For People With Obesity, Weight Loss Isn’t the Only Way to Prevent Kidney Disease

People with obesity who can walk at a brisk pace and maintain a stable weight may be able to help reduce their risk of developing chronic kidney disease, a new study suggests.

Obesity has long been considered a risk factor for chronic kidney disease, and is also often associated with other conditions that can contribute to impaired kidney function, like type 2 diabetes and high blood pressure. While weight loss is one way people may be able to reduce the risk, the new study explored whether it’s possible to minimize the risk without shedding excess pounds.

Researchers followed about 1,200 adults with obesity who didn’t have kidney issues or diabetes for roughly a decade to see what happened to their kidneys over time. During the study period, about 15 percent of the participants, or 176 people, developed chronic kidney disease and 86 died.

People with a slow walking pace of less than 2 miles per hour were 48 percent more likely to develop chronic kidney disease than participants with a faster pace, according to study results published in Obesity. The risk also climbed by 34 percent for every 5 kilograms (11 pounds) people gained during follow-up.

Weight Gain Can Strain the Kidneys

“Weight gain can cause direct strain on kidney function and increase risks of hypertension and diabetes, which are leading causes of chronic kidney disease,” says lead study author Meera Nair Harhay, MD, MPH, a professor at Drexel University College of Medicine in Philadelphia and nephrologist at the University of Pennsylvania Transplant Institute.

“Even though we know of many health benefits of weight loss in obesity, we did not observe an association between weight loss and kidney disease risk in our study,” Dr. Harhay adds. “Perhaps that link was not as apparent in our study because our population did not have other risk factors, such as diabetes, cardiovascular disease, or severe obesity — the study excluded individuals who weighed more than 300 pounds.”

One limitation of the study is that researchers didn’t know whether any weight loss in the study was intentional, or due to underlying medical issues. Similarly, researchers lacked data on why certain participants had slower walking speeds, such as the potential for conditions like arthritis that may be treated with medications that increase the risk of kidney disease.

Study Affirms Benefits of Exercise Even When It Doesn’t Lead to Weight Loss

Even with these caveats, the study results offer fresh evidence of the benefits of keeping up with a consistent physical activity routine, and increasing it if possible, says Catherine Clase, a professor and nephrologist at McMaster University and St. Joseph’s Healthcare Hamilton in Ontario, Canada, who wasn’t involved in the new research.

A study published last month in the European Journal of Preventive Cardiology, for example, found that walking just 4,000 steps a day — roughly two miles — could significantly reduce the risk of premature death.

“It’s possible that walking leads to overall benefits to the vascular system, which might explain the connection with lower risk of kidney disease,” Clase says. But speed doesn’t need to be the main goal when people try to get more exercise, she adds.

“People can look at their current activity levels and try to increase daily steps safely, rather than focusing on walking faster,” Clase advises. “Walking speed will naturally increase with stamina and strength, which will increase with daily practice.”