Detecting microalbuminuria by urinary albumin/creatinine concentration ratio.
BACKGROUND
Microalbuminuria, i.e. a subclinical increase of the albumin excretion rate in urine, may be a novel atherosclerotic risk factor. This study aimed to test whether microalbuminuria can be identified by measurement of urinary albumin concentration or urinary albumin/creatinine concentration ratio, instead of the usual measurement of the albumin excretion rate in a timed urine collection.


METHODS
All 2579 subjects analysed were screened in a population based epidemiological study. Participants with diabetes mellitus, renal disease, haematuria, or urinary tract infection were not included. Urinary albumin (Ualb) and creatinine (Ucreat) concentrations were measured in an overnight collected sample by enzyme-linked immunosorbent and colorimetric assays, respectively. Urinary albumin excretion rate (UAER) and urinary albumin/creatinine concentration ratio (Ualb/Ucreat) were calculated.


RESULTS
The correlation between Ualb and UAER was 0.72 (n = 2579, P < 0.001), and the correlation between Ualb/Ucreat and UAER was 0.81 (n = 2579, P < 0.001). In the detection of microalbuminuria, the nosographic sensitivity and specificity, and the diagnostic specificity were 58%, 97%, and 66% for Ualb, and 73%, 97%, and 73% for Ualb/Ucreat, respectively.


CONCLUSIONS
It is concluded that measurement of the albumin/creatinine concentration ratio is a specific and quite sensitive alternative to measurement of the urinary albumin excretion rate in timed collections, when screening for microalbuminuria.
Jensen
J S
JS
Department of Medicine P., Rigshospitalet, University of Copenhagen, Denmark.
Clausen
P
P
Borch-Johnsen
K
K
Jensen
G
G
Feldt-Rasmussen
B
B
D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000517:prevention & control*; D003404:Creatinine / Q000652:urine*; D005240:Feasibility Studies; D006801:Humans; D006973:Hypertension / Q000652:urine; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009994:Osmolar Concentration; D012680:Sensitivity and Specificity
D003404:Creatinine