Mediation Effect of Folate on the Effect of Particulate matter and Anemia Indicators: KoCHENS-MOM study

Abstract

BACKGROUND AND AIM: Housewives do a lot of house chores such as cleaning and laundry, so they are directly exposed to indoor particulate matter (PM). Indoor PM exposure is a potential factor that increases systemic inflammation and affects erythropoiesis. This study aimed to investigate the association between indoor PM exposure and anemia indicators (hemoglobin, MCV, MCH, MCHC) in housewives. We also examined the indirect effect of indoor PM exposure on indicators of anemia mediated by folate. METHODS: In our housewife cohort study, we recruited a total of 284 housewives (from 2017 to 2021) in Seoul and Ulsan, Republic of Korea. We used indoor PM2.5 and PM10 data measured by the gravimetric and sensor method, as well as blood test results, including folate and anemia indicators such as hemoglobin, MCV, MCH, and MCHC. Multiple linear regression was performed to evaluate the association between indoor PM exposure and anemia indicators. Mediation analysis was used to examine the indirect effect of indoor PM exposure on indicators of anemia mediated by folate. RESULTS:The increase in the level of indoor PM2.5 was associated with a decrease in Hemoglobin (B: -0.029, SE: 0.012, P0.001), Hematocrit (B: -0.089, SE: 0.038, P0.001), MCV (B: -0.14, SE: 0.047, P0.001) and MCH (B: -0.047, SE: 0.016, P0.001). Mediation analysis confirmed protective mediating effect of folate (p0.001) on indoor PM affecting anemia indicators. CONCLUSIONS:The indoor PM exposure was significantly associated with the decrease of hemoglobin, MCV, MCH, and MCHC in housewives. These associations suggest that exposure to indoor PM is a risk factor of anemia in housewives. Therefore, indoor PM exposure should be managed to prevent anemia in the housewives. In addition, this study shows that folate can be used for prevention at the individual level to control and complement the potential pathways of PM2.5-induced oxidative stress. KEYWORDS: Mediation Effect, Folate, PM2.5, Anemia, Housewives, KoCHENS