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Long-term exposure to fine particulate matter and dementia incidence: A cohort study in Hong Kong
Jinjun Ran, C Mary Schooling, Lefei Han, Shengzhi Sun, Shi Zhao, Xiaohong Zhang, King-Pan Chan, Fang Guo et al.. Environmental pollution (Barking, Essex : 1987), 2020-12-25
Topic: Air pollution and environmental exposures
Recent studies suggested that long-term exposure to fine particulate matter (PM2.5) was related to a higher risk of dementia incidence or hospitalizations in western populations, but the evidence is limited in Asian cities. Here we explored the link between long-term PM2.5 exposure and dementia incidence in the Hong Kong population and whether it varied by population sub-group. We utilized a Hong Kong Chinese cohort of 66,820 people aged ≥65 years who were voluntarily enrolled during 1998-2001 and were followed up to 2011. Prevalent dementia cases were excluded based on the face-to-face interview at baseline. We ascertained the first occurrence of hospitalization for all-cause dementia and major subtypes during the follow-up period. We assessed PM2.5 concentrations using a satellite data-based model with a 1 × 1 km2 resolution on the residential address. Cox proportional hazards models were adopted to estimate associations of annual mean PM2.5 exposure with dementia incidence, adjusting for potential confounders. We identified 1183 incident cases of all-cause dementia during the follow-up period, of which 655 (55.4%) were cases of Alzheimer's disease, and 334 (28.2%) were those of vascular dementia. We found a positive association between annual mean PM2.5 exposure and all-cause dementia incidence in the fully adjusted model. The estimated hazard ratio was 1.06 (95% confidence interval (CI): 1.00, 1.13) per every 3.8 μg/m3 increase in annual mean PM2.5 exposure. And the estimated HRs for Alzheimer's disease and vascular dementia were 1.03 (95% CI: 0.94, 1.12) and 1.09 (95% CI: 0.98, 1.22), respectively. We did not find effect modifications by age, sex, BMI, hypertension, diabetes, or heart disease on the associations. Results suggest that long-term exposure to PM2.5 is associated with a higher risk of dementia incidence in the Asian population.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Ran, J., Schooling, C. M., Han, L., Sun, S., Zhao, S., Zhang, X., et al. (2021). Long-term exposure to fine particulate matter and dementia incidence: A cohort study in Hong Kong. Environmental pollution (Barking, Essex : 1987). https://doi.org/10.1016/j.envpol.2020.116303
Vancouver
Ran J, Schooling CM, Han L, Sun S, Zhao S, Zhang X, et al. Long-term exposure to fine particulate matter and dementia incidence: A cohort study in Hong Kong. Environmental pollution (Barking, Essex : 1987). 2021. doi:10.1016/j.envpol.2020.116303. PMID: 33370610.
BibTeX
@article{ran2021-33370610,
author = {Ran, Jinjun and Schooling, C Mary and Han, Lefei and Sun, Shengzhi and Zhao, Shi and Zhang, Xiaohong and Chan, King-Pan and Guo, Fang and others},
title = {{Long-term exposure to fine particulate matter and dementia incidence: A cohort study in Hong Kong}},
journal = {Environmental pollution (Barking, Essex : 1987)},
year = {2021},
doi = {10.1016/j.envpol.2020.116303},
pmid = {33370610},
url = {https://doi.org/10.1016/j.envpol.2020.116303}
}
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Key findings
- Recent studies suggested that long-term exposure to fine particulate matter (PM2.5) was related to a higher risk of dementia incidence or hospitalizations in western populations, but the evidence is limited in Asian cities.
- We found a positive association between annual mean PM2.5 exposure and all-cause dementia incidence in the fully adjusted model.
- Results suggest that long-term exposure to PM2.5 is associated with a higher risk of dementia incidence in the Asian population.
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Study details
- Participants66,820
- Effect size55.4%; 28.2%
- Evidence strengthModerate
How this study scored 61/100
Published in a peer-reviewed journal. Scored zero for study design and randomised / blinded because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record, multi-centre collaboration and free to read, so those were left out: it earned 34 of the 56 points we could judge it on, which is 61 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Environmental pollution (Barking, Essex : 1987)) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| 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 | 66,820 participants |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| 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 | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 33370610) |
| Free to read | — / 2 | Access not recorded — left out of this score |
| Points | 34 / 56 | Scored on 10 of 20 parts. We have no data for the rest, so they are left out: 34 of the 56 points we could judge it on is 61 out of 100. |
| Total | 61 / 100 | — |
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