Short-Term and Long-Term Effects of Inhaled Ultrafine Particles on Blood Markers of Cardiovascular Diseases: A Systematic Review and Meta-Analysis

Background/Objectives: Air pollution is the highest environmental risk factor of mortality and morbidity worldwide, leading to over 4 million deaths each year. Among different air pollutants, ultrafine particles (UFPs) constitute the highest risk factor of cardiovascular diseases (CVDs). Epidemiological studies have associated UFPs with the short- and long-term imbalance of numerous blood markers. Our objective was to systematically review the short-term and long-term impact of UFP exposure on blood markers of CVDs. Methods: We prepared the systematic review of CVD blood markers and meta-analyses of the short- and long-term effects of UFP exposure on high-sensitivity C-reactive protein (hsCRP) concentration. The eligibility criteria were established with the use of the Provider, Enrollment, Chain, and Ownership System (PECOS) model, and the literature search was conducted in Web of Science, PubMed, and Scopus databases from 1 January 2013 to 9 January 2025. The risk of bias (RoB) was prepared according to a World Health Organization (WHO) template. Results: The results showed an increase in hsCRP as a result of both short-term and long-term UFPs. Moreover, IL-6 and IL-1β together with other inflammatory markers increased after short-term UFP exposure. In addition, different nucleic acids, among which were miR-24-3p and let-7d-5p, were differentially expressed (DE) as a result of short-term UFP exposure. Chronic exposure to UFPs could lead to a persistent increase in hsCRP and other blood markers of CVDs. Conclusions: Our findings underline that UFPs may lead to the development and/or worsening of cardiovascular outcomes in fragile populations living in air-polluted areas.