Microscopic hematuria is a risk factor of incident chronic kidney disease in the Korean general population: a community-based prospective cohort study

Prevalence and associated factors for asymptomatic microscopic hematuria in adults in the PERSIAN Guilan cohort study (PGCS)

Although hematuria is not life-threatening, some could be the result of a more severe condition. Our objectives are to report on the prevalence and risk factors of asymptomatic microscopic hematuria (AMH) in the prospective epidemiological research studies of the Iranian adults (PERSIAN) Guilan cohort study (PGCS) population. This cross-sectional study was conducted from 2014 to 2017 and consisted of 10,520 individuals aged 35-70. Data collection was conducted using a questionnaire during a face-to-face interview. The urine analyses (UA) were done up to 2 h after sample collection. Based on a urine microscopy evaluation, AMH is defined as 3 or more red blood cells per high power field (HPF). Simple and multiple logistic regression analysis was conducted to explore factors associated with AMH. The prevalence of AMH in this study was 34.1% and was more prevalent in participants of older ages and female gender as well as those with low educational level, underweight-body mass index (BMI), high physical activity, smoking, alcohol consumption, and kidney stone disease. On the other hand, obesity, opium, and diabetes decreased the likelihood of AMH. The results of the present study shed light on the prevalence and risk factors of AMH and suggested that a significant portion of the study population is affected by AMH. Considering the lack of consensus on a definite clinical guideline for AMH in our country, the results of the present study could be used to design a unit algorithm for screening and therapy of AMH.

Synergistic effect of proteinuria on dipstick hematuria-related decline in kidney function: The Japan Specific Health Checkups (J-SHC) Study

BACKGROUND

The effect of isolated hematuria without proteinuria on kidney function decline, and the modification by the severity of proteinuria in general population are not fully elucidated.

METHODS

Participants were included in the Japan Specific Health Checkups Study between 2008 and 2014. The exposure of interest was the frequency of dipstick hematuria during the observation. In each proteinuria frequency category (non-, occasional, persistent), hematuria-related decline in the eGFR rate was examined by analysis of covariance (ANCOVA). eGFR decline trajectories were also assessed using mixed-effects models.

RESULTS

Among the 552,951 participants, 146,753 (26.5%) had hematuria, and 56,021 (10.1%) and 8,061 (1.5%) had occasional and persistent proteinuria, respectively. During the median follow-up of 3.0 years, annual change in eGFR decline in participants with hematuria was significantly faster than in those without hematuria (mean [95% confidence interval]: - 0.95 [- 0.98 to - 0.92] vs - 0.86 [- 0.87 to - 0.84] mL/min/1.73 m2/year; P < 0.001). In ANCOVA, the hematuria-related annual eGFR decline rate increased as proteinuria frequency categories increased (differences in annual eGFR decline rate between participants with and without hematuria: 0.08 [0.06 to 0.09] in participants with non-proteinuria category, 0.17 [0.15 to 0.18] in occasional proteinuria category, and 0.68 [0.65 to 0.71] mL/min/1.73 m2/year in persistent proteinuria category; P for interaction < 0.001). Similar results were obtained by the linear mixed-effect model.

CONCLUSIONS

Proteinuria has a synergistic effect on dipstick hematuria-related decline in kidney function. Among the general population without proteinuria throughout the observational period, the "isolated hematuria"-related eGFR decline was statistically significant but the difference was small.

Risk of CKD Following Detection of Microscopic Hematuria: A Retrospective Cohort Study

RATIONALE & OBJECTIVE

Microscopic hematuria is an uncertain risk factor for chronic kidney disease (CKD). We investigated the association between persistent or single episodes of microscopic hematuria and the development of incident CKD, overall and separately among men and women.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

A total of 232,220 Korean adults without CKD at baseline who underwent repeated regular health examinations at Kangbuk Samsung Health Study formed the study cohort.

EXPOSURE

Microscopic hematuria was defined by≥5 red blood cells per high-power field. Participants were categorized into 1 of 4 groups according to the presence of hematuria at 2 consecutive examinations: (1) no hematuria at both examinations (reference group); (2) hematuria followed by no hematuria (regressed hematuria group); (3) no hematuria followed by hematuria (developed hematuria group); and (4) hematuria at both examinations (persistent hematuria group).

OUTCOME

CKD was defined as an estimated glomerular filtration rate<60mL/min/1.73m² or proteinuria (1+or more on dipstick examination).

ANALYTICAL APPROACH

Semiparametric proportional hazards models were used to estimate hazard ratios.

RESULTS

During a 4.8-year median follow-up period, 2,392 participants developed CKD. Multivariable-adjusted hazard ratios for incident CKD, comparing the regressed, developed, and persistent hematuria groups to the no-hematuria group were 1.85 (95% CI, 1.35-2.53), 3.18 (95% CI, 2.54-3.98), and 5.23 (95% CI, 4.15-6.59), respectively. The association between persistent hematuria and incident CKD was stronger in men than women (P for interaction<0.001), although a statistically significant association was observed in both sexes.

LIMITATIONS

Lack of albuminuria and inability to consider specific glomerular diseases.

CONCLUSIONS

Men and women with microscopic hematuria, especially persistent hematuria, may be at increased risk of CKD.

Association of microscopic hematuria with long-term mortality in patients with hypertensive crisis

BACKGROUND

Microscopic hematuria is associated with increased risk of developing chronic kidney function impairment and even death. However, data on the long-term mortality risk associated with microscopic hematuria among patients with hypertensive crisis are scarce. We hypothesized that microscopic hematuria at initial presentation in patients with hypertensive crisis would be associated with increased long-term mortality.

METHODS

This retrospective study included patients admitted to the emergency department between 2016 and 2019 for hypertensive crisis (systolic blood pressure ≥ 180 mmHg or diastolic blood pressure ≥ 110 mmHg). Microscopic hematuria was defined as ≥ 3 red blood cells per high-power field on microscopic evaluation of urine.

RESULTS

Among 3595 patients, 1359 (37.8%) had microscopic hematuria. The 3-year all-cause mortality in patients with and without microscopic hematuria was 25.5% and 16.3%, respectively. After adjusting for confounding variables, patients with microscopic hematuria (adjusted HR, 1.30; 95% CI 1.10-1.54) showed a significantly higher risk of 3-year all-cause mortality than patients without microscopic hematuria. In a subgroup analysis based on the presence of proteinuria, microscopic hematuria was a significant predictor of all-cause mortality in patients without proteinuria (adjusted HR, 1.61; 95% CI 1.28-2.03) but not in patients with proteinuria.

CONCLUSION

Microscopic hematuria was a significant predictor of all-cause mortality in patients with hypertensive crisis. Our study suggests that microscopic hematuria can be a useful prognostic marker and may permit early detection of patients with an increased risk of death. Clinicians in the emergency department should consider screening for kidney function using urine analysis during the initial assessment of patients with hypertensive crisis.

Evaluation of Renal Function and Urinalysis in Children With Simple Febrile Convulsions

Febrile convulsion (FC) is the most prevalent type of seizure in children. Febrile diseases have been associated with alterations in kidney function and urine indices. Therefore, in this study, renal function and urine analysis were examined in children with simple FC. The study comprised children with simple FC who were referred to the Amirkabir hospital in Arak between 2020 and 2021. Children were examined for urinalysis and kidney function by assessing the estimated glomerular filtration rate (eGFR). A total of 157 patients with FC were admitted. Hematuria, proteinuria, and pyuria were detected in 8.9%, 1.9%, and 5.1% of cases, respectively. The urine cultures of 2 children were positive. Moreover, it was found that in simple FC, eGFR decreases regardless of gender (P > .05), although kidney function decreases more in children older than 24 months. In conclusion, all children with FC must undergo renal function assessments. Furthermore, urinalysis and urine culture are advised to rule out infection.

Association between 3-Year Repetitive Isolated Hematuria and eGFR Deterioration in an Apparently Healthy Population: A Retrospective Cohort Study

Microscopic hematuria is being increasingly recognized as a major indicator of kidney deterioration. Persistent hematuria may better detect estimated glomerular filtration rate (eGFR) deterioration and potential glomerulonephritis. We conducted a retrospective cohort study to investigate the associations between persistent hematuria: the frequency or consistency of positive dipstick hematuria defined by the preceding 3 years urinalyses, and eGFR deterioration over 5 years and abnormal urinalyses suggesting potential glomerulonephritis (hematuria 1+ or higher, 2+ or higher, proteinuria, and hematuria and proteinuria) 5 years later, among adult participants with positive dipstick hematuria at baseline in a large-scale Japanese health checkup setting (n = 2104). There was no significant association between persistent hematuria and eGFR deterioration over 5 years. The higher the frequency of preceding hematuria, the greater the RR of hematuria 5 years later; RRs of hematuria with preceding thrice, twice, or once hematuria were 3.64 [95% CI, 3.11-4.25], 2.97 [95% CI, 2.52-3.51], or 1.91 [95% CI, 1.58-2.30] for "hematuria 1+ or higher," and 7.13 [95% CI, 5.17-9.83], 4.26 [95% CI, 3.02-6.02], or 2.23 [95% CI, 1.52-3.27] for "hematuria 2+ or higher". The presence of both hematuria and proteinuria 5 years later was only associated with preceding thrice hematuria (RR: 2.35 [95% CI, 1.37-4.03]). In conclusion, persistent hematuria for 3 years was associated with hematuria and proteinuria that were suggesting glomerulonephritis, but not associated with eGFR deterioration over 5 years. Multiple dipstick urinalyses over years can add some values to detect potential glomerulonephritis as an early sign of chronic kidney diseases.

Hematuria and subsequent long-term risk of end-stage kidney disease: A Danish population-based cohort study

BACKGROUND

Hematuria is a frequent incidental clinical finding and may be a symptom of pre-existing underlying benign or malignant urinary tract or kidney disease. However, in patients with no apparent underlying cause of hematuria, long-term prognosis of hematuria remains unknown.

OBJECTIVES

To assess the long-term risk of end-stage-kidney disease (ESKD) in patients with a hospital-based hematuria diagnosis and no apparent underlying cause.

METHODS

Patients with a hospital diagnosis of hematuria were included and matched in a 1:5 ratio with comparison persons from the background population by age, sex and residency. We calculated the cumulative risk of ESKD considering death as a competing risk. Furthermore, we computed unadjusted and adjusted hazard ratios with 95% confidence intervals using Cox hazard regression with adjustment for age, sex, and comorbidities.

RESULTS

We included 170,189 hematuria-diagnosed patients. The absolute 10-year risk of ESKD was 0.7% (95%CI: 0.7-0.8) in patients with hematuria and 0.4% (95%CI: 0.3-0.4) in comparison persons, hence yielding an overall adjusted hazard ratio of 1.6 (95%CI: 1.4-1.7). Hematuria also increased the risk of EKSD in patients with pre-existing comorbidities like diabetes (adjusted HR: 1.3 [95%CI: 1.1-1.5]) and urogenital cancer (adjusted HR: 1.4 ([95%CI: 1.1-1.9]), whereas no association was observed in patients with previous kidney disease (adjusted HR: 0.9 (95%CI: 0.8-1.0).

CONCLUSION

A hospital-based hematuria diagnosis in patients with no apparent underlying cause of hematuria is a marker of an increased risk of future ESKD.

Association of Hematuria with Renal Progression and Survival in Patients Who Underwent Living Donor Liver Transplant

Background: This study aimed to determine the association between episodic or persistent hematuria after liver transplantation and long-term renal outcomes. Methods: Patients who underwent living donor liver transplantation between July 2005 and June 2019 were recruited and divided into two groups based on the finding of microscopic or gross hematuria after transplantation. All patients were followed up from the index date until the end date in May 2020. The risks of chronic kidney disease, death, and 30% and 50% declines in estimated glomerular filtration rate (eGFR) were compared between groups. Results: A total of 295 patients underwent urinalysis for various reasons after undergoing transplantation. Hematuria was detected in 100 patients (group A) but was not present in 195 patients (group B). Compared with group B, group A had a higher risk of renal progression, including eGFR decline >50% [aHR = 3.447 (95%CI: 2.24~5.30), p < 0.001] and worse survival. In addition, patients who took non-steroidal anti-inflammatory drugs (NSAIDs) continuously for over seven days within six months before transplant surgery had high risks of rapid renal progression, including a >30% decline in eGFR [aHR = 1.572 (95%CI: 1.12~2.21), p = 0.009)]. Conclusion: Development of hematuria after surgery in patients who underwent living donor liver transplant and were exposed to NSAIDs before surgery were associated with worse long-term renal dysfunction and survival.

Remission of Proteinuria May Protect against Progression to Chronic Kidney Disease in Pediatric-Onset IgA Nephropathy

Immunoglobulin A nephropathy (IgAN) is one of the most common primary glomerulopathies diagnosed in children and adolescents. This study aimed to evaluate the clinical features in and outcomes of pediatric IgAN over the last 30 years. Patients who were diagnosed before age of 18 at 20 centers in Korea were evaluated retrospectively. Of the 1154 patients (768 males, 386 females) with a median follow-up of 5 years, 5.6% (n = 65) progressed to stage 3–5 chronic kidney disease (CKD). The 10- and 20-year CKD-free survival rates were 91.2% and 75.6%, respectively. Outcomes did not differ when comparing those in Korea who were diagnosed prior to versus after the year 2000. On multivariate analysis, combined asymptomatic hematuria and proteinuria as presenting symptoms and decreased renal function at the time of biopsy were associated with progression to CKD, while remission of proteinuria was negatively associated with this outcome. Patients who presented with gross hematuria or nephrotic syndrome tended toward positive outcomes, especially if they ultimately achieved remission. While remission of proteinuria might imply that the disease is inherently less aggressive, it also can be achieved by management. Therefore, more aggressive management might be required for pediatric-onset IgAN.