Liquefied Petroleum Gas or Biomass for Cooking and Effects on Blood Pressure: Results from the Household Air Pollution Intervention Network (HAPIN) Trial

Background Exposure to household air pollution from burning coal and biomass for cooking is associated with higher blood pressure and other adverse indicators of cardiovascular disease, the leading cause of death worldwide. Evidence demonstrating that switching from biomass to liquefied petroleum gas (LPG) will reduce blood pressure is limited.

As part of a larger trial of 3200 households, we conducted a randomized trial of 342 women aged 40 to 79 years who lived in households using biomass for cooking in rural areas of Guatemala, India, Peru, and Rwanda to assess the effects of a free LPG stove and fuel intervention. Systolic blood pressure (one of four primary outcomes) was measured once prior to randomization and up to five times after randomization over 18 months.

A total of 418 participants were randomized (n=209 to intervention, and n=209 to control). Mean (standard deviation) systolic blood pressure at baseline was 112.7 (14.9) mmHg and 112.6 (14.7) mmHg in intervention and control participants, respectively. Adherence within the intervention arm was high. Among the 342 participants with a valid baseline and at least one valid post-randomization blood pressure measurement, mean (SD) post-randomization average systolic blood pressure was 111.5 (13.2) mmHg in the intervention arm and 111.9 (12.5) mmHg in the control arm, with an adjusted mean of difference of - 0.56 mmHg (95% confidence interval, -2.19 to 1.07, p-value = 0.50).

We did not observe evidence that an 18-month LPG stove and fuel intervention reduced blood pressure in women. Competing Interest Statement The authors have declared no competing interest. Clinical Trial NCT02944682 Funding Statement The HAPIN trial was funded by the U.S. National Institutes of Health (NIH cooperative agreement 1UM1HL134590) in collaboration with the Bill & Melinda Gates Foundation (OPP113127). The conclusions and opinions expressed in this work are those of the author(s) alone and shall not be attributed to the Gates Foundation or the NIH. Under the grant conditions of the Gates Foundation, a Creative Commons Attribution 4.0 License has already been assigned to the Author Accepted Manuscript version that might arise from this submission. Please note works submitted as a preprint have not undergone a peer review process. No authors or their institutions at any time received payment or services from a third party for any aspect of the submitted work. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics Committee/IRB of Emory University (00089799) gave ethical approval for this work Ethics Committee/IRB of Johns Hopkins University (00007403) gave ethical approval for this work Ethics Committee/IRB of Sri Ramachandra Institute of Higher Education and Research (IEC-NI/16/JUL/54/49) gave ethical approval for this work Ethics Committee/IRB of the Indian Council of Medical Research Health Ministry Screening Committee (5/8/4-30/(Env)/Indo-US/2016-NCD-I) gave ethical approval for this work Ethics Committee/IRB of the Universidad del Valle de Guatemala (146-08-2016) gave ethical approval for this work Ethics Committee/IRB of the Guatemalan Ministry of Health National Ethics Committee (11-2016) gave ethical approval for this work Ethics Committee/IRB of Asociacion Benefica PRISMA-Peru (CE2981.17; CE2008.18; CE0028.20; CE0291.21) gave ethical approval for this work Ethics Committee/IRB of the London School of Hygiene and Tropical Medicine (11664) gave ethical approval for this work Ethics Committee/IRB of the Rwandan National Ethics Committee (853/RNEC/2016; 317/2017; 357/2018; 194/2019; 929/2020; 64/2021) gave ethical approval for this work Ethics Committee/IRB of Washington University in St. Louis (201611159) gave ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Footnotes * The views expressed here are soley the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the US Government. (deceased) Data Availability All data produced in the present work are available upon reasonable request to the authors