Baseline characteristics of cohort members without PD and PD cases (mean (SD) or per cent), The Singapore Chinese Health Study
| PD cases (n=411) | Non-PD participants (n=59 838) | p Value | |
|---|---|---|---|
| Age (years) at recruitment | 61.5 (7.2) | 56.5 (8.0) | <0.0001 |
| Body mass index (kg/m2) | 23.0 (2.9) | 23.1 (3.3) | 0.35 |
| Sex (%) | |||
| Males | 218 (53.0) | 26 591 (44.4) | 0.0005 |
| Females | 193 (47.0) | 33 247 (55.6) | |
| Dialect (%) | |||
| Cantonese | 176 (42.8) | 27 723 (46.3) | 0.15 |
| Hokkien | 235 (57.2) | 32 115 (53.7) | |
| Level of education (%) | |||
| No formal education | 111 (27.0) | 16 149 (27.0) | 0.032 |
| Primary school (1–6 years) | 205 (49.9) | 26 614 (44.5) | |
| Secondary school and above | 95 (23.1 | 17 075 (28.5) | |
| Smoking status (%) | |||
| Never smoker | 296 (72.0) | 41 577 (69.5) | 0.007 |
| Former smoker | 57 (13.9) | 6513 (10.9) | |
| Current smoker | 58 (14.1) | 11 748 (19.6) | |
| Black tea intake (%) | |||
| Non/monthly | 302 (73.5) | 42 987 (71.8) | 0.12 |
| Weekly | 76 (18.5) | 10 182 (17.0) | |
| Daily | 33 (8.0) | 6669 (11.2) | |
| Total energy (kcal/day) | 1529 (554) | 1548 (520) | 0.46 |
| Dietary intake (energy-adjusted) | |||
| Caffeine (mg/day) | 125.5 (102.2) | 148.5 (106.2) | <0.0001 |
| Total fatty acids (g/day) | 42.4 (9.6) | 43.8 (10.3) | 0.003 |
| Saturated fatty acids (g/day) | 14.8 (4.3) | 15.5 (4.6) | 0.001 |
| Monounsaturated fatty acids (g/day) | 14.3 (3.5) | 14.8 (3.8) | 0.003 |
| n-3 Polyunsaturated fatty acids (g/day) | 0.88 (0.3) | 0.89 (0.3) | 0.63 |
| n-6 Polyunsaturated fatty acids (g/day) | 7.8 (3.0) | 7.9 (3.1) | 0.73 |
| Cholesterol (mg/day) | 157.7 (65.5) | 173.0 (74.3) | <0.0001 |
p Value by χ2 or student's t test.
PD, Parkinson's disease