Reduction of household air pollution through clean fuel intervention and recovery of cellular immune balance.

BACKGROUND: We conducted a clean fuel intervention trial (Bangladesh Global Environmental and Occupational Health (GEOHealth) (NCT02824237) with liquefied petroleum gas (LPG) for 26 months among rural Bangladeshi women chronically exposed to household air pollution (HAP) from biomass fuel (BMF) use. We aimed to evaluate the effect of HAP reduction following LPG intervention on immune response outcome. METHODS: We supplied LPG cook stove and refills in cylinder in 200 households for 26 months. We measured personal exposure to HAP [particulate matter 2.5 (PM2·5), black carbon (BC) and carbon monoxide (CO)] in 200 women (main cook) by personal monitors at pre- and post-intervention. Immune function was assessed before and after intervention, in blood collected within 2 weeks of HAP measurements. Primary endpoints included reduction in HAP, lymphocyte proliferation and oxidative stress response, and alterations in T and B cell proportions. FINDINGS: Exclusive LPG use for 26 months resulted in significant reduction in PM2·5 (43.5%), BC (13%) and CO (48%) exposure in the women. For one unit decrease in BC, Treg cells and memory B cells increased by 7% and 34% respectively, in the peripheral circulation. One unit decrease in CO was significantly associated with increase in early B cells and plasmablasts by 66% and 5% respectively. For one unit decrease in BC, percent-dividing cells, proliferation and expansion indices increased by 2%, 0.4%, and 1%, respectively. INTERPRETATION: Reduced personal exposure to HAP through clean fuel intervention was related to a return towards cellular immune balance.

Awareness and control of hypertension in Bangladesh: follow-up of a hypertensive cohort.

OBJECTIVES: To assess the effect of awareness and advice to seek care on blood pressure (BP) control among patients with hypertension in Bangladesh. DESIGN: Longitudinal study. SETTING: The study was carried out in icddr,b surveillance sites at rural Matlab in Chandpur district and semi-urban Kamalapur in Dhaka, Bangladesh. PARTICIPANTS: Randomly selected men and non-pregnant women aged 20 years or older without any acute illness or history of any vascular events such as stroke or acute myocardial infarction. MAIN OUTCOME MEASURE: Hypertension was defined as systolic BP (SBP) ≥140 and/or diastolic BP (DBP) ≥90 mm Hg or as self-reported hypertension under medication. We advised patients to seek care from a qualified provider and to adopt a healthy lifestyle. We compared changes in BP from baseline to follow-up at around 6 months. RESULTS: Overall, 17.1% (n=287) of participants had hypertension at baseline with significantly higher prevalence in the semi-urban than in the rural population (23.6% vs 10.8%; p<0.001); half were unaware of their condition. At follow-up, 83% (n=204) reported a visit to any healthcare provider. In the semi-urban area, a higher proportion of patients visited medically qualified practitioners than in the rural area (76.7% vs 36.6%, p<0.000). SBP (-3.3±20.7 mm Hg; p<0.01) and DBP (-2.0±13.0 mm Hg; p<0.02) were lower at follow-up. Those who visited medically qualified practitioners had significant SBP (-3.9±22.4 mm Hg; p<0.03) and DBP (-2.7±14.1 mm Hg; p<0.02) reduction. BP reduction did not reach statistical significance among those visiting a pharmacist or their village doctors. Overall, half of the patients with hypertension achieved the BP control goal (BP<140/90 mm Hg). CONCLUSIONS: Awareness and simple health messages increase provider visit, reduce blood pressure and improve BP control in hypertensive Bangladeshis. Longer-term follow-up is required to verify the sustainability.