Serum urate predicts long-term risk of acute coronary events in women after a transient ischaemic attack and stroke.
BACKGROUND
Several studies have shown serum urate to be an independent risk factor for vascular disease, but others have not, although a stronger association in women than in men has been a consistent finding. Studies of stroke patients have shown possible associations between urate level and stroke severity, but there have been no large cohort studies of the effect of urate on the long-term risk of future vascular events in patients with a transient ischaemic attack (TIA) or stroke. We studied this relationship in 2 independent cohorts.


METHODS
Individual data on 15,483 patient-years of follow-up from the UK-TIA trial (13,182 patient-years) and the Oxford TIA study (2,301 patient-years) were analyzed. Hazard ratios (per unit increase of baseline urate in mg/dl) for the risks of stroke and acute coronary events (ACE) were obtained from Cox models stratified by study, with and without adjustment for potential confounders. Potential interactions between urate and baseline characteristics were also assessed.


RESULTS
Linear associations between urate and risk of ACE were found in both studies: pooled age- and sex-adjusted hazard ratio = 1.17, 95% CI 1.06-1.30, per unit increase of urate (p = 0.003). Sex, body mass index and previous myocardial infarction or angina were effect modifiers, but only the effect of sex remained after adjustment for other risk factors (p = 0.002), with a 5th:1st quintile hazard ratio of 4.23 (1.97-9.07, p < 0.0001) in women and 1.09 (0.70-1.71, p = 0.69) in men. These findings were consistent across the 2 studies. No associations were found between urate level and either risk or severity of stroke.


CONCLUSIONS
High urate levels were independent predictors of long-term risk of ACE in women who had a TIA or stroke, but not in men, in 2 independent studies. Urate levels could be useful in identifying women at high risk of coronary events in routine practice.
Koton
Silvia
S
Stanley Steyer School of Health Professions, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
Howard
Sally C
SC
Warlow
Charles P
CP
Murphy
Michael F G
MF
Rothwell
Peter M
PM
D000208:Acute Disease; D000368:Aged; D001241:Aspirin / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D003327:Coronary Disease / Q000097:blood / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D020521:Stroke / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D013997:Time Factors; D006113:United Kingdom; D015854:Up-Regulation; D014527:Uric Acid / Q000097:blood*
D015415:Biomarkers; D010975:Platelet Aggregation Inhibitors; D014527:Uric Acid; D001241:Aspirin