TABLE 1.
Selected baseline characteristics of case and control subjects1
| Characteristics | Cases (n = 295) | Controls (n = 587)2 | P3 |
| Age, y | 65 (57–71)4 | 65 (57–71) | 0.88 |
| Male sex, n (%) | 184 (62.4) | 365 (62.2) | 0.96 |
| Serum DBP, nmol/L | 5378.9 (2841.2–8954.5) | 5358.2 (2949.8–8828.6) | 0.63 |
| Serum 25(OH)D, nmol/L | 60.9 (28.2–93.3) | 63.2 (35.4–90.7) | 0.24 |
| Season of blood draw: sunny season,5 n (%) | 134 (45.4) | 268 (45.7) | 0.95 |
| Residential sun exposure at study entry,6 n (%) | 0.98 | ||
| Low sun | 138 (46.8) | 273 (46.5) | |
| Moderate sun | 132 (44.8) | 262 (44.6) | |
| High sun | 25 (8.5) | 52 (8.9) | |
| Race, n (%) | 1.00 | ||
| White, non-Hispanic | 266 (90.2) | 529 (90.1) | |
| Black, non-Hispanic | 9 (3.1) | 18 (3.1) | |
| Hispanic | 4 (1.4) | 8 (1.4) | |
| Asian/Pacific Islander | 16 (5.4) | 32 (5.5) | |
| Height, cm | |||
| Male | 177.8 (167.6–185.4) | 177.8 (170.2–185.4) | 0.44 |
| Female | 162.6 (152.4–170.2) | 162.6 (154.9–170.2) | 0.94 |
| BMI, kg/m2 | 26.6 (22.4–32.6) | 26.6 (21.8–32.5) | 0.38 |
| WHO cutoffs, n (%) | 0.51 | ||
| <25.0 kg/m2 | 98 (33.2) | 208 (35.4) | |
| ≥25.0 and <30.0 kg/m2 | 130 (44.1) | 265 (45.1) | |
| ≥30.0 kg/m2 | 67 (22.7) | 114 (19.4) | |
| Smoking status, n (%) | <0.001 | ||
| Never | 111 (37.6) | 292 (49.7) | |
| Former | |||
| Quit ≥15 y | 74 (25.1) | 170 (29.0) | |
| Quit <15 y | 54 (18.3) | 83 (14.1) | |
| Current | 56 (19.0) | 42 (7.2) | |
| History of diabetes mellitus, n (%) | 38 (12.9) | 49 (8.4) | 0.03 |
| Family history of pancreatic cancer, n (%) | 10 (3.4) | 16 (2.7) | 0.58 |
| Dietary intake per day7 | |||
| Red meat, g | 74.8 (31.5–138.4) | 74.1 (26.7–131.7) | 0.46 |
| Alcohol, g | 1.5 (0.001–39.6) | 1.4 (0.001–33.2) | 0.69 |
| Nutrients | |||
| Vitamin D, μg | |||
| Food | 5.3 (2.5–8.7) | 5.4 (2.8–9.4) | 0.53 |
| Supplemental | 1.4 (0.00–19.4) | 0.00 (0.00–20.0) | 0.79 |
| Total | 11.9 (3.1–23.2) | 10.1 (3.5–24.1) | 0.82 |
| Calcium, mg | |||
| Food | 929.2 (604.0–1390.9) | 966.2 (638.8–1436.1) | 0.08 |
| Supplemental | 162.0 (0.00–662.0) | 100.0 (0.00–800.0) | 0.74 |
| Total | 1090.1 (673.2–1948.5) | 1156.6 (715.8–2060.2) | 0.23 |
| Total vitamin A,8 RE | 1587.3 (1042.2–2537.5) | 1644.2 (1076.2–2708.9) | 0.38 |
| Vigorous physical activity of ≥4 h/wk, n (%)7 | 56 (19.0) | 151 (25.7) | 0.026 |
DBP, vitamin D–binding protein; RE, retinol equivalents; 25(OH)D, 25-hydroxyvitamin D.
Three controls did not have vitamin D–binding protein data and were thus excluded from the analysis.
P values for categorical and continuous variables were based on chi-square test and Wilcoxon’s rank-sum test, respectively.
Median; interdecile range in parentheses (all such values).
Sunny season was defined as June–October; low sun season was defined as November–May.
Residential regions based on ranges of UV radiation levels obtained from annual Robertson-Berger (R-B) meters in states in which screening centers are located: low sun (≤105 R-B meters; Detroit, MI; Minneapolis, MN; and Marshfield, WI), moderate sun (113–134 R-B meters; Pittsburgh, PA; St. Louis, MO; Denver, CO; Washington, DC; and Salt Lake City, UT), and high sun (≥154 R-B meters; Birmingham, AL, and Honolulu, HI) (13).
Based on data for n = 275 cases and n = 554 controls; 20 cases and 33 controls had missing dietary questionnaires, missing data for all of the dietary variables, or missing physical activity data. All foods and nutrients were energy adjusted except for supplements and alcohol.
Total vitamin A includes vitamin A from food and supplements.