[Parathormone, cyclic AMP, 1,25 dihydroxyvitamin D and osteocalcin in hypercalciuric renal lithiasis]

A study was undertaken in 46 subjects; 21 patients diagnosed as having HRL and 25 volunteers patients. Biochemical and hormonal analyses were performed in the study population, including determination of Ca, P, Mg, Cr in blood and urine, phosphate tubular resorption (PTR), maximum tubular phosphate resorption (MTPR), fasting calcium secretion (FCS), alkaline phosphatase (AP), hydroxyprolinuria (HPR), osteocalcin (BGP), parathormone (PTH), cAMP, and 1-25(OH)2D. The stone formers showed lower calcemia values (p less than or equal to 0.005d), higher phosphaturia, and magnesiuria (p less than or equal to 0.0005), higher FCS (P less than or equal to 0.005) and higher values for PTH (p less than or equal to 0.01) and cAMP (p less than or equal to 0.0025). No significant differences were observed for the other parameters evaluated. Classification of the patient group into 2 subgroups (renal SbR and absorptive SbA) according to FCS values greater or lower that 0.16 mg/dl, the SbR patient group revealed a higher PTH and 1-25(OH)2D values (p less than or equal to 0.05). There appears to be no increase of bone resorption since AP, HPR, and BGP values in our patients fell within normal ranges. The 1-25(OH)2D levels were also normal and, with respect to the control group, were only elevated for the SbR patient group, whose PTH levels were also observed to be elevated. These increments appear to be related and may result in intermediate forms between renal and absorptive hypercalciuria.