levels lower than those that cause lead nephropathy have also been reported as nephrotoxic in patients from developed countries that had chronic kidney disease or were at risk because of hypertension or diabetes mellitus. lead poisoning inhibits excretion of the waste product urate and causes a predisposition for gout, in which urate builds up. this condition is known as saturnine gout. cardiovascular system evidence suggests lead exposure is associated with high blood pressure, and studies have also found connections between lead exposure and coronary heart disease, heart rate variability, and death from stroke, but this evidence is more limited. people who have been exposed to higher concentrations of lead may be at a higher risk for cardiac autonomic dysfunction on days when ozone and fine particles are higher. reproductive system lead affects both the male and female reproductive systems. in men, when blood lead levels exceed 40 μg/dl, sperm count is reduced and changes occur in volume of sperm, their motility, and their morphology. a pregnant woman's elevated blood lead level can lead to miscarriage, prematurity, low birth weight, and problems with development during childhood. lead is able to pass through the placenta and into breast milk, and blood lead levels in mothers and infants are usually similar. a fetus may be poisoned in utero if lead from the mother's bones is subsequently mobilized by the changes in metabolism due to pregnancy; increased calcium intake in pregnancy may help mitigate this phenomenon. nervous system the brains of adults who were exposed to lead as children show decreased volume, especially in the prefrontal cortex, on mri. areas of volume loss are shown in color over a template of a normal brain. an infographic explaining lead poisoning