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.

Hemostatic abnormalities in endocrine and metabolic disorders

“…Some small case-control studies suggested the presence of a prothrombotic tendency in acromegalic patients that might partially contribute to the development of cardiovascular complications (1). For example, in a small case-control study, Wildbrett et al (84) reported higher levels of plasma PAI-1 and t-PA in 23 patients with active acromegaly than in healthy controls. Moreover, a positive, significant association was observed between plasma insulin-like growth factor 1 (IGF1), GH, and PAI-1 levels among these patients (84).…”

“…For example, in a small case-control study, Wildbrett et al (84) reported higher levels of plasma PAI-1 and t-PA in 23 patients with active acromegaly than in healthy controls. Moreover, a positive, significant association was observed between plasma insulin-like growth factor 1 (IGF1), GH, and PAI-1 levels among these patients (84). Recently, Erem et al (6) reported higher plasma fibrinogen, antithrombin, and PAI-1 levels, and lower protein S activity and TFPI levels in 22 patients with active acromegaly than those in 22 age-matched healthy controls.…”

Hypophysenstörungen und sekundärer Diabetes mellitus

“…Parallel und im Zusammenhang zu Störungen im Kohlenhydratstoffwechsel treten auch Veränderungen im Lipidstoffwechsel auf, im Sinne einer erhöhten Atherogenität: Hypertriglyzeridämie, erhöhte Apo-E-, Apo-AI-und Lp(a)-Konzentrationen sowie höhere "Small-dense-LDL-Subfraktionen" und postprandiale Lipoprotein-Remnant-Konzentrationen [26,29].…”

Medical consequences of acromegaly: What are the effects of biochemical control?

“…GH stimulates apolipoprotein E (Apo-E) and apolipoprotein A-I (Apo A-I) secretion [47]. Moreover, elevated levels of serum lipoprotein (a) concentrations have been found in both active patients and in those with controlled disease [48].…”