Effect of a clean stove intervention on inflammatory biomarkers in pregnant women in Ibadan, Nigeria: A randomized controlled study

Abstract

Background: Exposure to household air pollution (HAP) has been linked to systemic inflammation. We determined the impact of transition from traditional firewood/kerosene stove to bioethanol-burning stove on inflammatory biomarkers in pregnant Nigerian women. Methods: Women (n = 324), cooking with kerosene/firewood, were recruited during their first trimester of pregnancy from June 2013–October 2015 and were randomly allocated to either control (n = 162) or intervention (n = 162) group using web-based randomization. Controls continued to use their own firewood/kerosene stove, while intervention participants received bioethanol CleanCook stoves. Serum concentrations of retinol-binding protein (RBP), malondialdehyde (MDA), tumor necrosis factor alpha (TNF)-α, interleukin (IL)-6, and IL-8 were measured by ELISA. Results: After excluding 53 women (loss of follow-up, untimely biomarker assessments, incorrect dates of enrollment), data from 271 women were included in analysis. Mean (SD) change in RBP, MDA, TNF-α, IL-6, and IL-8 between baseline and third trimester was −2.16 (4.47), −19.6 (46.4), 3.72 (37.2), 0.51 (14.4), and 13.2 (197), respectively, in intervention and −2.25 (4.30), −24.6 (43.6), 7.17 (32.6), −1.79, (11.4), and 31.3 (296) in control groups. None of these changes differed significantly between the two treatment arms. However, changes from baseline in TNF-α levels were significantly different between intervention and control groups in subset of women (n = 99) using firewood before trial (−7.03 [32.9] vs. +12.4 [33.6]; 95% CI for group difference: −35.4 to −3.4, p = 0.018). Conclusions: Decrease in TNF-α concentration from baseline to third trimesters in intervention group women could indicate reduced cardiovascular stress and prothrombotic effects from decreased HAP. Our findings suggest that ethanol-burning stoves may mitigate cardiovascular health risks. Keywords: Cleancook stove, Bio-ethanol, Cytokines, Systemic inflammation, Pregnant women, Nigeria