Belly Fat Increases Risk of Kidney Damage, Study Says
Apr 15th, 2013
People who carry excessive fat around their bellies may have to worry more than their looks. A new study suggests that they also have higher risk of kidney damage.
The study measured renal blood flow of 315 men and women in the Netherlands. Researchers found that those with higher waist-to-hip ratios also had higher blood pressure in their kidneys, even if they had normal weight.
High blood pressure can damage small blood vessels in the kidneys and decrease their ability to eliminate waste from the blood.
Researchers found that for every one-unit increase in waist-to-hip ratio, the glomeruli (tiny filters in the kidneys) loses about 4 milliliters of blood flow per minute.
By comparison, normal aging reduces glomerular filtration rate by about 1 milliliter per minute every year.
The finding was particularly striking to the researchers because “we found that association in healthy subjects who didn’t have high blood pressure or diabetes,” said Arjan Kwakernaak, co-author and doctoral student at the University of Groningen Medical Center.
The association held true regardless of the individual’s body weight. Furthermore, bigger people have even higher risks.
“If you have a higher waist-to-hip ratio and you are overweight, you have even a higher risk of having elevated kidney blood pressure,” Kwakernaak said.
The study was published online April 11 in the Journal of the American Society of Nephrology.
Researchers do not fully understand how belly fat damages the kidneys, and the study doesn’t show that abdominal fat is directly responsible for changes in the kidney. The findings are consistent with previous studies that have shown that excess fat around the midsection increases the risk for diabetes and heart disease, which are linked to renal problems.
The study wasn’t able to show when the waist-to-hip ratio starts to do the damage.
According to the World Health Organization, abdominal obesity is having a waist-to-hip ratio of over 0.85 for women and over 0.9 for men.