Fractional excretion of calcium, a sensitive marker for calcium wasting in cadmium-exposed women

In Cadmium (Cd)-exposed populations there is urinary calcium (Ca) loss which reflects Ca loss from the bone, decreased bone mass, and osteoporosis later in life, to which women are particularly vulnerable. A sensitive screening method to detect critical Ca wasting is required to provide warning of an increased osteoporosis risk. We used Fractional Excretion of Calcium (FECa) to study Ca wasting in Cd-exposed population. FECa sensitivity to Ca loss was compared to that of serum Ca, urinary Ca and intact parathyroid hormone. Mean FECa in the exposed group was 1.5 times higher than in the control group, and a dose-effect relationship to Cd exposure level was observed. FECa showed a relationship to Cd exposure level even following adjustment for a renal dysfunction marker. We conclude that FECa has a better sensitivity than urinary Ca and serum Ca. The use of FECa as an indicator of Ca wasting in Cd exposed women is recommended.