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Association Between Periodontitis
Needing Surgical Treatment and
Subsequent Diabetes Risk: A
Population-Based Cohort Study
Shih-Yi Lin,*
†‡
Cheng-Li Lin,
§i
Jiung-Hsiun Liu,
†‡
I-Kuan Wang,*
†‡
Wu-Huei Hsu,*
†
Chao-Jung Chen,
¶#
I-Wen Ting,
†‡
I-Ting Wu,** Fung-Chang Sung,
§i
Chiu-Ching Huang,*
†‡
and Yen-Jung Chang
††
Background: It is well known that patients with diabetes
have higher extent and severity of periodontitis, but the
backward relationship is little investigated. The relationship
between periodontitis needing dental surgery and subse-
quent type 2 diabetes mellitus (DMT2) in those individuals
without diabetes was assessed.
Methods: This is a retrospective cohort study using data
from the national health insurance system of Taiwan. The
periodontitis cohort involved 22,299 patients, excluding
those with diabetes already or those diagnosed with diabetes
within 1 year from baseline. Each study participant was ran-
domly frequency matched by age, sex, and index year with
one individual from the general population without peri-
odontitis. Cox proportional hazards regression analysis was
used to estimate the influence of periodontitis on the risk of
diabetes.
Results: The mean follow-up period is 5.47 –3.54 years.
Overall, the subsequent incidence of DMT2 was 1.24-fold
higher in the periodontitis cohort than in the control cohort,
with an adjusted hazard ratio of 1.19 (95% confidence inter-
val =1.10 to 1.29) after controlling for sex, age, and comor-
bidities.
Conclusions: This is the largest nation-based study exam-
ining the risk of diabetes in Asian patients with periodontitis.
Those patients with periodontitis needing dental surgery
have increased risk of future diabetes within 2 years com-
pared with those participants with periodontitis not requiring
dental surgery. J Periodontol 2014;85:779-786.
KEY WORDS
Diabetes mellitus, type 2; periodontitis; retrospective
studies.
Type 2 diabetes mellitus (DMT2) is
a major global health concern.
The prevalence of diabetes is
increasing rapidly, not only in the in-
dustrialized countries but also in
low-middle income countries.
1,2
The
pathogenesis of DMT2 involves a com-
plicated genetic–environmental interac-
tion. Family history, ethnicity, age, and
obesity might play contributing roles.
3,4
Along with the pathologic process, in-
sulin resistance accompanied by b-cell
dysfunction ensues and is the critical
determinant of developing glucose in-
tolerance and diabetes.
5
Chronic low-
grade inflammation has been proposed
to be the link between insulin resistance,
metabolic syndrome, and DMT2.
6
Stud-
ies have investigated the pathogenic
role of inflammatory mediators, such as
tumor necrosis factor (TNF)-alpha and
interleukin (IL)-6, in the development
of diabetes.
7-9
However, not many
researchers have investigated the as-
sociation between the clinical condition
of chronic inflammation and incident
diabetes.
Periodontitis, a common but complex
disease, manifests chronic infection and
inflammation of the supporting tissues
of the teeth.
10
The effects of periodontitis
might be systemic, rather than being
limited to the teeth and periodontium
* Institute of Clinical Medical Science, China Medical University College of Medicine,
Taichung, Taiwan.
† Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
‡ Division of Nephrology and Kidney Institute, China Medical University Hospital.
§ Management Office for Health Data, China Medical University Hospital.
iDepartment of Public Health, China Medical University, Taichung, Taiwan.
¶ Graduate Institute of Integrated Medicine, China Medical University.
# Proteomics Core Laboratory, Department of Medical Research, China Medical University
Hospital.
** Department of Dentistry, China Medical University Hospital.
†† Department of Health Promotion and Health Education, National Taiwan Normal
University, Taipei, Taiwan. doi: 10.1902/jop.2013.130357
779
J Periodontol • June 2014
only.
11
Therefore, periodontitis might provide a
clinical model to investigate the possible role of
chronic inflammation on health. Periodontitis has
been reported to be associated with strokes and
rheumatoid arthritis.
12,13
Until now, two studies
have attempted to demonstrate an association be-
tween periodontitis and incident diabetes.
14,15
Demmer et al.
14
have reported baseline periodontal
disease as an independent predictor of future di-
abetes in the US population, but the results are
limited because of the inability to exclude un-
diagnosed diabetes at baseline. In a study of Jap-
anese adults, Ide et al.
15
did not find a significant
association between periodontitis and DMT2. Be-
cause periodontitis is common worldwide, knowing
its relationship with glucose homeostasis is impor-
tant for public health management. Moreover, it has
been shown that early detection of glucose in-
tolerance or DMT2 improves the clinical outcome
through lifestyle intervention or pharmacotherapy.
16
DMT2 is an increasing epidemic in Asia.
2
In light of
uncertainties regarding the association of peri-
odontitis and incident diabetes, nation-based in-
surance claims data were used to investigate the
risk of incident diabetes in an Asian diabetic-free
cohort with periodontitis.
MATERIALS AND METHODS
Data Sources
The Taiwan Department of Health integrated 13
health insurance schemes into a universal insurance
program in March 1995. This insurance program has
covered 99% of the total 23.74 million citizens and
contracted with 97% of hospitals and clinics in
Taiwan.
17
The National Health Research Institute
has computerized medical claims and selected sets
of health care data for administrative use and research
with information on the basic patient demographic
status, disease codes, health care rendered, medi-
cations prescribed, admissions, discharges, medical
institutions, and physicians providing the services,
etc. The scrambled identifications secured the
patients’ confidentiality. Thus, this study is ex-
empted from ethics review. The present study data
comes from a database containing complete
medical claims for 1 million people randomly
sampled from the entire insured population. No
significant differences exist in the age, sex, and
insured amount distributions among patients in
this selected database and the original National
Health Insurance Research Database (NHIRD).
This database was used to follow the study cohort
over time. Codes of the International Classification
of Diseases, Ninth Revision, Clinical Modification
(ICD-9-CM) were applied to retrieve information on
diagnosis.
Study Participants
Adult patients aged ‡40 years were enrolled with
periodontal disease based on claims data (ICD-9-CM
codes 523.4 and 523.5) from January 1, 1997 to
December 31, 2009. To ensure the accuracy and
severity of periodontitis, those who underwent peri-
odontal surgery including subgingival curettage
(procedure codes 91006C, 91007C, and 91008C)
and periodontal flap procedure (procedure codes
91009C and 91010C) were selected as the severe
periodontitis cohort. A comparison cohort was se-
lected randomly from those with periodontitis who
did not receive periodontal surgery. The index date
was defined as the date the periodontal surgery was
received. The index date was designated time t
0
, the
first year time t
1
, the second year time t
2
, and an-
nually thereafter (time t
n
). All patients with type 1
diabetes or DMT2 diagnosed before the index date
or any diabetes recorded between time t
0
and time
t
1
were excluded. The control cohort was matched
with the study cohort at a ratio of 1:1 and matched
by sex, age, and index year using the same exclu-
sion criteria. The proportionality assumption based
on the Schoenfeld residuals was tested and found
that the assumption was violated. In the subsequent
analyses, the follow-up period and fitted separate
models were stratified.
Outcome Measures
The primary outcome is the development of DMT2,
which was determined as patients who have been
diagnosed with ICD-9-CM codes 250 at least two
times and concomitantly received antidiabetes
medications. Each study participant was followed
until DMT2 (ICD-9-CM code 250 and who received
antidiabetes agents) was diagnosed or until the time
the participant was censored for loss to follow-up,
death, termination of insurance, or by the end of
follow-up, December 31, 2010. Participants with
hypertension (ICD-9-CM codes 401 to 405), hyper-
lipidemia (ICD-9-CM code 272), coronary artery
disease (ICD-9-CM codes 410 to 414), and obesity
(ICD-9-CM codes 278.00 to 278.01) identified before
the index date were considered as comorbidities.
Statistical Analyses
Statistical software
‡‡
was used for all statistical
analyses. The x
2
test for categorical variables and t
test for continuous variables were used to examine
the difference in the distributions of sociodemo-
graphic and comorbidities between the study and the
comparison cohort.
Cox proportional hazards regression analysis
was used to estimate the risk of diabetes in associ-
ation with periodontitis. The follow-up period was
‡‡ SAS v.9.1 for Windows, SAS Institute, Cary, NC.
780
Periodontitis and Risk of Diabetes Volume 85 • Number 6
partitioned into four segments: 1) within 2 years
(time t
1
to t
3
), 2) 3 to 5 years (time t
4
to t
6
), 3) 6 to 8
years (time t
7
to t
9
), and 4) >8 years (time t
9
to t
n
).
The Poisson regression model was used to examine
how the incidence density rates, the incidence rate
ratio (IRR), and 95% confidence intervals (CIs) of
DMT2 differed for categorical variables or over time.
The event-free survival functions for incident di-
abetes between two cohorts were assessed using the
Kaplan–Meier method, and the log-rank test was
used to examine the difference. All significant levels
were set at a two-tailed Pvalue.
RESULTS
The mean follow-up period is 5.47 –3.54 years. The
periodontitis cohort included 22,299 participants,
and the non-periodontitis cohort involved 22,302
participants during the period from 1997 to 2010
(Table 1). The severe periodontitis and comparison
cohorts were similar in distributions of age and sex,
with a mean age of 53.0 years. The dominant sex was
male (51.8%). The severe periodontitis cohort was
more prevalent with comorbidities, including hy-
pertension, hyperlipidemia, coronary artery disease
(CAD), and obesity (all Pvalues <0.05). The in-
cidence of diabetes was 1.24-fold higher in the severe
periodontitis cohort than in the comparison cohort
(11.3 versus 9.16 per 1,000 person-years), with an
adjusted hazard ratio (HR) of 1.19 (95% CI =1.10 to
1.29; Table 2). The IRR of diabetes was higher for
males than females. Generally, the incidence of di-
abetes increased with age in both cohorts. However,
the age-specific analysis showed that the IRR of
DMT2 is younger in the severe periodontitis cohort
than the control cohort. The adjusted HRs showed
that age, income, hypertension, and hyperlipidemia
were significant risk factors for DMT2.
Table 3 shows that the incidence of DMT2 in the se-
vere periodontitis cohort decreased with follow-up year,
whereas that in the comparison cohort was increasing.
The severe periodontitis cohort
to the comparison cohort IRR
was the highest in the earlier
period,fromtimet
1
to time t
3
(12.7 versus 9.82 per 1,000
person-years), with an ad-
justed HR of 1.23. The elevated
risk disappeared after being
followed up for 6 years. The
cumulative incidence of diabe-
tes was higher in the severe
periodontitis cohort than the
comparison cohort during the
entire follow-up period (log-
rank test, P<0.001; Fig. 1).
DISCUSSION
In this population-based co-
hort study, the association
between periodontitis and
risk of diabetes was con-
firmed. In both cohorts, the
incidence of diabetes in-
creased with age. Participants
with comorbidities of hyper-
tension, hyperlipidemia, and
lower income at baseline are
associated with increased risk
of incident diabetes. More-
over, increased risk of de-
veloping diabetes associated
with severe periodontitis is
observed from time t
1
to time
t
3
after the periodontal sur-
gery. Although the elevated
risk disappeared after being
Ta b l e 1 .
Baseline Characteristics Between Periodontitis Cohorts With
and Without Surgical Treatment in from 1997 to 2010
Periodontitis Needing Surgical Treatment
No (N =22,302) Yes (N =22,299) Pvalue
Age, mean –SD (years) 53.0 –9.69 53.0 –9.60 0.98
†
Stratified age (years)
40 to 64 19,030 (85.3) 19,062 (85.5) 0.64*
‡65 3,272 (14.7) 3,237 (14.5)
Sex
Females 10,759 (48.2) 10,759 (48.3) 0.99*
Males 11,543 (51.8) 11,540 (51.8)
Urbanization
1 (highest) 6,611 (29.6) 8,621 (38.7) <0.001*
2 6,661 (29.9) 6,808 (30.5)
3 4,016 (18.0) 3,583 (16.1)
4 (lowest) 5,014 (22.5) 3,286 (14.7)
Income (NT$)
‡
<15,840 5,165 (23.2) 4,894 (22.0) <0.001*
15,841 to 25,000 11,075 (49.7) 8,551 (38.4)
>25,000 6,062 (27.2) 8,854 (39.7)
Comorbidity
Hypertension 5,432 (24.4) 5,674 (25.5) 0.008*
Hyperlipidemia 3,381 (15.2) 4,361 (19.6) <0.001*
CAD 2,303 (10.3) 2,810 (12.6) <0.001*
Obesity 193 (0.87) 269 (1.21) <0.001*
CAD =coronary artery disease.
Data are presented as n (%) unless otherwise noted. Data for Urbanization representing ‘‘Yes’’ cohorts had one
patient with missing information in totals.
*x
2
test.
† Two-sample ttest.
‡ NT$ =New Taiwan dollars per month. One New Taiwan dollar =US $0.03.
J Periodontol • June 2014 Lin, Lin, Liu et al.
781
followed up for 6 years, the cumulative incidence of
diabetes remained significantly higher in the severe
periodontitis cohort than the comparison cohort during
the entire follow-up period. The above finding suggests
that those patients with periodontitis requiring dental
surgery might have a higher risk of developing diabetes
within 3 years than those patients with periodontitis
who needed no surgery treatment.
Ample clinical studies have established a well-
described bidirectional relationship between diabetes
and periodontitis: patients with diabetes tend to have
periodontitis, and the severity of periodontitis would
influence the glycemic control in established di-
abetes.
18-20
Up to the present, only two clinical
studies have evaluated the risk of incident diabetes in
individuals with periodontitis.
14,15
However, the two
Table 2.
Incidence and Adjusted HR of Diabetes Adjusted by Sex, Age, Urbanization, Income, and
Comorbidity Compared Between Periodontitis Cohorts With and Without Surgical
Treatment
Periodontitis Needing Surgical Treatment
No Yes
Cases Person-Years Rate*Cases Person-Years Rate*IRR
†
(95% CI) Adjusted HR
‡
(95% CI)
All 1,113 121,460 9.16 1,388 122,346 11.3 1.24 (1.18 to 1.30)
§
1.19 (1.10 to 1.29)
§
Sex
Females 515 58,229 8.84 559 58,329 9.58 1.08 (1.01 to 1.17)
i
1 (Reference)
Males 598 63,231 9.46 829 64,017 13.0 1.37 (1.28 to 1.47)
§
1.22 (1.13 to 1.33)
§
Pfor group ·sex interaction 0.004
Age (years)
40 to 64 868 104,818 8.28 1,069 105,154 10.2 1.23 (1.16 to 1.30)
§
1 (Reference)
‡65 245 16,642 14.7 319 17,192 18.6 1.26 (1.11 to 1.43)
§
1.16 (1.04 to 1.29)
§
Urbanization
1 (highest) 315 35,713 8.82 535 47,686 11.2 1.27 (1.11 to 1.46)
§
1 (Reference)
2 357 36,299 9.83 460 38,026 12.1 1.23 (1.07 to 1.41)
§
1.06 (0.97 to 1.17)
3 175 21,266 8.23 204 19,042 10.7 1.30 (1.06 to 1.59)
i
0.94 (0.84 to 1.05)
4 (lowest) 266 28,181 9.44 189 17,585 10.8 1.09 (0.98 to 1.21) 0.93 (0.84 to 1.04)
Income (NT$)
¶
<15,840 310 27,714 11.2 379 27,714 13.7 1.22 (1.10 to 1.36)
§
1.18 (1.06 to 1.31)
i
15,841 to 25,000 541 60,930 8.88 496 45,066 11.0 1.24 (1.15 to 1.34)
§
1.09 (0.99 to 1.19)
>25,000 262 32,816 7.98 513 49,566 10.4 1.30 (1.18 to 1.42)
§
1 (Reference)
Comorbidity
Hypertension
No 629 94,663 6.64 788 93,742 8.41 1.27 (1.19 to 1.34)
§
1 (Reference)
Yes 484 26,797 18.1 600 28,604 21.0 1.16 (1.05 to 1.28)
i
2.14 (1.96 to 2.35)
§
Hyperlipidemia
No 815 105,500 7.73 979 101,721 9.62 1.25 (1.18 to 1.32)
§
1 (Reference)
Yes 298 15,960 18.7 409 20,625 19.8 1.06 (0.94 to 1.19) 1.67 (1.53 to 1.84)
§
CAD
No 923 110,175 8.38 1,121 108,056 10.4 1.24 (1.17 to 1.31)
§
1 (Reference)
Yes 190 11,285 16.8 267 14,290 18.7 1.11 (0.96 to 1.28) 1.01 (0.90 to 1.13)
Obesity
No 1,101 120,723 9.12 1,374 121,268 11.3 1.24 (1.19 to 1.30)
§
1 (Reference)
Yes 12 737 16.3 14 1,078 13.0 0.77 (0.49 to 1.21) 0.97 (0.67 to 1.41)
Data for Urbanization representing ‘‘Person-Years’’ cohorts had one patient with missing information in totals.
* Incidence rate, per 1,000 person-years.
†IRR=incident rate ratio.
‡ Adjusted HR =multivariable analysis including sex, age, income, urbanization, and comorbidities of hypertension, CAD, hyperlipidemia, and obesity.
§P<0.01.
iP<0.001.
¶ NT$ =New Taiwan dollars per month. One New Taiwan dollar =US $0.03.
Periodontitis and Risk of Diabetes Volume 85 • Number 6
782
studies have yielded apparently conflicting results.
In the first National Health and Nutrition Examina-
tion Survey and its epidemiologic follow-up study,
Demmer et al.
14
found that dentate participants with
severe tooth loss have an odds ratio of 1.7 for incident
diabetes compared with those who have less tooth
loss. Demmer et al.
14
used the periodontal index
21
at
the initial dental surveillance, which could not reflect
tooth mobility, attachment loss, or furcation in-
volvement. The study is limited in its vague method of
assessing periodontitis and inability to exclude un-
diagnosed diabetes at baseline.
14
In contrast, the
study by Ide et al.
15
for Japanese individuals aged 30
to 59 years revealed no apparent association be-
tween periodontal disease and incident diabetes, but
the results of the specific study participants cannot be
generalized to the whole general population. Fur-
thermore, they used the community periodontal in-
dex,
22
which is being questioned as a reliable
epidemiologic tool because of its inability to reflect
the true periodontal status.
23
The present study might provide a way to reconcile
these findings. Because the severity of periodontitis
varied from mild gingivitis to edentulism, the intra-
observer difference and misclassification of peri-
odontitis severity may cause disparity in defining
periodontitis among studies. In addition, periodontitis
is indeed highly prevalent among the adult pop-
ulation. A German dental survey assessed recently
that >70% of adults have periodontitis, and at least
one quarter of them present the severe form.
24
Therapy for periodontitis included systemic, hygiene,
corrective, and supportive treatment.
25
Therefore,
the present study defines only those who received
dental surgery for periodontitis as study participants.
It is reported that 91% of adults in Taiwan were af-
fected with periodontitis;
26
thus, a control group
randomly selected from participants with periodontitis,
matched in 1:1 ratio by sex, age, and index year, was
generated. Based on this study design, a significant
increasing risk of incident diabetes in the study co-
hort was found when compared with the control.
There are several possible explanations and evidence
for the present finding. Chronic inflammation of
periodontitis might represent a triggering factor for
insulin resistance.
27
The inflamed periodontium with
high vascularity might provide an endocrine-like
origin for proinflammatory mediators, such as TNF-
a, IL-6, and IL-1, which are all reported to have
insulin-antagonizing actions.
28
The periodontal
Ta b l e 3 .
HR for Diabetes Compared Between Periodontitis Cohorts With and Without Surgical
Treatment by Follow-Up Duration
Periodontitis Needing Surgical Treatment
No Yes
Follow-up Time (years) Cases Person-Years Rate*Cases Person-Years Rate*IRR
†
(95% CI) Adjusted HR
‡
(95% CI)
£2(t
1
to t
3
)581 59,194 9.82 750 59,265 12.7 1.29 (1.22 to 1.36)
§
1.23 (1.11 to 1.37)
§
3–5 (t
4
to t
6
) 301 34,493 8.73 351 34,765 10.1 1.16 (1.08 to 1.24)
§
1.12 (0.96 to 1.30)
6–8 (t
7
to t
9
) 149 17,859 8.34 181 18,159 9.97 1.19 (1.09 to 1.31)
§
1.18 (0.95 to 1.46)
>8(>t
9
) 82 9,914 8.27 106 10,158 10.4 1.26 (1.11 to 1.44)
§
1.22 (0.92 to 1.63)
* Incidence rate, per 1,000 person-years.
†IRR=incident rate ratio.
‡ Adjusted HR =multivariable analysis including sex, age income, urbanization, and comorbidities of hypertension, CAD, hyperlipidemia, and obesity.
§P<0.001.
Figure 1.
Cumulative incidence of diabetes compared between periodontitis
cohorts with and without surgical treatment.
J Periodontol • June 2014 Lin, Lin, Liu et al.
783
microflora, mostly Gram-negative bacteria, might
generate endotoxemia and further worsen insulin re-
sistance.
28
Pussinen et al.
29
reported that endotoxemia
is associated with an increased risk of incident di-
abetes, and the risk is independent of the metabolic
syndrome.
30
In a subgroup analysis of the Hisayama
study, Saito et al.
31
observed that deep pockets are
related to current and future glucose intolerance. Their
findings suggest that periodontitis might be a risk
factor for DMT2 but failed to confirm this hypothesis in
their study. Furthermore, in an animal model of Zucker
diabetic fatty rats, Watanabe et al.
32
found that peri-
odontitis could accelerate the onset of severe insulin
resistance and DMT2. These studies have clearly
indicated an important relationship between peri-
odontitis and potential glucose intolerance, as well
as diabetes. The present findings that patients with
periodontitis needing dental surgery are at increased
risk of diabetes might reflect that it is the severity of
periodontitis rather than treatment that might be
associated with the development of diabetes. Thus,
it would suggest that preventing worsening of peri-
odontitis severity might lessen the risk of diabetes
in those patients with mild periodontitis. Additional
studies might be needed to investigate this re-
lationship.
The present results also reveal that lower income
at baseline had an HR of 1.18 for incident diabetes.
Therefore, it may be assumed that it is the poverty
that contributes to both the development of peri-
odontitis and diabetes in the present study. It was
stated that low socioeconomic status aggravated
the periodontal condition in individuals with DMT2.
33
Additional attempts are needed to minimize the ef-
fects of socioeconomic disparities on incidence of
diabetes and periodontitis. In another aspect, it was
also found that patients receiving periodontal surgery
indeed were wealthier than the comparison partici-
pants. This might explain why only an association
within 3 years of follow-up was seen, because
wealthier people might receive more medical care
and have their diabetes diagnosed sooner.
34
Furthermore, the present results suggest that in-
creased risk of developing diabetes associated with
severe periodontitis is observed within 2 years (be-
tween time t
1
and time t
3
) after periodontal surgery.
Demmer et al.
14
reported that no dose–response
association could be established between the severity
of periodontitis and risk of future diabetes. The
present result showed that the elevated risk of di-
abetes disappeared after being followed up for
3 years. Because the present study cohort enrolled
only those with the worst periodontal status needing
dental surgery, the excess risk of diabetes between
time t
1
and time t
3
is likely attributable to the pre-
existing glucose intolerance and insulin resistance of
past long-term chronic periodontitis. Conversely,
another explanation for the slightly higher HR is that
some patients with periodontitis have underlying
diabetes without being diagnosed before the index
year, and this would fit the observation that the di-
agnosis of diabetes is higher in the patients with
periodontitis in the short term.
The present study has several limitations that
should be considered when interpreting the results.
First, although the incent diabetes diagnosed within 1
year from baseline was excluded, the causal re-
lationships between periodontitis and subsequent
diabetes could not be confirmed. However, it is noted
that the association between periodontitis needing
surgery and the risk of subsequent diabetes existed
within 3 years of follow-up. Second, there is no
precise information about smoking status, lifestyle,
family history, and body mass index. However, this
situation might happen in both groups. Third, certain
participants were followed for a short observation
period (5.47 –3.54 years). However, because the
present findings also indicated the significant effect in
the short period (within 3 years), the short obser-
vation period would further strengthen the present
results. Fourth, there was no precise data about the
severity of periodontitis. However, the dental surgery
for periodontitis in the NHIRD needs strict pre-
operative evaluation and assessment reported in
electronic medical records. The potential for di-
agnostic bias is unlikely. Finally, there are imbal-
ances of comorbidities between the present study
and comparison cohorts. Certain selection bias may
exist, but these confounding factors were adjusted
for. The selection bias would be lessened minimally in
this study. The present study has several strengths.
The comprehensive, detailed, constant, and long-
term follow-up electronic medical records of NHIRD
enable the investigation of a temporal relationship
between periodontitis and diabetes. The nation-
based setting, the universal access to health care,
and the large study size may make the present results
more generalizable and interpretable. Furthermore,
the accuracy of diagnosis based on NHIRD has been
ensured and established.
35,36
CONCLUSIONS
To our knowledge, this is the first nation-based
study demonstrating the chronologic association
between periodontitis and incident diabetes in the
Asian population. Asian diabetes has several unique
characteristics, including a substantial increase of
affected individuals over short periods, relatively
younger onset, and less obesity.
2
There are studies
demonstrating that the diabetes in Asia could be
related to major clinical events, such as cancer,
coronary heart disease, end-stage renal disease, and
Periodontitis and Risk of Diabetes Volume 85 • Number 6
784
stroke.
37-39
Considering the huge health conse-
quences and economic impact of the diabetes epi-
demic, several diabetic risks scores have been
proposed.
3,40,41
Strong evidence exists that screening
and lifestyle intervention of high-risk cases for di-
abetes is protective and cost effective.
42
The phe-
nomenon was observed that, within 3 years of follow-
up, the association between periodontitis and the
risk of developing diabetes existed. The present re-
sults may help to early screen and introduce inter-
vention into this potentially high-risk group for future
diabetes.
ACKNOWLEDGMENT
The authors report no conflicts of interest related to
this study.
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Correspondence: Dr. Yen-Jung Chang, Department of
Health Promotion and Health Education, National Taiwan
Normal University, 162 He-Ping E. Rd., Sec. 1, Da-An
District, Taipei 106, Taiwan. Fax: 886-2-2363-0326;
e-mail: yjchang2012@gmail.com.
Submitted June 6, 2013; accepted for publication August
21, 2013.
Periodontitis and Risk of Diabetes Volume 85 • Number 6
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