Table 1.
Characteristic of study sample with and without arthritis
| Arthritis (n = 1510) | Non-arthritis (n = 9584) | P value | |
|---|---|---|---|
| Age (years) | 47.99 ± 9.36 | 37.59 ± 11.34 | < 0.001 |
| Age groups | |||
| 20–29 years | 5.97 | 30.31 | < 0.001 |
| 30–39 years | 12.38 | 26.12 | |
| 40–49 years | 27.09 | 24.53 | |
| 50–59 years | 54.56 | 19.04 | |
| Gender (%) | |||
| Male | 43.92 | 53.83 | < 0.001 |
| Female | 56.08 | 46.17 | |
| Race (%) | |||
| Mexican American | 6.07 | 11.06 | < 0.001 |
| Other Hispanic | 5.07 | 7.71 | |
| Non-Hispanic White | 68.41 | 58.80 | |
| Non-Hispanic Black | 12.47 | 12.32 | |
| Other race—including multi-racial | 7.97 | 10.11 | |
| Educational level (%) | |||
| Less than 9th grade | 3.94 | 3.96 | < 0.001 |
| 9th–11th grade | 11.83 | 9.02 | |
| High school graduate/GED or equivalent | 22.99 | 21.67 | |
| Some college or AA degree | 35.13 | 32.47 | |
| College graduate or above | 26.11 | 32.87 | |
| Not recorded | 0 | 0.01 | |
| Body mass index (kg/m2) | 31.71 ± 8.00 | 28.56 ± 6.56 | < 0.001 |
| Ratio of family income to poverty | 2.95 ± 1.72 | 2.94 ± 1.66 | 0.821 |
| Vigorous recreational activities (%) | |||
| Yes | 19.99 | 36.63 | < 0.001 |
| No | 80.01 | 63.37 | |
| Smoked at least 100 cigarettes in life (%) | |||
| Yes | 51.38 | 38.63 | < 0.001 |
| No | 48.59 | 61.35 | |
| Not recorded | 0.03 | 0.02 | |
| Blood urea nitrogen (mmol/L) | 4.82 ± 1.71 | 4.54 ± 1.49 | < 0.001 |
| Total protein (g/L) | 70.60 ± 4.45 | 71.58 ± 4.29 | < 0.001 |
| Total cholesterol (mmol/L) | 5.11 ± 1.04 | 4.91 ± 1.02 | < 0.001 |
| Alkaline phosphatase (U/L) | 71.50 ± 22.57 | 66.32 ± 22.73 | < 0.001 |
| Serum uric acid(μmol/L) | 323.79 ± 84.78 | 318.53 ± 80.72 | 0.019 |
| Serum sodium (mmol/L) | 139.12 ± 2.43 | 139.25 ± 2.21 | 0.037 |
| Serum potassium (mmol/L) | 3.95 ± 0.33 | 3.97 ± 0.31 | 0.122 |
| Serum phosphorus (mmol/L) | 1.20 ± 0.17 | 1.20 ± 0.18 | 0.397 |
| Serum calcium (mmol/L) | 2.34 ± 0.09 | 2.34 ± 0.08 | 0.013 |
| Disease duration of arthritis (years) | 9.20 ± 8.90 | / | |
| Which type of arthritis was it? (%) | |||
| Osteoarthritis or degenerative arthritis | 41.61 | / | / |
| Rheumatoid arthritis | 17.45 | / | |
| Psoriatic arthritis | 2.73 | / | |
| Other | 0.17 | / | |
| Do not know or refused | 24.20 | / | |
| Lumbar bone mineral density (g/cm2) | 1.05 ± 0.16 | 1.04 ± 0.15 | 0.086 |
Mean ± SD for continuous variables: P value was calculated by weighted linear regression model
Percent for categorical variables: P value was calculated by weighted chi-square test