Table 3.
Association of physical activity in 1997-99 with cognitive decline over 15 years (1997-99 to 2012-13), using global cognitive z score
| Adjusted for age and sex | Adjusted for sociodemographic and behavioural factors* | Fully adjusted† | ||||||
|---|---|---|---|---|---|---|---|---|
| 15 year cognitive decline‡ (95% CI) | P value§ | 15 year cognitive decline‡ (95% CI) | P value§ | 15 year cognitive decline‡ (95% CI) | P value§ | |||
| Total physical activity | ||||||||
| <8 hours/week | −0.61 (−0.65 to −0.58) | Reference | −0.63 (−0.66 to −0.59) | Reference | −0.63 (−0.66 to −0.59) | Reference | ||
| 8-12 hours/week | −0.62 (−0.65 to −0.59) | 0.48 | −0.62 (−0.66 to −0.59) | 0.80 | −0.63 (−0.66 to −0.59) | 0.73 | ||
| ≥12 hours/week | −0.63 (−0.66 to −0.60) | 0.68 | −0.63 (−0.66 to −0.60) | 0.94 | −0.63 (−0.66 to −0.60) | 0.99 | ||
| Mild physical activity | ||||||||
| <5 hours/week | −0.61 (−0.65 to −0.57) | Reference | −0.62 (−0.66 to −0.59) | Reference | −0.62 (−0.66 to −0.59) | Reference | ||
| 5-9 hours/week | −0.63 (−0.66 to −0.60) | 0.56 | −0.63 (−0.66 to −0.60) | 0.73 | −0.63 (−0.66 to −0.60) | 0.67 | ||
| ≥9 hours/week | −0.62 (−0.66 to −0.59) | 0.43 | −0.63 (−0.66 to −0.60) | 0.72 | −0.63 (−0.67 to −0.60) | 0.69 | ||
| Moderate to vigorous physical activity | ||||||||
| <2 hours/week | −0.61 (−0.64 to −0.58) | Reference | −0.62 (−0.65 to −0.59) | Reference | −0.61 (−0.64 to −0.58) | Reference | ||
| 2-4 hours/week | −0.62 (−0.66 to −0.58) | 0.13 | −0.63 (−0.66 to −0.59) | 0.26 | −0.63 (−0.66 to −0.59) | 0.18 | ||
| ≥4 hours/week | −0.64 (−0.67 to −0.61) | 0.55 | −0.64 (−0.67 to −0.61) | 0.67 | −0.65 (−0.68 to −0.61) | 0.55 | ||
| Physical activity recommendations ¶ | ||||||||
| MVPA <2.5 hours/week | −0.61 (−0.64 to −0.59) | Reference | −0.62 (−0.65 to −0.60) | Reference | −0.62 (−0.65 to −0.59) | Reference | ||
| MVPA ≥2.5 hours/week | −0.63 (−0.65 to −0.60) | 0.45 | −0.63 (−0.66 to −0.61) | 0.66 | −0.63 (−0.66 to −0.61) | 0.55 | ||
Adjusted for age, sex, ethnicity, education, occupational position, marital status, smoking status, alcohol consumption, and fruit and vegetable consumption.
Additionally adjusted for hypertension, diabetes, body mass index, General Health Questionnaire score, cardiovascular disease, cardiovascular disease drugs, and SF-36 physical component score.
Estimated cognitive decline over 15 years (expressed in standard deviations using distribution of first wave of cognitive data in 1997-99) as a function of physical activity.
P for difference in decline in global cognitive score over 15 years by physical activity groups (drawn from test of interaction between physical activity categories and time from baseline).
Recommended level corresponds to moderate to vigorous physical activity (MVPA) ≥2.5 hours/week.