Renal acidification in hypothyroid man.

The role of thyroid hormone in renal hydrogen ion secretion remains largely unknown, and there is only limited information on renal acidification in hypothyroid patients. In the present study two of five adult male patients with untreated primary hypothyroidism and without clinical evidence of systemic autoimmune disease were unable to lower their urine pH appropriately after short duration acid-loading. Since, prior to acid-loading, their arterial blood gas values were within the normal range and urinary bicarbonate excretion was trival, the findings are consistent with the incomplete syndrome of distal renal tubular acidosis. Although the mechanism of this abnormality remains unknown, thyroxine deficiency per se may in part be responsible.