Serum lipoprotein changes following IGF-I normalization using a growth hormone receptor antagonist in acromegaly.

Summary objective Active acromegaly is associated with altered lipid metabolism. The purpose of this study was to investigate the effect of serum IGF-I normalization on serum lipoproteins and insulin, in patients with acromegaly receiving the GH receptor antagonist pegvisomant. patients Twenty patients (9 male, mean age 58·7 years, range 28–79) with active acromegaly (baseline serum IGF-I > 130% the age-related upper limit of normal) received pegvisomant and achieved a normal serum IGF-I [585·2 ± 54·3 (mean ± SEM) to 169·2 ± 13·9 ng/ml, P < 0·0001]. measurements Total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, triglyceride (TG), apolipoprotein B (apo B), apolipoprotein A1 (apo A1), lipoprotein a [Lp(a)] and insulin were measured in a single batch analysis on samples obtained at baseline and the first occasion of serum IGF-I normalization. Low-density lipoprotein (LDL) was calculated using the Friedewald formula. Paired analysis was performed using Student’s paired t -test and the Wilcoxon signed rank test. results Normalization of serum IGF-I resulted in an increase in TC (5·0 ± 0·3 to 5·7 ± 0·4 mmol/l, P = 0·0068), an increase in LDL (3·0 ± 0·25 to 3·7 ± 0·31 mmol/l, P = 0·0093) and an increase in apo B (110·6 ± 7·76 to 127·1 ± 8·86 mg/l, P = 0·0014). TC and LDL increased in all but four patients. Despite a significant fall in fasting insulin levels (9·9 to 8·3 mU/l, range 8·85–19·8 to 6·33–11·6, P < 0·001) and insulin resistance (2·7 to 1·9, range 1·2–10·4 to 1–6·2, P < 0·001), mean serum TG and HDL levels were unaffected by IGF-I normalization. The protein component of HDL, apo A1, increased (153 ± 4 to 166·4 ± 5·43 mg/l, P = 0·026) and Lp(a) declined (median 342... [ABSTRACT FROM AUTHOR]