FRIDAY, June 30, 2006 (HealthDay News) -- Mental stress may have a stronger effect on the kidney function of black adolescents compared to whites, a new study finds.
In a study of 276 healthy young adults, black youths showed higher levels of microalbumin and lower levels of sodium in urine -- signs of possible kidney damage and high stress levels.
Researchers at the Medical College of Georgia in Augusta studied the link between "stress-induced pressure natriuresis" (SIPN) and levels of microalbumin (a marker of kidney function) in the urine between both white and black adolescents.
SIPN occurs when stress impairs natriuresis -- sodium excretion via the urine. Previous studies have noted that SIPN appears to be more prevalent in blacks and has also been linked to alterations in heart function.
One hundred eighty-nine black and 87 white participants were given two hours of rest with no stress, then one hour of mental stress, followed by another two hour no-stress rest period.
The Georgia team showed that, in samples of blood and urine drawn hourly, urine levels of microalbumin were higher and sodium levels were lower in black adolescents. Blood pressure readings -- taken every 15 minutes -- showed that overall, the black participants had higher blood pressure than the white participants.
"Stress-induced pressure natriuresis is related to microalbumin in African American youth," study author Dr. Coral Hanevold, associate professor of pediatrics, said in a prepared statement. Hanevold also concluded from the results that in young black adults, "stress may lead to high blood pressure, which in turn, may influence kidney function. Over time, these processes could lead to permanent kidney damage."
Results of the study were presented at this week's annual meeting of the International Society on Hypertension in Blacks, in Atlanta.
More information
The National Kidney Foundation has more information on kidney disease.
