RECOMBINANT HUMAN INSULIN-LIKE GROWTH-FACTOR-I DECREASES SERUM LIPOPROTEIN(A) CONCENTRATIONS IN NORMAL ADULT MEN

OBJECTIVE Lipoprotein(a) is a lipoprotein fraction associated with ath erosclerosis. The serum concentration of lipoprotein(a) has been shown to be mainly genetically determined but recently evidence for hormona l regulation has been presented. The aim of the present study was to i nvestigate the effects of insulin-like growth factor-I on serum lipopr oteins, especially lipoprotein(a). DESIGN The effects of one week of I GF-I treatment were studied in an open trial. SUBJECTS Ten healthy men , who participated in a pharmacokinetic study, were given recombinant human insulin-like growth factor-I (40 mu g/kg/day) as daily subcutane ous injections. MEASUREMENTS Serum samples for measurements of lipopro teins were taken after an overnight fast before and after 7 days of tr eatment. RESULTS There was a decrease in serum lipoprotein(a) concentr ation (18.5 +/- 5.5%) in nine of the subjects, and a slight increase i n one of the subjects with the lowest concentrations. Also serum; apol ipoprotein (b) (6.3 +/- 2.2%), serum cholesterol (10.6 +/- 1.8%) and s erum triglyceride (14.8 +/- 4.8%) concentrations decreased. An unexpec ted finding was that fasting serum glucose concentrations increased (1 3 +/- 4%). CONCLUSION Insulin-like growth factor-I is involved in the regulation of lipoprotein(a) concentrations, which might have novel th erapeutic implications.