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Background and Objectives: Primary gout has traditionally been associated with obesity, arterial hypertension, and abnormal lipid and glucose homeostasis, but we do not know the prevalence of these vascular risk factors in patients with primary gout from a Mediterranean country., Patients and Method: All patients with primary gout and 2 or more acute arthritis episodes documented by a physician were selected for the study. The diagnosis of MS required ≥3 criteria (ATP III). Patients were classified in two groups: decreased (underexcretors) and normal (normoexcretors) uric acid excretion related to serum urate levels., Results: One hundred and four patients (mean age, 59 years; 100 males) with primary gout were included in the study. MS was diagnosed in 38 subjects (37%). The most frequent triad defining MS was an increased waist circumference, blood pressure, and trygliceride levels. The prevalence of type 2 diabetes mellitus (T2D) was significantly higher in patients with the MS (21/38, 55%) as compared with subjects without the MS (3/66, 5%; p<0.001). Mean serum urate level in patients with and without MS was identical (8.1 mg/dL), but mean 24-hour uric acid excretion was significantly lower in the former than in the latter (444±110 mg/24-hour/1,73 m2 versus 546±221 mg/day/1,73 m2; p=0.009)., Conclusions: The condition of the MS occurs in about one-third of the patients with primary gout. Increased waist circumference, blood pressure, and triglycerides levels is the most frequent MS triad. Diminished urinary uric acid excretion is more severe in gout patients with the MS.

The reference range for urinary uric acid excretion has not been precisely defined. Different urinary variables have been proposed to determine the renal contribution to increased or decreased serum urate concentrations. We examined which urinary variable best indicates uric acid excretion over a wide range of serum urate concentrations. Purine metabolism was studied in 10 healthy male subjects (aged 26-58 years) both at their endogenous normal serum urate levels (normouricemic state) and after the oral administration of allopurinol (300 mg/24 h for 5 days) and ribonucleic acid (4 g/8 h for 4 days) to decrease (hypouricemic state) and increase (hyperuricemic state) serum urate concentrations, respectively. The results from patients with several conditions known to affect uric acid synthesis and/or the renal excretion of uric acid were used to validate a constructed nomogram. Over a wide range of mean serum urate levels (from 2.7 to 9.5 mg/dL) and mean 24-hour urinary uric acid excretion (171 to 1368 mg/[24 h 1.73 m(2)]), the highest correlation coefficient between serum urate and uric acid excretion was obtained for the 24-hour uric acid determination (r = 0.928; P < .001). The constructed nomogram allowed the definition of the mechanism underlying hyperuricemia and hypouricemia in patients with a myriad of diseases known to affect purine metabolism. The urinary variable that best correlates with a wide range of serum urate concentrations is 24-hour urinary uric acid excretion. The constructed nomogram allows the identification of the kidney contribution to a given purine metabolic abnormality., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Clinical Case: A 42 year-old male was assessed for a subacute, bilateral and progressive visual loss. His medical history included chronic hepatitis C infection and Evans syndrome. On fundal examination, multiple areas of neurosensorial and retinal pigmented epithelium detachment were observed in the region of both macula. A few days later, his general health deteriorated and he was noted to have a high fever and adenopathy. Biopsy of an enlarged lateral cervical lymph node demonstrated the existence of a diffuse large B cell lymphoma. After several cycles of chemotherapy, he experienced a progressive and bilateral improvement of his vision, which was accompanied by a reattachment of the previously detached areas., Discussion: A bilateral and serous macular detachment may be the initial manifestation of a diffuse large B cell lymphoma. The prognosis of these retinal lesions may be favourable if lymphoma remission is achieved.