P3
SERUM URIC ACID CONCENTRATION IN CKD STAGE 3
Kirk A, Fluck R, McIntyre C, Taal M
Department of Renal Medicine, Royal Derby Hospital
BACKGROUND: Chronic kidney disease (CKD) is an independent risk factor for
cardiovascular (CV) events. Elevated serum uric acid (SUA) has been proposed as a mediator
of this association. Our aim was to investigate factors influencing SUA and associations
between SUA and CV risk factors in people with CKD stage 3.
METHODS: We studied 1741 volunteers with previous eGFR 30-59 mls/min/1.73m2. From
each participant, medical history,
demographics, blood and urine were analysed.
RESULTS: Median age was 74 years. 60.4% of participants were female. Median eGFR was
53.2mls/min/l.73m2. Median SUA was 379 μmol/L with 22.5% having hyperuricaemia.
Univariate analysis identified positive correlations with age, serum phosphate, total protein,
bicarbonate, cholesterol, HDL cholesterol, BMI, waist:hip ratio and pack
years of smoking while an inverse correlation was observed with eGFR. Being male, diabetic,
socially deprived (lowest quintile) or receiving diuretics was associated with a significantly
higher SUA. Allopurinol treatment was associated with lower SUA. Multivariable analysis
identified eGFR, diuretics, male gender, BMI, allopurinol and serum
total protein as independent determinants of SUA (Adjusted R2=0.39). SUA concentration did
not correlate with arterial pulsewave velocity but did with other markers of CV risk including
diastolic blood pressure, skin
autofluorescence, urine albumin:creatinine ratio and high sensitivity CRP. SUA was higher in
those with past history of cardiovascular disease.
CONCLUSIONS: SUA concentration is elevated in a significant proportion of persons with
early CKD and is associated with several potentially modifiable factors. Correlations with
several CV risk factors suggest that SUA may itself be a useful marker of CV risk. This will
be tested during planned long term follow up of the cohort. Further randomized trials are
required to assess the potential benefits of lowering SUA in people with CKD.