Table 1a compares the characteristics of participants who completed the baseline examination, with participants retained in the analyses. No major differences between the two groups other than the retention of fewer males, suggesting minimal bias from the exclusions. Among those retained in the analyses, mean age was 49 years (SD = 6.5), 16.8% were current smokers, 62.5% were physically active, 6.2% had diabetes, 62.7% had a family history of hypertension, and 65.9% had moderate/severe periodontitis. Over the follow-up period, 106 (19.6%) developed hypertension, and 16.1% had prehypertension (data not shown). Table 1b shows baseline characteristics by periodontitis severity. Proportions of males, smokers, and participants with prediabetes/diabetes were higher among those with severe periodontitis.
Table 1
a: Descriptive statistics of baseline characteristics of study participants (% or mean ± SD) Table 1a: Descriptive statistics of baseline characteristics of study participants (% or mean ± SD)
|
| All baseline (n = 1028) | Retained in analysis (n = 540) |
Age (years), mean ± SD | 50.7 ± 6.8 | 49.0 ± 6.5 |
Male | 27.0 | 22.0 |
Smoking | 16.5 | 16.8 |
Former | 18.1 | 20.9 |
Current | 16.5 | 16.8 |
Annual Income (<$20,000) | 54.3 | 56.5 |
Education | | |
< High School | 11.2 | 10.8 |
High School | 44.0 | 42.4 |
≥ Some College | 44.8 | 46.0 |
Physical Activity | | |
No physical activity | 36.4 | 37.5 |
Some physical activity | 7.3 | 6.8 |
Vigorous physical activity | 56.3 | 55.7 |
Obese | 64.1 | 57.4 |
Alcohol consumption (g/day) | 2.3 ± 5.8 | 2.2 ± 6.1 |
Waist circumference (cm) | 106.3 ± 14.1 | 104.1 ± 13.0 |
Pre-diabetes | 52.5 | 47.9 |
Diabetes | 7.5 | 6.2 |
Family history of Hypertension | 63.9 | 62.7 |
Plaque score | 0.8 ± 0.6 | 0.8 ± 0.6 |
Number of sites with bleeding on probing | 12.4 ± 12.0 | 12.7 ± 12.2 |
Always add salt to food | 4.8 | 4.8 |
Elevated blood pressure | 31.3 | 31.8 |
Periodontitis (moderate/severe) | 67.2 | 65.9 |
Mean PD (mm) | 1.4 ± 0.9 | 1.5 ± 1.0 |
Mean CAL (mm) | 1.8 ± 1.2 | 1.7 ± 1.2 |
Dental Caries | 9.2 ± 0.8 | 8.9 ± 1.2 |
Number of teeth | 23.5 ± 4.4 | 23.8 ± 4.2 |
Table 1b: Baseline characteristics by periodontitis severity.
| | |
Sociodemographic and clinical characteristics | Level | Mild Periodontitis | Moderate Periodontitis | Severe Periodontitis |
Number of participants | | 183 | 243 | 114 |
Age (years), mean ± SD | | 47.0 (5.6) | 50.0 (6.8) | 50.1 (6.6) |
Male | | 16.9%) | 21.8% | 30.7% |
Smoking | Current | 13.1% | 21.8% | 31.6% |
| Former | 16.4% | 16.9% | 21.1% |
| None | 70.5% | 61.3% | 47.4% |
Annual Income | <$20,000 | 61.7% | 58.0% | 53.2% |
| >$20,000 | 38.3% | 42.0% | 46.8% |
Education | < High School | 11.4% | 10.6% | 12.1% |
| High School | 42.7% | 49.0% | 44.9% |
| ≥ Some College | 45.9% | 40.4% | 43.0 |
Physical activity | None | 36.6% | 35.8% | 41.2% |
| Some | 6.0% | 6.6% | 8.8% |
| Vigorous | 57.4% | 57.6% | 50.0% |
BMI (SD) | | 32.4 (5.4) | 32.5 (6.1) | 32.4 (5.5) |
Alcohol consumption (g/day), mean (SD) | | 1.9 (7.1) | 2.1 (5.6) | 2.7 (5.2) |
Waist circumference, mean (SD) | | 103.3 (12.8) | 103.9 (12.8) | 105.0 (13.0) |
Diabetes | Normoglycemic | 54.1% | 44.0% | 36.8% |
| Pre-diabetes | 42.1% | 48.6% | 55.3% |
| Diabetes | 3.8% | 7.4% | 7.9% |
Family history of hypertension | No | 36.1% | 44.9% | 43.9% |
| Yes | 63.9% | 55.1% | 56.1% |
Plaque Score | | 0.7 (0.5) | 0.8 (0.3) | 0.9 (0.6) |
BOP, mean (SD) | | 0.2 (0.2) | 0.3 (0.2) | 0.5 (0.3) |
Always add salt to food | Yes | 4.7% | 4.8% | 4.8% |
| No | 95.3% | 95.2% | 95.2% |
Elevated Blood Pressure | Yes | 32.6% | 35.8% | 36.0% |
| No | 69.4% | 64.2% | 64.0% |
PD, mean (SD) | | 1.6 (0.3) | 2.0 (0.4) | 3.0 (1.0) |
CAL (mm), mean (SD) | | 1.0 (0.3) | 1.9 (0.7) | 3.5 (1.6) |
Dental caries, mean (SD) | | 10.2 (9.1) | 9.8 (8.5) | 7.6 (4.6) |
Baseline number of teeth | 1–10 | 1.1% | 1.6% | 1.8% |
| 11–16 | 2.7% | 4.5% | 6.1% |
| 17–24 | 33.9% | 44.0% | 51.8% |
| 25–32 | 62.3% | 49.8% | 40.4% |
In Poisson regression models relating periodontitis with the development of hypertension, baseline periodontitis was not statistically significantly associated with the risk of incident hypertension (Table 2). However, severe periodontitis significantly increased the risk of incident prehypertension/hypertension by 47% (95% CI: 1.01–2.17) after adjusting for age, sex, smoking status, family history of hypertension, diabetes, waist circumference, alcohol consumption, and physical activity). We explored whether selected baseline covariates modified the association between periodontitis and hypertension (Table 3a) and prehypertension/hypertension (Table 3b). Participants 55 years and over with severe periodontitis had four-fold elevated risk of incident hypertension than those below 55 years without periodontitis (IRR: 4.46, 95% CI: 1.40–14.22) after adjusting for age, sex, smoking status, physical activity, alcohol consumption, waist circumference, diabetes, and family history of hypertension. Similarly, participants 55 years and over with severe periodontitis had about a three-fold increased risk of developing incident prehypertension/hypertension than those aged 55 or younger without periodontitis (IRR: 2.98, 95% CI: 1.19, 7.49). In addition, females with severe periodontitis had a higher risk of incident prehypertension/hypertension (IRR: 1.55, 95% CI: 1.03–2.34) than males without periodontitis after adjusting for age, smoking status, physical activity, alcohol consumption, waist circumference, diabetes, and blood pressure medication. Obese individuals with severe periodontitis also had a higher risk of incident prehypertension/hypertension (IRR: 1.55, 95% CI: 1.02–2.35) than normal weight individuals without periodontitis after adjusting for age, sex, smoking status, physical activity, alcohol consumption, waist circumference, diabetes, and blood pressure medication.
Table 2
Multivariable-adjusted associations (Incidence Rate Ratios) relating periodontitis with the development of hypertension and combined prehypertension/hypertension.
| Hypertension | Prehypertension/hypertension |
IRR | 95% CI | P | IRR | 95% CI | P |
Periodontitis+ | | | | | | |
None | 1.00 | - | - | 1.00 | - | - |
Mild | 1.68 | 0.87–3.25 | 0.12 | 1.13 | 0.68–1.87 | 0.22 |
Moderate | 0.68 | 0.39–1.20 | 0.19 | 0.94 | 0.65–1.34 | 0.10 |
Severe | 1.02 | 0.54–1.95 | 0.95 | 1.47 | 1.01–2.17 | 0.04 |
Mean PD | 1.03 | 0.79–1.35 | 0.82 | 1.19 | 0.90–1.42 | 0.09 |
Mean CAL | 0.94 | 0.79–1.50 | 0.51 | 0.99 | 0.87–1.36 | 0.24 |
Number of teeth at baseline | |
25–32 | 1.00 | - | - | 1.00 | - | - |
17–24 | 0.82 | 0.54–1.25 | 0.35 | 0.89 | 0.71–1.22 | 0.29 |
11–16 | 0.95 | 0.37–2.49 | 0.92 | 0.94 | 0.87–1.40 | 0.78 |
1–10 | 1.08 | 0.26–4.57 | 0.91 | 1.11 | 0.99–2.68 | 0.87 |
*Adjusted for age, sex, smoking status, family history of hypertension, diabetes, waist circumference, alcohol consumption, and physical activity.
+Severe periodontitis was defined as having two or more interproximal sites with CAL ≥ 6 mm and at least one interproximal site with PD ≥ 5 mm. Moderate periodontitis was defined as having two or more interproximal sites with CAL ≥ 4 mm or two or more interproximal sites with PD ≥ 5 mm. Mild periodontitis was defined as having at least two interproximal sites with CAL ≥ 3 mm, at least two interproximal sites with CAL ≥ 3 mm, and at least two interproximal sites with PD ≥ 5 mm.
Table 3a: Incidence rate ratios relating periodontitis and incidence of hypertension during the follow-up period within subgroups defined by baseline characteristics.
| | | |
Subgroups | N | IRR+ (95% CI) | |
Mild Periodontitis | Moderate Periodontitis | Severe Periodontitis | |
Age | | |
<55 | 424 | 1.41 (0.70, 2.86) | 0.56 (0.29, 1.08) | 0.71 (0.32, 1.59) | |
≥ 55 | 116 | 3.77 (0.32, 4.51) | 1.58 (0.57, 4.38) | 4.46* (1.40, 14.22) | |
Sex | | |
Male | 119 | 2.57 (0.50, 13.29) | 0.36 (0.10, 1.37) | 0.53 (0.07, 4.28) | |
Female | 421 | 1.12 (0.49, 2.57) | 0.67 (0.37, 1.22) | 1.07 (0.53, 2.18) | |
Smoking | | |
Never | 332 | 0.86 (0.28, 2.71) | 0.46 (0.20, 1.03) | 1.10 (0.48, 2.52) | |
Ever | 208 | 2.17 (0.75, 6.27) | 0.91 (0.33, 2.47) | 0.79 (0.27, 2.26) | |
Physical activity | | |
No | 245 | 0.99 (0.29, 3.60) | 0.77 (0.34, 1.76) | 1.05 (0.37, 3.03) | |
Yes | 295 | 2.57* (1.20, 5.50) | 0.56 (0.23, 1.41) | 0.92 (0.35, 2.40) | |
BMI | | |
Overweight | 232 | 1.61 (0.53, 4.88) | 0.49 (0.18, 1.34) | 0.50 (0.10, 2.43) | |
Obese | 308 | 2.43* (1.08, 5.50) | 0.92 (0.47, 1.79) | 1.65 (0.78, 3.51) | |
Antihypertensive medication use | | |
No | 521 | 1.59 (0.72, 3.48) | 0.70 (0.36, 1.38) | 0.88 (0.41, 1.86) | |
Yes | 19 | 0.70 (0.43, 1.14) | 0.69 (0.42, 1.14) | 1.53 (0.73, 3.21) | |
Alcohol consumption | | |
Not current | 297 | 2.37 (0.99, 5.63) | 0.85 (0.41, 1.78) | 0.70 (0.20, 2.51) | |
Current | 243 | 1.26 (0.45, 3.38) | 0.46 (0.20, 1.08) | 1.08 (0.47, 2.49) | |
+Adjusted for age, sex, smoking status, physical activity, alcohol consumption, waist circumference, diabetes,
and family history of hypertension.
*Statistically significant at 0.05 level
Table 3b: Incidence Rate Ratios relating periodontitis and the development of prehypertension/hypertension during the follow-up within subgroups defined by baseline characteristics.
| | . |
Subgroups | N | IRR+ (95% CI) |
Mild Periodontitis | Moderate Periodontitis | Severe Periodontitis |
Age | |
<55 | 424 | 1.11 (0.67, 1.83) | 0.93 (0.62, 1.39) | 1.27 (0.81, 1.99) |
≥ 55 | 116 | 1.22 (0.16, 9.58) | 1.16 (0.51, 2.67) | 2.98* (1.19, 7.49) |
Sex | |
Male | 119 | 1.68 (0.62, 4.56) | 0.59 (0.22, 1.56) | 0.60 (0.18, 2.04) |
Female | 421 | 0.84 (0.46, 1.53) | 0.92 (0.63, 1.36) | 1.55* (1.03, 2.34) |
Smoking | |
Never | 332 | 0.80 (0.39, 1.63) | 0.70 (0.44, 1.10) | 1.47 (0.92, 2.36) |
Ever | 208 | 2.05 (0.85, 4.96) | 1.63 (0.73, 3.63) | 1.74 (0.79, 3.84) |
Physical activity | |
No | 245 | 1.04 (0.43, 2.49) | 0.96 (0.54, 1.73) | 1.40 (0.71, 2.77) |
Yes | 295 | 1.26 (0.69, 2.31) | 0.97 (0.59, 1.60) | 1.49 (0.91, 2.43) |
BMI | |
Overweight | 232 | 1.52 (0.63, 3.63) | 1.14 (0.59, 2.23) | 1.47 (0.67, 3.21) |
Obese | 308 | 1.15 (0.62, 2.14) | 0.87 (0.57, 1.34) | 1.55* (1.02, 2.35) |
Antihypertensive medication use | |
No | 521 | 1.13 (0.65, 1.98) | 0.98 (0.65, 1.47) | 1.43 (0.93, 2.21) |
Yes | 19 | 0.70 (0.43, 1.14) | 0.69 (0.42, 1.14) | 1.53 (0.73, 3.21) |
Alcohol consumption | |
Not current | 297 | 1.36 (0.71, 2.68) | 1.11 (0.68, 1.80) | 1.11 (0.59, 2.10) |
Current | 243 | 1.06 (0.51, 2.23) | 0.74 (0.42, 1.30) | 1.54 (0.88, 2.71) |
+Adjusted for age, sex, smoking status, physical activity, alcohol consumption, waist circumference, diabetes, BP medication
*Statistically significant at 0.05 level