Given the wide diversity of causes of hematuria, ranging from simple urinary tract infections with rapid recovery to severe glomerulonephritis with fast decline in kidney function, it is essential to recognize the underlying disease. The first objective of the assessment is to determine whether the cause of the hematuria is medically significant. The combination of hematuria with proteinuria, the presence of hypertension, or worsening kidney function can represent signs of progressive kidney disease. Differentiating the various causes of hematuria is often simple and obvious based on the clinical signs and gross appearance of the urine. However, in some instances, additional non-invasive investigations, such as ultrasound imaging, urinary red cell morphology, measurement of calcium and other solutes in the urine, evaluation of kidney function, and protein excretion, are needed to elucidate the nature of the hematuria. Taking a detailed family history can help in establishing the underlying cause in cases of familial hematuria. On the other hand, the decision to perform a kidney biopsy in children with asymptomatic hematuria remains a challenging issue for clinicians. Ultimately, the frequency of diagnosis of glomerular involvement causing hematuria may depend on the threshold for performing a kidney biopsy. The following review will focus on the diagnostics of hematuria, starting with difficulties regarding its definition, followed by various means to differentiate between urinary, glomerular, and other causes, and finally reviewing the most common diseases that, due to their frequency or their effect on kidney function, present a diagnostic challenge in everyday practice.

Diabetic cardiovascular complications are associated with up to 50% mortality, and current therapies are not effective enough. Renin–angiotensin–aldosterone system inhibitors (RAASis) are the standard of care for diabetic patients with hypertension and albuminuria. Based on our previous studies reporting the renoprotective effects of low-dose RAASis, here, we hypothesized that low-dose RAASi treatment has cardioprotective and antifibrotic benefits in type 1 diabetes mellitus (T1DM). After five weeks of T1DM, adult male Wistar rats received low doses of ramipril, losartan, or eplerenone for two weeks. Heart rate, blood pressure, and pulse wave velocity (PWV) were recorded. Aortic intima–media thickness (IMT), collagen accumulation, and myocardial fibrosis were assessed. All RAASis reduced PWV elevation, prevented the progression of myocardial fibrosis, and normalized B-type natriuretic peptide, troponin I, and fibroblast growth factor 23 levels without affecting blood pressure. Interestingly, only eplerenone reversed the decline in Klotho levels and reduced IMT and fibrosis in the media of the aorta. Our comparative analysis suggests that mineralocorticoid receptor antagonists, particularly eplerenone, may offer superior efficacy in halting both the arterial and the myocardial injuries in T1DM compared to angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor blockers.

Central pulse wave velocity (PWV) is a marker of arterial stiffness and is calculated by dividing the pulse wave travel distance by the transit time. However, there is no consensus as to the ideal distance measurement in children. The aim of our study was to identify the more reliable method to assess the distance measurement in the pediatric age. Carotid-femoral PWV was measured by applanation tonometry in 988 healthy children aged 6.5-19.9 years. Two different surface distances were assessed: the subtraction method, representing the distance from the suprasternal notch to the femoral artery minus the distance from the carotid artery to the suprasternal notch, and the direct method, consisting of 80% of the distance from the carotid artery to the femoral artery. Both these methods were compared with the actual path length determined by magnetic resonance imaging (MRI) in 31 children. Subtraction and direct methods were significantly correlated in patients aged <14 years and the corresponding PWV values showed a good agreement. In children aged ≥14 years, a significant difference between the two methods was found: subtraction - direct distance = -45 ± 28 mm, with a significant difference in the resulting PWV values = -0.57 ± 0.35 m/s (p < 0.0001). This result was confirmed by MRI, showing a 10% overestimation in distance measurement by the direct method in subjects aged ≥14 years, resulting in a significantly higher PWV. These data suggest a greater reliability of the subtractive method of distance measurement compared to the direct method in children.