Table 1.

Baseline characteristics of the study population according to cohort

HPFS (n=42,991)NHS I (n=62,252)NHS II (n=88,852)
Age (yr)54 (10)51 (7)37 (5)
Nonwhites (%)4.85.55.9
Diabetes (%)2.82.91.0
High BP (%)21.420.86.4
Gout (%)5.11.80.3
Body mass index (kg/m2)a25 (24, 27)24 (22, 27)23 (21, 27)
Use of thiazides (%)9.212.81.8
Daily intakes
 Calcium (mg)a766 (559, 1125)826 (591, 1199)908 (644, 1297)
 Potassium (mg)a3263 (2608, 4019)3001 (2417, 3667)2808 (2236, 3471)
 Animal proteins (g)a64 (49, 80)54 (42, 68)61 (47, 77)
 Phytate (mg)a844 (615, 1139)661 (495, 877)724 (547, 946)
 Vitamin C (mg)a227 (137, 517)194 (120, 384)157 (99, 260)
 Alcohol (g)a5.8 (0.9, 14.9)2.0 (0.0, 9.1)0.9 (0.0, 3.5)
 Energy (cal)1989 (618)1746 (527)1791 (547)
Sugar-sweetened cola (servings/mo)a2 (2, 5)2 (2, 3)2 (2, 5)
Artificially sweetened cola (servings/mo)a2 (2, 13)3 (2, 14)13 (2, 32)
Sugar-sweetened noncola (servings/mo)a1 (1, 2)1 (1, 2)1 (1, 2)
Artificially sweetened noncola (servings/mo)a1 (1, 2)1 (1, 4)1 (1, 2)
Coffee (servings/mo)a26 (1, 75)30 (1, 75)12 (1, 75)
Decaffeinated coffee (servings/mo)a2 (1, 26)2 (1, 30)1 (1, 4)
Tea (servings/mo)a2 (1, 12)2 (1, 30)4 (1, 30)
Red wine (servings/mo)a1 (1, 2)1 (1, 2)1 (1, 1)
White wine (servings/mo)a2 (1, 4)1 (1, 4)1 (1, 2)
Beer (servings/mo)a2 (1, 12)1 (1, 1)1 (1, 1)
Liquor (servings/mo)a2 (1, 12)1 (1, 2)1 (1, 1)
Apple juice (servings/mo)a1 (1, 2)1 (1, 2)1 (1, 2)
Grapefruit juice (servings/mo)a1 (1, 2)1 (1, 2)1 (1, 1)
Orange juice (servings/mo)a12 (2, 26)12 (2, 30)4 (2, 12)
Tomato juice (servings/mo)a1 (1, 2)1 (1, 2)1 (1, 2)
Other juice (servings/mo)a1 (1, 2)1 (1, 4)2 (1, 4)
Punch (servings/mo)a1 (1, 2)1 (1, 2)2 (1, 4)
Whole milk (servings/mo)a1 (1, 1)1 (1, 2)1 (1, 1)
Skim milk (servings/mo)a12 (1, 30)12 (1, 30)26 (4, 30)
Water (servings/mo)a75 (30, 135)75 (30, 135)75 (30, 135)
  • Continuous variables reported as mean (SD). HPFS, Health Professionals Follow-Up Study; NHS I, Nurses’ Health Study I; NHS II, Nurses’ Health Study II.

  • a Median (first and third quartiles).