The Effect of Personal Protective Aids on Hypertension and Diabetes in People Exposed to High Levels of Air Pollution

Air pollution is the largest environmental cause of disease and premature death in the world today, disproportionally affecting low- and middle-income countries (LMICs) such as India. Numerous studies have shown that exposure to particulate matter <2.5 µm (PM2.5) can contribute to cardiovascular disease and mortality, which is partially attributable to the development of cardiometabolic conditions such as hypertension and diabetes. We hypothesize that the use of personal protective aids (home air-purifier and N-95 mask) can decrease systolic blood pressure (SBP) in people with hypertension and decrease fasting blood glucose (FBG) in those with diabetes.

This is a prospective randomized cross-over study in Dalkhola, India- an area of high ambient PM2.5 levels. Participants between 18 and 70 years of age with hypertension (n=130) and diabetes (n=33) will be invited to participate in the study. They will be randomized to either an intervention or control arm for 4 weeks, after which they will cross over to the other arm following a 2-week washout period. The intervention period will consist of using an indoor air-purifier at night and an N-95 mask when outdoors. Control period will involve using an identical air purifier and facemask, with the filter removed (sham filtration). Participants and outcome assessors will be blinded.

The primary outcome of the study is the absolute reduction in SBP among people with hypertension and absolute reduction in FBG among people with diabetes.

This is the first randomized controlled trial to evaluate personal protective aids as a therapeutic measure in people with hypertension and diabetes exposed to high levels of PM2.5. Given the high burden of air pollution in LMICs, there is an urgent need for adaptation measures targeting people at high risk for mortality from this exposure. The results of our study will demonstrate if personal protective aids can be a viable adaptation measure for people living with hypertension and diabetes in areas with a high burden of air pollution.

Inclusion criteria

Hypertension arm

• Individuals age 18-70 years old with systolic blood pressure between 130-160 mmHg, regardless of medication use
• Stable hypertension for the past 3 months with no medication changes
• No planned medication changes for the duration of the study
• Exposure to outdoor air pollution above a certain threshold (pollution levels will be measured using AirVeda devices)
• Individuals who sleep in a closed space (such as a bedroom) for minimum of 6 hours/daily.
• Use of gas (LPG)/electricity for cooking purposes

Diabetes arm

• Individuals age 18-70 years old with fasting blood glucose between 126-180 mg/dL, regardless of medication use
• Stable diabetes for the past 3 months with no medication changes
• No planned medication changes for the duration of the study
• Exposure to outdoor air pollution above a certain threshold (pollution levels will be measured using AirVeda devices)
• Individuals who sleep in a closed space (such as a bedroom) for minimum of 6 hours/daily.
• Use of gas (LPG)/electricity for cooking purposes

Exclusion criteria

• Unwilling to participate
• Unstable blood pressure and/or blood glucose level requiring frequent medication changes
• Individual suffering from a physical or mental illness that precludes active study participation
• Current smoker
• Planned vacation/absence from the study site
• Patients with life expectancy < 12 months
• Pregnant patients