Obesity has become one of the biggest health challenges in the world today. It increases the risk of many serious illnesses such as heart disease, type 2 diabetes, and some cancers.
The condition affects hundreds of millions of people, yet there are still very few safe and effective medicines to treat severe obesity.
This makes life even harder for people who are already struggling to lose weight and keep it off.
Now, scientists at Johns Hopkins Medicine may have found a new ray of hope. They have been studying a medicine that was first created to help people with Alzheimer’s disease, schizophrenia, and sickle cell disease. While it didn’t succeed for those illnesses, it may hold great promise for tackling obesity.
The drug works by blocking an enzyme in the body called PDE9. Enzymes are special proteins that control chemical reactions in our bodies. PDE9 is involved in processes that affect the heart and metabolism.
In tests with mice, blocking PDE9 helped reduce obesity and fatty liver disease, and even improved heart health. What is most exciting is that these benefits happened without the mice having to eat less or exercise more.
The idea to study PDE9 came from earlier work done by the same research team in 2015. Back then, they discovered that PDE9 is active in the heart and can make heart problems worse, especially when blood pressure is high. Knowing this, the researchers wondered if blocking PDE9 could also improve other health problems linked to obesity.
The type of medicine used in the study is called a PDE9 inhibitor. Medicines in this group are still experimental and not yet available to the public. They work in a way similar to Viagra, which blocks a related enzyme called PDE5. Both enzymes control a chemical in the body known as cyclic GMP, which helps regulate many important functions.
In this new mouse study, the team wanted to see if blocking PDE9 could do more than just help the heart. They tested whether it could also lower blood pressure, improve blood sugar levels, reduce cholesterol and triglycerides, and shrink extra body fat around the waist.
The drug they tested, called PF-04447943, was originally made by the company Pfizer to treat Alzheimer’s disease. While it did not work for that purpose, it was found to be safe in clinical trials with more than 100 people, with no serious side effects.
This finding is especially important because obesity rates are so high. According to the U.S. Centers for Disease Control and Prevention (CDC), over 40% of Americans are obese, and about 43% of women over age 60 fall into this category.
If the results seen in mice also happen in humans, someone weighing 250 pounds could possibly lose around 50 pounds by taking a PDE9 inhibitor pill—without changing their diet or exercise routine.
The study, led by researcher David Kass and published in the Journal of Clinical Investigation, challenges the old belief that obesity is caused only by overeating.
It suggests that other biological factors, like enzymes, also play a major role in weight gain. This could mean that in the future, managing weight might not always require extreme lifestyle changes.
Still, more research is needed before this medicine can be given to people for obesity. Scientists must prove it works in humans and is safe for long-term use. But if those studies are successful, this discovery could lead to a groundbreaking treatment, offering new hope to millions who struggle with their weight every day.
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