Table 1.
The relationship between dietary thiamine intake and cognitive decline using two-piecewise linear regression*
| Inflection point, mg/day | n | Mean (SD) | β (95% CI) | P value | R2 |
| Estimate (95% CI) | |||||
| Decline rate in global cognitive scores, points/5 years | |||||
| Model 1 | |||||
| 0.67 (0.51 to 0.82) | 0.270 | ||||
| <0.67 | 570 | 2.89 (11.13) | −7.43 (−18.79 to 3.93) | 0.200 | |
| ≥0.67 | 2536 | 2.09 (11.12) | 3.10 (1.35 to 4.85) | <0.001 | |
| Model 2 | |||||
| 0.68 (0.56 to 0.80) | 0.312 | ||||
| <0.68 | 617 | 2.80 (10.95) | −7.13 (−18.77 to 4.50) | 0.230 | |
| ≥0.68 | 2489 | 2.09 (11.16) | 4.24 (2.22 to 6.27) | <0.001 | |
| Decline rate in composite cognitive scores, SU/5 years | |||||
| Model 1 | |||||
| 0.66 (0.52 to 0.81) | 0.256 | ||||
| <0.66 | 527 | 0.43 (1.47) | −0.90 (−2.50 to 0.70) | 0.271 | |
| ≥0.66 | 2579 | 0.29 (1.43) | 0.33 (0.10 to 0.55) | 0.005 | |
| Model 2 | |||||
| 0.68 (0.56 to 0.80) | 0.297 | ||||
| <0.68 | 617 | 0.40 (1.46) | −1.00 (−2.56 to 0.56) | 0.208 | |
| ≥0.68 | 2489 | 0.29 (1.44) | 0.49 (0.23 to 0.76) | <0.001 | |
p values less than 0.05 are shown in bold.
*Model 1 was adjusted for age, sex, global score, as well as the intakes of carbohydrate, protein and fat. Model 2 was further adjusted for smoking, alcohol consumption, BMI, SBP, DBP, education level, occupation, region, urban or rural residency, self-reported diabetes, antihypertensive medicine, physical activity, as well as the intakes of fibre, sodium and potassium.
BMI, body mass index; CI, confidence interval; DBP, diastolic blood pressure; SBP, systolic blood pressure; SD, standard deviation; SU, standard units by averaging z scores.