Clinical utility of trace proteinuria for microalbuminuria screening in the general population

Clin Exp Nephrol. 2007 Mar;11(1):51-5. doi: 10.1007/s10157-006-0458-z. Epub 2007 Mar 28.


Background: The urine dipstick test that regards > 1+ proteinuria as positive is unsuitable for microalbuminuria screening owing to its low sensitivity in the general population. We conducted a cross-sectional survey to examine whether trace proteinuria could be an indicator of microalbuminuria.

Methods: The subjects were 2321 participants in a community-based health check-up in Takahata, Japan. Dipstick tests for proteinuria and the urine albumin-creatinine ratio (UACR) measurement were performed with single-spot urine specimens collected early in the morning. The results of the dipstick tests were recorded as (-), trace, (1+), (2+), and (3+). Micro- and macroalbuminuria were defined as UACR 30-300 mg/g and > 300 mg/g, respectively.

Results: Overall, the prevalence and median UACR levels of urine protein (-), trace, (1+), (2+), and (3+) were 92.0% (8.8 mg/g), 3.5% (43 mg/g), 2.6% (81 mg/g), 1.4% (315 mg/g), and 0.5% (1073 mg/g), respectively. Within the trace proteinuria category, the prevalence of microalbuminuria in all subjects, men, subjects >or=60 years, diabetic subjects, and hypertensive subjects was 59.3%, 73.8%, 71.2%, 88.9%, and 68.0%, respectively. By regarding trace proteinuria as positive, the sensitivity of the urine protein dipstick test for micro- and macroalbuminuria was improved (from 23.3% to 37.1%), while its specificity was not significantly changed (from 98.9% to 97.3%).

Conclusion: Trace proteinuria could be a useful indicator of microalbuminuria in the general population, and especially in subjects at high risk of cardiovascular disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Albuminuria / diagnosis*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Reagent Strips
  • Urinalysis


  • Reagent Strips