Household air pollution from biomass-burning cookstoves and metabolic syndrome, blood lipid concentrations, and waist circumference in Honduran women: A cross-sectional study

Background: Household air pollution from cooking with solid fuels affects nearly 3 billion people worldwide and is responsible for an estimated 2.5 million premature deaths and 77 million disability-adjusted life years annually. Investigating the effect of household air pollution on indicators of cardiometabolic disease, such as metabolic syndrome, can help clarify the pathways between this widespread exposure and cardiovascular diseases, which are increasing in low- and middle-income countries. Methods: Our cross-sectional study of 150 women in rural Honduras (76 with traditional stoves and 74 with cleaner-burning Justa stoves) explored the effect of household air pollution exposure on cardiovascular disease risk factors. Household air pollution was measured by stove type and 24-h average kitchen and personal fine particulate matter [PM2.5] mass and black carbon concentrations. Health endpoints included non-fasting total cholesterol, high-density lipoprotein, calculated low-density lipoprotein, triglycerides, waist circumference to indicate abdominal obesity, and presence of metabolic syndrome (defined by current modified international guidelines: waist circumference >= 80 cm plus any two of the following: triglycerides > 200 mg/dL, HDL < 50 mg/dL, systolic blood pressure >= 130 mmHg, diastolic blood pressure >= 85 mmHg, or glycated hemoglobin > 5.6%). Results: Forty percent of women met the criteria for metabolic syndrome. The prevalence ratio [PR] for metabolic syndrome (versus normal) per interquartile range increase in kitchen PM2.5 and kitchen black carbon was 1.16 (95% confidence interval [CI]: 1.01-1.34) per 312 mu g/m(3) increase in PM2.5, and 1.07 (95% CI: 1.03-1.12) per 73 mu g/m(3) increase in black carbon. There is suggestive evidence of a stronger effect in women >= 40 years of age compared to women < 40 (p-value for interaction = 0.12 for personal PM2.5). There was no evidence of associations between all other exposure metrics and health endpoints. Conclusions: The prevalence of metabolic syndrome among our study population was high compared to global estimates. We observed a suggestive effect between metabolic syndrome and exposure to household air pollution. These results for metabolic syndrome may be driven by specific syndrome components, such as blood pressure. Longitudinal research with repeated health and exposure measures is needed to better understand the link between household air pollution and indicators of cardiometabolic disease risk.