To explore the association between long-term exposure to PM2.5 and the risk of gastric intestinal metaplasia (IM), and to analyze the heterogeneity of the associations across age, sex, and the form of medical consultation.
A case-control study was conducted, including patients first diagnosed with IM (case group, n=8 822) and chronic gastritis (CG) controls (n=191 840) at the Second Affiliated Hospital of Army Medical University between January 2012 and September 2024. Population-weighted average concentrations of air pollutants (PM2.5, SO2, CO, NO2, O3) over the 3-year period prior to diagnosis were calculated as exposure metrics. Single- and dual-pollutant logistic regression models were used to estimate PM2.5 effects, with subgroup analyses stratified by sex, age, and the form of medical consultation. Restricted cubic spline (RCS) models were used to explore the nonlinear associations. The 1-year and 5-year exposure windows were used as sensitivity analyses.
IM patients (mean age 57.521 years) were older than CG controls (49.254 years), with higher proportions of males (58.3% vs. 42.7%) and inpatients (15.6% vs. 4.7%). After adjusting for calendar year and province, single-pollutant models revealed that each 10μg/m3 increase in PM2.5 exposure was associated with 35% (OR=1.35, 95% CI: 1.27–1.43), 39% (OR=1.39, 95% CI: 1.32–1.47), and 38% (OR=1.38, 95% CI: 1.31–1.46) elevated IM risks for 1-, 3-, and 5-year exposure windows, respectively. Effects remained stable after adjusting for SO2, O3, or CO, but attenuated (while still significant) when adjusting for NO2. Subgroup analyses showed no significant heterogeneity across age, sex, and the form of medical consultation. RCS indicated a nonlinear dose-response relationship between PM2.5 and log-transformed IM risk (P<0.001).
Long-term PM2.5 exposure is significantly associated with an increased IM risk, with consistent effects across sex, age, and the form of medical consultation subgroups.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |