SERUM URIC-ACID AND RELATED FACTORS IN 500 HOSPITALIZED SUBJECTS

The study purpose was to determine the following in a large sample of hospitalized patients: (1) the prevalence of hyperuricemia, (2) the as sociation of hyperuricemia with other metabolic disorders, and (3) the factors independently predicting hyperuricemia. Five hundred adult pa tients (250 men and 250 women) were randomly selected from those admit ted as inpatients over a period of 5 months. In all patients, body mas s index (BMI), blood pressure, and serum glucose, lipid, creatinine, u rea nitrogen, and urate concentrations were measured. The presence of diseases or use of medications known to affect serum urate levels were recorded. The mean level of serum urate was 5.6 mg/dL in the whole sa mple, 6.0 mg/dL in men and 5.3 mg/dL in women (P = .003, men v women). The prevalence of hyperuricemia was 27.6% (28.8% and 26.4% in men v w omen, P = nonsignificant). A definite or probable secondary hyperurice mia was found in 87.7% of the subjects. Hyperuricemia was rarely isola ted (21%), whereas it was frequently associated with hypertension (60. 1%), hyperlipidemia (31.2%), diabetes (28.3%), and obesity (21.7%). In 26.8% of the subjects, hyperuricemia was associated with two metaboli c disorders, in 13.8% with three, and in 2.9% with four. Multiple meta bolic disorders (three to four) were found in 16.7% of subjects with h yperuricemia. Serum urate levels progressively increased across a rang e of subjects from those without diabetes, hyperlipidemia, hypertensio n, or obesity to those with one, two, or a greater number of associate d metabolic abnormalities. Multiple stepwise regression analysis showe d that 43% of serum urate variability was explained by urea nitrogen l evels, triglyceride levels, diuretic therapy, the inverse of creatinin e (as an index linearly related to creatinine clearance), and BMI. The se results indicate that in hospitalized subjects, hyperuricemia is (1 ) frequent, (2) a secondary phenomenon in most cases, and (3) frequent ly associated with other metabolic disorders. The major predictors of high serum urate levels are BMI, triglycerides, parameters of renal fu nction, and use of diuretics. These variables explain a large proporti on of serum urate variability. Copyright (C) 1996 by W.B. Saunders Com pany