Individuals who were underweight at birth are at increased risk of developing a condition called secondary focal segmental glomerulosclerosis, according to a study appearing in the January 2009 issue of the Clinical Journal of the American Society Nephrology ( CJASN ).
Because birth history is often overlooked by kidney specialists who take care of adult patients, this risk factor is likely to be under-recognized.
Patients with focal segmental glomerulosclerosis develop scarring of glomeruli, the filtering units of the kidney. This development can cause a decline in kidney function and leakage of protein into the urine.
Low birth weight (less than 5.5 pounds) caused by prematurity or slow growth prior to birth is a risk factor for adult hypertension, coronary heart disease, stroke, diabetes, and other diseases. However, its association with the development of focal segmental glomerulosclerosis has not been reported.
To investigate this potential link, Vivette D'Agati, MD, of the Columbia University College of Physicians & Surgeons in New York City, NY, and her colleagues studied six patients (two women and four men) who had clinical indications of this condition and who were born prematurely and of a very low birth weight. The patients' average age was 32 years, and their average birth weight was 3.3 pounds. They all were born between 22 and 30 weeks of gestation, compared with full-term babies who are born between 37 and 42 weeks.
The researchers performed urine tests that measured whether protein was leaking into the urine and blood tests that indicated how well the patients' kidneys were functioning. They also biopsied the patients' kidneys to analyze the tissue. All of their measurements and tests indicated that the patients had developed focal segmental glomerulosclerosis.