THE EFFECT OF RECOMBINANT HUMAN GH REPLACEMENT THERAPY ON LIPOPROTEIN(A) AND OTHER LIPID PARAMETERS IN ADULTS WITH ACQUIRED GH DEFICIENCY -RESULTS OF A DOUBLE-BLIND AND PLACEBO-CONTROLLED TRIAL

The effect of GH substitution on serum lipids and lipoproteins, and in particular lipoprotein(a) (Lp(a)), was investigated in 32 adults with postoperative (acquired) GH deficiency as part of a double-blind, pla cebo-controlled trial. Seventeen men and fifteen women, aged 18-59 yea rs (mean 42 years) from two centres (Hannover and Gottingen) were rand omly assigned to two groups. Group P (placebo) received placebo for th e first 12 months and recombinant human GH (rhGH) for the following 12 months (open phase). Group V (verum) was treated with rhGH for two co nsecutive periods of 12 months each. The target dose of rhGH was 2 U/m (2) per day, given subcutaneously daily at bedtime. Serum concentratio ns of Lp(a), total cholesterol (TC), low-density lipoprotein cholester ol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycer ides were determined at 0, 12 and 24 months. In group V, Lp(a) increas ed significantly in the first as well as in the second year of treatme nt (P=0.02, 12 months versus baseline; P=0.016, 24 months versus 12 mo nths), In contrast, Lp(a) levels remained unchanged in group P during the first 12 months (P=0.826 versus baseline), but increased significa ntly (P=0.002) during the second year, when all patients were administ ered GH. The increase in Lp(a) after 12 months of rhGH replacement the rapy in all 32 patients was significant for Lp(a) baseline concentrati ons both above and below 20 mg/dl and was independent of the apolipopr otein(a) isoforms. Total and LDL-C decreased significantly after 1 yea r and triglycerides after 2 years in group V. A significant reduction was also observed in the TC/HDL-C and the LDL-C/HDL-C ratios, Our stud y shows an unfavorable effect of rhGH replacement therapy on Lp(a) lev els, which is, however, counteracted by a favorable effect of rhGH on TC, LDL-C and the TC/LDL-C and LDL-C/HDL-C ratios.