Table 1.
Characteristics of participants by sex and quintile of energy-adjusted dietary vitamin B6 intake a
| Characteristics b | Men | Women | ||||
|---|---|---|---|---|---|---|
| Quintiles of dietary vitamin B6 intake | Quintiles of dietary vitamin B6 intake | |||||
| Q1 | Q3 | Q5 | Q1 | Q3 | Q5 | |
| Age at baseline (years), mean (SD) | 55.77 (9.82) | 55.39 (9.73) | 54.57 (9.51) | 55.05 (9.41) | 52.36 (8.99) | 50.87 (8.36) |
| Body mass index (kg/m2), mean (SD) | 23.56 (3.1) | 23.62 (3.02) | 24.11 (3.07) | 24.26 (3.67) | 23.89 (3.4) | 24.13 (3.28) |
| Physical activity (MET-h/week), mean (SD) | 59.21 (33.93) | 58.55 (33.24) | 62.84 (36.18) | 106.36 (45.37) | 104.49 (43.87) | 110.8 (47.14) |
| Total energy (kcal/d), mean (SD) | 2049.9 (481.8) | 1821.89 (445.87) | 1993.1 (492.57) | 1781.7 (410.95) | 1597.97 (363.81) | 1750.45 (419.64) |
| Rice (g/d), mean (SD) | 423.27 (44.37) | 365.89 (35.03) | 303.53 (55) | 364.95 (41.9) | 308.2 (31.1) | 252.46 (44.69) |
| Fruit (g/d), mean (SD) | 66.83 (69.95) | 143.39 (89.3) | 240.49 (157.5) | 120.88 (98.27) | 247.12 (116.69) | 420.25 (197.97) |
| Vegetables (g/d), mean (SD) | 183.55 (90.32) | 318.73 (101.46) | 530.16 (215.77) | 162.15 (81.52) | 277.27 (95.55) | 449.51 (192.05) |
| Fish (g/d), mean (SD) | 26.71 (27.72) | 49.49 (35.54) | 75.81 (59.84) | 27.23 (28.51) | 49.16 (35.05) | 71.55 (56.16) |
| Red meat (g/d), mean (SD) | 41.37 (30.19) | 61.6 (30.8) | 78.79 (51.05) | 33.77 (24.03) | 50.28 (26.13) | 60.77 (42.45) |
| Education, N (%) | ||||||
| Elementary school or less | 1241 (10.38) | 712 (5.96) | 454 (3.8) | 5371 (35.93) | 2905 (19.43) | 1802 (12.06) |
| Middle school | 4710 (39.41) | 3902 (32.66) | 3406 (28.5) | 5239 (35.05) | 5590 (37.4) | 5632 (37.68) |
| High school | 4074 (34.09) | 4430 (37.08) | 4537 (37.97) | 3039 (20.33) | 4255 (28.47) | 4970 (33.25) |
| Professional education/college or higher | 1925 (16.11) | 2904 (24.31) | 3552 (29.73) | 1298 (8.68) | 2198 (14.7) | 2542 (17.01) |
| Income c, N (%) | ||||||
| Low | 2021 (16.91) | 1338 (11.2) | 1280 (10.71) | 3118 (20.86) | 2252 (15.07) | 2071 (13.86) |
| Lower middle | 5635 (47.15) | 5119 (42.84) | 4577 (38.3) | 6101 (40.82) | 5634 (37.69) | 5494 (36.76) |
| Upper middle | 3562 (29.81) | 4347 (36.38) | 4507 (37.72) | 3874 (25.92) | 4281 (28.64) | 4223 (28.26) |
| High | 732 (6.13) | 1144 (9.57) | 1585 (13.26) | 1854 (12.4) | 2781 (18.6) | 3158 (21.13) |
| Occupation, N (%) | ||||||
| House wife | - | - | - | 96 (0.64) | 49 (0.33) | 43 (0.29) |
| Professional, administrator | 2371 (19.84) | 3257 (27.26) | 3712 (31.07) | 3083 (20.63) | 4486 (30.01) | 4982 (33.33) |
| Clerical or service worker | 2470 (20.67) | 2598 (21.74) | 2815 (23.56) | 3054 (20.43) | 3068 (20.52) | 3186 (21.32) |
| Manual laborer | 7109 (59.49) | 6093 (51) | 5422 (45.38) | 8714 (58.3) | 7345 (49.14) | 6735 (45.06) |
| Smoke status, N (%) | ||||||
| Never smoker | 3128 (26.18) | 3715 (31.09) | 4005 (33.52) | 14300 (95.67) | 14597 (97.65) | 14615 (97.79) |
| Pack-years<20 | 1260 (10.54) | 1299 (10.87) | 1315 (11.01) | 90 (0.6) | 60 (0.4) | 45 (0.3) |
| Pack-years>=20 | 7562 (63.28) | 6934 (58.03) | 6629 (55.48) | 557 (3.73) | 291 (1.95) | 286 (1.91) |
| Alcohol intake, N (%) | ||||||
| Never drinker | 8458 (70.78) | 7999 (66.95) | 7380 (61.76) | 14694 (98.31) | 14687 (98.25) | 14574 (97.51) |
| <=2 drinks/day | 2045 (17.11) | 2459 (20.58) | 2647 (22.15) | 234 (1.57) | 247 (1.65) | 343 (2.29) |
| >2 drinks/day | 1447 (12.11) | 1490 (12.47) | 1922 (16.09) | 19 (0.13) | 14 (0.09) | 29 (0.19) |
| History of diabetes, N (%) | 645 (5.4) | 782 (6.55) | 706 (5.91) | 855 (5.72) | 669 (4.48) | 437 (2.92) |
| History of hypertension, N (%) | 3445 (28.83) | 3541 (29.64) | 3541 (29.63) | 3882 (25.97) | 3547 (23.73) | 3328 (22.27) |
| History of coronary heart disease, N (%) | 537 (4.49) | 610 (5.11) | 664 (5.56) | 1137 (7.61) | 1089 (7.29) | 1064 (7.12) |
| History of stroke, N (%) | 508 (4.25) | 446 (3.73) | 391 (3.27) | 228 (1.53) | 162 (1.08) | 124 (0.83) |
| Family history of cancer, N (%) | 3294 (27.56) | 3451 (28.88) | 3516 (29.43) | 3699 (24.75) | 4014 (26.85) | 4167 (27.88) |
| Supplemental B vitamins users, N (%) | 924 (7.73) | 1304 (10.91) | 1664 (13.93) | 1173 (7.85) | 1605 (10.74) | 1913 (12.8) |
| Menopause status, N (%) | - | - | - | 8960 (59.95) | 7198 (48.15) | 6332 (42.37) |
| Hormone replacement therapy, N (%) | - | - | - | 201 (1.34) | 280 (1.87) | 426 (2.85) |
Abbreviation: Q, quintiles; SMHS, Shanghai Men’s Health Study; SWHS, Shanghai Women’s Health Study; SD, standard deviation.
All exposures were associated with dietary vitamin B6 intake, with P<0.001 for trends across categories, except for history of diabetes in men (P=0.057), history of hypertension in men (P=0.007) and women (P=0.006).
Food intake (except for energy) was energy-adjusted by residual methods.
Income level, four categories: Low: less than ¥10000 per family per year for women and less than ¥500 per person per month for men; lower middle: ¥10000–19999 per family per year for women and ¥500–999 per person per month for men; Upper middle: ¥20000–29999 per family per year for women and ¥1000–1999 per person per month for men; high: greater than ¥30000 per family per year for women and more than ¥2000 per person per month for men.