The unrecognized prevalence of chronic kidney disease in diabetes.
BACKGROUND
Diabetes mellitus and chronic kidney disease (CKD) are common and exhibit synergistic associations with premature mortality. Current diabetes guidelines in the UK recommend annual urinary albumin and serum creatinine determinations to screen for diabetic kidney disease. The aim of this study was to estimate the burden of CKD in patients with diabetes and examine the ability of serum creatinine and albuminuria to detect clinically meaningful CKD compared with estimated glomerular filtration rate (eGFR).


METHODS
All adults known to have diabetes in primary and secondary care in Salford, UK, alive with independent renal function on 1 January 2004 were included in this observational study (n=7596). Demographic and laboratory parameters were obtained from the Electronic Patient Record. eGFR was determined using the 4-variable modification of diet in renal disease (MDRD) formula. Clinically meaningful CKD was defined as an eGFR <60 ml/min/1.73 m(2).


RESULTS
Creatinine and albuminuria were measured in the preceding 2 years in 82.3 and 55.2% of subjects, respectively. In patients with CKD, normoalbuminuria was present in 48.8%, and serum creatinine was normal (<or=120 micromol/l) in 54.7%. An abnormal serum creatinine (>or=120 micromol/l) had a sensitivity and specificity of 45.3 and 100%, respectively, to identify CKD. The combination of abnormal creatinine and albuminuria had an improved performance but still failed to detect a large number with CKD (sensitivity 82.4%, specificity 75.4%). Serum creatinine failed to identify CKD more often in females (OR 8.22, CI 6.56-10.29).


CONCLUSIONS
Undiagnosed CKD is common in diabetes. Current screening strategies, based on creatinine or albuminuria, fail to identify a considerable number of subjects with CKD. Incorporating eGFR into screening for CKD would identify individuals earlier in the natural history of the disease and enable early effective treatment to delay progression of CKD.
Middleton
Rachel J
RJ
Department of Renal Medicine, Hope Hospital, Stott Lane, Salford M6 8HD, UK, and Chronic Disease Research Group and University of Minnesota, Minneapolis, USA. Rachel.middleton@srht.nhs.uk
Foley
Robert N
RN
Hegarty
Janet
J
Cheung
Ching M
CM
McElduff
Patrick
P
Gibson
J Martin
JM
Kalra
Philip A
PA
O'Donoghue
Donal J
DJ
New
John P
JP
D000328:Adult; D017677:Age Distribution; D000704:Analysis of Variance; D001786:Blood Glucose / Q000032:analysis; D015331:Cohort Studies; D015897:Comorbidity; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000453:epidemiology*; D003928:Diabetic Nephropathies / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000453:epidemiology*; D007677:Kidney Function Tests; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011336:Probability; D011379:Prognosis; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D006113:United Kingdom / Q000453:epidemiology
D001786:Blood Glucose