Table 1. Baseline characteristics of participants according to tertile of total Okinawan vegetables intake.
| Tertiles of total Okinawan vegetables intake | P valuesa | ||||||
| Lowest (T1) | Second (T2) | Highest (T3) | |||||
| Men | |||||||
| n | 1,560 | 1,561 | 1,560 | ||||
| Age, years | 57.4 | (7.9) | 58.2 | (7.9) | 58.8 | (7.7) | <0.0001 |
| BMI, kg/m2 | 24.7 | (3.1) | 24.5 | (2.9) | 24.7 | (3.1) | 0.9898 |
| Total physical activity, METs | 33.6 | (6.6) | 34.2 | (6.6) | 34.6 | (6.7) | 0.0004 |
| Current smoker, % | 34.3 | 33.2 | 29.3 | 0.0029 | |||
| Current drinker, % | 75.3 | 72.9 | 68.7 | <0.0001 | |||
| Family history of diabetes, % | 4.9 | 5.6 | 4.4 | 0.5111 | |||
| History of hypertension, % | 14.3 | 14.6 | 15.1 | 0.5108 | |||
| Study area (Chubu) | 922 | (59.1) | 841 | (53.9) | 750 | (48.1) | <0.0001 |
| (Miyako) | 638 | (40.9) | 720 | (46.1) | 810 | (51.9) | |
| Daily food and nutrient intake | |||||||
| Total energy intake, kcal | 2,136 | (863) | 2,132 | (771) | 2,107 | (767) | 0.6572 |
| Carbohydrate, % of energy | 49.0 | (12.0) | 48.5 | (10.4) | 49.6 | (9.7) | 0.1515 |
| Fat, % of energy | 24.8 | (8.9) | 27.2 | (8.2) | 28.4 | (7.5) | <0.0001 |
| Protein, % of energy | 12.4 | (2.8) | 13.2 | (2.5) | 13.6 | (2.4) | <0.0001 |
| Calcium, mg | 422.5 | (243.9) | 457.9 | (215.7) | 522.5 | (218.4) | <0.0001 |
| Magnesium, mg | 270.3 | (74.0) | 301.8 | (80.3) | 341.9 | (89.2) | <0.0001 |
| Dietary fiber, g | 8.3 | (3.2) | 10.7 | (3.4) | 14.1 | (4.7) | <0.0001 |
| Vitamin D, µg | 5.8 | (4.1) | 6.7 | (3.9) | 6.9 | (4.3) | <0.0001 |
| Polyunsaturated fatty acids, g | 11.8 | (3.6) | 13.8 | (3.6) | 15.7 | (3.7) | <0.0001 |
| Vegetables (except for Okinawan vegetables), g | 121.9 | (85.7) | 170.3 | (93.2) | 226.2 | (125.4) | <0.0001 |
| Fruits (except for papaya), g | 101.0 | (102.5) | 126.6 | (104.8) | 154.3 | (112.8) | <0.0001 |
| Meat, g | 86.6 | (54.6) | 90.2 | (53.1) | 83.8 | (49.1) | 0.2878 |
| Rice, g | 548.2 | (171.7) | 532.9 | (149.9) | 523.5 | (145.1) | <0.0001 |
| Fish, g | 59.5 | (47.3) | 70.1 | (42.4) | 72.4 | (43.7) | <0.0001 |
| Coffee, g | 217.8 | (288.0) | 179.7 | (214.6) | 160.1 | (199.6) | <0.0001 |
| Total intake of Okinawan vegetables, g | 17.2 | (7.2) | 44.5 | (9.8) | 113.7 | (65.7) | <0.0001 |
| Pak choi | 1.6 | (2.5) | 4.6 | (5.7) | 10.9 | (15.9) | <0.0001 |
| Leaf mustard | 1.7 | (2.2) | 4.5 | (5.1) | 11.7 | (15.0) | <0.0001 |
| Bitter gourd | 7.0 | (5.2) | 18.6 | (10.8) | 45.3 | (38.4) | <0.0001 |
| Swiss chard | 0.9 | (2.1) | 2.5 | (4.5) | 8.6 | (18.0) | <0.0001 |
| Loofah | 3.1 | (3.0) | 8.4 | (7.3) | 25.3 | (25.7) | <0.0001 |
| Mugwort | 0.2 | (0.5) | 0.3 | (0.5) | 0.5 | (0.9) | <0.0001 |
| Papaya | 2.5 | (2.7) | 5.2 | (5.9) | 9.9 | (13.9) | <0.0001 |
| Women | |||||||
| n | 1,997 | 1,998 | 1,998 | ||||
| Age, years | 57.9 | (8.2) | 58.0 | (7.9) | 58.9 | (8.0) | 0.0009 |
| BMI, kg/m2 | 24.3 | (3.3) | 24.3 | (3.3) | 24.5 | (3.2) | 0.0682 |
| Total physical activity, METs | 32.6 | (5.7) | 33.3 | (5.7) | 33.4 | (5.9) | <0.0001 |
| Current smoker, % | 3.5 | 2.8 | 2.1 | 0.0124 | |||
| Current drinker, % | 9.8 | 9.1 | 7.0 | 0.0016 | |||
| Family history of diabetes, % | 6.0 | 5.0 | 6.5 | 0.5453 | |||
| History of hypertension, % | 12.8 | 11.6 | 14.8 | 0.0611 | |||
| Study area (Chubu) | 1,211 | (60.0) | 1,127 | (56.4) | 1,040 | (52.1) | <0.0001 |
| (Miyako) | 786 | (39.4) | 871 | (43.6) | 958 | (47.9) | |
| Daily food and nutrient intake | |||||||
| Total energy intake, kcal | 1,811 | (745) | 1,813 | (662) | 1,776 | (638) | 0.3787 |
| Carbohydrate, % of energy | 52.4 | (10.6) | 52.4 | (9.2) | 53.3 | (8.3) | 0.0174 |
| Fat, % of energy | 31.0 | (9.2) | 31.4 | (7.8) | 31.2 | (7.0) | 0.2543 |
| Protein, % of energy | 14.2 | (2.4) | 14.5 | (2.3) | 14.5 | (2.2) | 0.0001 |
| Calcium, mg | 474.9 | (252.3) | 501.6 | (217.8) | 558.7 | (207.5) | <0.0001 |
| Magnesium, mg | 265.7 | (74.6) | 292.2 | (73.2) | 334.3 | (82.2) | <0.0001 |
| Dietary fiber, g | 9.7 | (3.6) | 11.8 | (3.5) | 15.3 | (4.6) | <0.0001 |
| Vitamin D, µg | 5.7 | (3.4) | 6.3 | (4.3) | 6.4 | (4.1) | <0.0001 |
| Polyunsaturated fatty acids, g | 12.7 | (3.3) | 13.8 | (3.1) | 15.3 | (3.3) | <0.0001 |
| Vegetables (except for Okinawan vegetables), g | 149.7 | (106.8) | 186.6 | (108.2) | 242.7 | (121.2) | <0.0001 |
| Fruits (except for papaya), g | 129.7 | (122.3) | 157.8 | (120.3) | 176.8 | (121.8) | <0.0001 |
| Meat, g | 83.2 | (51.1) | 77.1 | (44.8) | 65.3 | (40.8) | <0.0001 |
| Rice, g | 474.7 | (135.0) | 455.4 | (117.0) | 444.4 | (118.0) | <0.0001 |
| Fish, g | 55.6 | (40.8) | 62.9 | (41.1) | 64.5 | (40.5) | <0.0001 |
| Coffee, g | 151.7 | (178.6) | 150.5 | (167.4) | 128.8 | (154.6) | <0.0001 |
| Total intake of Okinawan vegetables, g | 20.4 | (8.2) | 50.0 | (10.1) | 123.5 | (75.4) | <0.0001 |
| Pak choi | 2.3 | (3.3) | 5.9 | (6.9) | 13.6 | (16.0) | <0.0001 |
| Leaf mustard | 2.1 | (2.8) | 5.1 | (5.5) | 12.7 | (16.1) | <0.0001 |
| Bitter gourd | 7.8 | (5.7) | 19.7 | (11.2) | 45.5 | (37.1) | <0.0001 |
| Swiss chard | 1.0 | (2.2) | 3.0 | (5.4) | 9.8 | (20.7) | <0.0001 |
| Loofah | 3.6 | (3.5) | 9.6 | (7.8) | 26.7 | (29.4) | <0.0001 |
| Mugwort | 0.2 | (0.5) | 3.0 | (5.4) | 0.5 | (1.0) | <0.0001 |
| Papaya | 3.2 | (3.3) | 6.0 | (6.8) | 13.0 | (24.6) | <0.0001 |
Values are expressed as mean (standard deviation) or number (%).
aDetermined by using Chi-square test for categorical variables and linear regression analysis for continuous variables with assignment of ordinal numbers 0–3 to categories of total Okinawan vegetable intake.