Nephron mass and cardiovascular and renal disease risks.

The nephron endowment begins with the complex process of nephrogenesis, which is controlled through genetic and environmental influences from preconception up until approximately 36 weeks of gestation. The total number of nephrons in human beings averages about 1 million per kidney but varies up to 10-fold, from approximately 200,000 to more than 2 million. Low nephron mass is associated with the development of hypertension and, in some ethnic populations, the concurrence of cardiovascular and renal disease risks in later life. Kidney size and nephron number also are related directly to birth weight with persons born preterm or with evidence of intrauterine growth restriction more likely to develop certain diseases in later life.