Do Antibiotics Increase Stroke and Heart Attack Risk in Women?

Antibiotic use is associated with an increased risk for suffering a heart attack, as well as stroke, in women.

The new study published in the European Heart Journal included 36,429 women who were initially free of cardiovascular disease (CVD) and cancer in the Nurses’ Health Study. The researchers estimated hazard ratios for the CVD (a composite of coronary heart disease or stroke) according to the age of antibiotic use (young age, 20-39; middle age, 40-59; and late age, 60 and older) adulthood. Average follow-up was 7.6 years. A total of 1,056 women developed CVD during the study period.

Do Antibiotics Increase Stroke and Heart Attack Risk in Women?
Credit: European Heart Journal and Prof. Lu Qi of Tulane University

According to the results, women who used antibiotics long-term (for two months or more) in late adulthood were at a significantly increased risk of CVD (HR=1.32; 95% CI, 1.03 to 1.70) compared to those who did not use antibiotics regularly late in life (see Graphic). The was after adjustment for covariates like demographics, diet and lifestyle, overuse reasons, obesity, disease status, and use of other medications. Antibiotic use in young adulthood was not significantly associated with incidence of CVD. The researchers wrote that their findings were not influenced by the presence of other major disease, or by medication usage.

In a press release about the study, Professor Lu Qi, director of the Tulane University Obesity Research Centre at Tulane University in New Orleans, and an adjunct professor of nutrition at Harvard T.C. Chan School of Public Health, Boston, said that one possible reason for the link could be that antibiotics alter the balance of the gut micro-environment, thereby destroying  probiotic bacteria and increasing virus prevalence, or the presence of other disease-causing agents.

“Antibiotic use is the most critical factor in altering the balance of microorganisms in the gut. Previous studies have shown a link between alterations in the microbiotic environment of the gut and inflammation and narrowing of the blood vessels, stroke and heart disease,” Prof. Qi said in the press release.