HMG-CoA reductase inhibitors, other lipid-lowering medication, antiplatelet therapy, and the risk of venous thrombosis.
BACKGROUND
Statins [3-hydroxymethyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors] and antiplatelet therapy reduce the risk of atherosclerotic disease. Besides a reduction of lipid levels, statins might also have antithrombotic and anti-inflammatory properties, and anti-platelet therapy reduces clot formation. We have studied the risk of venous thrombosis with use of statins, other lipid-lowering medication, and antiplatelet therapy.


METHODS
Patients with a first episode of deep vein thrombosis in the leg or pulmonary embolism between March 1999 and September 2004 were included in a large population-based case-control study (MEGA study). Control subjects were partners of patients (53%) or recruited via a random-digit-dialing method (47%). Participants reported different all-medication use in a questionnaire.


RESULTS
Of 4538 patients, 154 used statins (3.3%), as did 354 of 5914 control subjects (5.7%). The use of statins [odds ratio (OR) 0.45; 95% confidence interval (CI) 0.36-0.56] but not other lipid-lowering medications (OR 1.22; 95% CI 0.62-2.43), was associated with a reduced venous thrombosis risk as compared with individuals who did not use any lipid-lowering medication, after adjustment for age, sex, body mass index, atherosclerotic disease, antiplatelet therapy and use of vitamin K antagonists. Different types and various durations of statin therapy were all associated with a decreased venous thrombosis risk. Antiplatelet therapy also reduced venous thrombosis risk (OR 0.56; 95% CI 0.42-0.74). However, sensitivity analyses suggested that this effect is most likely explained by a so-called 'healthy user effect'. Simultaneous use of medication most strongly reduced venous thrombosis risk.


CONCLUSIONS
These results suggest that the use of various types of statins is associated with a reduced risk of venous thrombosis, whereas antiplatelet therapy and other lipid-lowering medications are not.
Ramcharan
A S
AS
Department of Clinical Epidemiology, Leiden University Medical Centre, the Netherlands.
Van Stralen
K J
KJ
Snoep
J D
JD
Mantel-Teeuwisse
A K
AK
Rosendaal
F R
FR
Doggen
C J M
CJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D000960:Hypolipidemic Agents / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D012306:Risk; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D020246:Venous Thrombosis / Q000188:drug therapy* / Q000453:epidemiology; D014812:Vitamin K / Q000037:antagonists & inhibitors; D055815:Young Adult
D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D000960:Hypolipidemic Agents; D010975:Platelet Aggregation Inhibitors; D014812:Vitamin K