Preliminary study on the relation between serum growth hormone and 1,25-dihydroxyvitamin D3 in acromegalic patients]

Eight acromegalic patients were treated with SMS 201-995 for 12 months. At the 3rd, 6th and 12th month from the beginning of treatment, blood samples of these patients were taken for determination of growth hormone (GH), 1,25-(OH)2D3, SMC, calcium and phosphorus. The serum levels of GH decreased significantly at the 3rd, 6th and 12th months compared with the basal levels before treatment (P less than 0.01, P less than 0.05 and P less than 0.05 respectively). The concentrations of serum 1,25-(OH)2D3 and SMC also decreased significantly. Mean serum GH, 1,25-(OH)2D3 and SMC levels were reduced from 34.8 +/- 10.7 to 15.5 +/- 5.9 ng/ml (P less than 0.05), 76.2 +/- 2.7 to 45.9 +/- 8.3 pg/ml (P less than 0.05) and 8.5 +/- 1.2 to 4.4 +/- 1.0 U (P less than 0.05) respectively at the 12th month after treatment. Serum phosphorus levels reduced from 4.7 +/- 0.4 to 4.1 +/- 0.2 mg% (P less than 0.05) at the 6th month after treatment, but there was no change in the serum levels of total calcium. The treatment with SMS 201-995 directly evoked a reduction of serum GH in acromegalic patients and at the same time, the levels of serum SMC and 1,25-(OH)2D3 were decreased. The results suggest that GH may stimulate indirectly the production of 1,25-(OH)2D3 through the mediation of SMC.