Growth hormone treatment in adults with GH deficiency: effects on new biochemical markers of bone and collagen turnover.

Serum bone Gla protein (BGP) and bone alkaline phosphatase (B-AP), markers of bone formation, carboxyterminal cross-linked telopeptide of type I collagen (ICTP), marker of bone resorption, and aminoterminal propeptide of type III procollagen (PIIINP) levels, index of collagen synthesis, were determined in 8 adults (mean age +/- SE: 29.6 +/- 1.2 yr) with childhood onset GHD before and after 3 and 6 months of recombinant GH treatment (0.5 IU/kg/week). Before treatment, mean BGP (3.8 +/- .5 ng/ml) and B-AP (44.9 +/- 6.9 IU/L) were significantly (P < 0.001 and p < 0.05, respectively) lower than those recorded in normals (5.4 +/- 0.1 ng/ml and 61.8 +/- 1.9 IU/L, respectively), while serum ICTP and PIIINP levels were similar to those found in controls (ICTP: 4.7 +/- 0.8 vs 4.1 +/- 0.3 ng/ml; PIIINP: 3.7 +/- 0.6 vs 3.2 +/- 0.2 ng/ml). BGP and ICTP levels significantly (p < 0.005) increased after 3 (28.4 +/- 5.3 ng/ml and 17.5 +/- 2.8 ng/ml, respectively) and 6 months (25.1 +/- 5.0 ng/ml and 15.0 +/- 1.9 ng/ml, respectively) of recombinant GH treatment. B-AP levels significantly (p < 0.01) increased during the treatment (basal: 44.9 +/- 6.9 IU/L, 3rd month: 173.6 +/- 40 IU/L, 6th month: 194.4 +/- 40 IU/L), while non B-AP levels remained similar to those recorded in basal condition. Serum PIIINP levels significantly (p < 0.0001) rose up after 3 (12.5 +/- 1.4 ng/ml) and 6 months (10.2 +/- 0.8 ng/ml). Serum BGP and ICTP levels were directly (r = 0.85, p < 0.001; r = 0.53, p < 0.01) correlated with serum IGF-I levels.(ABSTRACT TRUNCATED AT 250 WORDS)