Table 1.
General Characteristics of Participants according to prevalent rheumatoid factor seropositivity (RF+): Dentate participants aged ≥ 60 years, without ACR-defined rheumatoid arthritis, enrolled in NHANES III 1988–1992. (N=2461)
| Characteristic | Unweighted All (n=2461) |
Weighted All |
RF+ n= 143 (4.9%) |
RF− n= 2318 (95.1%) |
P value |
|---|---|---|---|---|---|
| Self Report RA | 7 | 6 | 16 | 5 | 0.01 |
| Age (years) | 70.2 ± 7.5 | 69.4 ± 0.3 | 70.2 ± 0.7 | 69.4 ± 0.4 | 0.24 |
| Female (%) | 51 | 57 | 61 | 57 | 0.53 |
| Race/Ethnicity (%) | 0.25 | ||||
| Non-Hispanic White | 56 | 85 | 79 | 85 | |
| Non-Hispanic Black | 19 | 7 | 12 | 7 | |
| Mexican-American | 23 | 3 | 3 | 3 | |
| Other | 3 | 5 | 6 | 5 | |
| Education (%) | 0.64 | ||||
| < 12th grade | 50 | 32 | 33 | 32 | |
| 12th grade | 26 | 34 | 37 | 33 | |
| >12th grade | 24 | 34 | 30 | 35 | |
| Smoking Status (%) | 0.54 | ||||
| Never | 49 | 49 | 45 | 49 | |
| Former | 37 | 39 | 38 | 39 | |
| Current | 14 | 12 | 17 | 12 | |
| Pack Years of Smoking | 15.9 ±29.4 | 17.5 ± 1.0 | 18.8 ± 3.8 | 17.5 ± 1.0 | 0.73 |
| Alcohol use (%) | 0.38 | ||||
| Never | 21 | 18 | 17 | 18 | |
| Former | 44 | 41 | 49 | 41 | |
| Current | 35 | 40 | 34 | 41 | |
| Systolic Blood Pressure (mmHg) |
137.9 ± 22.5 | 134.8 ± 0.7 | 131.5 ± 2.4 | 134.8 ± 0.7 | 0.17 |
| Diastolic Blood Pressure (mmHg) |
72.8 ± 12.0 | 72.4 ± 0.4 | 68.1 ± 1.7 | 72.6 ± 0.4 | 0.02 |
| Hypertension | 42 | 37 | 36 | 37 | 0.77 |
| White Blood Cell Count (cells/mm3) |
7.1 ± 2.6 | 7.0 ± 0.1 | 6.6 ± 0.2 | 7.0 ± 0.1 | 0.02 |
| Mean probing depth (mm) | 1.6 ± 0.6 | 1.5 ± 0.03 | 1.6 ± 0.06 | 1.5 ± 0.02 | 0.16 |
| Percentage of probing depths ≥ 4mm (%) |
4.5 ± 11.0 | 2.9 ± 0.3 | 3.7 ± 0.9 | 2.8 ± 0.3 | 0.38 |
| Percentage of sites with bleeding on probing (%) |
14.2 ± 21.1 | 11.3 ± 0.7 | 12.0 ± 1.7 | 11.1 ± 0.7 | 0.55 |
| Mean attachment loss (mm) | 2.2 ±1.5 | 1.9 ± 0.1 | 2.1 ± 0.2 | 1.9 ± 0.1 | 0.15 |
| Percentage of site with attachment loss ≥ 5mm (%) |
11.7 ± 21.3 | 8.4 ± 0.7 | 10.9 ± 2.1 | 8.2 ± 0.7 | 0.22 |
| C-reactive Protein (mg/dl) | 0.55 ± 1.1 | 0.49 ± 0.02 | 0.51 ± 0.06 | 0.48 ± 0.02 | 0.69 |
| LDL- cholesterol | 140.9 ± 37.6 | 142.5 ± 1.4 | 141.7 ± 6.0 | 142.4 ± 1.5 | 0.91 |
| HDL- cholesterol | 51.3 ± 16.1 | 51.8 ± 0.5 | 49.7 ± 2.3 | 51.9 ± 0.5 | 0.34 |
| Body Mass Index BMI (kg/m2) |
27.4 ± 5.0 | 27.0 ± 0.1 | 26.0 ± 0.5 | 27.1 ± 0.1 | 0.02 |
| Lymphocytes (percent of 100 cells) |
31.7 ±11.3 | 31.6 ± 0.5 | 32.8 ± 2.0 | 31.5 ± 0.5 | 0.53 |
| Monocytes (percent of 100 cells) |
5.8 ± 3.3 | 5.9 ± 0.2 | 6.3 ± 0.6 | 5.9 ± 0.2 | 0.46 |
| Log-transformed P.gingivalis antibody level (fg/ml) |
6.2 ± 2.2 | 5.7 ± 0.08 | 5.7 ± 0.2 | 5.7 ± 0.09 | 0.82 |
Note: Values shown are either percent or mean (SD). Weighted results incorporate survey weights making the results generalizable to the civilian non-institutionalized US population aged ≥ 60 years and RA free. Results presented among RF subgroups are weighted including the prevalence of RF+ and Rao-Scott Modified Chi square and T-tests were used as appropriate to test for differences across RF positivity.
Subsamples due to missing data: n = 2393 with pack years data; n = 2392 with systolic blood pressure, diastolic blood pressure and hypertension; n = 2434 with white blood cell count; n = 1020 with LDL counts; n = 2441 with HDL counts; n = 747 with lymphocytes and monocytes counts.
Self Report RA represents patients who self-reported a doctor diagnosis of RA in an interviewer administered questionnaire regardless of physical exam results or serology.