Effects of Uric Acid Lowering Therapy in Patients With Essential Arterial Hypertension

Abstract

Background Asymptomatic hyperuricemia (AHU) is defined as elevated serum uric acid (UA) concentration without symptoms. This study aimed to determine the effects of AHU treatment with allopurinol on selected hypertension mediated organ damage (HMOD) indices in patients with uncomplicated essential arterial hypertension (AH). MethodsPatients aged 30-70 years with AHU and essential hypertension grade 1-2 with adequate blood pressure (BP) control, without previous urate lowering therapy (ULT) were divided into two groups: a) receiving allopurinol (ULT group) and b) age-and sex matched patients without ULT (control group). Both groups received UA-lowering diet. BP (office, 24 hour and central), echocardiographic parameters, pulse-wave velocity, carotid intima-media thickness (IMT) and lab tests (high-sensitivity C-reactive protein (hs-CRP) were measured at baseline and at 6 months follow-up.ResultsOut of 100 participants 87 completed the study (44 ULT patients and 43 controls). At 6 months follow-up, there was a significantly greater reduction in serum UA concentration in the ULT group than in the control group (464±68.8 µmol/l vs 314±55.6 µmol/l, p<0.0001). Patients receiving allopurinol had significant reductions in office systolic (137±11.8 mmHg vs 134±9.3 mmHg; p=0.025) and diastolic BP (83±9.9 mmHg vs 79±8.7 mmHg, p=0.017), central systolic BP (56±8.9 mmHg vs 51±12.9 mmHg, p=0.046), pulse pressure (43±10.4 mmHg vs 39±11.2 mmHg, p=0.017), IMT (0.773±0.121 mm vs 0.752±0.13 mm, p=0.044), left atrium volume index (40±13.5 ml/m2 vs 38±12.3 ml/m2, p=0.044), and hs-CRP level (3.36±2.73 mg/l vs 2.74±1.91 mg/l, p=0.028) compared to controls. The decrease in UA concentration was significantly related to the reduction in IMT (R=0.37, p<0.001), central SBP (R=0.26, p=0.015) and hs-CRP concentration (R=0.30, p=0.004). Multivariate regression analysis revealed the independent relationship between reduction in IMT and UA lowering (R=0.3234, R2=0.0722, p<0.026).ConclusionsIn patients with AH and asymptomatic hyperuricemia treatment with allopurinol leads to further improvement in BP control and reduction in HMOD intensity, in particular IMT. The decrease in hs-CRP concentration associated with ULT may have a beneficial effect on patient long-term prognosis.