Lack of association between chronic exposure to biomass fuel smoke and markers of right ventricular pressure overload at high altitude.

BACKGROUND: Chronic exposure to biomass fuel smoke has been implicated in the development of pulmonary hypertension and right ventricular pressure/volume overload through activation of inflammation, increase in vascular resistance, and endothelial dysfunction. We sought to compare N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) and echocardiography-derived pulmonary artery systolic pressure (PASP) levels in a high-altitude population-based study in Peru with and without chronic exposure to biomass fuel smoke. METHODS: NT-pro-BNP levels were measured in 519 adults (275 with and 244 without chronic exposure to biomass fuel smoke). Participants answered sociodemographics and clinical history questionnaires, underwent a clinical examination and blood testing for cardiopulmonary biomarkers. PASP was measured in a subgroup of 153 (31%) subjects. RESULTS: The study group consisted of 280 men (54%) and 239 women (46%). Average age was 56 years and average body mass index was 27 kg/m(2). In multivariable analysis, there was no association between chronic exposure to biomass fuel smoke and NT-pro-BNP (P = .31) or PASP (P = .31). In the subgroup in which both NT-pro-BNP levels and PASP were measured, there was strong evidence of an association between these two variables (ρ = 0.24, 95% CI 0.09-0.39; P = .003). We found that age, high sensitivity C-reactive protein, being male, and systolic blood pressure were positively associated with NT-pro-BNP levels whereas body mass index, low-density/high-density lipoprotein ratio, and Homeostasis Model of Assessment-Insulin Resistance were negatively associated (all P ≤ .02). CONCLUSIONS: In this population-based study in a high-altitude setting, neither NT-pro-BNP levels nor echocardiography-derived PASP were associated with chronic exposure to biomass fuel smoke.

Chronic exposure to biomass fuel is associated with increased carotid artery intima-media thickness and a higher prevalence of atherosclerotic plaque.

BACKGROUND: Biomass fuels are used for cooking in the majority of rural households worldwide. While their use is associated with an increased risk of lung diseases and all-cause mortality, the effects on cardiovascular disease (CVD) are not well characterised. Exposure to biomass fuel smoke has been associated with lung-mediated inflammation and oxidative stress, which may increase the risk of atherosclerosis as evaluated by carotid intima-media thickness (CIMT), carotid atherosclerotic plaque prevalence and blood pressure. METHODS: A cross-sectional study was performed in 266 adults aged ≥35 years in Puno, Peru (3825 m above sea level). We stratified participants by their long-term history of exposure to clean fuel (n=112) or biomass fuel (n=154) and measured 24 h indoor particulate matter (PM2.5) in a random subset (n=84). Participants completed questionnaires and underwent a clinical assessment, laboratory analyses and carotid artery ultrasound. The main outcome measures were CIMT, carotid plaque and blood pressure. RESULTS: The groups were similar in age and gender. The biomass fuel group had greater unadjusted mean CIMT (0.66 vs 0.60 mm; p<0.001), carotid plaque prevalence (26% vs 14%; p=0.03), systolic blood pressure (118 vs 111 mm Hg; p<0.001) and median household PM2.5 (280 vs 14 µg/m(3); p<0.001). In multivariable regression, the biomass fuel group had greater mean CIMT (mean difference=0.03 mm, 95% CI 0.01 to 0.06; p=0.02), a higher prevalence of carotid plaques (OR=2.6, 95% CI 1.1 to 6.0; p=0.03) and higher systolic blood pressure (mean difference=9.2 mm Hg, 95% CI 5.4 to 13.0; p<0.001). CONCLUSIONS: Chronic exposure to biomass fuel was associated with increased CIMT, increased prevalence of atherosclerotic plaques and higher blood pressure. These findings identify biomass fuel use as a risk factor for CVD, which may have important global health implications.