Table 2.
Population characteristics (n = 3010) of The Maastricht Study
| All participants (n = 3010) | No knee pain (n = 2364) | Clinical knee osteoarthritis (n = 427) | |
|---|---|---|---|
| Age (years) | 60.0 (8.14) | 59.7 (8.30) | 62.5 (6.54) |
| Sex (% male) | 50.6 | 51.6 | 41.2 |
| Highest education (n, %) | |||
| Low | 32.9 | 30.9 | 44.6 |
| Medium | 28.0 | 27.6 | 26.6 |
| High | 39.1 | 41.1 | 28.8 |
| Smoking (n, %) | |||
| Never | 35.4 | 35.6 | 33.5 |
| Former | 52.1 | 51.5 | 55.3 |
| Current | 12.5 | 12.9 | 11.2 |
| BMI (kg/m2) (n, %) | 27.0 (4.52) | 26.7 (4.30) | 29.0 (5.34) |
| Normal | 35.9 | 38.0 | 23.0 |
| Overweight | 42.2 | 42.5 | 39.6 |
| Obese | 21.9 | 19.4 | 37.5 |
| Type 2 diabetes (n, %) | 27.5 | 25.9 | 37.7 |
| History of sport-related knee injury (%) | 25.9 | 22.8 | 39.1 |
| Occupational exposure to knee loading (%) | |||
| No squatting or kneeling | 76.4 | 77.9 | 70.6 |
| Squatting or kneeling without lifting | 3.5 | 3.5 | 4.0 |
| Squatting or kneeling with lifting | 20.1 | 18.6 | 25.4 |
| Dietary intake | |||
| Energy (kcal/day) | 2178 (603) | 2182 (603) | 2123 (595) |
| Vegetables (g/day) | 181 (99.0) | 180 (97.5) | 185 (100) |
| Fruits (g/day) | 195 (145) | 195 (146) | 207 (143) |
| Meat (g/day) | 111 (58.8) | 110 (57.5) | 116 (61.0) |
| Fish and shellfish (g/day) | 24.4 (21.9) | 24.7 (22.1) | 22.5 (20.6) |
| Alcohol use (%) | 18.1 | 17.2 | 25.9 |
| None | 56.1 | 56.8 | 50.4 |
| Low | 25.3 | 26.0 | 23.7 |
| High | 18.1 | 17.2 | 25.9 |
| Vitamin A (mcg/day) | 721 (652) | 719 (653) | 713 (655) |
| Vitamin C (mg/day) | 128 (61.2) | 127 (60.8) | 134 (62.5) |
| Vitamin D (mcg/day) | 3.88 (1.90) | 3.90 (1.90) | 3.75 (1.93) |
| Vitamin E (mg/day) | 14.4 (5.66) | 14.4 (5.53) | 14.2 (5.84) |
| Calcium (mg/day) | 965 (385) | 965 (383) | 953 (381) |
| Phosphorus (mg/day) | 1564 (442) | 1562 (439) | 1550 (454) |
| Magnesium (mg/day) | 376 (102) | 375 (100) | 371 (107) |
| Zinc (mg/day) | 11.1 (3.02) | 11.1 (2.98) | 11.0 (3.09) |
Values are presented as mean (SD) or proportions
Normal: < 25.00 kg/m2, Overweight: ≥ 25.00 to < 30.00 kg/m2, Obese: ≥ 30.00 kg/m2
Alcohol use—Low: ≤ 14 units (glasses)/week for men and ≤ 7 units/week for women, High: > 14 units/week for men and > 7 units/week for women
BMI body mass index, SD standard deviation