Heavy teens at higher risk for kidney disease

By MyHealthNewsDaily staff

Being obese or overweight during adolescence may raise the risk of having debilitating kidney disease later in life, according to a new study from Israel.

Teens in the study who were overweight at age 17 were three times more likely to have end-stage renal disease (ESRD) over the next 25 years, compared with the general population, according to the 25-year study of more than 1 million people. Obese teens were nearly seven times more likely to have ESRD, the study found. The only treatments for ERSD are dialysis and kidney transplant.

The researchers, led by Dr. Asaf Vivante of the Israeli Defense Forces Medical Corps, used data gathered between 1967 and 1997 on 1.2 million adolescents who, at age 17, were examined for fitness for Israeli military service. The researchers tracked cases of ESRD using a national registry of the disease.

Results showed that 874 study participants (713 men, 161 women) were treated for ESRD over the next 25 years. This translates to a rate of 2.87 cases per 100,000 people yearly. Among those who were overweight at age 17, there were 6.08 cases per 100,000 people yearly, and among obese teens, there were 13.4 cases per 100,000 people yearly.

The study is published online today (Oct. 29) in the journal Archives of Internal Medicine.

More than a third of children and adolescents in the U.S. are overweight or obese, according to the Centers for Disease Control and Prevention (CDC).

Previous research has linked higher body mass indexes with an increased risk of type 2 diabetes, which itself raises the risk of ESRD (sometimes referred to as diabetic ERSD), the researchers said.

In the new study, the researchers looked at the risk of ESRD in overweight and obese people both with and without diabetes.

They found that those who were overweight at age 17 were six times more likely to develop diabetic ESRD, compared with normal-weight teens. But they were also twice as likely to have non-diabetic ESRD.

Among those who were obese, the risks were higher — obesity at age 17 was linked with a 19-fold increase in diabetic ESRD, and a three-fold increase in risk of non-diabetic ESRD.

Still, in noting the relatively small number of study participants who developed ESRD, the researchers wrote that the condition remains relatively rare. However, a much greater number of people may be in the earlier stages of chronic kidney disease, they said. In general, 2 percent of people with chronic kidney disease go on to develop ESRD.

The study "adds the development of end-stage renal disease (ESRD) to the list of adverse outcomes associated with adolescent overweight and obesity," said Dr. Kirsten Johansen, a nephrologist at the San Francisco Veterans Affairs Medical Center, in an editorial accompanying the new study in the journal.

Exactly how being overweight may lead to kidney disease remains unclear, Johansen wrote. Some evidence suggests that obesity directly injures the kidneys. It could also be that obese people have imbalances in hormones, such as renin and aldosterone, which affect kidney function, or that the link is mediated by other unhealthy behaviors, such as poor diet, smoking and sedentary behavior.

"Eating and physical activity patterns that are focused on consuming fewer calories, making informed food choices, and being physically active can help people attain and maintain a healthy weight, reduce their risk for chronic disease, and promote overall health," Johansen wrote.

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