Millions of people around the world receive medicines before surgery to help them relax and reduce anxiety.
One of the most commonly used medicines is midazolam. It helps patients feel calm and sleepy before an operation.
It also causes temporary memory loss, which means many people do not remember the procedure afterward. For decades, doctors have considered it a safe and effective medicine when used correctly.
However, a new study suggests there may be an important detail that doctors should pay closer attention to. According to research published in Frontiers in Cardiovascular Medicine, the time of day when midazolam is given could influence the risk of heart injury after surgery.
The research was led by Dr. Tobias Eckle and his team at the University of Colorado Anschutz Medical Campus. The scientists examined medical records from more than 1.7 million patients who received midazolam before surgery. They found that more than 16,000 patients developed signs of heart injury after their operations.
When the researchers looked deeper into the data, they noticed an unexpected pattern. Patients who had surgery at night appeared to have a higher risk of heart injury than those who had surgery during the day. The increased risk was especially noticeable in people who were otherwise healthy and did not already have serious heart disease.
The surprising discovery raised an important question. Why would the same medicine appear to have different effects depending on the time of day?
To answer this question, the scientists turned to laboratory studies using mice. Their experiments focused on a gene called PER2. Genes are pieces of DNA that tell our cells how to work.
The PER2 gene is part of the body’s natural internal clock, known as the circadian rhythm. This clock helps control many daily body functions, including sleeping, waking, hormone production, metabolism, and how different organs respond to stress.
Light is one of the strongest signals that controls the circadian rhythm. During the day and night, the activity of many genes changes naturally. The PER2 gene is especially important because it helps protect heart cells from damage, particularly when the heart is under stress.
The mouse experiments showed that midazolam may reduce the activity of the PER2 gene during the night. This finding is important because PER2 levels are already naturally lower at night. If the medicine lowers them even further, the heart may lose some of its natural protection, making injury more likely during or after surgery.
The researchers also explained how midazolam works. The medicine increases the activity of a brain chemical called GABA. GABA slows down nerve activity, helping people feel relaxed, calm, and sleepy. This is why midazolam is widely used before medical procedures.
However, the new study suggests that the same biological pathways that create this calming effect may also influence the heart’s protective systems during the night.
Although these findings are important, they do not mean patients should avoid midazolam or stop using it.
The medicine continues to play a valuable role in modern healthcare and has helped millions of patients safely undergo surgery and other medical procedures. Instead, the study highlights the need for doctors and researchers to better understand when certain medicines should be given.
This growing area of research is known as chronomedicine. Chronomedicine studies how the body’s biological clock changes the way medicines work. Scientists have already learned that some drugs work better or cause fewer side effects when taken at certain times of the day.
For example, some blood pressure medicines are more effective when taken at night. This new study suggests that sedatives used before surgery may also benefit from careful timing.
The researchers believe more studies are needed before any changes are made to medical practice. Future clinical trials will need to confirm whether adjusting the timing of midazolam could lower the risk of heart injury in people having nighttime surgery.
The study reminds us that even small details can matter in medicine. The type of medicine is important, but so is the time it is given. By understanding how the body’s natural clock affects different treatments, doctors may one day make surgery even safer and improve recovery for many patients around the world.
If you care about heart health, please read studies that apple juice could benefit your heart health, and Yogurt may help lower the death risks in heart disease.
For more information about health, please see recent studies that Vitamin D deficiency can increase heart disease risk, and results showing Zinc and vitamin B6 linked to lower death risk in heart disease.
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