Urinary cyclic nucleotide levels in patients with hyper- and hypothyroidism.

Urinary cyclic AMP, cyclic GMP and creatinine excretion were measured in 38 patients with hyperthyroidism, 32 patients with hypothyroidism and in 57 normal subjects. The excretion of both cyclic nucleotides was significantly increased in hyperthyroid females, but not in hyperthyroid males. The cyclic nucleotides/creatinine ratios, however, were uniformly elevated in both male and female hyperthyroid subjects and this was due, in part, to decreased creatinine excretion. Cyclic AMP excretion was significantly decreased in the hypothyroid subjects, but the cyclic AMP/creatinine ratios were not significantly different from normal. There were no significant alterations in cyclic GMP and cyclic GMP/creatinine ratios in the male hypothyroid patients, but ratios in the female patients were slightly greater than in the normals. These results demonstrate that hyper- and hypothyroidism may be associated with appreciable alterations in urinary cyclic nucleotide levels and that there may be sex-related differences in the patterns of urinary excretion of these nucleotides. The cyclic nucleotide levels herein described in patients with hyper- and hypothyroidism are qualitatively and, in some instances, quantitatively similar to those found in patients with hyper- and hypoparathyroidism, respectively.