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Dose-response association between device-measured physical activity and incident dementia: a prospective study from UK Biobank
Petermann-Rocha F, Lyall DM, Gray SR, Gill JMR, Sattar N, Welsh P, et al.. BMC Medicine, 2021-12-02
Topic: Risk, prevention and care in population studies
Background Previous cohort studies have investigated the relationship between self-reported physical activity (PA) and dementia. Evidence from objective device-measured PA data is lacking. This study aimed to explore the association of device-measured PA with the risk of dementia incidence and common subtypes (Alzheimer's disease [AD] and vascular dementia) using the UK Biobank study. Methods 84,854 participants (55.8% women), invited to participate in the device-measured PA between 2013 and 2015, were included in this prospective cohort study. Wrist accelerometers were used to measure light, moderate, vigorous, moderate-to-vigorous PA (MVPA) and total PA intensity and duration (MET/min/week). Incident dementia (fatal and non-fatal) was extracted from hospital episodes records for incidence and death register for mortality. Incidence follow-up was carried out until the end of March 2021in England and Scotland and the end of March 2018 in Wales. Mortality data were available until February 2021. Nonlinear associations were first investigated using penalised cubic splines fitted in the Cox proportional hazard models. In addition, using MVPA, five categories were created. Associations of these categories with the outcomes were investigated using Cox proportional hazard models. Analyses were adjusted for sociodemographic, lifestyle and health-related factors. Results After a median follow-up of 6.3 years, 678 individuals were diagnosed with dementia. Evidence of nonlinearity was observed for all PA modes and all-cause dementia. For categories of MVPA, there was a significant trend towards a low risk of overall dementia when higher levels of MVPA were achieved (HR trend 0.66 [95% CI 0.62 to 0.70]. The lowest risk was identified in individuals who performed more than 1200 MET/min/week, those who had 84% (95% CI 0.12 to 0.21) lower risk of incident dementia compared to those who performed Conclusions Participants with higher PA levels had a lower risk of incident dementia than those less active, independently of sociodemographic, lifestyle factors and comorbidity. Considering that the majority of previous studies have reported this association using self-reported data, our findings highlight the strong inverse association between PA objectively measured and incident dementia.
Key findings
- Results After a median follow-up of 6.3 years, 678 individuals were diagnosed with dementia.
- For categories of MVPA, there was a significant trend towards a low risk of overall dementia when higher levels of MVPA were achieved (HR trend 0.66 [95% CI 0.62 to 0.70].
- The lowest risk was identified in individuals who performed more than 1200 MET/min/week, those who had 84% (95% CI 0.12 to 0.21) lower risk of incident dementia compared to those who performed < 300 MET/min/week.
- Considering that the majority of previous studies have reported this association using self-reported data, our findings highlight the strong inverse association between PA objectively measured and incident dementia.
Why it matters
This UK Biobank cohort using device-measured activity found that higher activity levels were linked to lower dementia risk. Being observational, it shows an association and cannot prove that activity prevents dementia.
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Study details
- Study designcohort
- Participants84,854
- Effect sizeHR 0.16 (95% CI 0.12-0.21) for >1,200 vs <300 MET-min/week of moderate-to-vigorous activity
- Evidence strengthModerate
Limitations
Short follow-up leaves room for reverse causation; single week of accelerometry; the very large effect may partly reflect prodromal inactivity.
How this study scored 66/100
Published in a peer-reviewed journal, and it is a cohort study following people over time. Scored zero for randomised / blinded because the record does not state it. We have no data on free to read, so that was left out: it earned 65 of the 98 points we could judge it on, which is 66 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (BMC Medicine) |
| Journal's citation record | 3 / 4 | BMC Medicine: journal h-index 259 (OpenAlex, 2026-10-29) |
| Study design | 7 / 12 | A cohort study following people over time |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 3 / 5 | 2021 — within 6 year(s) of the newest study here |
| Sample size | 4 / 4 | 84,854 participants |
| Effect reported | 3 / 3 | Effect reported with a statistic (interval, p-value, ratio or similar) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 4 / 7 | Cited 58 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 8.3 citations a year over 7 year(s) since 2021 |
| Impact for its field and year | 3 / 6 | Cited 5.9× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 1 other studies in this library |
| Still being cited | 2 / 4 | Cited 35 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Carlos A. Celis-Morales: h-index 71 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of Glasgow: institution h-index 1,600 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 5 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 34852818) |
| Free to read | — / 2 | Access not recorded — left out of this score |
| Points | 65 / 98 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 65 of the 98 points we could judge it on is 66 out of 100. |
| Total | 66 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
Full text: free to read — PubMed Central lists this copy as free to read: the link above (checked 10 Oct 2026).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Petermann-Rocha, F., Lyall, D. M., Gray, SR., Gill, J. M. R., Sattar, N., Welsh, P., et al. (2021). Dose-response association between device-measured physical activity and incident dementia: a prospective study from UK Biobank. BMC Medicine. https://doi.org/10.1186/s12916-021-02172-5
Vancouver
Petermann-Rocha F, Lyall DM, Gray SR, Gill JMR, Sattar N, Welsh P, et al. Dose-response association between device-measured physical activity and incident dementia: a prospective study from UK Biobank. BMC Medicine. 2021. doi:10.1186/s12916-021-02172-5. PMID: 34852818.
BibTeX
@article{petermannrocha2021-34852818,
author = {Petermann-Rocha, F. and Lyall, D. M. and Gray, SR. and Gill, J. M. R. and Sattar, N. and Welsh, P. and others},
title = {{Dose-response association between device-measured physical activity and incident dementia: a prospective study from UK Biobank}},
journal = {BMC Medicine},
year = {2021},
doi = {10.1186/s12916-021-02172-5},
pmid = {34852818},
url = {https://doi.org/10.1186/s12916-021-02172-5}
}
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