Table 1.
Clinical characteristics at the time of biomarker measurements (at or near the end of the DCCT) for all DCCT/EDIC participants with measurement of vitamin D metabolites (n = 1193) and for the subset of DCCT/EDIC participants with additional measurement of PTH and FGF-23 (n = 300)
| All measured participants | Subset of participants with PTH and FGF-23 | |
|---|---|---|
| n | 1193 | 300 |
| Age (yr) | 32.4 (2.6) | 32.3 (2.6) |
| Duration of diabetes (yr) | 7.5 (0.6) | 5.8 (0.6) |
| Female sex, n (%) | 564 (47%) | 113 (44%) |
| Non-white race, n (%) | 42 (4%) | 15 (5%) |
| DCCT intensive diabetes therapy, n (%) | 596 (50%) | 157 (48%) |
| Current smoking, n (%) | 236 (18%) | 58 (17%) |
| Hypertension, n (%) | 96 (8%) | 14 (5%) |
| Body mass index (kg/m2) | 25.7 (1.9) | 25.9 (1.9) |
| Systolic blood pressure (mm Hg) | 114.9 (3.4) | 114.8 (3.4) |
| Diastolic blood pressure (mm Hg) | 74.0 (2.9) | 74.2 (2.8) |
| Hemoglobin A1c (%) | 8.1 (1.3) | 8.3 (1.3) |
| AER (mg/24 h) | 11.8 (1.6) | 10.3 (1.4) |
| Serum creatinine (mg/dl) | 0.7 (1.2) | 0.7 (1.2) |
| eGFR (ml/min/1.73 m2) | 107.7 (16.2) | 109.6 (15.3) |
| Iothalamate GFR (ml/min) | 133.0 (4.9) | |
| Total 25(OH)D (ng/ml) | 25.4 (3.0) | 25.6 (3.1) |
| 24,25(OH)2D3 (ng/ml) | 4.1 (1.5) | 4.1 (1.5) |
| Total 1,25(OH)2D (pg/ml) | 41.3 (3.4) | 44.9 (3.5) |
| FGF-23 (pg/ml) | 31.4 (3.0) | |
| PTH (pg/ml) | 30.8 (3.7) |
Cell contents are expressed as number (percentage) or mean (sd), except for AER, which is summarized as geometric mean (geometric sd).