Random albumin/creatinine ratio for quantification of proteinuria in manifest pre-eclampsia.
OBJECTIVE
1) To assess the correlation between urine albumin/creatinine ratio (ACR) and 24-hour urine albumin excretion in women with pre-eclampsia, 2) to study the influence of potential confounders on this correlation and 3) to assess the variability of ACR between voids during a 24-hour period.


METHODS
Prospective study.


METHODS
Fetal maternity ward, university hospital.


METHODS
Women with pre-eclampsia scheduled for quantitative albumin measurement with a 24-hour urine collection.


METHODS
Random urine samples were obtained for analysis of ACRs during the time of 24-hour urine collections in 31 women. ACRs were also measured from the complete 24-hour collections. In five additional women, serial urine samples were obtained during the 24-hour collection.


METHODS
Correlation between ACRs and albumin amount in 24-hour urine samples. Variability of the ACRs during a 24-hour collection.


RESULTS
The random ACR was poorly correlated to 24-hour excretion of urine albumin (R(2)= 0.42). Adjustment for maternal age and nifedipine medication significantly (P= 0.044 and P= 0.023, respectively) improved the correlation (R(2)= 0.60). The mean variability (highest/lowest) of ACR during a 24-hour period was 222%. The ACR from the 24-hour collection had an excellent correlation to 24-hour excretion of urine albumin (R(2)= 0.96).


CONCLUSIONS
In women with pre-eclampsia, random ACR is not stable during the day and cannot predict 24-hour urine protein excretion accurately. ACR from the 24-hour collection is an accurate predictor of total albumin amount and can be used to minimise errors from incomplete collections.
Wikström
A-K
AK
Department of Women's and Children's Health, University Hospital, Uppsala, Sweden. anna-karin.wikstrom@kbh.uu.se
Wikström
J
J
Larsson
A
A
Olovsson
M
M
D000419:Albuminuria / Q000175:diagnosis*; D015415:Biomarkers / Q000652:urine; D002940:Circadian Rhythm; D003404:Creatinine / Q000652:urine*; D005260:Female; D006801:Humans; D011225:Pre-Eclampsia / Q000175:diagnosis*; D011247:Pregnancy; D011446:Prospective Studies; D016482:Urinalysis / Q000379:methods
D015415:Biomarkers; D003404:Creatinine