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Updated: Dec 25, 2025
Experimental and Imaging Techniques for Examining Fibrin Clot Structures in Normal and Diseased States
Published on: April 1, 2015
Prothrombotic fibrin network characteristics in patients with acromegaly: a novel mechanism for vascular
Nikolaos Kyriakakis1,2, Nikoletta Pechlivani2, Julie Lynch1
1Department of Endocrinology, Leeds Centre for Diabetes and Endocrinology, St James's University Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, UK.
Insights
Patients with active acromegaly exhibit denser blood clots, increasing their risk of thrombosis. This suggests that prothrombotic fibrin networks contribute to the heightened vascular risk in acromegaly.
Area of Science:
- Endocrinology
- Cardiovascular Medicine
- Hematology
Background:
- Acromegaly, a condition of GH/IGF-1 excess, is linked to increased cardiovascular mortality.
- The underlying mechanisms, particularly concerning vascular disease, require further elucidation.
Purpose of the Study:
- To investigate whether GH/IGF-1 excess adversely affects fibrin network characteristics, thereby increasing vascular disease risk.
- To compare fibrin network properties in patients with active acromegaly versus those in remission and healthy controls.
Main Methods:
- Cross-sectional study involving 40 acromegaly patients and 40 matched controls.
- Analysis of clot structure using turbidimetric assay and laser scanning confocal microscopy (LSCM).
- Assessment of metabolic profile, body composition, fibrinogen, and PAI-1 levels.
Main Results:
- Active acromegaly patients displayed higher fibrinogen levels and clot absorbance compared to controls, even after adjusting for BMI.
- Laser scanning confocal microscopy revealed increased fibrin network density specifically in patients with active acromegaly.
- Higher BMI, fat mass, and skinfold thickness correlated with increased clot density and prolonged lysis time.
Conclusions:
- Active acromegaly is associated with more compact blood clots, indicating an elevated thrombosis risk.
- Prothrombotic fibrin networks represent a potential mechanism contributing to the increased vascular risk observed in active acromegaly.
Objective:
There remains increased cardiovascular mortality in patients with acromegaly. This study aims to evaluate whether GH/IGF-1 excess increases vascular disease by adversely affecting fibrin network characteristics.
Design:
Cross-sectional study in 40 patients with acromegaly (21 males, age 53 ± 13 years) and 40 age/gender-matched controls.
Methods:
Clot structure was analysed using a validated turbidimetric assay and fibrin networks were visualised by laser scanning confocal microscopy (LSCM). Metabolic profile parameters, body composition, plasma fibrinogen and PAI-1 were also assessed.
Results:
Twenty-two patients had active acromegaly and 18 were in remission. There was no difference in qualitative patient characteristics between the two groups. Both groups had less favourable body composition and cardiovascular risk profile compared with controls. Despite no difference in clot formation and lysis parameters between the two patient groups, active disease patients had higher fibrinogen and clot maximum absorbance compared with controls, after adjusting for BMI (3.8 ± 0.2 vs 2.6 ± 0.2 mg/mL, P < 0.001; and 0.39 ± 0.02 vs 0.33 ± 0.01 arbitrary units, P = 0.03, respectively). Patients in remission had higher fibrinogen compared with controls following adjustment for BMI (3.3 ± 0.2 vs 2.6 ± 0.2 mg/mL, P = 0.02) but not clot maximum absorbance (0.35 ± 0.03 vs 0.33 ± 0.02 arbitrary units, P = 0.6). LSCM showed increased fibrin network density only in active disease patients, consistent with turbidimetric analysis. In addition to active disease, BMI, fat mass and skinfold thickness were associated with higher clot density and longer lysis time.
Conclusions:
Patients with active acromegaly have more compact clots, thus conferring increased thrombosis risk. Prothrombotic fibrin networks may represent one mechanism for enhanced vascular risk in active acromegaly.
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