Having an apple-shaped body, with fat concentrated mainly in the abdominal area, as opposed to a pear-shaped body, with fat mainly around the hips, is associated with elevated blood pressure in the kidneys and an increased risk of kidney disease, even in individuals who maintain a normal body weight. The finding appears today in the Journal of the American Society of Nephrology.
Previous research attributed the increased risk of renal disease in people with apple-shaped bodies to excess weight, hypertension, abnormal levels of lipids, and diabetes. But the new findings, by researchers with the University of Groningen, University Medical Center Groningen in The Netherlands, suggest those factors may not be the most important ones. The researchers studied blood flow within the kidney in 315 healthy persons with a mean body mass index (BMI) of 24.9, which is considered normal weight. They found that study participants with apple-shaped bodies (a waist-to-hip ratio on or above 0.8) had elevated blood pressure in the kidneys, resulting in lower kidney function and lower kidney blood flow, even after adjusting for sex, age, mean arterial pressure, and BMI. This finding suggests elevated blood pressure in the kidneys may be the cause for increased risk of developing kidney disease later in life.
“We found that apple-shaped persons—even if totally healthy and with a normal blood pressure—have an elevated blood pressure in their kidneys,” said Arjan Kwakernaak, an MD/PhD candidate and lead author of the study, in a release. “When they are also overweight or obese, this is even worse.”
High blood pressure in the kidneys can be treated by restricting salt consumption or with drugs that block a network of hormones that regulates blood pressure and water balance in the body. “Our current data suggest that such interventions could be particularly useful in subjects with a central body fat distribution,” Kwakernaak said.