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Jai Ganesh

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Chronic Kidney Disease

Chronic Kidney Disease

Gist

What Is Chronic Kidney Disease? Chronic kidney disease (CKD) means your kidneys are damaged and can't filter blood the way they should. The main risk factors for developing kidney disease are diabetes, high blood pressure, heart disease, and a family history of kidney failure.

Summary

Chronic kidney disease (CKD)—or chronic renal failure (CRF), as it was historically termed—is a term that encompasses all degrees of decreased kidney function, from damaged–at risk through mild, moderate, and severe chronic kidney failure.  CKD is a worldwide public health problem. In the United States, there is a rising incidence and prevalence of kidney failure, with poor outcomes and high cost.

CKD is more prevalent in the elderly population Almost half of the patients with CKD are older than 70 years. However, while younger patients with CKD typically experience progressive loss of kidney function, 30% of patients over 65 years of age with CKD have stable disease.

CKD is associated with an increased risk of cardiovascular disease and end-stage kidney disease (ESKD). Kidney disease is the 10th leading cause of death in the United States.

The Kidney Disease Outcomes Quality Initiative (KDOQI) of the National Kidney Foundation (NKF) established a definition and classification of CKD in 2002.  The KDOQI and the international guideline group Kidney Disease Improving Global Outcomes (KDIGO) subsequently updated these guidelines.  These guidelines have allowed better communication among physicians and have facilitated intervention at the different stages of the disease.

The guidelines define CKD as either kidney damage or a decreased glomerular filtration rate (GFR) of less than 60 mL/min/1.73 m^2 for at least 3 months. Whatever the underlying etiology, once the loss of nephrons and reduction of functional renal mass reaches a certain point, the remaining nephrons begin a process of irreversible sclerosis that leads to a progressive decline in the GFR.

Hyperparathyroidism is one of the pathologic manifestations of CKD.

Details

Chronic kidney disease (CKD) is a type of kidney disease in which a gradual loss of kidney function occurs over a period of months to years. Initially generally no symptoms are seen, but later symptoms may include leg swelling, feeling tired, vomiting, loss of appetite, and confusion. Complications can relate to hormonal dysfunction of the kidneys and include (in chronological order) high blood pressure (often related to activation of the renin–angiotensin system), bone disease, and anemia. Additionally CKD patients have markedly increased cardiovascular complications with increased risks of death and hospitalization.

Causes of chronic kidney disease include diabetes, high blood pressure, glomerulonephritis, and polycystic kidney disease. Risk factors include a family history of chronic kidney disease. Diagnosis is by blood tests to measure the estimated glomerular filtration rate (eGFR), and a urine test to measure albumin. Ultrasound or kidney biopsy may be performed to determine the underlying cause. Several severity-based staging systems are in use.

Screening at-risk people is recommended. Initial treatments may include medications to lower blood pressure, blood sugar, and cholesterol. Angiotensin converting enzyme inhibitors (ACEIs) or angiotensin II receptor antagonists (ARBs) are generally first-line agents for blood pressure control, as they slow progression of the kidney disease and the risk of heart disease. Loop diuretics may be used to control edema and, if needed, to further lower blood pressure. NSAIDs should be avoided. Other recommended measures include staying active, and certain dietary changes such as a low-salt diet and the right amount of protein. Treatments for anemia and bone disease may also be required. Severe disease requires hemodialysis, peritoneal dialysis, or a kidney transplant for survival.

Chronic kidney disease affected 753 million people globally in 2016 (417 million females and 336 million males.) In 2015, it caused 1.2 million deaths, up from 409,000 in 1990. The causes that contribute to the greatest number of deaths are high blood pressure at 550,000, followed by diabetes at 418,000, and glomerulonephritis at 238,000.

Signs and symptoms

CKD is initially without symptoms, and is usually detected on routine screening blood work by either an increase in serum creatinine, or protein in the urine. As the kidney function decreases, more unpleasant symptoms may emerge:

* Blood pressure is increased due to fluid overload and production of vasoactive hormones created by the kidney via the renin–angiotensin system, increasing the risk of developing hypertension and heart failure. People with CKD are more likely than the general population to develop atherosclerosis with consequent cardiovascular disease, an effect that may be at least partly mediated by uremic toxins. People with both CKD and cardiovascular disease have significantly worse prognoses than those with only cardiovascular disease.
* Urea accumulates, leading to azotemia and ultimately uremia (symptoms ranging from lethargy to pericarditis and encephalopathy). Due to its high systemic concentration, urea is excreted in eccrine sweat at high concentrations and crystallizes on skin as the sweat evaporates ("uremic frost").
* Potassium accumulates in the blood (hyperkalemia with a range of symptoms including malaise and potentially fatal cardiac arrhythmias). Hyperkalemia usually does not develop until the glomerular filtration rate falls to less than 20–25 mL/min/1.73 m^2, when the kidneys have decreased ability to excrete potassium. Hyperkalemia in CKD can be exacerbated by acidemia (which leads to extracellular shift of potassium) and from lack of insulin.
* Fluid overload symptoms may range from mild edema to life-threatening pulmonary edema.
* Hyperphosphatemia results from poor phosphate elimination in the kidney, and contributes to increased cardiovascular risk by causing vascular calcification. Circulating concentrations of fibroblast growth factor-23 (FGF-23) increase progressively as the kidney capacity for phosphate excretion declines, which may contribute to left ventricular hypertrophy and increased mortality in people with CKD .
* Hypocalcemia results from 1,25 dihydroxyvitamin D3 deficiency (caused by high FGF-23 and reduced kidney mass) and resistance to the action of parathyroid hormone.[30] Osteocytes are responsible for the increased production of FGF-23, which is a potent inhibitor of the enzyme 1-alpha-hydroxylase (responsible for the conversion of 25-hydroxycholecalciferol into 1,25 dihydroxyvitamin D3). Later, this progresses to secondary hyperparathyroidism, kidney osteodystrophy, and vascular calcification that further impairs cardiac function. An extreme consequence is the occurrence of the rare condition named calciphylaxis.
* Changes in mineral and bone metabolism that may cause 1) abnormalities of calcium, phosphorus (phosphate), parathyroid hormone, or vitamin D metabolism; 2) abnormalities in bone turnover, mineralization, volume, linear growth, or strength (kidney osteodystrophy); and 3) vascular or other soft-tissue calcification. CKD-mineral and bone disorders have been associated with poor outcomes.
* Metabolic acidosis may result from decreased capacity to generate enough ammonia from the cells of the proximal tubule. Acidemia affects the function of enzymes and increases excitability of cardiac and neuronal membranes by the promotion of hyperkalemia.
* Anemia is common and is especially prevalent in those requiring haemodialysis. It is multifactorial in cause, but includes increased inflammation, reduction in erythropoietin, and hyperuricemia leading to bone-marrow suppression. Hypoproliferative anemia occurs due to inadequate production of erythropoietin by the kidneys.
* In later stages, cachexia may develop, leading to unintentional weight loss, muscle wasting, weakness, and anorexia.
* Cognitive decline in patients experiencing CKD is an emerging symptom revealed in research literature. Current research suggests that patients with CKD face a 35-40% higher likelihood of cognitive decline and or dementia. This relation is dependent on the severity of CKD in each patient; although emerging literature indicates that patients at all stages of CKD will have a higher risk of developing these cognitive issues.
* Sexual dysfunction is very common in both men and women with CKD. A majority of men have a reduced gender drive, difficulty obtaining an erection, and reaching orgasm, and the problems get worse with age. Most women have trouble with sexual arousal, and painful menstruation and problems with performing and enjoying gender are common.

Additional Information

Chronic kidney disease (CKD), commonly known as chronic kidney failure, is a condition in which the kidneys gradually lose function. Wastes and surplus fluids are filtered from your blood and expelled as urine by your kidneys. When chronic kidney disease progresses, your body might accumulate harmful quantities of fluid, electrolytes, and wastes. You may have few indications or symptoms in the early stages of chronic renal disease. Chronic renal disease may not be seen until your kidney function has deteriorated severely.

Chronic renal disease refers to a group of disorders that harm your kidneys and reduce their ability to keep you healthy by performing the tasks outlined. If your kidney condition worsens, wastes in your blood might build up to dangerously high levels, making you unwell. High blood pressure, anemia (low blood count), weak bones, poor nutritional status, and nerve damage are all possible problems. Every 30 minutes, your kidneys, which are each about the size of a computer mouse, filter all of your blood. They put forth a lot of effort to get rid of wastes, poisons, and excess fluid. They also aid in the control of blood pressure, the stimulation of red blood cell synthesis, the maintenance of healthy bones, and the regulation of vital blood molecules.

Symptoms

The majority of people do not experience significant symptoms until their renal disease has progressed. You may, however, observe that you:

* Feel tired and have less energy
* Trouble while concentrating
* Poor appetite
* Trouble sleeping
* Muscle cramping at night
* Swollen feet and ankles
* Puffiness around the eyes
* Dry, itchy skin
* Often urination

Chronic renal disease can strike anyone at any age. However, some people are more susceptible to kidney disease than others. If you do any of the following, you may be at a higher risk for kidney disease:

* Diabetes
* High blood pressure
* Family history of kidney failure

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