Maha F.doc

J Bagh College Dentistry Vol. 26(2), June 2014 Assessment of serum

Oral and Maxillofacial Surgery and Periodontics 111

Assessment of serum Interleukin-1β and its correlation
with periodontal health status during pregnancy

Nadia M. Kazem, B.D.S. (1)
Maha Sh. Mahmood, B.D.S, M.Sc. (2)

ABSTRACT
Background: Pregnancy is a stressful state of increased inflammatory activity, and pregnancy – associated hormone
changes can influence periodontal tissues, these inflammatory activity lead to production of inflammatory
mediators. Interleukin 1 beta (IL-1β) is a potent pro-inflammatory cytokines that is consistently associated with
periodontal diseases. This study was designed to determine the periodontal health status and detect the serum level
of IL-1β in the healthy pregnant women at first, second and third trimester and compare it with healthy non pregnant
women, and determine its correlation with different clinical periodontal parameters.
Materials and Methods: Subjects included in the study were sixty six (66) healthy pregnant women with an age range
of 20-35 years old. They were divided into three subgroups according to gestational age, as twenty two (22) women
in each trimester. Also the sample included fifteen (15) married, non pregnant women and didn’t take
contraceptive pills, as control group with same age rang of 20- 35 years. Clinical periodontal parameters were
measured in this study (plaque index, gingival index, bleeding on probing, probing pocket depth and clinical
attachment level). Blood samples were collected from all women under study (pregnant & non pregnant women) to
asses concentrations of IL-1β by mean of enzyme – linked immune sorbent assay (ELISA).
Results: Highly significant statistical differences were observed among the study groups regarding the gingival index
(GI)with p-value( 0.007) and the percentages of bleeding on probing (BOP) p- value(0.00), a significant difference
regarding the probing pocket depth ( PPD) with p-value (0.046) ,and non significant statistical differences regarding
the plaque index (PLI), p-value(0.6) and clinical attachment level (CAL) with p-value (0.371). Interleukin 1-beta ( IL-
1β) serum level showed a highly statistical significant difference among the study groups with p-value (0.00).A
pregnant women showed higher level than non pregnant with a higher value in the second trimester.
Conclusions: The present result revealed that the serum level of IL-1β was higher in pregnant women than non
pregnant women with a highly significant difference. The IL-1β serum concentration reaches the maximum value in
the second trimester of pregnancy. Nevertheless there were weak correlations between clinical periodontal
parameters and serum level of IL-1β.
Key words: Interleukin 1β, Pregnancy, Periodontal health status. (J Bagh Coll Dentistry 2014; 26(2): 111-115).

الخالصة
یؤدي ھذا النشاط االلتھابي الى انتاج وسطاء التھابات مثل . كما ان التغیرات الھرمونیة المصاحبة للحمل تؤثر في انسجة ماحول االسنان , الحمل ھو حالة مرھقة من زیادة النشاط االلتھابي . الخلفیة
تم تصمیم ھذه الدراسة لتحدید الحالة الصحیة النسجة ماحول االسنان . بیتا ھو من السایتوكینات الموالیة لاللتھابات القویة الذي یرتبط باستمرار مع امراض انسجة ماحول االسنان 1المدور الخلوي .سایتوكینات ال

.وتحدید عالقتھ مع معلمات ماحول االسنان السریریة المختلفة , ت مختلفة من الحمل ومقارنتھا مع النساء غیر الحوامل بیتا في النساء الحوامل في فترا 1وكشف المستوى المصلي للسایتوكین
امراءة حامل في كل 22سنة تم تقسیمھن الى ثالث مجموعات فرعیة وفقا لعمر او مرحلة الحمل الى ) 35-20(من النساء الحوامل تراوحت اعمارھن بین ) 66(وستین شمل البحث ستة .المواد وطرائق العمل

كانت معلمات . سنة ) 35-20(كمجموعة مقارنة بنفس متوسط االعمار من ,من النساء المتزوجات غیر الحوامل ولم یاخذن حبوب منع الحمل ) 15(وشملت العینة خمسة عشر. فصل من فصول الحمل الثالثة
تم جمع عینات الدم من جمیع النساء قید .دان االنسجة الرابطةماحول االسنان المستخدمة في ھذه الدراسة ھي مؤشر الصفیحة الجرثومیة و مؤشر التھابات اللثة والنزف عند التسمیر وعمق جیوب اللثة وفق

بیتا باستخدام تقنیة مقایسة االنزیم المرتبط الممتز المناعیة1لتقییم التركیزات المصلیة للسایتوكین ) الحوامل وغیر الحوامل( الدراسة
التوجد فروق فیما یتعلق بمؤشر . یتعلق بعمق جیوب اللثة ھناك فرق كبیر فیما ,یة عالیة بین مجموعات الدراسة یشأن مؤشر التھاب اللثة ومؤشر النزف عند التسمیر لوحظ وجود فروق ذات داللة احصائ.النتائج

بیتا في الفصل 1اعلى قیمة للمدور الخلوي.واظھرت. یة بین مجموعات الدراسة مع بیتا فروقات ذات داللة احصائیة عال1اظھر المستوى المصلي للمدور الخلوي . الصفیحة الجرثومیة وفقدان االنسجة الرابطة
.p=0.00.الثاني من الحمل

بیتا 1المصلي للمدور الخلوي التركیز .النساء غیر الحوامل مع فروق ذات داللة إحصائیة عالیة بیتا كان أعلى في النساء الحوامل من 1كشفت النتیجة الحالیة أن المستوى المصلي من المدور الخلوي االستنتاج
.بیتا1ك وجود عالقة ضعیفة بین المعلمات السریریة ومستوى المصل من المدور الخلوي ومع ذلك كان ھنا. یصل القیمة القصوى في الثلث الثاني من الحمل

INTRODUCTION
Periodontal disease is a common chronic

inflammatory condition of infectious origin that
results in breakdown of the periodontium .When
the inflammation is confined to the soft tissue, it
is called gingivitis. Gingivitis is often caused by
inadequate oral hygiene, and it is reversible with
appropriate oral home care. Untreated gingivitis
may develop into periodontitis, which results in
loss of connective tissue attachment and bone
around teeth (1).

In some individuals, gingivitis may exist as an
independent clinical condition without
progressing to periodontitis. How gingivitis progr-

(1)M.Sc. student Department of Periodontics. College of Dentistry.
University of Baghdad.
(2)Assistant Professor. Department of Periodontics. College of
Dentistry. University of Baghdad.

esses to periodontitis is still unclear. On the other
hand, periodontitis appears to be more specific
inflammatory response to specific periodontal
pathogens residing in the subgingival biofilm.
Nonetheless, it must be noted that, although
bacteria are necessary for disease initiation, they
are not sufficient to cause disease progression
unless there is an associated inflammatory
response within a susceptible host (2). The
bacterial insult at the biofilm-gingival interface
results in the direct destruction of host tissues
through bacterial virulence factors such as
collagenases and leukotoxins, and indirectly
through the activation of host inflammatory cells
such as neutrophils and macrophages ,which in
response to the pathogenic biofilm release effector
molecules such as prostaglandin E2 (3) and
proinflammatory cytokines such as interleukin-

J Bagh College Dentistry Vol. 26(2), June 2014 Assessment of serum

Oral and Maxillofacial Surgery and Periodontics 112

1beta (IL-1β) (4), tumor necrosis factor-alpha
(TNF-α) (5). These signaling molecules modulate
the inflammatory process through the autocrine
and paracrine activation of inflammatory cells,
through mechanisms of chemotaxis (6).
Interleukin-1 is one of the major pro-
inflammatory cytokine involved in the
pathogenesis of periodontitis (7). Its effects range
from regulation of inflammatory mediators to
catabolic effects on osteoclasts and activation of
matrix metalloproteinases (8).

Pregnancy is a physiological process that
affects profoundly even healthy women and there
are many physiological ,anatomic and
biochemical changes that mimic disease processes
.(9)In most studies changes in oral health of
pregnant women have been noticed in the
condition of the dental hard tissue (dental caries)
and soft tissue (periodontium) ,where many
results showed an increase in the severity of
dental caries and periodontal diseases especially
gingivitis.(10,11) During pregnancy, progesterone
levels increase 10-fold and estrogen level 30-
fold compared to those observed on menstrual
cycle due to their continuous production.
Physiological changes in metabolism include oral
microbial species, immune response and cell
metabolism. The increase in progesterone results
in greater vascular permeability, gingival edema,
crevicular fluid levels and prostaglandin
production, which may lead to gingival
inflammation (12). The depth of periodontal
pockets may increase as pregnancy progresses
(13,14); however, the level of activity of the disease
does not necessarily result in loss of periodontal
clinical attachment level (14). There is,
nonetheless, a consensus that pregnant women
suffer a decline in periodontal health status. In
spite of some studies showing no association
between periodontitis and adverse perinatal
outcomes (15) a growing number of studies
indicate that the consequences of periodontitis
activity during pregnancy may affect delivery
outcomes, contributing towards prematurity,
neonates with low birth weight, small for
gestational age and fetal growth restriction (3,16,17).

Within the last two decades, a large number of
cross-sectional, case-control, and cohort
observational studies were carried out to
investigate periodontal disease as a risk factor for
adverse pregnancy outcomes (18). Which involved
miscarriage, preeclampsia, preterm birth (PTB),
low birth weight (LBW), and/or preterm low birth
weight (PLBW) (19). Results of these studies
presented conflicting findings. Most studies
reported positive association (20-22). While the
researches reporting no significant association

took up a small portion (23,24).
The classical theory of ‘focal infection’
speculated that oral foci of infection might be a
contributing factor in triggering systemic
inflammatory response. Investigators
hypothesized that hematogenous translocation of
periodontal bacteria and their products or pro-
inflammatory mediators from sites of periodontal
infection into the fetal membranes, placenta, and
amniotic cavity would induce pathological
processes that could result in adverse outcomes
(25).

MATERIALS AND METHODS

Subjects included in the study were drawn
from patients attending the health care center of
AL-Ameen city and AL-Alweea teaching
hospital. The study groups included sixty six
pregnant women with an age range of 20-35 years
old. They were divided into three subgroups
according to gestational age, as twenty two
women in each trimester, also the sample included
fifteen married, non pregnant women and didn’t
take contraceptive pills, as control group with an
age range of 20-35 years old.

Exclusion criteria: 1- smokers, 2- systemic
antibiotic therapy or anti inflammatory therapy
within the last three months, 3- previous
periodontal treatment within the last three months.

Clinical periodontal parameters were measured
for all women by using periodontal probe by same
examiner. The four surfaces of all teeth except 3rd
molar were examined, the collected data included:
PLI, GI, BOP, PPD and CAL. Two ml of venous
blood were drawn from pregnant women and non
pregnant (control group). Blood sample was
collected in a serum separator tube (SST) and
allow samples to clot for 30 minutes before
centrifugation for 15 minutes at 1000 rpm. Collect
serum and stored samples at –20°C. till used
.The analysis was done by Enzyme Linked
Immuno Sorbent Assay (ELISA) for quantitative
determination of interleukin1β (IL-1β) in serum.
The laboratory analysis was done in the Teaching
Laboratories of Baghdad Medical City.

RESULTS
Non significant statistical differences were
observed among the study groups regarding the
plaque index (PLI), p-value (0.6) (Table 1).Highly
significant statistical differences were observed
among the study groups regarding the gingival
index (GI) with p-value (0.007) (Table2), and the
percentages of bleeding on probing (BOP) p-
value (0.00) (Table 3), a significant difference
regarding the probing pocket depth ( PPD) with
p-value (0.046) (Table4). Non significant

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Oral and Maxillofacial Surgery and Periodontics 113

statistical differences were observed in clinical
attachment level (CAL) with p-value (0.371)
(Table5). Interleukin 1-beta (IL-1β) serum level
showed a highly statistical significant difference
among the study groups with p-value (0.00)
(Table6), also showed the higher value of IL-1β in
the second trimester. The correlation between
means of serum IL-1β and means of PLI for each
study group (Table7). In the 1st trimester, there
was a significant positive strong correlation
between the means of PLI & IL-1β. While there
were non significant positive correlation between
the mean of plaque &IL-1β in the 2nd, 3rd trimester
and control group. Also show positive non
significant correlations between IL-1β serum level
and means of GI in the 1st and 2nd trimesters
while there were negative non significant
correlation in the 3rd trimester and control group
(Table7). IL-1β serum concentration show
positive but non significant correlations with the
percentages of bleeding on probing (BOP) (Table
8) and probing pocket depth (PPD) (Table9) in all
study groups . Positive non significant
correlations also observed between IL-1β &CAL
in the 1st trimester & control group while there is
significant positive correlation in the 3rd trimester
and there is no correlation in the 2nd trimester
(Table 9).

Table1: The mean values of PLI of each
study group with comparison of sig. among

the groups
Groups Mean Pl.I + S.D. p.value Sig.

1st 1.45 0.46

0.60

N.S.

2nd 1.25 0.58
3rd 1.43 0.36

Control 1.06 0.48
ANOVA = 2.578

Table 2: The mean values of GI of each study
group with comparison of sig. among the

groups
Groups Mean GI. + S.D. p.value Sig.

1st 1.115 0.22
0.007

2nd 1.231 0.36
3rd 1.346 0.37

Control 1.050 0.10
ANOVA = 4.297

Table 3: The Chi values of BOP with
comparison of sig. among the groups
Groups Chi DF P.value Sig.

1st

60.682

3 0.00

2nd
3rd

Control

Table 4: The mean values of PPD of each
study group with comparison of sig. among

the groups
Groups Mean PPD. + S.D. p.value Sig.

1st 2.22 2.09
0.046 S

2nd 2.54 1.96
3rd 2.72 1.90

Control 0.93 1.94
ANOVA = 2.783

Table 5: The mean values of CAL of each

study group with comparison of sig. among
the groups

Groups Mean CAL. + S.D. p.value Sig.
1st 1.045 1.58

0.371 NS

2nd 1.22 1.52
3rd 1.36 1.46

Control 0.53 0.96
ANOVA =0.371

Table 6: The mean values of IL-1β of each
study group with comparison of sig. among

the groups
Groups Mean IL-1β + S.D. p.value Sig.

1st 17.227 0.585

0.00 HS 2
nd 19.282 1.22

3rd 18.841 1.23
Control 17.477 0.51

ANOVA =21.754

Table 7: The correlations between mean of
PLI, GI for each study group with the means

of IL-1β

Parameters Serum IL-1β Groups r p. value

1st 0.659 0.01
2nd 0.196 0.382
3rd 0.247 0.268

Control 0.358 0.19

1st 0.13 0.564
2nd 0.191 0.395
3rd -0.271 0.223

Control -0.235 0.399

Table 8: The correlations between mean of
BOP for each study group with the means of

IL-1β
Parameter Serum IL-1β Groups r p. value

BOP

1st 0.115 0.609
2nd 0.255 0.252
3rd 0.154 0.49

Control 0.396 0.144

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Oral and Maxillofacial Surgery and Periodontics 114

DISCUSSION

The present study showed that mean of plaque
index was higher among pregnant groups
especially in the first trimester followed by third
trimester. This finding is in agreement with other
study (26). This finding may be due to increased in
the oral hygiene negligence during pregnancy
especially in the fist trimester due to nausea and
gag reflex. While during third trimester pregnant
women may become restless, exhausted and
anxious also it has been thought that pregnant
women tend to avoid dental care because they
believe poor oral health to be a routine
consequence of pregnancy and because of fear
that dental care would harm the fetus (27).The
increased in the severity of gingivitis during
pregnancy may be exaggerated due to arise in
circulation level of progesterone affecting the
gingival microvasculature (28). Elevated
progesterone levels in pregnancy enhance
capillary permeability and dilatation, resulting in
increased gingival exudate (29).

In the present study there was gradual increase
in the numbers and percentages of bleeding sites
during pregnancy, this could be related to the
increased level of estrogen and progesterone
during pregnancy has a special effect on the
periodontium, which would enhance the reaction
to local stimulation and lead to the occurrence or
increase of inflammation in gingival (30). This
study reported that the probing depth scores
increased gradually in the first, second and in the
third trimester when reach maximum level, this
result in accordance with other studies (31-33). This
could be related to the extended period of the
inflammation. Also could be attributed to the
quick effect of increasing progesterone &
estradiol level which lead to the formation of
prostaglandins & also the presence of high counts
of Prevotella Intermedia (33).

There was no statistical difference between
pregnant and non pregnant women (control group)
in the CAL, this agreed with other study (34). In

this study, they reported there was no support to
the assumption that the wider distribution and
increased severity of gingival inflammation in the
course of pregnancy will cause lasting injuries to
the periodontium.

In this investigation we can notice the serum
level of IL-1β increased from first to the third
trimester .This finding was in accordance with
(35,36) who demonstrated that the serum level of
IL-1β, IL-6 and IL-8 increased during the
gestation period, and reached the maximum value
in the second trimester of pregnancy. This may be
related to increased gingival inflammation during
second trimester which will affect the level of
inflammatory mediators produced by fibroblast
and macrophage (37). Nevertheless there were
weak correlations between clinical periodontal
parameters and serum level of IL-1β, this may be
due to small samples size in this study.

As conclusion; pregnant women have higher
PLI, GI, BOP, deeper periodontal pockets and
more clinical attachment loss in comparison with
non pregnant women. Deep pockets and clinical
attachment loss were low among pregnant
women. The serum level of IL-1β was higher in
pregnant women than non pregnant women with a
highly significant difference. The IL-1β serum
concentration reaches the maximum value in the
second trimester of pregnancy. Nevertheless there
were weak correlations between clinical
periodontal parameters and serum level of IL-1β.

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