Chronic Kidney Disease "CKD" is a state of progressive loss of kidney functions which ultimately leads to the requirement of renal replacement therapy. The true measure as to what percent of the total population suffer from CKD is difficult to estimate as most patients are asymptomatic until kidney functions have been significantly impaired. The CDC estimates about 15% of American adults to be suffering from CKD.
Chronic kidney diseases are kidney damages that last for at least 3 months and are characterized by structural or functional damages to the kidney. These abnormalities may or may not present with decreased glomerular filtration rate (GFR). GFR is the measure of how much blood is filtered by the kidney in a minute.
Causes of CKDCKD is usually multifactorial in its development; multiple factors that damage the kidney combine leading to impaired kidney function. Various conditions implicated include:
- Hereditary: You are at a higher risk of developing CKD if your family members suffer from it. Diabetes: Diabetes is the leading cause of chronic kidney disease in the United States. An increase in levels of blood glucose causes damage to the blood vessels in the kidney compromising the functions of the kidney.
- Hypertension: Increased pressure in the vessels of your kidney over a considerable period causes it to weaken and narrow leading to impaired kidney functions.
- Pathologies of kidney tissue: Damage to intrinsic tissues of the kidney can lead to impaired functions
- Obstructive nephropathies: Conditions causing blockage of urine passage lead to a backflow of urine into the nephrons (functional unit of the kidney) and ultimately disrupts function.
- Cystic Diseases: Cystic disease of kidneys has also been shown to lead to functional impairment.
- Nephrotoxic drugs: Chronic use of painkillers and Lithium has been shown to increase the risk of CKD.
Signs and Symptoms of Chronic Kidney DiseaseSymptoms are multi-systemic and may include:
- Fatigue and weakness
- Nausea and vomiting
- Fluid retention leading to swelling in different parts of the body
- Easy skin bruising
- Difficulty breathing
- Loss of appetite
- Irritability and lack of concentration
- Bone and joint pain
- Increased predisposition to fractures
- Exercise intolerance
- Leg cramps, numbness, and restlessness
- Decreased libido
Diagnosis of Chronic Kidney DiseaseThe diagnosis of CKD is done based on:
Medical History and physical examination: This helps identify the presence of different causative factors leading to Chronic Kidney Disease.
Imaging Studies: USG or CT scan of your abdomen and kidneys helps identify kidney pathologies.
Blood tests: Blood tests to estimate the level of waste products like creatinine. It also helps identify abnormalities in the acid-base balance of the body
Urine test: This helps estimate GFR and check for the presence of excess proteins or blood in the urine.
Management of Chronic Kidney DiseaseThere is no definite cure for chronic kidney disease as of now. Treatment measures are directed at symptomatic relief, prevention of disease progression, and reducing complications, and restoring quality of life. Main treatment strategies include:
Lifestyle modification: Altering certain habits can help reduce disease progression and prevent complications. Quitting smoking, exercising, and having a balanced diet are few important lifestyle interventions. Salt intake should be consumed in moderation and painkillers should be avoided unless prescribed.
Medications: There are no specific medications for treating chronic kidney diseases. Drugs are used to reduce problems leading to chronic kidney disease and prevent complications. It includes:
Anti-hypertensives: Drugs of class ACE-Inhibitors are often used in people with chronic kidney disease with associated high BP. ACE-Inhibitors also help reduce the loss of proteins from urine reducing the risk of disease advancement.
Anti-Diabetics: These drugs help reduce excess blood sugar levels and prevent disease advancement.
Statins: Excessively elevated levels of cholesterol are a common finding in patients with chronic kidney disease. Statin groups of drugs reduce the rate of cholesterol synthesis and help prevent complications and slow the rate of disease advancement in CKD.
Recombinant erythropoietin: It helps correct anemia associated with chronic kidney disease. Correct dosing of the drug is important to prevent hypertension and blood vessel occlusion associated with high dosing.
Phosphorous Binders: Drugs like calcium carbonate help bind to and remove excess phosphorous from the body, and help in the treatment of renal bone diseases.
Renal replacement therapy: Dialysis and renal transplantation are reserved for use in end-stage kidney disease with minimal kidney function to replace excretory functions of the kidney.
Treatment Modalities Currently Undergoing Clinical Trials
- AZD57: A clinical trial to evaluate the efficacy, safety, and pharmacokinetics (PK) of AZD57 in patients having chronic kidney disease with proteinuria is in its second phase. AZD57 belongs to 5-lipoxygenase activating protein inhibitors group of drugs and has shown to be effective in treating CKD and coronary heart disease.
- Sodium Bicarbonate: Studies have shown patients of CKD are prone to developing cardiovascular complications especially during exercises. These patients show an exaggerated rise in BP following exercise. A study is being conducted to further learn about the mechanism of exercise intolerance and assess the use of sodium bicarbonate to improve abnormal hemodynamic response to exercise. It is currently under phase 2 of its clinical trial.
- Iron Sulphate: A study to establish the efficacy and safety of oral irons in the treatment of CKD with anemia in children is currently underway. The addition of oral iron is thought to improve anemia in such patients. The study aims at comparing the outcomes of a patient taking iron therapy to those not taking it. It is currently in phase 4 of its clinical trial.
- Fisetin: Fisetin is an anti-oxidant drug. Its effect on kidney function, markers of inflammation, and physical functioning in patients with advanced chronic kidney disease, especially diabetics is currently being studied and is in Phase 2 of its clinical trial. The study aims at assessing its safety and efficacy in relieving symptoms in patients with CKD secondary to diabetic nephropathy.
- Pirfenidone: Pirfenidone is being studied as a promising new potential in treating patients with chronic kidney disease. The study which is currently in Phase 2 of the clinical trial aims at assessing Pirfenidone's efficacy in reducing fibrosis of the kidneys which is a proven factor in the development of kidney diseases.
Drawz P, Rahman M. Chronic kidney disease. Ann Intern Med 2015; 162(11): ITC1-16. [PubMed]