Determined at Birth? Kidney makeup may set hypertension risk
By Nathan Seppa
In the kidneys, clusters of capillaries and tubes called nephrons filter gallons of blood every day and direct the impurities to the urine. According to a current theory, people lacking a full complement of nephrons are at increased risk of developing high blood pressure.
A study from Germany now finds hard evidence for this phenomenon and suggests that the number of nephrons in each person’s kidney is set at birth.
The theory linking nephron number and blood pressure has long been championed by Barry M. Brenner of Harvard Medical School and Brigham and Women’s Hospital in Boston. He holds that when nephrons are in short supply, and therefore overworked, there’s a release of hormones and retention of sodium by the kidneys. Both contribute to hypertension. Since Brenner first proposed his theory in 1988, research in animals has found that a shortage of nephrons correlates with high blood pressure.