Table 3.
Linear regression coefficients (95% confidence interval) for cognitive function test Z-scores according to FEV1/FVC at baseline, adjusted for potential confounders
| Median (IQR), L | Quintiles of FEV1/FVC | P-trend | Per SD | ||||
|---|---|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | Q5 | |||
| 0.68 (0.64–0.70) | 0.73 (0.72–0.74) | 0.76 (0.76–0.77) | 0.79 (0.78–0.80) | 0.82 (0.81–0.84) | |||
| Pairs matching | 0.00 | 0.00 (−0.01, 0.01) | 0.01 (0.00, 0.02) | 0.02 (0.01, 0.03) | 0.02 (0.01, 0.03) | <0.001 | 0.01 (0.00, 0.01) |
| Reaction time | 0.00 | 0.02 (0.01, 0.03) | 0.02 (0.01, 0.03) | 0.02 (0.01, 0.03) | 0.02 (0.01, 0.03) | 0.004 | 0.01 (0.01, 0.02) |
| Fluid intelligence | 0.00 | 0.01 (−0.01, 0.03) | 0.00 (−0.01, 0.02) | 0.00 (−0.02, 0.02) | 0.01 (−0.00, 0.03) | 0.31 | 0.00 (−0.00, 0.01) |
| Numeric memory | 0.00 | −0.01 (−0.04, 0.02) | 0.01 (−0.03, 0.04) | −0.01 (−0.04, 0.03) | 0.01 (−0.03, 0.04) | 0.78 | 0.00 (−0.01, 0.01) |
| Trail making B-A | 0.00 | 0.05 (0.01, 0.09) | 0.06 (0.02, 0.09) | 0.06 (0.02, 0.10) | 0.05 (0.01, 0.09) | 0.004 | 0.03 (0.01, 0.04) |
| Symbol digit | 0.00 | 0.04 (0.01, 0.08) | 0.03 (−0.01, 0.06) | 0.05 (0.02, 0.08) | 0.04 (0.00, 0.07) | 0.04 | 0.02 (0.00, 0.03) |
| Matrix pattern | 0.00 | 0.03 (−0.00, 0.07) | 0.03 (−0.01, 0.07) | 0.03 (−0.01, 0.07) | 0.01 (−0.03, 0.04) | 0.66 | 0.01 (−0.01, 0.02) |
| Tower rearranging | 0.00 | 0.02 (−0.02, 0.06) | 0.00 (−0.04, 0.04) | 0.06 (0.02, 0.10) | 0.04 (0.00, 0.08) | 0.007 | 0.02 (0.01, 0.04) |
| Paired learning | 0.00 | 0.01 (−0.03, 0.05) | 0.03 (−0.00, 0.07) | 0.05 (0.01, 0.08) | 0.03 (−0.01, 0.07) | 0.02 | 0.01 (0.00, 0.03) |
| G-factor | |||||||
| All tests at baseline | 0.00 | −0.01 (−0.03, 0.02) | 0.00 (−0.02, 0.02) | −0.01 (−0.03, 0.02) | 0.01 (−0.02, 0.03) | 0.72 | 0.00 (−0.01, 0.01) |
| EF at Visit 2 | 0.00 | 0.04 (0.02, 0.06) | 0.03 (0.01, 0.05) | 0.05 (0.03, 0.07) | 0.04 (0.02, 0.06) | <0.001 | 0.02 (0.01, 0.03) |
| All tests at Visit 2 | 0.00 | 0.03 (0.01, 0.06) | 0.03 (0.00, 0.05) | 0.04 (0.02, 0.07) | 0.03 (0.01, 0.06) | 0.004 | 0.02 (0.01, 0.03) |
The multivariable model included age, sex, assessment centre, Townsend deprivation index, 12 potentially modifiable risk factors for dementia including education, hearing loss, traumatic brain injury, hypertension, alcohol >21 units per week, obesity, smoking, depression, social isolation, physical inactivity, air pollution and diabetes and APOE4 alleles. Pairs matching, reaction time, fluid intelligence and numeric memory tests carried out at baseline were used. Trail making B-A, symbol digit, matrix pattern, tower rearranging and paired learning tests were carried out at Visit 2. Of participants included in genetic analyses, sample sizes with lung function measures ranged from 322 887 to 25 845.
EF, executive function (five components); g-factor, general cognitive ability; IQR, interquartile range.