Baseline characteristics of participants
A total of 3,402 patients were included once the proper exclusion criteria were applied, including 1,704 males and 3,546 females. Figure 1 gives specific information and shows how participants are screened. Table 1 Outlines the basic characteristics of groups with and without periodontitis. Periodontitis was detected in 1,740 of the 3,402 participants, and the overall periodontitis prevalence was 51.14%. In terms of gender distribution, males accounted for 50.08% and females accounted for 49.91%.
Table 1
Baseline characteristics of participants (N = 3,402).
Characteristics | Total N = 3402 | No Periodontitis N = 1662 | Periodontitis N = 1740 | P-value |
Age (years) | 57.556 ± 11.658 | 55.288 ± 11.504 | 59.722 ± 11.392 | < 0.001 |
AIP | -0.082 ± 0.756 | -0.144 ± 0.752 | -0.023 ± 0.755 | < 0.001 |
BMI(kg/㎡) | 29.384 ± 6.564 | 29.268 ± 6.458 | 29.494 ± 6.665 | 0.316 |
Vitamin D intake (mcg) | 68.390 ± 28.190 | 72.210 ± 28.232 | 64.740 ± 27.668 | < 0.001 |
Gender (%) | | | | < 0.001 |
Male | 1704 (50.088%) | 683 (41.095%) | 1021 (58.678%) | |
Female | 1698 (49.912%) | 979 (58.905%) | 719 (41.322%) | |
Race (%) | | | | < 0.001 |
Mexican American | 470 (13.815%) | 180 (10.830%) | 290 (16.667%) | |
Other Hispanic | 358 (10.523%) | 177 (10.650%) | 181 (10.402%) | |
Non-Hispanic White | 1554 (45.679%) | 870 (52.347%) | 684 (39.310%) | |
Non-Hispanic Black | 676 (19.871%) | 262 (15.764%) | 414 (23.793%) | |
Other Race - Including Multi-Racial | 344 (10.112%) | 173 (10.409%) | 171 (9.828%) | |
Marital status (%) | | | | < 0.001 |
Married | 2043 (60.053%) | 1061 (63.839%) | 982 (56.437%) | |
Widowed/divorced | 782 (22.986%) | 362 (21.781%) | 420 (24.138%) | |
Single | 575 (16.902%) | 239 (14.380%) | 336 (19.310%) | |
Not recorded | 2 (0.059%) | 0 (0.000%) | 2 (0.115%) | |
Education level (%) | | | | < 0.001 |
Less than high school | 801 (23.545%) | 261 (15.704%) | 540 (31.034%) | |
High school | 731 (21.487%) | 309 (18.592%) | 422 (24.253%) | |
More than high school | 1863 (54.762%) | 1091 (65.644%) | 772 (44.368%) | |
Not recorded | 7 (0.206%) | 1 (0.060%) | 6 (0.345%) | |
Annual household income (%) | | | | < 0.001 |
< $20,000 | 605 (17.784%) | 212 (12.756%) | 393 (22.586%) | |
≥ $20,000 | 2671 (78.513%) | 1393 (83.815%) | 1278 (73.448%) | |
Not recorded | 126 (3.704%) | 57 (3.430%) | 69 (3.966%) | |
Annual alcohol consumption (%) | | | | 0.575 |
At least 12 alcohol drinks | 2453 (72.105%) | 1199 (72.142%) | 1254 (72.069%) | |
Less than 12 alcohol drinks | 945 (27.778%) | 460 (27.677%) | 485 (27.874%) | |
Not recorded | 4 (0.118%) | 3 (0.181%) | 1 (0.057%) | |
Smoked at least 100 cigarettes in life (%) | | | | < 0.001 |
Yes | 1538 (45.209%) | 603 (36.282%) | 935 (53.736%) | |
No | 1861 (54.703%) | 1059 (63.718%) | 802 (46.092%) | |
Not recorded | 3 (0.088%) | 0 (0.000%) | 3 (0.172%) | |
Hypertension (%) | | | | < 0.001 |
Yes | 1517 (44.591%) | 678 (40.794%) | 839 (48.218%) | |
No | 1881 (55.291%) | 983 (59.146%) | 898 (51.609%) | |
Not recorded | 4 (0.118%) | 1 (0.060%) | 3 (0.172%) | |
General health condition (%) | | | | < 0.001 |
Healthy | 2590 (76.132%) | 1346 (80.987%) | 1244 (71.494%) | |
Unhealthy | 811 (23.839%) | 316 (19.013%) | 495 (28.448%) | |
Not recorded | 1 (0.029%) | 0 (0.000%) | 1 (0.057%) | |
Number of flossing/a week (%) | | | | < 0.001 |
Never | 1053 (30.952%) | 386 (23.225%) | 667 (38.333%) | |
Rarely | 506 (14.874%) | 274 (16.486%) | 232 (13.333%) | |
Moderately | 579 (17.019%) | 341 (20.517%) | 238 (13.678%) | |
Frequently | 1264 (37.155%) | 661 (39.771%) | 603 (34.655%) | |
Continuous variables: Survey-weighted mean +/ -SD, p-value determined from survey weighted linear regression.
Categorical variables: Survey-weighted percentage, p-values were determined by a survey weighted chi-square test.
Logistic regression analysis
The relationship between AIP and periodontitis, BMI (BMI ≥ 25) and periodontitis was shown in Table 3, which was obtained by multivariate logistic regression analysis. In the original model, AIP was significantly positively associated with periodontitis, with an odds ratio of 1.239 (1.132, 1.355) p < 0.0001). Even after taking age, gender, and race into consideration, the strong and positive correlation in Model 2 persisted to be highly significant (OR = 1.24; 95%CI: 1.12–1.36; P < 0.0001). The relationship between AIP and periodontitis was still statistically significant in Model 3, which was based on Model 2 (OR = 1.14; 95%CI: 1.03–1.26; P = 0.0124). This was even after taking into consideration factors including educational background, marital status, smoking habits, alcohol consumption, as well as any associated medical disorders (such diabetes, hypertension, and frequency of flossing). Despite adjusting for all confounding variables in model 4, the notable correlations mentioned earlier persist with statistical significance (OR = 1.12; 95% CI: 1.01–1.25; P = 0.0090). This indicates that with each incremental rise in AIP, there is a 12% increase in the likelihood of developing periodontitis. After AIP was divided into quartiles, the correlation between AIP and periodontitis still existed, and the trend test was statistically significant (P < 0.05). In Model 4, when the highest quartile of AIP was compared with the lowest quartile, the incidence of periodontitis increased by 30%. In addition, we found a significant association between BMI (BMI ≥ 25) and periodontitis. Upon adjusting for all factors in Model 4, individuals classified as overweight exhibited a 2% higher risk of developing periodontitis in comparison to those with a BMI < 25 (OR = 1.02; 95% CI: 1.01–1.04; P = 0.0050). The results of multiple logistic regression analysis to examine the relationship between AIP and BMI (BMI ≥ 25) are shown in Table 4. In the unadjusted model, AIP was negatively correlated with BMI (BMI ≥ 25) (OR = 0.776; 95%CI: 0.468–1.083; P < 0.0001). Following adjustments for gender, age, and race in Model 2, a noteworthy association emerged between AIP and BMI (BMI ≥ 25) (OR = 1.33; 95% CI: 1.01–1.64; P < 0.0001). Model 3, incorporating controls for education level, marital status, smoking habits, alcohol consumption, as well as hypertension, diabetes, and flossing practices from Model 2, continued to reveal a significant correlation between AIP and periodontitis (OR = 1.28; 95% CI: 0.96–1.59; P < 0.0001). However, Model 4 demonstrated an inverse relationship between AIP and BMI (BMI ≥ 25) (OR = 0.85; 95% CI: 0.54–1.16; P < 0.0001) upon adjusting for all variables.
Table 3
Odds Ratios and 95% Confidence Intervals for Periodontitis According to AIP and BMI
Exposure | OR (95% CI), P value |
Model 1 | Model 2 | Model 3 | Model 4 |
AIP (continuous) | 1.24 (1.132, 1.355) < 0.0001 | 1.24 (1.12, 1.36) < 0.0001 | 1.14 (1.03, 1.26) 0.0124 | 1.12 (1.01, 1.25) 0.0090 |
AIP (quartile) | | | | |
Quartile 1 | Reference | Reference | Reference | Reference |
Quartile 2 | 1.43 (1.180, 1.729) 0.0003 | 1.30 (1.06, 1.60) 0.0107 | 1.26 (1.02, 1.56) 0.0328 | 1.25 (1.01, 1.55) 0.0378 |
Quartile 3 | 1.52 (1.252, 1.835) < 0.0001 | 1.33 (1.08, 1.63) 0.0065 | 1.21 (0.98, 1.50) 0.0783 | 1.21 (0.97, 1.50) 0.0885 |
Quartile 4 | 1.53 (1.260, 1.847) < 0.0001 | 1.49 (1.21, 1.84) 0.0002 | 1.31 (1.05, 1.64) 0.0154 | 1.30 (1.04, 1.62) 0.0215 |
P for trend | < 0.001 | < 0.001 | 0.034 | 0.037 |
BMI | | | | |
<=25 | Reference | Reference | Reference | Reference |
> 25 | 1.01 (0.997, 1.023) 0.1473 | 1.03 (1.011, 1.041) 0.0005 | 1.02 (1.007, 1.037) 0.0047 | 1.02 (1.01, 1.04) 0.0050 |
Model 1: no adjustment for covariates.
Model 2: adjusted for sex, age, and race.
Model 3: age, race, sex, smoking, annual alcohol consumption, annual household income, Marital status, education level, hypertension.
Model 4: age, race, sex, smoking, annual alcohol consumption, annual household income, Marital status, education level, hypertension, general health condition, number of floss uses, energy.
Table 4
Multiple Logistic Regression of the Association Between AIP and BMI
Exposure | OR (95% CI), P value |
Model 1 | Model 2 | Model 3 | Model 4 |
AIP (continuous) | 0.776 (0.468, 1.083) < 0.0001 | 1.33 (1.01, 1.64) < 0.0001 | 1.28 (0.96, 1.59) < 0.0001 | 0.85 (0.54, 1.16) < 0.0001 |
AIP (quartile) | | | | |
Quartile 1 | Reference | Reference | Reference | Reference |
Quartile 2 | 0.10 (-0.60, 0.81) 0.7739 | 0.85 (0.16, 1.54) 0.0153 | 0.78 (0.09, 1.47) 0.0269 | 0.64 (-0.03, 1.31) 0.0603 |
Quartile 3 | 1.27 (0.59, 1.95) 0.0003 | 2.23 (1.55, 2.90) < 0.0001 | 2.15 (1.47, 2.83) < 0.0001 | 1.79 (1.13, 2.45) < 0.0001 |
Quartile 4 | 1.60 (0.93, 2.28) < 0.0001 | 2.84 (2.16, 3.52) < 0.0001 | 2.72 (2.03, 3.41) < 0.0001 | 2.03 (1.35, 2.70) < 0.0001 |
P for trend | <0.001 | < 0.001 | < 0.001 | < 0.001 |
Model 1: no adjustments were made for covariates.
Model 2: adjusted for sex, age, and race.
Model 3: age, race, gender, smoked at least 100 cigarettes in life, annual alcohol consumption, annual household income, Marital status, education level, hypertension.
Model 4: age, race, gender, smoked at least 100 cigarettes in life, annual alcohol consumption, annual household income, Marital status, education level, hypertension. General health condition; number of flossing/a week, energy.