P153
REPEAT TESTING SIGNIFICANTLY REDUCES THE ESTIMATED PREVALENCE
OF CHRONIC KIDNEY DISEASE AND IDENTIFIES A POPULATION WITH
INCREASED CARDIOVASCULAR RISK
Brook, M1, Bottomley, M1, Mevada, C2, Kalachik, A3, James, T2, Harden, P1
1
Oxford Kidney Unit, Churchill Hospital, Oxford, 2Department of Biochemistry, John
Radcliffe Hospital, Oxford, 3National Centre for Nephrology, 4th City Hospital, Minsk,
Belarus
INTRODUCTION: Chronic kidney disease (CKD) is a global healthcare problem with a
worldwide prevalence estimated to be in the region of 4-12%. Furthermore, individuals with
CKD are known to be at increased risk of cardiovascular morbidity and mortality. Many studies
estimating CKD prevalence have been based on measurements at a single point in time. In
contrast, the National Kidney Foundation Kidney Disease Outcomes Quality Initiative
(KDOQI) guidelines state that abnormal findings should persist for at least 3 months. In this
study we sought to establish the prevalence of CKD and determine cardiovascular risk amongst
the population of Belarus. Furthermore, we aimed to investigate the impact of repeat testing
after 3 months on such outcomes.
METHODS: 512 participants were recruited from a presumed healthy population of factory
workers in Minsk, Belarus. Blood pressure was measured and a questionnaire completed
addressing health issues, lifestyle and medications. Blood and urine samples were used to
determine eGFR, serum total and HDL cholesterol and urinary albumin:creatinine ratio. 142
workers with an initial analysis indicating CKD or eGFR within 1 standard deviation of
abnormal consented to repeat urine and blood analysis 3 months later. 10-year general
cardiovascular disease risk was calculated according to criteria determined by the Framingham
Study.
RESULTS: Of 512 recruits, 42 participants were initially given a provisional diagnosis of CKD
giving a point prevalence of 8.2%. On repeat testing, 21 of these participants (50%) provided
normal results reducing the estimated prevalence of CKD to 4.1%. Such findings were
consistent across CKD stages 1-3. Analysis of cardiovascular risk amongst the 142 participants
who underwent repeat testing revealed a mean risk of 11.9% for development of general
cardiovascular disease within the next 10 years. No increase in cardiovascular risk was seen
amongst those whose initial test alone indicated CKD. However, identification of those patients
with a diagnosis of CKD based on repeat abnormalities at 3 months identified a population
whose 10 year general cardiovascular risk is significantly elevated to 16.5% (p<0.05). Further
analysis of this population revealed a significantly increased mean score for hypertension (3 vs
1.96, p<0.05).
CONCLUSIONS: In this study we established a prevalence of chronic kidney disease of
4.1% amongst the working population of Belarus and identified a particularly high level
of general cardiovascular risk amongst the population. Moreover, we demonstrated that
repeated testing for CKD significantly reduced the estimated prevalence of disease and
revealed a population with an increased risk of developing cardiovascular disease within
10 years likely related to hypertension. These results demonstrate the importance of
repeated testing before making a formal diagnosis of CKD. Such measures result in a
reliable diagnosis but also allow identification of patients who require a thorough
assessment and aggressive management of cardiovascular risk factors.