[Reappraisal of the water test in adrenocortical exploration]

The water-loading test (Robinson's test) has been used since 1941 to evaluate the adrenocortical function. Due to this technique, impaired water excretion has become a classical feature of adrenal deficiency. The purpose of this study was to assess the reliability of this test when compared with modern procedures for adrenal exploration. Water excretion was decreased in 23 cortisol-deficient patients but also in 16 out of 58 subjects (27%) with normal adrenal biological tests. We consider that this simple test, although old-fashioned, remains useful since normal diuresis after 2 hours is sufficient to rule out a cortisol deficiency.