Incidence of isolated dipstick hematuria and its association with the glomerular filtration rate: a cross-sectional study from the Korean National Health and Nutrition Examination Survey V (2010-2012)

Abstract

Purpose: To investigate the incidence of isolated hematuria and its relationship to the glomerular filtration rate (GFR).

Methods: Data from the Korean National Health and Nutrition Examination Survey V were used. A stratified, three-stage, clustered probability design was used to collect representative data on the Korean population. Ultimately, 18,587 participants were included. The incidence of isolated dipstick hematuria and its relationship with the GFR (estimated by the Chronic Kidney Disease Epidemiology Collaboration equation) were evaluated.

Results: The analysis showed that 31.8% of the population had isolated hematuria, the incidence of which significantly increased with age (P trend < 0.001). As the severity of hematuria increased, the ratio of GFR < 60 ml/min/1.73 m(2) and 60 ml/min/1.73 m(2) ≤ GFR < 90 ml/min/1.73 m(2) was significantly increased (P trend < 0.001). After adjusting for the confounders, the mean GFR of the grade 3+ (grades 3, 4, 5) hematuria group was significantly reduced compared to that of the negative, grade 1, and grade 2 hematuria groups (with an adjusted mean ± standard error of 94.0 ± 0.8 vs. 97.2 ± 0.3 ml/min/1.73 m(2), P < 0.001). Additionally, the odds ratio of the grade 3+ hematuria group for a GFR < 60 ml/min/1.73 m(2) was significantly increased compared to that of the negative, grade 1, and grade 2 hematuria groups after adjusting for the confounders (adjusted odds ratio 1.468, 95% confidence interval 1.049-2.054, P = 0.025).

Conclusion: An effective health policy for hematuria screening is needed for older age groups. A strategy of careful checkups and counseling regarding renal function is necessary for patients with isolated hematuria.

Keywords: Glomerular filtration rate; Hematuria; Incidence.