UT research shows cigarette smoke exposure increases scar tissue in kidney, heart

---

Smoking cigarettes leads to fibrosis in the kidneys and heart and accelerates kidney disease, according to research at The University of Toledo.

“Smoking is bad for the kidneys and heart together,” said Dr. Christopher Drummond, postdoctoral fellow in the Cardiovascular Division of the UT College of Medicine and Life Sciences. “Tobacco and nicotine increase the formation of injury or scarring called fibrosis. That reduces cardiac function, so your heart isn’t operating as efficiently. It also makes it so your kidneys can’t filter toxins from your blood as effectively.”

His research titled “Cigarette Smoking Causes Epigenetic Changes Associated With Cardiorenal Fibrosis,” which was funded by a grant from the National Institutes of Health and done in collaboration with the University of California at San Diego, recently was published in the journal Physiological Genomics.

“The results of this study are a public health concern because a significant portion of the U.S. population suffers from kidney disease and heart-related side effects,” Drummond said. “When you smoke, you’re speeding up the development of kidney disease.”

An estimated 26 million Americans have chronic kidney disease, according to the National Kidney Foundation.

Drummond exposed two groups of rats to cigarette smoke five days a week for four weeks. One group had chronic kidney disease. The other group had normal renal function. Drummond compared those two groups with two control groups of rats — one with chronic kidney disease and one with normal kidney function — that were kept in a room with no smoke.

“We designed and built a system to expose rats to a constant concentration of smoke from cigarettes,” Drummond said. “Those were lit and the animals inhaled around five cigarettes’ worth of combustible smoke a day.”

In the smoke groups, researchers found a decrease in the genetic material called microRNA associated with slowing or preventing fibrosis in the organ tissue.

Smoking alone drove the rats into renal dysfunction, according to Drummond. Also, blood pressure increased, the heart enlarged, and scar tissue developed in the heart muscle and kidneys.

“If you are concerned or have a pre-existing condition, quitting smoking is one of the best things you can do to improve your health,” Drummond said.

He is currently investigating the effects of e-cigarettes on the kidney and heart.