Does second-hand smoke contribute to oxidative stress in heart attack patients?

This study investigated whether environmental cigarette smoke caused oxidative stress in patients that had experienced a heart attack

Oxidative stress refers to when there is a high level of oxidants in the body. Oxidants are produced as part of a normal process when we breathe in oxygen, but air pollution, smoking, and obesity dramatically increase the level of oxidants in the body and can cause DNA and cell damage. Oxidative stress has been linked to several diseases such as arthritis, cancer and cardiovascular disease.

Cardiovascular disease is a heart disorder caused by narrowed or blocked blood vessels that can lead to a heart attack or stroke. Smoking increases blood pressure and increases the tendency of blood to clot, leading to narrowed or blocked blood vessels. Second-hand smoke has been shown to carry up to 90% of the risk of cardiovascular disease associated with first-hand smoking. 

This study investigated whether environmental (second-hand) cigarette smoke causes oxidative stress in patients who had had a heart attack. The study included 1,261 patients that were hospitalised with a heart attack. 60 patients who had never smoked but had been exposed to second-hand smoke were compared with 60 patients that had never smoked nor been exposed to second-hand smoke. 

Three biomarkers for oxidative stress were measured. Biomarkers are natural body substances or measurements associated with a disease.

It was found that second-hand smoke was associated with increases in 2 of the 3 oxidative stress biomarkers. 

The authors concluded that exposure to environmental smoke increases oxidative stress, which has previously been shown to increase the risk of cardiovascular disease progression. 

The study did not obtain information about the patients' lifestyles such as physical activity or diet. Therefore it cannot be determined whether second hand smoke solely contributed to oxidative stress, or whether it was a mixture of bad lifestyle choices. 

If you or someone you know smoke or are exposed to smoke, talk to a doctor about the risks of developing cardiovascular disease and what you can do to reduce these risks.