Background
Methods
Study design
Setting
Participants
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Inclusion criteria [28]: patients over the age of 18 years; no history of any genetic syndrome causing periodontitis as its manifestation (e.g., Papillon-Lefèvre syndrome, Leukocyte Adhesion Deficiency, Chédiak-Higashi syndrome,…); no uncontrolled metabolic disease; no active neoplasm; no history of chemotherapy within the last 3 months; no history of radiotherapy within the last 6 months; no immunosuppressive therapy; not pregnant; having either a healthy periodontium or mild localized gingivitis or generalized periodontitis.
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Exclusion criteria [28]: metabolic disease proven to be uncontrolled (determined by attending physician’s notes); periodontal examination not clinically possible; necrotizing periodontitis; fewer than 10 teeth remaining; superinfection with other infectious agents; diagnosis of a new neoplasm or relapse of an old neoplasm; history of intravenous drug abuse; history of comprehensive periodontal treatment within the last 6 months; and withdrawal from participation.
Periodontal examination
Serum and saliva sampling
Medical data collection
Definitions and groups
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Healthy Periodontium (HP): healthy periodontium, reduced but healthy periodontium, localized mild gingivitis
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Mild to moderate periodontitis (MP): generalized stage I or II periodontitis
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Severe periodontitis (SP): generalized stage III or IV periodontitis
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Liver: Aspartate transaminase or alanine transaminase levels higher than 3 times their normal upper limit (NUL); bilirubin levels or phosphatase alkaline levels higher than 2 times their NUL [33].
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Kidney: ≥ 50% increase in creatinine levels compared to baseline in a 7-day period or ≥ 0.3 mg/dL increase in creatinine levels in a 48-h period [34].
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Mild to moderate COVID-19 (MC): Flu-like Manifestations, Fever, Respiratory Symptoms
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Severe to critical COVID-19 (SC): Respiratory Distress, Respiratory Rate > 30, Passive Oxygenation 90% or below, Assisted Oxygenation 93% or below, ICU Transfer, Invasive Ventilation, 50% or more Radiographic Involvement, Shock, Multiorgan Failure, Sepsis
Confounders and covariates
Bias reduction, sample size calculation, data analysis
Results
Participants
General results
Variable | Subcategory | Na | Average ± SDb | Min | Max | Range |
Temperature (Celsius) | Max | 110 | 37.23 ± 0.47 | 36.5 | 40 | 3.5 |
Min | 106 | 36.27 ± 0.46 | 34.2 | 37.4 | 3.2 | |
L3Ac | 106 | 36.69 ± 0.26 | 36.2 | 37.4 | 1.2 | |
Blood Pressure (mmHg) | Systolic L3A | 113 | 114.88 ± 12.35 | 93.33 | 150 | 56.7 |
Diastolic L3A | 113 | 71.86 ± 9.11 | 53.33 | 110 | 56.7 | |
Respiratory Rate (per minute) | Max | 107 | 21.07 ± 4.76 | 15 | 46 | 31 |
L3A | 105 | 18.01 ± 1.09 | 15 | 20.5 | 5.5 | |
Oxygen Saturation (%) | Assisted Oxygenation L3A | 81 | 95.28 ± 2.85 | 81 | 99.7 | 18.7 |
Passive Oxygenation Max | 101 | 93.33 ± 3.71 | 82 | 100 | 18 | |
Passive Oxygenation Min | 106 | 86.18 ± 7.2 | 52 | 98 | 46 | |
Passive Oxygenation L3A | 99 | 90.82 ± 4.83 | 73 | 98 | 25 | |
Baseline | 111 | 85.44 ± 10.85 | 42 | 98 | 56 | |
CT Scan Lung Involvement | Extent (%) | 119 | 35.97 ± 16.83 | 5 | 75 | 70 |
Variable | Subcategory | n | Count | Ratio (%)d | ||
CT Scan Lung Involvement Appearance | Ground Glass Opacities (GGO) | 119 | 63 | 52.9 | ||
Consolidations | 7 | 5.9 | ||||
Atelectasis | 5 | 4.2 | ||||
Nodular | 4 | 3.4 | ||||
Embolic | 1 | 0.8 | ||||
GGO + Consolidations | 18 | 15.1 | ||||
GGO + Atelectasis | 9 | 7.6 | ||||
GGO + Embolic | 8 | 6.7 | ||||
GGO + Nodular | 4 | 3.4 | ||||
Significant Medical History Items | Hypertension | 122 | 41 | 33.6 | ||
Diabetes Mellitus | 16 | 13.1 | ||||
Neoplasm (in remission) | 14 | 11.5 | ||||
Chronic Obstructive Pulmonary Disease | 13 | 10.7 | ||||
End-Stage Renal disease | 10 | 8.2 | ||||
Coronary Artery Disease | 10 | 8.2 | ||||
Autoimmune Disorder | 10 | 8.2 | ||||
Hypothyroidism | 7 | 5.7 | ||||
Asthma | 6 | 4.9 | ||||
Cerebrovascular Accident | 5 | 4.1 | ||||
Chronic Kidney Disease | 4 | 3.3 | ||||
Smoking | Yes | 111 | 30 | 27 | ||
Former | 3 | 2.7 | ||||
No | 78 | 70.3 | ||||
COVID-19 Associated Organ Involvement | Liver | 122 | 17 | 13.9 | ||
Hemato/Vascular | 10 | 8.2 | ||||
Kidney | 7 | 5.7 | ||||
Multiple Organs | 8 | 6.5 | ||||
ICU Admission | Yes | 122 | 27 | 22.1 | ||
No | 95 | 77.9 | ||||
Adverse Event | Yes | 122 | 34 | 27.9 | ||
No | 88 | 72.1 | ||||
COVID-19 Severity | Mild to Moderate | 122 | 66 | 54.1 | ||
Severe to Critical | 56 | 45.9 | ||||
Periodontitis Severity | Healthy / Localized Mild Gingivitis | 122 | 37 | 30.3 | ||
Generalized Stage I or II | 42 | 34.4 | ||||
Generalized Stage III or IV | 43 | 35.2 |
Association between COVID-19, periodontitis, age, and sex
Disease | Group | Sex Frequency (%) | Chi2 Test | |
Male | Female | |||
COVID-19 | MC | 33 (52.4%) | 33 (55.9%) | Chi2 = 0.155 P = 0.69 |
SC | 30 (47.6%) | 26 (44.1%) | ||
Periodontitis | HP | 14 (22.2%) | 23 (39%) | Chi2 = 9.17 P = 0.01* |
MP | 19 (30.2%) | 23 (39%) | ||
SP | 30 (47.6%) | 13 (22%) | ||
Disease | Group | Age Mean + SDa | Test | |
COVID-19 | MC | 49.71 ± 13.89 | Independent t-test P = 0.004* | |
SC | 56.48 ± 11.76 | |||
Periodontitis | HP | 43.16 ± 12.2 | ANOVA test P < 0.001* | |
MP | 54.98 ± 11.95 | |||
SP | 59.02 ± 10.94 |
Association between COVID-19 and periodontitis
Variable | Frequency (%) | Chi2 Test | ||||
---|---|---|---|---|---|---|
Periodontitis Severity | ||||||
COVID-19 Severity | Group | HP | MP | SP | Total | Chi2 = 22.062 P < 0.001* |
MC | 27 (73%) | 28 (66.7%) | 11 (25.6%) | 66 | ||
SC | 10 (27%) | 14 (33.3%) | 32 (74.4%) | 56 | ||
Total | 37 | 42 | 43 | 122 |
Outcome | Parameter | Group | Crude Analysis | Adjusted Combined Analysisa | ||
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P Value | Odds Ratio (95% CIb) | P Value | Odds Ratio (95% CI) | |||
Severe to Critical COVID-19 | Periodontitis Severity | HPc | - | 1.0 | - | 1.0 |
MP | 0.544 | 1.350 (0.513 – 3.556) | 0.528 | 1.551 (0.397 – 6.052) | ||
SP | < 0.001* | 7.855 (2.896 – 21.305) | 0.047* | 4.247 (1.020 – 17.683) | ||
Serum IL-6 | - | 0.002* | 1.049 (1.017 – 1.082) | 0.033* | 1.075 (1.006 – 1.148) | |
Saliva IL-6 | - | 0.009* | 1.147 (1.035 – 1.272) | - | - | |
Serum CRP | - | 0.097 | 1.014 (0.998 – 1.030) | 0.495 | 0.991 (0.966 – 1.017) | |
Saliva CRP | - | 0.333 | 1.084 (0.920 – 1.277) | - | - | |
Mean CAL | - | < 0.001* | 1.857 (1.424 – 2.423) | - | - | |
Mean GI | - | 0.003* | 1.907 (1.242 – 2.926) | - | - | |
Mean MSBI | - | 0.003* | 2.059 (1.277 – 3.322) | - | - | |
Remaining Teeth | - | < 0.001* | 0.807 (0.728 – 0.894) | - | - | |
Age | - | 0.006* | 1.042 (1.012 – 1.073) | 0.109 | 1.042 (0.991 – 1.095) | |
Sex | Femalec | - | 1.0 | - | 1.0 | |
Male | 0.694 | 1.154 (0.565 – 2.354) | 0.466 | 0.646 (0.2 – 2.088) | ||
Comorbidity | Noc | - | 1.0 | - | 1.0 | |
Yes | 0.045* | 2.211 (1.016 – 4.809) | 0.370 | 1.732 (0.521 – 5.755) |
Association between COVID-19, periodontitis, and levels of CRP and IL-6
Marker | COVID-19 Severity | Mean ± Standard Deviation (number of available data) | ANCOVAa | ||||
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Periodontitis Severity Group | Modelb | P Value | |||||
HP | MP | SP | Total | ||||
Serum CRP (mg/dL) | MC | 18.48 ± 23.52 (26) | 27.77 ± 23.96 (22) | 38.09 ± 24.11 (11) | 25.60 ± 24.51 (59) | COVID-19 Only | 0.063 |
Periodontitis Only | 0.098 | ||||||
SC | 26.43 ± 23.64 (7) | 40.44 ± 25.06 (12) | 32.75 ± 24.74 (24) | 33.87 ± 24.53 (43) | Interaction Model: | ||
COVID-19 | 0.152 | ||||||
Total | 20.17 ± 23.41 (33) | 32.24 ± 24.75 (34) | 34.43 ± 24.32 (35) | 29.09 ± 24.74 (102) | Periodontitis | 0.131 | |
COVID-19 × Perio | 0.225 | ||||||
Saliva CRP (mg/dL) | MC | 0.83 ± 1.68 (26) | 1.27 ± 2.69 (22) | 2.45 ± 2.91 (11) | 1.30 ± 2.38 (59) | COVID-19 Only | 0.230 |
Periodontitis Only | 0.080 | ||||||
SC | 0.43 ± 1.13 (7) | 2.33 ± 2.39 (12) | 1.87 ± 2.66 (24) | 1.77 ± 2.44 (43) | Interaction Model: | ||
COVID-19 | 0.587 | ||||||
Total | 0.75 ± 1.58 (33) | 1.65 ± 2.60 (34) | 2.06 ± 2.71 (35) | 1.50 ± 2.40 (102) | Periodontitis | 0.063 | |
COVID-19 × Perio | 0.276 | ||||||
Serum IL-6 (pg/dL) | MC | 5.52 ± 8.71 (25) | 9.82 ± 14.03 (25) | 9.71 ± 8.81 (11) | 8.04 ± 11.25 (61) | COVID-19 Only | < 0.001* |
Periodontitis Only | 0.002* | ||||||
SC | 9.53 ± 6.09 (7) | 15.13 ± 14.28 (14) | 23.52 ± 23.56 (25) | 18.84 ± 19.74 (46) | Interaction Model: | ||
COVID-19 | 0.002* | ||||||
Total | 6.39 ± 8.29 (32) | 11.73 ± 14.16 (39) | 19.30 ± 21.08 (36) | 12.68 ± 16.31 (107) | Periodontitis | 0.101 | |
COVID-19 × Perio | 0.596 | ||||||
Saliva IL-6 (pg/dL) | MC | 1.37 ± 1.56 (25) | 3.28 ± 5.39 (25) | 3.11 ± 2.55 (11) | 2.47 ± 3.81 (61) | COVID-19 Only | < 0.001* |
Periodontitis Only | 0.006* | ||||||
SC | 2.43 ± 1.52 (7) | 5.35 ± 6.14 (14) | 7.17 ± 8.22 (25) | 5.90 ± 7.08 (46) | Interaction Model: | ||
COVID-19 | 0.004* | ||||||
Total | 1.60 ± 1.59 (32) | 4.03 ± 5.68 (39) | 5.93 ± 7.20 (36) | 3.94 ± 5.69 (107) | Periodontitis | 0.101 | |
COVID-19 × Perio | 0.744 |
Association between adverse events and periodontal parameters
Variable | Mean ± Standard Deviation | Logistic Regressiona | ||
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Adverse Event | P Value | Odds Ratio (95% Confidence Interval) | ||
No | Yes | |||
Mean Clinical Attachment Level | 1.61 ± 1.53 | 2.83 ± 1.53 | 0.004* | 1.649 (1.171 – 2.323) |
Mean Gingival Index | 1.28 ± 0.88 | 1.83 ± 0.85 | 0.035* | 1.846 (1.045 – 3.261) |
Mean Modified Sulcus Bleeding Index | 0.98 ± 0.77 | 1.44 ± 0.83 | 0.055 | 1.773 (0.988 – 3.181) |
Teeth Remaining | 24.15 ± 4.02 | 21.29 ± 4.22 | 0.023* | 0.875 (0.780 – 0.982) |
Association between periodontitis and length of stay
Periodontitis Group | Mean + Standard Deviation (days) | Median (days) | Interquartile Range (days) | Kruskal–Wallis test |
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HP | 8.0 ± 3.88 | 7.0 | 5.0 | Kruskal–Wallis H = 11.245 P Value = 0.004* |
MP | 9.64 ± 7.95 | 7.5 | 5.0 | |
SP | 12.74 ± 10.84 | 9.0 | 8.0 |