Why Do People with Apple-Shaped Bodies Have an Increased Risk of Kidney Disease?

High blood pressure in the kidneys may be the answerHighlights• People with apple-shaped bodies tend to have lower kidney function, lower kidney blood flow, and higher blood pressure within the kidneys than people with pear-shaped bodies.• The findings may help explain why people with apple-shaped bodies are more likely than those with pear-shaped bodies to develop kidney disease.

Newswise — Washington, DC (April 11, 2013) — High blood pressure in the kidneys of people with apple-shaped bodies may be responsible for their increased risk of developing kidney disease later in life, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The findings suggest that these individuals may benefit from treatments that reduce kidney blood pressure.

People with “apple-shaped” bodies—when fat is concentrated mostly in the abdominal area—are more likely than those with “pear-shaped” bodies to develop kidney disease. The mechanisms underlying this risk are not well understood.

To study the issue, Arjan Kwakernaak, MD/PhD candidate (University Medical Center Groningen, in The Netherlands) and his colleagues looked for links between waist-to-hip ratio, which reflects central body fat distribution, and kidney measures in 315 healthy individuals with an average body mass index of 24.9 kg/m2. (A body mass index of 18.5 to 24.9 kg/m2 is considered normal weight.)

Higher waist-to-hip ratios were associated with lower kidney function, lower kidney blood flow, and higher blood pressure within the kidneys.

“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,” said Kwakernaak.

This suggests that elevated blood pressure in the kidneys of individuals with apple-shaped bodies may be responsible for their increased risk of developing kidney disease later in life. Previous studies have shown that high blood pressure in the kidneys can be treated through salt restriction or with drugs that block what is known as the renin-angiotensin-aldosterone system. “Our current data suggest that such interventions could be particularly useful in subjects with a central body fat distribution,” said Kwakernaak.

Study co-authors include Dorien Zelle, PhD candidate, Stephan Bakker, MD, PhD, and Gerjan Navis, MD, PhD.

Disclosures: The authors reported no financial disclosures.

The article, entitled “Central Body Fat Distribution Is Associated with Unfavorable Renal Hemodynamics Independent of Body Mass Index,” will appear online at http://jasn.asnjournals.org/ on April 11, 2013, doi: 10.1681/ASN.2012050460.

The content of this article does not reflect the views or opinions of The American Society of Nephrology (ASN). Responsibility for the information and views expressed therein lies entirely with the author(s). ASN does not offer medical advice. All content in ASN publications is for informational purposes only, and is not intended to cover all possible uses, directions, precautions, drug interactions, or adverse effects. This content should not be used during a medical emergency or for the diagnosis or treatment of any medical condition. Please consult your doctor or other qualified health care provider if you have any questions about a medical condition, or before taking any drug, changing your diet or commencing or discontinuing any course of treatment. Do not ignore or delay obtaining professional medical advice because of information accessed through ASN. Call 911 or your doctor for all medical emergencies.

Founded in 1966, and with more than 13,500 members, the American Society of Nephrology (ASN) leads the fight against kidney disease by educating health professionals, sharing new knowledge, advancing research, and advocating the highest quality care for patients.

# # #