How pneumonia and sepsis put you at risk of heart disease

The wall of most human arteries is composed of three layers. The innermost layer, the endothelium, is made up of smooth muscle cells. The next layer, the media also contains smooth muscle cells while the third outermost layer, the adventitia, consists of looser connective tissue, nerve endings, mast cells and small blood vessels called the vasa vasorum that supply the walls of larger arteries and veins. These layers can be inflamed, swell up, have lesions and thicken which in turn narrows the vessels and thus affects the flow of blood. These may contribute to blood clots and thus ultimately prevent oxygen from reaching vital organs therefore, contribute to a cardiovascular diseases such as heart attacks and strokes.

Adults with pneumonia or sepsis have an increased risk of heart failure and heart attacks within a year of infection, new research has shown.

The two infections lead to inflammation which is a known risk for cardiovascular disease. Research by Swedish researchers published in the European Journal of Preventive

Cardiology shows that the cardiovascular risk more than doubled in the second and third year after infection and persisted for at least five years.

INFECTIONS IN ADULTHOOD ASSOCIATED WITH HIGHER RISK

People who smoke indoors, use kerosene, animal waste, charcoal and wood fuel for lighting and cooking—especially in rural Kenya — are at an increased risk of contracting pneumonia. The acute respiratory infection, killed 22,473 Kenyans in 2015, up from 21,640 in 2013, with major fatalities among children under the age of five.

The elderly and people whose immunity is compromised, such as those with HIV, are also not spared from the disease. The Ministry of Health says that residents of Nairobi, Kisii, Nyanza and parts of central Kenya are prone to the disease.

While patients with sepsis (an infection of the blood) or pneumonia may recover they will still have the inflammatory biomarker, which circulate in the body after the infection.
Researchers say that severe infections in adulthood are associated with a higher risk of cardiovascular disease, though they are not sure if the higher risk persists for several years after infection.

“Conventional cardiovascular risk factors are still important, but infection may be the primary source of risk for a limited time,” said Professor Scott Montgomery, the director of clinical epidemiology at the Örebro University in Sweden, and one of the authors of the study.

“Our findings provide another reason to protect against infection and suggest that there is a post-infection window of increased cardiovascular disease risk. We did not study any interventions that could be initiated during this period, but preventative therapies such as statins could be investigated,” he added.

When the researchers examined the relationship between other risk factors such as high blood pressure, overweight, obesity, poorer physical fitness, and household crowding in childhood, they found that infection was associated with the highest magnitude of cardiovascular disease risk in the first three years post-infection.

The study followed 236,739 men born between 1952 and 1956.

Associations between a first infection with sepsis or pneumonia that resulted in hospital admission with subsequent cardiovascular disease risk at pre-specified time intervals post-infection were analysed.

Researchers found that infection was associated with a six-fold raised risk of cardiovascular disease during the first year after the infection. In the second and third years following an infection, cardiovascular disease risk remained raised by 2.47 and 2.12 times respectively.