Teenagers who’ve packed on extra pounds have a significantly increased risk of developing kidney disease as a young adult, a new study finds.

Obesity increased risk of later kidney disease as much as ninefold in boys and fourfold in girls, according to results published recently in the journal JAMA Pediatrics.

Even a few extra pounds increased a teen’s risk of kidney disease, researchers found.

“The association was evident even in persons with high-normal BMI in adolescence, was more pronounced in men and appeared before the age of 30 years,” wrote the research team led by Dr. Avishai Tsur, of the Hebrew University Department of Military Medicine in Israel.

Prior research has linked high BMI to kidney disease in older folks, but there hasn’t been much investigation into the potential risks of childhood obesity for kidney health, the researchers said.

The study tracked more than 593,000 Israeli adolescents ages 16 to 20 who were born after 1974, all of whom underwent medical assessments for mandatory military service.

After an average follow-up of 13 years, researchers found that nearly 2,000 of the participants had developed early chronic kidney disease.

The teens’ risk of kidney disease increased with their excess weight, results show.

Boys with severe obesity had a nine times higher risk of kidney disease, while those with mild obesity had a nearly seven times higher risk and those who were overweight had a fourfold increased risk.

The same was true of girls – a four times higher risk for severe obesity, nearly three times higher risk for mild obesity, and more than doubled risk for overweight.

Even those with a high-normal BMI were at increased risk — 80% higher for boys and 40% higher for girls. High-normal participants averaged a BMI of about 22. A healthy BMI runs from 18.5 to 24.9.

“These findings are a harbinger of the potentially preventable, increasing likelihood of developing chronic kidney disease and subsequent cardiovascular disease,” the researchers wrote.

The association held even after controlling for other kidney risk factors, researchers said.

“Our analysis suggests that even in the absence of incident diabetes or hypertension, the risk is increased by 1.5- to 2.7-fold for persons with overweight and obesity in adolescence,” they wrote.

It’s not yet clear why excess weight damages the kidneys, researchers said. High blood pressure, elevated cholesterol levels and hormone disruptions linked to obesity all might play a factor.

More information

The U.S. Centers for Disease Control and Prevention has more about the health effects of excess weight.

SOURCE: Hebrew University, news release, Jan. 3, 2024