased activity of xanthine oxidase.8 Uric acid
all aseptic precaution blood samples were collected
is filtered, reabsorbed and secreted by the kidney.9 The
from all the study subjects for estimation of serum uric
most commonly accepted explanation for
acid concentration. Serum uric acid level was
hyperuricemia in PE is increased reabsorption and
estimated by colorimetric assay. Statistical analysis
decreased excretion of uric acid.10
was performed by using computer based software,
Uric acid has the ability to promote inflammation, Statistical Package for Social Science (SPSS) for
oxidative stress and endothelial dysfunction which windows version 14. Mean values of different
could promote hypertension, vascular disease and parameters were compared to see the differences
renal disease. An increased serum uric acid level between two groups by using Student’s unpaired ‘t’
indicates underlying oxidative stress. Increased test. Chi-square test was performed to find the
oxidative stress and formation of Reactive Oxygen
statistical difference regarding gravida distribution
Species (ROS) have been proposed as another
between groups. For all statistical analysis, ‘p’ value
contributing source of hyperuricemia noted in PE apart
<0.05 was considered as a lowest level of significance.
from renal dysfunction.10 Uric acid is a potent
mediator of inflammation. Uric acid stimulates
monocytes to produce pro-inflammatory cytokines Results
IL-1β, IL-6 and TNF-α. In preeclamptic women
increased concentration of circulating TNF-α was Age distribution and comparison between groups are
positively correlated to circulating uric acid presented in Table I. Most of the subjects belonged to
concentration.11 The analysis of a combination 21-30 years of age group (case 78%, control 90%). The
biochemical marker, particularly markers related to mean±SD of age between case and control was
vascular dysfunction, such as increased uric acid 24.06±3.71 years and 24.66±3.22 years respectively. The
concentration may enrich our ability to predict and difference was not statistically significant (p = 0.39).

Delta Med Col J.Jul 2013;1(2) 47

Original Article

Table I: Distribution and comparison of age in Table V shows the comparison of serum uric acid
study subjects. concentration between cases and controls. Mean±SD
serum uric acid level in cases and controls were
Age (years) Case (n=50) control (n=50) t-value p-value
7.01±1.90 mg/dl and 4.55±1.63 mg/dl respectively.
≤ 20 6 (12%) 3 (6%)
21-30 39 (78%) 45 (90%)
The level was significantly higher in cases than that of
31-40 5 (10%) 2 (4%)
controls (p = 0.0001).
Mean±SD 24.06±3.71 24.66±3.22 -0.86 0.39 Table V: comparison of serum uric acid
Range 18-35 18-32 concentration between cases and controls
Base line parameters in terms of gestational age, Study subjects Serum uric acid (mg/dl) t-value p-value
gravida and ante natal check up are shown in Table II, Mean±SD
III and IV.
Mean±SD of gestational age in case and control was Case (n=50) 7.01±1.90
6.97 0.0001
33.50±2.55 weeks and 33.60±2.95 weeks respectively. Control (n=50) 4.55±1.63
On the other hand most of the subjects were primi both
in case and control group. Both the parameters did not
differ significantly (p>0.05). Majority of the subjects
in both groups had irregular antenatal check up. Discussion
Table II: Distribution and comparison of The study was aimed to find the association between
gestational age in study subjects serum uric acid and preeclampsia. In the present study
no statistically significant difference was observed
Study Gestational age (weeks) t-value p-value between two groups regarding maternal age and
subjects Mean±SD
gestational age.
Case (n=50) 33.50±2.55
(29-38)
The study reveals incidence of preeclampsia was high
-0.181 0.86
Control (n=50) 33.60±2.95 in primigravid. Similar conclusion was drawn by
(30-38) Odegard et al.13 where they showed nulliparity as a risk
factor for preeclampsia.
Table III: Distribution and comparison of gravida
in study subjects Maximum number of cases and controls received
irregular antenatal check up. The study reveals the
Study Gravida chi square p-value frequency of regular antenatal check up is less in
subjects Primi Multi value preeclamptic patients compared to normal pregnant
Case (n=50) 38 (76%) 12 (24%) women.
3.66 0.06
Hyperuricemia is a common finding in preeclamptic
Control (n=50) 29 (58%) 21 (42%)
pregnancies evident from early pregnancy. Elevated
Table IV: Status of antenatal check up in study serum uric acid concentrations were first noted in
subjects preeclamptic women in the late 1800s. Since that time
numerous reports have demonstrated a relationship
Antenatal check up Case (n= 50) Case (n= 50) between uric acid concentration and severity of the
diseases.14 Severity of PE increases with increasing
Regular 2 (4%) 18 (36%)
uric acid concentration.6 Hyperuricemia is considered
Irregular 26 (52%) 20 (40%) as a risk factor for hypertension, cardiovascular disease
and renal disease, but the role of uric acid in the
None 22 (44%) 12 (24%)
pathophysiology of PE is still not well understood.

48 Delta Med Col J.Jul 2013;1(2)

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While this concept is largely unstudied, we expand 5. Lancet M, Fisher IL. The value of blood uric acid in
upon ideas forwarded by Kang et al.15 to share in the toxemia of pregnancy. J Obstet Gynecol.
hypothesis that an elevated concentration of uric acid in 1956;63:116-19.
preeclamptic women is not simply a marker of disease
severity but rather contributes directly to the 6. Brainbridge SA, Roberts JM. Uric acid as a pathogenic
pathogenesis of disorder. In the present study, we have factor in preeclampsia. Placenta. 2008; 29:67-72.
found that mean serum uric acid concentration were
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normal pregnant women. A good number of studies
women with gestational hyperuricemia at delivery. Am
done previously had revealed similar findings.4,6,16
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acid is a poor predictor of PE.17-19 The development of 8. Johnson RJ, Kang DH, Feig D, Kivligh S, Kanellis J,
methods to predict and prevent PE in early pregnancy Watanabe S, Tuttle KR, Rodriguez IB, Herrera AJ,
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Mazzali M. Is there a pathogenic role of uric acid in
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do appear to identify a subset of preeclamptic women hypertension in pregnancy. Q J Med. 1979;48:593-602.
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maternal complications in the management of women Gynecol. 1996;174:288-91.
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