TABLE 1.
Baseline age-standardized characteristics of study participants by quintiles of energy-adjusted total furocoumarin intake in the NHS and HPFS1
| Intake quintiles | |||||
|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | Q5 | |
| Women (NHS, 1984) | |||||
| Participants, n | 15,108 | 14,966 | 15,115 | 15,051 | 15,051 |
| Age, y | 49 ± 7 | 50 ± 7 | 50 ± 7 | 51 ± 7 | 52 ± 10 |
| Furocoumarin intake, μg/d | 0.00 ± 0.00 | 22.0 ± 36.0 | 183 ± 45.0 | 419 ± 112 | 1750 ± 1570 |
| Total citrus intake, serving/d | 0.30 ± 0.40 | 0.90 ± 0.70 | 0.90 ± 0.60 | 0.90 ± 0.60 | 1.40 ± 0.90 |
| Total energy intake, kcal/d | 1680 ± 588 | 1890 ± 575 | 1950 ± 388 | 1660 ± 493 | 1540 ± 470 |
| UV exposure at residence, mW/m2 | 194 ± 28 | 191 ± 27 | 192 ± 26 | 192 ± 28 | 191 ± 28 |
| Family history of melanoma | 2.6 | 2.9 | 2.8 | 2.7 | 2.7 |
| Red/blonde hair | 16 | 16 | 16 | 15 | 16 |
| Painful burn or blistering reaction to sun exposure as a child/adolescent | 36 | 36 | 35 | 33 | 34 |
| ≥6 lifetime sunburns | 8 | 7 | 8 | 7 | 7 |
| ≥6 moles on the arms | 5 | 5 | 4 | 5 | 5 |
| Physical exam | 68 | 72 | 72 | 72 | 73 |
| BMI, kg/m2 | 25 ± 5 | 25 ± 5 | 25 ± 5 | 25 ± 5 | 25 ± 4 |
| Physical activity, MET h/wk | 12 ± 18 | 14 ± 20 | 15 ± 21 | 17 ± 22 | 19 ± 25 |
| Alcohol intake, g/d | 6.50 ± 12.2 | 7.00 ± 11.9 | 7.40 ± 11.5 | 6.90 ± 10.6 | 6.90 ± 10.3 |
| Current smoking | 33 | 26 | 22 | 21 | 20 |
| Men (HPFS, 1986) | |||||
| Participants, n | 8364 | 10,599 | 9498 | 9497 | 9495 |
| Age, y | 52 ± 10 | 54 ± 10 | 53 ± 10 | 55 ± 10 | 57 ± 10 |
| Furocoumarin intake, μg/d | 0.00 ± 0.00 | 28.0 ± 48.0 | 241 ± 60.0 | 588 ± 169 | 2400 ± 1980 |
| Total citrus intake, serving/d | 0.20 ± 0.30 | 1.00 ± 0.80 | 0.90 ± 0.70 | 1.00 ± 0.70 | 1.60 ± 1.10 |
| Total energy intake, kcal/d | 1840 ± 603 | 2110 ± 591 | 2140 ± 426 | 1860 ± 567 | 1760 ± 496 |
| UV exposure at residence, mW/m2 | 194 ± 28 | 191 ± 27 | 192 ± 28 | 192 ± 28 | 191 ± 28 |
| Family history of melanoma | 3.0 | 3.1 | 3.5 | 3.3 | 2.4 |
| Red/blonde hair | 13.8 | 14.5 | 15.0 | 13.4 | 13.0 |
| Painful burn or blistering reaction to sun exposure as a child/adolescent | 54 | 55 | 57 | 55 | 53 |
| ≥6 lifetime sunburns | 36 | 36 | 36 | 35 | 33 |
| ≥6 moles on the arms | 5.1 | 5.0 | 5.4 | 6.1 | 5.4 |
| Physical exam | 73 | 76 | 77 | 77 | 80 |
| BMI, kg/m2 | 25 ± 5 | 25 ± 5 | 25 ± 5 | 25 ± 5 | 25 ± 5 |
| Physical activity level, MET h/wk | 16 ± 26 | 20 ± 29 | 21 ± 27 | 22 ± 29 | 24 ± 35 |
| Alcohol intake, g/d | 12.0 ± 18.0 | 13.0 ± 17.0 | 12.0 ± 16.0 | 11.0 ± 15.0 | 11.0 ± 14.0 |
| Current smoking | 15 | 11 | 9 | 8 | 7 |
1
Values are means ± SDs or percentages unless otherwise indicated, and standardized to the age distribution of the study population except for age and number of participants. HPFS, Health Professionals Follow-Up Study; MET, metabolic-equivalent; NHS, Nurses’ Health Study.