A Cross-Sectional Study on the Use of Urinalysis for Screening Early-Stage Renal Insufficiency

Proteinuria and hematuria detected by routine urinalysis can indicate impaired renal function. This study evaluated the effect of routine urinalysis in screening out patients with estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2 at an early stage and investigated its associated factors.

Healthy adults who underwent physical examination between September 2008 and September 2013 were enrolled in the study (n = 43,516). Urine was analyzed for protein, and red and white blood cells. Ten milliliter blood samples were collected for serum creatinine, urea, albumin and other parameters for the estimation of eGFR and renal function.

Abnormal routine urinalysis was found in 7.1% and eGFR <60 ml/min/1.73 m2 was found in 0.9% of subjects. Age and gender were similar in the overall and abnormal urinalysis populations (43 vs. 43 years and 36.7 vs. 38.2% females, respectively), but the eGFR <60 ml/min/1.73 m2 group were older (64 years, p < 0.001) with increased females (46.4%, p = 0.002). Sensitivity for predicting eGFR <60 ml/min/1.73 m2 was 0.110 and specificity was 0.928. Univariate and multivariate analyses in 6,318 subjects with more detailed clinical data suggested significant associations of sex (OR 0.058, 95% CI 0.030-0.113), age (OR 1.045, 95% CI 1.027-1.064), and high density lipoprotein (HDL) (OR 0.158, 95% CI 0.043-0.587) with eGFR <60 ml/min/1.73 m2.

Routine urinalysis showed a poor performance in the screening for early-stage renal insufficiency. In future, other screening methods should be considered. Age, gender and HDL were associated with eGFR <60 ml/min/1.73 m2.