Osteoprotegerin linked to VTE
MedWire News: Serum osteoprotegerin (OPG) may be involved in the development of thrombotic events, say researchers who found that levels of the protein are raised in patients with a history of venous thromboembolism (VTE).
Previous studies have shown a high prevalence of atherosclerotic disease and an increased risk for arterial events in patients with a history of unprovoked VTE.
"However, mechanisms underlying the association between arterial and venous disease are far from being clarified," say Marcello Rattazzi (University of Padova, Italy) and colleagues.
The OPG/receptor activator of nuclear factor-kappa B/RANK ligand axis - which plays an essential role in bone remodeling - has recently been implicated in vascular disease progression. In particular, OPG emerged both as an inhibitor of vascular calcification and a potent predictor of atherosclerotic disease.
To investigate the clinical connection between OPG and VTE, Rattazzi and team retrospectively evaluated OPG levels in 110 patients with objectively diagnosed VTE (deep vein thrombosis and/or pulmonary embolism) and in 110 age- and gender-matched controls with no history of VTE.
The researchers report in the Journal of Thrombosis and Haemostasis that VTE patients and controls had similar lipid profiles, blood pressure, glomerular filtration rates, blood glucose levels, and numbers of smokers, but VTE patients had a significantly greater mean body mass index (BMI; 26.8 vs 25.4 kg/m2) and a significantly higher mean serum OPG level (1100 vs 800 pg/mL) than controls.
Multivariate logistic regression analysis adjusted for age, gender, arterial hypertension, diabetes, hyperlipidemia, current smoking, and C-reactive protein, showed that only BMI and serum OPG levels were significantly associated with VTE.
The likelihood for VTE increased significantly with increasing OPG levels, such that patients in the highest tertile of OPG were 10 times more likely to have had VTE than those in the lowest tertile.
However, the retrospective nature of the study did not allow the researchers to identify a precise role for OPG during thrombogenesis, they remark
They speculate that "the increased OPG levels observed in patients with VTE might be indicative of a 'chronic,' latent insult of the venous system, which would represent the soil for thrombotic events."
"Alternatively OPG could be considered as an active mediator of the thrombotic process," they suggest.
Rattazzi and co-authors accept that the retrospective study design is a limitation. "Nevertheless, the significant difference in OPG levels observed between cases and controls should offer the opportunity to design further investigations aimed at clarifying its possible pathogenetic role and clinical utility in VTE," they conclude.
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By Laura Cowen