Lowering BP may reduce CVD risk in people exposed to air pollution

Intensive lowering of blood pressure (BP) is effective in reducing cardiovascular risk in patients exposed to high levels of air pollution, a new study suggests.

The findings indicated that intensive BP lowering (defined as goal systolic blood pressure lower than 120 mmHg) led to significant reduction in cardiovascular events (combination of heart attacks, strokes, heart failure, or death from cardiovascular diseases) especially in patients exposed to higher pollution levels.

"Air pollution impacts socio-economically disadvantaged patients to a higher degree. Living within a particular neighbourhood should not mean you are more likely to suffer from cardiovascular diseases," said lead author Sadeer Al-Kindi, Assistant Professor at the Case Western Reserve University in the US.

Air pollution, particularly fine particulate matter, has been implicated in cardiovascular risks, partly through effects on BP.

Particulate matter smaller than 2.5 microns is concentrated particles that develop from human impact on the environment, such as automobile exhaust, power generation and other fossil fuels. According to researchers, it poses the greatest threat to global health.

Earlier studies have shown that exposure to particulate matter smaller than 2.5 microns is associated with acute and chronic increases in BP as well as hypertension.

For the study, published in the journal Hypertension, the team sought to determine if intensive BP lowering on cardiovascular events is modified by air pollution exposure.

They linked integrated satellite-derived air pollution exposures with residential addresses for 9,286 patients enrolled in the trial.

The authors concluded that ambient air pollution may influence the benefit of intensive lowering of BP.

Lowering of BP is particularly beneficial for patients who are exposed to high levels of fine particulate matter, the researchers said.