This two-part study was a cross-sectional study conducted from 10/2020 to 05/2022 at 2 centres, Universiti Teknologi MARA (UiTM), Selangor, and the University of Malaya (UM), Kuala Lumpur. Ethical approval was obtained from the ethical committees of UiTM (REC/07/2020(MR/169) and UM (DF RD2018/0110 (L). Content validity index for item (I-CVI) and face validity was conducted to validate the questionnaire. A pilot study of 30 participant and intraexaminer training and calibration were carried out prior to study.
All children and adolescents below 18 years old with T1DM diagnosis at UM and UiTM were invited to participate in the study. They must be able to communicate in English and or Bahasa Melayu. However, those undergoing active orthodontic therapy or using any antibiotics or medications in the last three months that might cause gingival alteration such as drug-induced gingival enlargement was excluded.
The sample size was determined using Epi-Info StatCal® software based on the total number of the eligible T1DM patient (n = 166) [31] and the prevalence of diabetes test knowledge was 50.4% (11.6/ 23x 100)[32]. Considering an attrition rate of 10% with a 95% confidence level and acceptable margin of error of 5.6%, the final sample calculated was 118 (108 + 10%). A total of 113 T1DM patients were recruited. The participants and their parent(s) or caregiver(s) answered the questionnaire during their follow-ups. The questionnaire would be answered by parents of children below 16 years old. Subsequent appointments were arranged for the participants to undergo a dental examination.
Definition
Body mass index (BMI)
BMI was calculated as weight in kilograms divided by height in meters squared, i.e. BMI = weight (kg)/ height2 (m2). The calculated BMI was plotted on the CDC BMI-to-age chart for the respective gender [33] (Table 1).
Table 1
BMI classification
|
Definition
|
Underweight
|
< 5th percentile
|
Normal Weight
|
< 85th centile
|
Overweigh
|
≥ 85th but < 95th centile
|
Obesity
|
≥ 95th centile
|
Blood Pressure (BP)
In this study, BP was reported as systolic BP (SBP) and diastolic BP (DBP) percentiles for age/sex/height. The classification is based on the individual’s age plotted against the percentile of height in SBP or DBP (mmHg) of the respective gender [34]. The height percentile was obtained using the CDC height-for-age percentile of the respective gender. Based on American Academy of Paediatrics, BP categories and stages are as follows [35] (Table 2).
Table 2
Blood pressure classification
In children aged 1–13 years old
|
BP classification
|
Definition
|
Normal
|
< 90th percentile
|
Elevated
|
≥ 90th percentile to < 95th percentile, or 120/80 mm Hg to < 95th percentile (whichever is lower)
|
Stage 1 hypertension (HTN)
|
≥ 95th percentile to < 95th percentile + 12 mmHg, or 130/80 to 139/89 mm Hg (whichever is lower)
|
Stage 2 HTN
|
≥ 95th percentile + 12 mm Hg, or ≥ 140/90 mm Hg (whichever is lower)
|
In children aged ≥ 13 years
|
BP classification
|
Definition
|
Normal
|
< 120/<80 mm Hg
|
Elevated
|
120/<80 to 129/<80 mm Hg
|
Stage 1 HTN
|
130/80 to 139/89 mm Hg
|
Stage 2 HTN
|
≥ 140/90 mm Hg
|
Lipid profile
According to the International Society for Paediatrics and Adolescent Diabetes (ISPAD) and the American Diabetes Association (ADA) recommended low-density lipoprotein cholesterol (LDLC) of < 100 mg/dL (2.6 mmol/L) in youth with DM [36] (Table 3).
Table 3
Lipid profile (LDL-C classification)
Lipid Profile
|
|
LDL-C classification
|
Definition
|
Acceptable
|
< 100 mg/dL (< 2.6 mmol/L)
|
Borderline
|
100–129 mg/dL (2.6–3.3 mmol/L)
|
High
|
130–159 mg/dL (3.4–4.1 mmol/L)
|
Very high
|
160 mg/dL (> 4.1 mmol/ L)
|
High-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), Triglycerides (TG) can be can be categorised according to NIHBL 2011[37].
Table 4
Lipid profile (HDL-C, TC, TG)
Lipid profile
|
HDL-C Classification
|
Definition
|
Low
|
< 40 mg/dL (< 1 mmol/L)
|
Borderline
|
40–45 mg/dL (1-1.2 mmol/L)
|
High
|
> 45 mg/dL (> 1.2 mmol/L)
|
TC
|
Definition
|
High
|
≥ 200 mg/dL (≥ 5.2 mmol/L)
|
Borderline
|
170–199 mg/dL (4.4 to 5.2 mmol/L),
|
Acceptable
|
< 170 mg/dL (4.4 mmol/L).
|
TG of 0–9 years old children
|
TG classification
|
Definition
|
High
|
≥ 100 mg/dL (1.1 mmol/L)
|
Borderline
|
75–99 mg/dL (08 -1.1 mmol/L
|
Acceptable
|
< 75 mg/dL (0.8 mmol/L)
|
TG 10 to 19 years old
|
TG classification
|
Definition
|
High
|
≥ 130 mg/dL (1.5 mmol/L)
|
Borderline
|
90–129 mg/dL (1-1.5mmol/L)
|
Acceptable
|
< 90 mg/dL (1mmol/L)
|
HbA1c
HbA1c is a glycoprotein formed by a direct reaction between blood glucose and haemoglobin. It is routinely in clinical research and clinical practice to evaluate diabetes control. For children, adolescents, and young adults ≤ 25 years old. With access to comprehensive care, HbA1c of < 53 mmol/dL (7.0%) is recommended [38].
Study instrument
(i) Guided Questionnaire (GQ)
Self-reported questionnaires adopted from two recent studies were translated and validated to be used in this study [39, 40]. The GQ consisted of 14 items with eight items on patients’ baseline characteristics and six items on symptoms of PD.
(ii) Clinical Examination
a) Basic periodontal examination (BPE)
The GQ was used to screen for any PD comorbidity among the study participants. The screening result of GQ (positive or negative) was confirmed by a trained and calibrated principal investigator using the basic periodontal examination (BPE) for children and adolescents. The BPE codes formed the basis of the assessment for patients under 18 years old. The examined teeth included one tooth from each sextant, i.e. the upper right six (tooth 16), the upper right one (tooth 11), upper left six (tooth 26), lower left six (tooth 36), lower left one (tooth 31), and lower right six (tooth 46). The WHO 621 probe with a light probing force of 20-25g was used for this assessment. The modified BPE codes were as follows: 0- healthy, 1- bleeding on gentle probing, 2- calculus present and/or plaque retention factors, 3- the presence of 4- 5mm pocket, and 4- the presence of 6mm or more pocket, and *- furcation [41].
In children between 12 and 17 years with erupted permanent teeth, the full range of BPE codes (0 to 4) was used. For children aged between 7 and 11 years with mixed dentition, the BPE codes 0,1, and 2 were used. In the full primary dentition, BPE similar to the one used for children as young as 3 years of age was performed in which the highest BPE value per sextant was entered and the highest sextant value was considered as the individual BPE value [42]. Apart from that, PI [43] and GI [44] were also assessed.
Statistical analysis
Data analysis was performed using the Statistical Package for the Social Sciences (SPSS) Version 20.0. Association between the GQ and the clinical examination was assessed using the Pearson Chi-square test and Fisher exact test. A p-value < 0.05 was considered statistically significant. Diagnostic tests (sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and ROC curve) were performed to measure the performance of each question with the BPE as the reference for the periodontal evaluation. For this purpose, the periodontal status was dichotomised as ‘0’ for healthy and ‘1 and above’ for having PD.