Anomalies of lipoprotein pattern and fibrinolysis in acromegalic patients: relation to growth hormone levels and insulin-like growth factor I

Abstract

The influence of hGH and IGF-I levels on lipid-, lipoprotein metabolism and fibrinolysis were studied in 23 patients with active acromegaly (14 women and 9 men, mean age 49.8 +/- 2.1 years) compared to a sex, BMI and age-matched control group. Mean Lp(a) levels were significantly higher in acromegalics than in controls (469.8 +/- 140.1; n = 23 vs. 162.7 +/- 64.9 mg/l; n = 111; p < 0.01). We found elevated apolipoprotein A-I and Apo E-concentrations in acromegalic patients compared to controls (apo A-I: 1.79 +/- 0.06 vs. 1.46 +/- 0.04 g/l; p < 0.01; apo E: 98.35 +/- 6.4 vs. 72.53 +/- 3.38 mg/l; p < 0.05). 30% of the acromegalics showed increased plasminogen activator inhibitor activity (PAI) while 66% had increased tissue-type plasminogen activator (t-PA) concentrations. There was a correlation between hGH and Lp(a) (r = 0.414; p = 0.05), between hGH and PAI (r = -0.59; p < 0.005) and IGF-I and t-PA activity (r = -0.44; p < 0.05). In a subgroup of nine acromegalics Lp(a) was reduced by 32.2 +/- 6.7% (p < 0.05) after a six-month octreotide therapy and HDL2-cholesterol-concentration increased from 0.17 +/- 0.04 to 0.24 +/- 0.04 mmol/l (p < 0.05). In conclusion, our results demonstrate that elevated Lp(a)-concentrations and changes in fibrinolysis contribute to the cardiovascular complications and should therefore be controlled in acromegalic patients.