Microvascular dysfunction and kidney disease: Challenges and opportunities?

Abstract

Kidney disease is an underappreciated public health crisis.Approximately 20% of all hospital admissions and more than half of all critically ill patients admitted to the intensive care units have acute kidney injury or AKI. 1 Further, 15% of the general population, or 1 in every 7 adults, have chronic kidney disease or CKD. 2 Kidney disease is the 9th leading cause of death and adds considerably to the cost of health care. In 2017 alone, Medicare spent $36 billion caring for patients with end-stage kidney disease on dialysis and an additional $84 billion on those with CKD. Although the kidneys are relatively small and account for only 1% of the total body weight, almost 20% of the blood flow is directed to the kidney under resting conditions. The resistance to blood flow within the renal microcirculation is intricately regulated by hormonal, paracrine, autocrine, and neural controls, to alter blood flow and glomerular filtration rate. Undoubtedly from a clinical perspective, understanding the structure and function of the renal microvasculature is important for

Impact of the estimated glomerular filtration rate on long-term mortality in patients with hypertensive crisis visiting the emergency department

“…CKD is a direct cause of mortality and a risk factor for cardiovascular disease, and patients with hypertension and CKD have a high cardiovascular risk [ 28 ]. In addition, a decreased eGFR is not only representative of renal dysfunction but is also associated with various pathological conditions, such as inflammation, microvascular dysfunction, and enhanced oxidative stress, which share a common pathway in the development of atherosclerosis and heart failure [ 29 – 31 ]. In this regard, clinical guidelines recommend screening for CKD in individuals with hypertension and more intensive interventions in patients with CKD to prevent adverse outcomes [ 14 ].…”

Therapeutics of managing reduced red cell mass associated with chronic kidney disease – Is there a case for earlier intervention?

“…Furthermore, capillary rarefaction (microvessel loss leading to reduced density of capillaries) is associated with fibrosis in human CKD (Afsar et al, 2018;Krishnan et al, 2021) as has recently been demonstrated in feline CKD (Paschall et al, 2023). In theory, this could explain the strong relationship between reduced haematocrit and progression of CKD in the cat and, in turn, with the reduced survival.…”

“…Growth of the peritubular vascular network to supply increased oxygen demand is not likely to keep pace with this tubular hypertrophy process, the fibrosis increases the diffusion distance for oxygen from the peritubular capillary and the tubule, and thus, the red cell mass delivering oxygen to proximal tubules that are hypermetabolic will be critical. Furthermore, capillary rarefaction (microvessel loss leading to reduced density of capillaries) is associated with fibrosis in human CKD (Afsar et al, 2018; Krishnan et al, 2021) as has recently been demonstrated in feline CKD (Paschall et al, 2023). In theory, this could explain the strong relationship between reduced haematocrit and progression of CKD in the cat and, in turn, with the reduced survival.…”

Nanodrugs alleviate acute kidney injury: Manipulate RONS at kidney

“…Unfortunately, the complex structure and function of the kidney lead to a physiological state in which the tubules themselves are on the verge of suffocating [ 32 ]. The renal microcirculation is divided into two separate but interconnected capillary networks: the glomerular capillary network for filtration and the peritubular capillary network for reabsorption ( Fig.3 A, ii) [ 33 ]. This series of connections means that any blockage of upstream blood flow causes ischemia in the downstream vessels.…”