[Study on the independent association of uric acid levels with peripheral arterial disease in Chinese patients with coronary heart disease].

OBJECTIVE: To evaluate the relationship between uric acid (UA) and peripheral arterial disease (PAD) in Chinese patients with coronary heart disease (CHD).

METHODS: UA levels and PAD were evaluated in 3251 Chinese hospitalized patients with CHD (age > or = 50 years). PAD was diagnosed when the ankle-brachial index was < 0.9 but patients with an ankle-brachial index of > 1.4 were excluded because of false negative rate. Potential confounding variables with P < 0.10 were adjusted for multivariate analysis.

RESULTS: In univariate analysis, UA levels were higher in patients with PAD than in those without PAD (349.80 micromol/L +/- 128.45 micromol/L vs. 323.00 micromol/L +/- 110.72 micromol/L, P < 0.001). Rate of hyperuricemia in patients with PAD and without PAD were 31.62% and 22.48% (P < 0.001) respectively. Prevalence rates of PAD for quintiles of UA level were 23.2%, 27.4%, 36.1%, 43.2% and 72.7%, respectively (P-trend < 0.05). With UA level as a continuous variable, the multivariate-adjusted odds ratio for PAD was 1.002 (95% confidence interval: 1.001 - 1.002) (P < 0.001). The optimal cut-off point for UA as determined by the receiver operating characteristic curve, was 227.2 micromol/L. The sensitivity and specificity at this cut-off point were 84.6% and 20.3%, respectively. The area under curve was 0.521 (95% confidence interval: 0.504 - 0.547) and the multivariate-adjusted odds ratio for PAD for UA above this level was 1.292 (95% confidence interval: 1.047 - 1.596) (P < 0.01). The results, however, after exclusion those cases who used diuretics, were similar.

CONCLUSION: Elevated uric acid level seemed a significant and independent risk factor for PAD in Chinese hospitalized patients with CHD (age > or = 50 years).