Parathyroid gland function in subgroups of metabolically mediated urolithiasis as evaluated by serum parathyroid hormone, and urinary and nephrogenous cyclic nucleotides.

In healthy controls (n=34) and in the various metabolically defined subgroups of urolithiasis patients, including primary hyperparathyroidism (pHPT), parathyroid hormone (PTH) was studied using two different antisera, as were the cyclic nucleotides (cAMP; cGMP) and related variables in both urine and plasma; in addition, the nephrogenous components of the cyclic nucleotides were also determined. In nonpHPT (so-called idiopathic) stone disease, nephrogenous cAMP (2-h fasting urine) was significantly lower than normal in the normo-calciuric majority (n=60), and also lower than normal (medians) in all the other subgroups (absorptive hypercalciuria,n=15; renal hypercalciuria,n=23; uric acid lithiasis,n=17; uric/calcium oxalate lithiasis,n=12). In contrast, it was significantly elevated in pHPT (n=20), and only in this latter condition was nephrogenous cGMP (2-h urine) elevated. The total nucleotide production (sum of nephrogenous cAMP + nephrogenous cGMP) is again significantly lower only in normo-calciuric calcium stone disease. Except for high values in pHPT, no differences in plasma nucleotides are observed. Stone patients (idiopathic and pHPT) have significantly lower-than-normal serum phosphate and phosphate threshold in common. With the exception of pHPT, the differences in serum calcium are only minute, while ionised calcium is moderately elevated within the normal range in the serum of renal hypercalciuria patients.