PM2.5 mass and black carbon from biomass-burning cookstoves in relation to diabetic status and metabolic syndrome among Honduran women

Abstract

Introduction: Household air pollution (HAP) from inefficient biomass cookstoves is hypothesized to be a risk factor for metabolic disorders; however, epidemiologic evidence is lacking. We evaluated the association of PM2.5 (particulate matter<2.5μm) and black carbon (BC) exposure with diabetic status as defined by HbA1c (glycated hemoglobin) and metabolic syndrome in women in rural Honduras. Methods: We conducted a cross-sectional study of 107 female household cooks, 25-55 years of age, comparing traditional and improved-combustion biomass cookstoves. Integrated filter measures were collected to calculate area (inside the kitchen) and personal 24-hour PM2.5 and BC concentrations. HbA1c was analyzed as a binary (normal vs pre-diabetic/diabetic) variable. Metabolic syndrome was defined by a waist circumference ≥80cm plus any two of the following: triglycerides >150mg/dl, HDL <50mg/dl, systolic blood pressure ≥130mmHg, diastolic blood pressure ≥85mmHg or HbA1c >5.6%. Age, dietary diversity score, physical activity, and socioeconomic status were included in all logistic regression models. Results: An interquartile range (IQR) increase in area PM2.5 (312.01 μg/m3) was associated with a 66% higher prevalence of pre-diabetes/diabetes (OR=1.66, 95%CI: 1.05, 2.62) and with a 47% higher prevalence of metabolic syndrome (OR=1.47, 95%CI: 0.96, 2.25). An IQR increase in area BC (20.19 μg/m3) was associated with a 94% higher prevalence of pre-diabetes/diabetes (OR=1.94, 95%CI: 1.08, 3.47); results for metabolic syndrome were also suggestive (OR=1.39, 95%CI: 0.84, 2.28). For personal exposure measurements, results were similar to those for area exposure measures for pre-diabetes/diabetes; however, no evidence of an association was observed for metabolic syndrome. Conclusions: This is the first study to evaluate the association between exposure to HAP and prevalence of pre-diabetes/diabetes and metabolic syndrome, a growing burden of disease in low- and middle-income countries.