The Effects of Allopurinol on the Carotid Intima-media Thickness in Patients with Type 2 Diabetes and Asymptomatic Hyperuricemia: A Three-year Randomized Parallel-controlled Study

Objective The aim of this study was to investigate the long-term effective control of serum uric acid by allopurinol on the carotid intima-media thickness (IMT) in patients with type 2 diabetes (T2DM) and asymptomatic hyperuricemia (HUA). Methods This was a randomized open parallel-controlled study. In this study, 176 patients with T2DM and asymptomatic HUA were randomly allocated to the conventional or allopurinol treatment groups on the basis of a computer-generated random number table. Changes in the carotid IMT, biochemical indexes, high sensitive C-reactive protein (hs-CRP) and the incidence of hypertension in patients before and after three years of treatment were examined and compared between the groups. Results There were no statistically significant differences in the baseline characteristics of the study participants between the two treatment groups (p>0.05 for all). Nevertheless, the serum uric acid, triglyceride, and hs-CRP levels and the homeostasis assessment for insulin resistance (HOMA-IR), systolic blood pressure, diastolic blood pressure and the carotid IMT in the allopurinol group were significantly lower than those in the conventional group after three years of treatment (p<0.01 for all). The intention-to-treat analysis indicated that the incidence of new-onset hypertension in the allopurinol group showed a declining trend compared to that in the conventional treatment group (6.8% vs. 13.6%, p>0.05). Conclusion The long-term effective control of serum uric acid by allopurinol may improve insulin resistance, decrease the serum levels of hs-CRP, reduce the carotid IMT, and may delay the development of atherosclerosis in patients with T2DM and asymptomatic HUA.