Previous research has shown that having an apple-shaped body — that is, carrying more weight around the abdomen and having a larger waist — increases the risk of developing heart disease.

Now a new study, published in the Journal of the American Society of Nephrology, adds kidney problems to the risks faced by apple-shaped people.

The research done at the University Medical Center Groningen, in the Netherlands, included more than 300 people who were either overweight or had a healthy weight.

They found that apple-shaped people with a higher waist-to-hip ratio had lower kidney function, reduced kidney blood flow and higher blood pressure in the kidneys; and surprisingly, even in participants who were otherwise healthy.

Arjan Kwakernaak, leader of the study, said, "We found that apple-shaped persons - even if totally healthy and with a normal blood pressure - have an elevated blood pressure in their kidneys. When they are also overweight or obese, this is even worse."

Other studies have found that high blood pressure in the kidneys can be treated through sodium reduction or with targeted drug treatments. “Our current data suggest that such interventions could be particularly useful in subjects with a central body fat distribution,” said Kwakernaak.

A spokesman for Kidney Research UK told the BBC, "This is further evidence that there is a link between obesity and the growing problem of kidney disease, and that more needs to be done to make people aware of the importance of protecting kidney function."

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