[Hypocortisolism associated with nephrotic syndrome]

With nephrotic syndrome, cortisol levels may be falsely lowered by loss of cortisol-binding globulin (CBG) in the urine. An incorrect diagnosis of adrenal insufficiency could therefore be made.

We describe the case of a 52-year-old female with nephrotic syndrome that did not sufficiently respond to medication. Treatment management was complicated by symptomatic hypotension, which was thought to be caused by adrenal insufficiency. The cortisol levels in the blood were low and a clinical cause could not be identified. However, free cortisol in the saliva appeared normal and serum CBG levels were low; this therefore precluded adrenal insufficiency. After complete remission of the nephrotic syndrome, cortisol levels normalised.

The reduced cortisol level in this patient was caused by the reduced CBG level due to loss associated with nephrotic syndrome. First and foremost it is important to indicate an abnormal laboratory result within an existing disease, before making a new diagnosis of concomitant disease.