Body size measures, hemostatic and inflammatory markers and risk of venous thrombosis: The Longitudinal Investigation of Thromboembolism Etiology.
OBJECTIVE
Obesity is an important venous thrombosis (VT) risk factor but the reasons for this are unclear.


METHODS
In a cohort of 20,914 individuals aged 45 and older without prior VT, we calculated the relative risk (RR) of VT over 12.6years follow-up according to baseline body size measures, and studied whether associations were mediated by biomarkers of hemostasis and inflammation that are related to adiposity.


RESULTS
Greater levels of all body size measures (weight, height, waist, hip circumference, calf circumference, body-mass index, waist-hip ratio, fat mass and fat-free mass) were associated with increased risk of VT, with 4th versus 1st quartile RRs of 1.5-3.0. There were no multiplicative interactions of biomarkers with obesity status. Adjustment for biomarkers associated with VT risk and body size (factors VII and VIII, von Willebrand factor, partial thromboplastin time, D-dimer, C-reactive protein and factor XI) only marginally lowered, or did not impact, the RRs associated with body size measures.


CONCLUSIONS
Greater body size, by multiple measures, is a risk factor for VT. Associations were not mediated by circulating levels of studied biomarkers suggesting that body size relates to VT because of physical factors associated with blood flow, not the hypercoagulability or inflammation associated with adiposity.
University of Vermont, United States. Electronic address: mary.cushman@uvm.edu.
Mary
M
Cushman
Group Health Research Institute, United States.
Ellen S
ES
O'Meara
University of Washington, United States.
Susan R
SR
Heckbert
University of Vermont, United States.
Neil A
NA
Zakai
University of North Carolina, Chapel Hill, United States.
Wayne
W
Rosamond
University of Minnesota, United States.
Aaron R
AR
Folsom
D000368:Aged; D015415:Biomarkers / Q000097:blood; D049628:Body Size; D002097:C-Reactive Protein / Q000032:analysis; D015331:Cohort Studies; D005167:Factor VII / Q000032:analysis; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005500:Follow-Up Studies; D006487:Hemostasis; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000150:complications*; D012307:Risk Factors; D020246:Venous Thrombosis / Q000097:blood / Q000209:etiology*; D049629:Waist-Hip Ratio; D014841:von Willebrand Factor / Q000032:analysis
D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D014841:von Willebrand Factor; D005167:Factor VII; D002097:C-Reactive Protein
Blood coagulation; Inflammation; Obesity; Risk factor; Venous thrombosis