High testosterone levels are associated with an increased risk of atrial fibrillation in older men

Addressing cardiovascular issues in older adults is a critical area of public health. Atrial fibrillation (AFib) is a common and problematic heart rhythm disorder, and researchers are interested in understanding its risk factors.

A study published in the journal eClinicalMedicine examined the relationship between testosterone levels and AFib in more than 4,500 men. The researchers found that older men with higher levels of circulating testosterone had an increased risk of AFib. The results highlight the importance of closely monitoring AFib and testosterone levels in older men.

As research evolves, doctors may need to consider the risks of AFib when assessing the risks of testosterone therapy in older men.

Atrial Fibrillation: Dangers and Risk Factors

Atrial fibrillation occurs when the upper chambers of the heart beat irregularly. AFib is the most common type of abnormal heart rhythm, according to the Centers for Disease Control and Prevention (CDC). The CDC also estimates that by 2030, there will be 12.1 million people in the United States with AFib.

AFib can be dangerous because it increases the risk of blood clots that can lead to strokes in the brain.

Study author Kevin Rabie, D.O., a cardiologist at Memorial Herman who was not involved in the study, explained:

" Atrial fibrillation is a heart rhythm disorder that causes chaotic electrical activity and contractions in the upper chambers of the heart (atria). It can cause unpleasant symptoms, but it also increases the risk of stroke and weakens the heart. It is a condition that needs to be closely monitored and treated by a cardiologist."

While doctors can help treat AFib with certain medications and even surgery, it’s also important to consider how to reduce your risk of AFib. Some common risk factors for AFib include aging, a family history of AFib, panic disorders, excessive alcohol use, and smoking.

How does testosterone level affect AFib risk?

The researchers in the current study wanted to examine how testosterone levels in older men affect the risk of AFib. They noted that circulating testosterone levels typically decline with age, and that testosterone therapy has increased in older men.

Study author Mehran Movassaghi, MD, a board-certified urologist and director of Men's Health at Providence Saint John's Medical Center and assistant professor of urology at Saint John's Cancer Institute in Santa Monica, California, who was not involved in the study, explained:

“As patients age, their testosterone levels drop. Starting in their 30s, testosterone levels drop by one percent each year. Some patients who start with relatively high levels may never notice a change in their energy, mood, or sexual performance. However, patients typically begin to complain of symptoms around age 40, and at that age it is appropriate to check their levels. It is important not to simply treat a number, but to actually treat the symptoms that patients are experiencing.”

The researchers used data from the ASPirin in Reducing Events in the Elderly (ASPREE) study. The study included 4,570 healthy men. All participants were over the age of seventy and had no history of cardiovascular disease or thyroid cancer. About 12% of the participants had diabetes, and 75.9% had a history of hypertension.

The average follow-up time was 4.4 years. During follow-up, 286 men, or 6.2 percent, developed atrial fibrillation (AFib). The researchers were able to track the participants through annual in-person visits and phone calls every six months.

The researchers divided serum testosterone levels into quintiles and examined how participants' testosterone levels were associated with the incidence of atrial fibrillation.

The results of the study showed a nonlinear relationship between testosterone levels and the incidence of AFib. They found that men with testosterone levels in the highest quintiles had a higher risk of developing AFib than those with testosterone levels in the middle. Similar results were obtained after excluding participants who developed heart failure or other serious adverse cardiovascular events during follow-up.

The association was also found to be independent of several factors, including body mass index, alcohol consumption, diabetes and high blood pressure.

Study author Cammy Tran, BSci, MPH, of Monash University, noted:

"We studied 4,570 initially healthy older men aged 70 years and older and found that men with higher testosterone concentrations had almost twice the risk of developing atrial fibrillation during 4 years of follow-up compared with men with testosterone concentrations in the average range. Interestingly, the higher risk was found among men with testosterone concentrations in the normal range."