Cardiovascular Disease

Cardiovascular disease includes disorders of the heart and blood vessels. Heart attacks generally occur when insufficient oxygenated blood is able to reach the heart muscle, usually because the vessels supplying blood to the heart (the coronary arteries) are clogged with a fatty substance called atherosclerosis or when a piece of atherosclerosis breaks off and occludes a vessel.

The buildup of atherosclerosis in one's arteries is typically due to (1) being overweight, (2) smoking, (3) a diet rich in animal fats, and (4) insufficient exercise. Source: EPA- AirNow Atherosclerosis affects all arteries, not just the coronary arteries so that people at risk for a heart attack are also at increased risk for stroke (a "brain attack") and damage to the kidneys and other organs.

Obese individuals are three times more likely to suffer from cardiovascular disease than are people of normal weight. Houston’s automotive-centered lifestyle coupled with low-activity jobs increases one’s likelihood to gain unhealthy amounts of weight. In 2005, Men’s Fitness magazine rated Houston as the most obese city in America. It cites Houston’s love of television as one of the causes for its obesity. In addition, a recent study by researchers at the University of Texas School of Public Health documented the increasing prevalence of overweight among Texas schoolchildren (Hoelscher et al., 2004). They reported that Texas schoolchildren were overweight at a rate 46 percent higher than children of similar age nationally.

Smoking harms the heart as well as the lungs. Carbon monoxide and nicotine damage the lining on the walls of the heart, making it easier for cholesterol to build up on the walls. In addition, nicotine causes blood vessels to narrow, increasing the risk of clotting and of damage to the heart and other organs.

Heart attacks can also be caused by disturbances in the electrical signals that regulate the beating of the heart. These are called arrhythmias.

Air pollution has been linked to increased hospital admissions and death due to cardiovascular disease (Brunekreef B, 2002; Burnett RT, 1999; Dockery DW, 1993). Ozone, particulates, nitrogen dioxide and carbon monoxide have all been linked to exacerbations in cardiovascular symptoms. The mechanisms are still being studied but may include reduced oxygen carrying capacity, inflammatory responses, thickening of the blood, and disruption of the heart rate. Persons with congestive heart failure are particularly at risk.