Search

Particulate matter with aerodynamic diameter no larger than 2.5 µm (PM2.5) has been linked to cardiovascular diseases (CVDs) but evidence for vulnerability by sex remains unclear. We performed systematic review and meta-analysis to synthesize the state of scientific evidence on whether cardiovascular risks from PM2.5 differ for men compared to women. The databases Pubmed, Scopus, Embase, and GreenFILE were searched for studies published January 1995 to February 2020. Observational studies conducting subgroup analysis by sex for impacts of short-term or long-term exposure to PM2.5 on target CVDs were included. Data were independently extracted in duplicate and pooled with random-effects meta-regression. Risk ratios (RRs) for long-term exposure and percent changes in outcomes for short-term exposure were calculated per 10 µg m−3 PM2.5 increase. Quality of evidence of risk differences by sex was rated following Grading of Recommendations Assessment, Development and Evaluation (GRADE). A total of 12 502 articles were screened, with 61 meeting inclusion criteria. An additional 32 studies were added from citation chaining. RRs of all CVD mortality for long-term PM2.5 for men and women were the same (1.14; 95% CI: 1.09, 1.22) indicating no statistically different risks. Men and women did not have statistically different risks of daily CVD mortality, hospitalizations from all CVD, ischemic heart disease, cardiac arrest, acute myocardial infarction, and heart failure from short-term PM2.5 exposure (difference in % change in risk per 10 µg m−3 PM2.5: 0.04 (95% CI, −0.42–0.51); −0.05 (−0.47–0.38); 0.17 (−0.90, 1.24); 1.42 (−1.06, 3.97); 1.33 (−0.05, 2.73); and −0.48 (−1.94, 1.01), respectively). Analysis using GRADE found low or very low quality of evidence for sex differences for PM2.5-CVD risks. In conclusion, this meta-analysis and quality of evidence assessment of current observational studies found very limited evidence of the effect modification by sex for effects of PM2.5 on CVD outcomes in adults, which can inform clinical approaches and policies.

The consumption of processed meat has been associated with noncardia gastric cancer, but evidence regarding a possible role of red meat is more limited. Our study aims to quantify the association between meat consumption, namely white, red and processed meat, and the risk of gastric cancer, through individual participant data meta-analysis of studies participating in the “Stomach cancer Pooling (StoP) Project”. Data from 22 studies, including 11,443 cases and 28,029 controls, were used. Study-specific odds ratios (ORs) were pooled through a two-stage approach based on random-effects models. An exposure-response relationship was modeled, using one and two-order fractional polynomials, to evaluate the possible nonlinear association between meat intake and gastric cancer. An increased risk of gastric cancer was observed for the consumption of all types of meat (highest vs. lowest tertile), which was statistically significant for red (OR: 1.24; 95% CI: 1.00–1.53), processed (OR: 1.23; 95% CI: 1.06–1.43) and total meat (OR: 1.30; 95% CI: 1.09–1.55). Exposure-response analyses showed an increasing risk of gastric cancer with increasing consumption of both processed and red meat, with the highest OR being observed for an intake of 150 g/day of red meat (OR: 1.85; 95% CI: 1.56–2.20). This work provides robust evidence on the relation between the consumption of different types of meat and gastric cancer. Adherence to dietary recommendations to reduce meat consumption may contribute to a reduction in the burden of gastric cancer. Our study was supported by the Associazione Italiana per la Ricerca sul Cancro (AIRC), Project no. 21378 (Investigator Grant), by the Italian Ministry of Health (Young Researchers, GR-2011-02347943 to SB), by the Italian League for the Fight Against Cancer (LILT) and by the Associazione Industriale delle Carni e dei Salumi (ASSICA, to the Department of Clinical Sciences and Community Health, University of Milan). Our study was also funded by FEDER through the Operational Programme Competitiveness and Internationalization and national funding from the Foundation for Science and Technology – FCT (Portuguese Ministry of Science, Technology and Higher Education) under the Unidade de Investigação em Epidemiologia – Instituto de Saúde Pública da Universidade do Porto (EPIUnit) (POCI-01-0145-FEDER-006862; Ref. UID/DTP/04750/2013). AF (PD/BD/105823/2014) was awarded with an individual scholarship through national funding from FCT/MCTES. Individual grants attributed to ARC (SFRH/BD/102181/2014), and BP (SFRH/BPD/108751/2015) were funded by the FCT and the “Programa Operacional Capital Humano” (POCH/SE). SM was funded under the project “NEON-PC - Neuro-oncological complications of prostate cancer: longitudinal study of cognitive decline “ (POCI-01-0145-FEDER-032358; Ref. PTDC/SAU-EPI/32358/2017). Valentina Rosato was supported by a fellowship by the Italian Foundation for Cancer Research (FIRC #18104).