Effects of pharmacological reversal of hyperuricemia on features of the metabolic syndrome in patients with gouty arthritis.

Hyperuricemia has been associated in epidemiological studies with the development of obesity, hypertension, insulin resistance and type 2 diabetes. Nevertheless, it remains unclear whether lowering of serum uric acid (UA) alters any of the features of the metabolic syndrome. In this prospective study (ClinicalTrials.gov identifier: NCT01654276), 24 patients with gouty arthritis and hyperuricemia were treated for 6 months with the xanthine oxidase inhibitor febuxostat to lower serum UA to <6 mg/dL. Measurements of 24 hours ambulatory blood pressure (ABP) and serum and urine markers of the metabolic syndrome were measured at baseline and at the end of 6 months of febuxostat. The study population consisted of 18 men and 6 women, 18 of which completed the baseline and 6 months visits. Serum UA decreased significantly from 8.7±1.5 mg/dL at baseline to 4.4±1.1 mg/dL at 6 months (P<0.0001). During that time frame, there was no significant change in body mass index, systolic or diastolic blood pressure measured by 24 hours ABP monitor, serum glucose, insulin or homeostatic model assessment for insulin resistance, serum total and high-density lipoprotein-cholesterol, serum triglycerides or urine pH (P>0.05 for all). There was no correlation between parameters of the metabolic syndrome and the decline in serum UA or serum UA achieved at study end. In conclusion, in patients with gouty arthritis, UA lowering with febuxostat below 6 mg/dL had no significant impact on features of the metabolic syndrome.