Antibiotic Use in Older Women Links to Heightened Risk of Heart Disease Death

Lu Qi, MD, PhD, professor of epidemiology, Tulane University

Lu Qi, MD, PhD

According to preliminary research presented at the American Heart Association’s Epidemiology and Prevention | Lifestyle and Cardiometabolic Health Scientific Sessions 2018, women who take antibiotics for long periods, especially in late adulthood, have an increased risk of death from heart disease and in general.

It’s been known that antibiotic use is associated with long-lasting changes in gut microbiota however, until this study, researchers have yet to assess relatively health populations in order to determine how duration of antibiotic use at different times in adulthood may relate to all-cause and cause-specific risk of death.

“Gut microbiota alternations have been associated with a variety of life-threatening disorders, such as cardiovascular diseases and certain types of cancer,” Lu Qi, MD, PhD, professor of epidemiology, Tulane University, said in a statement.

To further examine this, researchers from Tulane University School of Public Health and Tropical Medicine and Harvard T.H. Chan School of Public Health studied 37,510 women, aged 60 years and older, who reported antibiotic use and were free of heart disease and cancer at the study’s start.

Women were classified into 4 groups based on the length of time antibiotics were used; not at all, less than 15 days, 15 days to less than 2 months, or 2 or more months. Researchers followed the study population for 8 years, from 2004 until June 2012.

“Antibiotic exposure affects balance and composition of the gut microbiome, even after one stops taking antibiotics; so, it is important to better understand how taking antibiotics might impact risks for chronic diseases and death,” Qi said.

Researchers concluded that women who took antibiotics for 2 months or longer in late adulthood, were 27% more likely to die from all causes throughout the study period than women who did not take antibiotics. Additionally, taking antibiotics for 2 or more months was associated with a 58% higher risk of cardiovascular death versus those who did not take antibiotics.

The association between long-term antibiotic use in late adulthood and heightened risk of death from all causes was more apparent in those who reported using antibiotics in middle adulthood (ages 40—59 years), compared to women who didn’t use antibiotics in middle adulthood.

“Although we observed a notable association between long-term antibiotic use and risk of death, it isn’t yet clear whether long-term antibiotic use is the specific cause of the association,” Qi added. “For example, women who reported antibiotic use might be sick in other unmeasured ways.”

It was noted that these associations existed regardless of traditional risk factors for death, including lifestyle factors, dietary habits, obesity, medication use and more. Additionally, researchers did not find an association between antibiotic use and death from cancer.

Since this is an observational study, it can only show a correlation between antibiotic use and heart disease. While this study doesn’t necessarily mean there's a causal link, further research is needed.

“The results, however, contribute to a better understanding of risk factors for all-cause and cardiovascular death. We now have good evidence that people who take antibiotics for long periods during adulthood may be a high-risk group to target for risk-factor modification to prevent heart disease and death.”