Kidney function worsens as obesity rises

With or without existing kidney disease, kidney function is more likely to decline over time the more severely obese a person is, a large study suggests.

Compared with adults who are merely overweight, people with the most severe obesity are twice as likely to develop impaired kidney function, the analysis has found.

People who aren't quite as obese have an 18-69% higher risk of developing kidney impairment.

Excess weight, especially around the belly, causes many adverse metabolic effects that impact the kidney, says lead author Dr Alex Chang from the Geisinger Health System in Pennsylvania, US.

"First, excess weight increases the sympathetic nervous system activity and hormones that result in increased sodium retention and higher blood pressure," Dr Chang says.

"Second, excess weight impairs the body's ability to move glucose from the blood into cells and can lead to diabetes