High plasma antidiuretic hormone in patients with cardiac failure: influence of age.

Plasma antidiuretic hormone (ADH) was greater in patients with cardiac failure than in healthy subjects. Plasma ADH increased significantly with age in both groups. Covariance analysis showed that the difference between patients and controls occurred whatever the age. Plasma sodium and plasma osmolality were lower in cardiac patients than in healthy subjects. This showed that increase in plasma ADH observed in patients was inappropriate since it coexisted with inhibitory levels of plasma osmolality. Plasma creatinine was greater in cardiac patients than in healthy subjects and for each group in elderly than in young people. But there was no significant correlation between plasma ADH and creatinine. This suggested that increase in plasma ADH observed in cardiac failure was due more to an augmented release than to a diminished catabolism. No clear influence of etiology, severity, length of the disease and treatment with diuretics could be demonstrated.