Table 1.
Baseline characteristics by quintiles of parathyroid hormone: The ARIC Study (1990–1992)
| Characteristics a | Quintile 1 (N=1,501) |
Quintile 2 (N=1,498) |
Quintile 3 (N=1,503) |
Quintile 4 (N=1,501) |
Quintile 5 (N=1,501) |
Linear trend Pc |
|---|---|---|---|---|---|---|
| Parathyroid hormones, pg/mL | ||||||
| Median | 24.9 | 32.0 | 38.2 | 45.2 | 58.1 | |
| Range | 3.2 – 28.8 | 28.9 – 34.9 | 35.0 – 41.5 | 41.6 – 50.1 | 50.2 – 162.6 | |
| Demographics | ||||||
| Age, years | 55.6 (5.5) | 56.0 (5.6) | 56.3 (5.6) | 56.1 (5.7) | 56.4 (5.6) | <0.001 |
| Male, % | 45.5 | 43.3 | 45.6 | 39.8 | 34.9 | <0.001 |
| Race, % | <0.001 | |||||
| White | 88.7 | 87.7 | 84.2 | 82.9 | 72.2 | |
| Black | 11.3 | 12.3 | 15.8 | 17.1 | 27.8 | |
| Education, % | 0.019 | |||||
| < High school | 16.2 | 15.0 | 17.3 | 14.6 | 16.4 | |
| high school | 46.3 | 44.4 | 41.4 | 41.4 | 40.9 | |
| > high school | 37.5 | 40.6 | 41.3 | 44.0 | 42.7 | |
| Behavioral Factors | ||||||
| Smoking status, % | <0.001 | |||||
| Current | 36.7 | 24.5 | 20.6 | 15.2 | 12.5 | |
| Past | 29.3 | 35.5 | 40.1 | 41.2 | 38.6 | |
| Never | 34.0 | 40.1 | 39.3 | 43.6 | 48.9 | |
| Drinking status, % | <0.001 | |||||
| Current | 63.8 | 64.2 | 62.1 | 60.5 | 56.3 | |
| Past | 19.3 | 16.9 | 18.6 | 16.5 | 17.6 | |
| Never | 16.8 | 18.9 | 19.3 | 23.0 | 26.1 | |
| Physical activity score | 2.5 (0.8) | 2.6 (0.8) | 2.6 (0.8) | 2.5 (0.8) | 2.4 (0.8) | <0.001 |
| Physiologic Characteristics | ||||||
| Systolic blood pressure, mmHg | 112 (13) | 113 (12) | 114 (12) | 115 (12) | 115 (12) | <0.001 |
| Diastolic blood pressure, mmHg | 68.0 (8.2) | 68.4 (8.3) | 69.4 (8.5) | 69.9 (8.1) | 70.5 (8.2) | <0.001 |
| Body mass index, kg/m2 | 25.9 (4.2) | 26.4 (4.3) | 26.8 (4.5) | 27.3 (4.7) | 28.5 (5.7) | <0.001 |
| Serum calcium, mg/dL | 9.38 (0.40) | 9.32 (0.38) | 9.29 (0.42) | 9.27 (0.39) | 9.26 (0.45) | <0.001 |
| Serum 25(OH)D, ng/dLb | 27.6 (8.5) | 26.6 (8.6) | 25.6 (8.0) | 24.1 (7.7) | 21.9 (7.9) | <0.001 |
| Serum phosphorus, mg/dL | 3.64 (0.49) | 3.59 (0.46) | 3.55 (0.47) | 3.51 (0.46) | 3.43 (0.47) | <0.001 |
| C-reactive protein, mg/L | 3.55 (6.14) | 3.43 (5.93) | 3.01 (4.85) | 3.71 (7.01) | 4.10 (8.01) | <0.001 |
| eGFR (SD), ml/min/1.73 m2 | 97.1 (14.4) | 97.1 (14.3) | 97.6 (14.1) | 98.5 (15.0) | 98.2 (15.7) | 0.038 |
GFR: glomerular filtration rate
a
For a continuous variable, mean (SD) was expressed unless specified
b
Adjusted for season by adding residuals, obtained from regression with 25(OH)D on season of visit, to overall mean value
c
Tested by modeling median values of the quintiles as a continuous variable