Objective: Acromegaly is associated with increased morbidity and mortality from cardiovascular disease and from stroke in particular. Fibrinogen is an established risk factor for stroke and myocardial infarction and high levels of plasminogen activator inhibitor-1 (PAI-1) activity were predictive of a recurrent myocardial infarction. The aim of this study was to analyse fibrinogen and PAI-1 activity in patients with acromegaly before and after treatment.
Patients: Twenty patients with acromegaly were compared with healthy controls matched for sex (12 men, 8 women), age (mean 53 +/- 7 years), body mass index (mean 26.5 +/- 2.5 kg/m2) and smoking. Fibrinogen was also compared with a random population sample of men and women (n = 392), aged 25-64 years, from the WHO's MONICA Project, Göteborg, Sweden.
Results: The acromegalic patients had a higher lean body mass of 65 +/- 11 vs 59 +/- 11 kg (P < 0.05), lower body fat of 17 +/- 8 vs 25 +/- 10 kg (P < 0.01), higher plasma fibrinogen of 4.0 +/- 0.9 vs 2.4 +/- 0.5 g/l (P < 0.001) and plasma insulin of 15 +/- 14 vs 7 +/- 2 mU/l (P < 0.01), serum triglycerides of 1.5 +/- 0.5 vs 1.2 +/- 0.5 mmol/l (P < 0.05), as well as serum insulin-like growth factor-I (IGF-I) levels of 742 +/- 271 vs 168 +/- 51 micrograms/l (P < 0.001) compared with the matched controls. PAI-1 activity was similar, as was total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting blood glucose and blood pressure for acromegalic patients compared with controls. All the acromegalic patients had higher fibrinogen levels (p < 0.001) than the population mean. Plasma fibrinogen correlated positively with serum IGF-I in acromegaly (r = 0.55, P < 0.05). Fibrinogen decreased to a mean value of 3.2 +/- 0.3 g/l on treatment.
Conclusion: Acromegaly is associated with high fibrinogen levels which may be one explanation for the increased risk of cardiovascular events, and stroke in particular, in this disease. Fibrinogen levels decreased following treatment of acromegaly.