Chronic Kidney Disease

Chronic kidney disease (CKD), also known as chronic renal failure (CRF), is a condition of decline in renal function over a long period, which could be mild, moderate, or severe. According to the guidelines, the glomerular filtration rate is used to define chronic kidney disease. It is defined as renal damage or decreased glomerular filtration rate (GFR) for at least 3 months. 

Chronic kidney disease is caused by some underlying condition that causes renal damage. In the long run, renal damage contributes to renal function decline and chronic kidney disease. The following disorders may cause renal function and structural deterioration of varying causes:

• Diabetes
• Hypertension 
• Vascular disease 
• Glomerular diseases (primary and secondary)
• Cystic kidney diseases 
• Urinary tract obstruction 
• Acute kidney injury due to several causes 
• Defects of the kidney present at birth 
• Kidney stones

Chronic kidney disease is classified into the following stages based upon GFR:

Stage 1- the GFR is normal, but there is some degree of renal damage. The normal GFR is 90ml/min.

Stage 2- GFR is mildly reduced to 60-69 ml/min.

Stage 3a- There is a moderate reduction in the GFR of 45-60 ml/min.

Stage 3b- GFR is moderately reduced to 30-45 ml/min. 

Stage 4- GFR is reduced to 15-30 ml/min. 

Stage 5- Kidney failure with GFR less than 15ml/ min. This stage usually requires kidney dialysis. 

Kidney disease is prevalent worldwide. In the United States, kidney disease is the ninth most leading cause of death. In people with advancing age, the disease progresses rapidly. Severe kidney disease or end-stage renal disease is usually seen in individuals of 60 years or more. It is seen in both genders with equal incidence. However, the mortality rate in men is higher than in women.

Risk factors for chronic kidney disease include:

• Hypertension 
• Diabetes 
• Certain drugs such as sulfonamides 
• Recreational drugs such as heroin 
• Infections (bacterial or viral) such as HIV infections 
• Autoimmune disorders such as SLE
• Homeopathic medicines with steroid base

Signs and symptoms of chronic kidney disease include:

• Muscle weakness
• Loss of body weight 
• Peripheral edema
• Hypertension 
• Anemia
• Blood or pussy discharge in the urine
• Nausea 
• Vomiting
• Diarrhea 
• Pruritis
• Anorexia
• Dry skin
• Tendency to bleed
• Fatigue 
• Increased somnolence 

Complications of end-stage renal disease (ESRD) include:

• Pericarditis leading to cardiac tamponade
• Encephalopathy that can lead to coma and death 
• Peripheral neuropathy 
• Restless leg syndrome 
• Erectile dysfunction
• Decreased fertility 
• Depression

• The most important marker for diagnosing chronic kidney disease is the glomerular filtration rate. If it is less than normal (less than 90ml/min) for three consecutive months or more, the diagnosis of chronic renal disease is made. 
• Other important markers that aid the diagnosis include the presence of albumin in urea (albuminuria) or increased albumin to creatinine ratio.
• Abnormal urine analysis with protein casts and sediments in the urine.
• Complete blood count with the evidence of anemia 
•  Serum electrolytes imbalances
• Lipid profile
• Serum vitamin D3 levels
• Parathyroid hormone levels
• Autoimmune antibodies such as anti-nuclear antibodies (ANAs) rule out autoimmune disorders.
• Imaging studies that include renal ultrasonography for the evidence of hydronephrosis. Other imaging studies include CT, MRI, pyelography, and radionuclide scanning. 
• Renal biopsy is performed when the diagnosis remains unclear after laboratory investigations and imaging studies.

Differential diagnoses of chronic renal disease include:

• Systemic lupus erythematosus 
• Urinary tract obstruction 
• Renal artery stenosis 
• Granulomatosis 
• Multiple myeloma 
• Alport syndrome 
• Acute kidney injury 
• Diabetic nephropathy 
• Basement membrane disease 
• Kidney stones 

Treatment for chronic kidney disease focuses on treating the underlying cause to prevent secondary manifestations of the disease and complications. It aims to reduce the progression of kidney damage, so the kidney function does not decline further. In the case of end-stage renal disease, the focus is to replace the renal function effectively.

• Anemia is treated by supplementation with erythropoietin or erythropoietin-iron complexes. 
• Serum electrolytes and vitamins such as phosphorus, calcium, and vitamin D are replaced by dietary modifications and oral supplements.
• Loop diuretics are given to treat volume overload and resulting edema. 
• End-stage renal disease is cured by renal replacement therapies that include dialysis (peritoneal dialysis and hemodialysis) and renal transplantation. 

The prognosis of chronic renal disease depends upon the following factors:

• Age at diagnosis 
• Stage of renal disease at diagnosis 
• The underlying cause of the renal disease 
• Individual patient factors such as the presence of comorbidities or infections
• Success and effectiveness of preventive therapy 
• Chronic kidney disease is associated with considerable morbidity and mortality, with a 76% increase in the mortality rate for stage 4 and stage 5 chronic renal disease. 

• Drugs and chemicals that damage kidneys should be avoided. These include sulfonamides, penicillin, most antibiotics, heroin, and certain metals.
• Dietary modifications include restricting salt and water intake to prevent edema and volume overload. Other modifications involve restricting a protein-rich diet, especially in the end-stage renal stage. Fruits and vegetables in the diet, especially alkali inducing, are shown to improve glomerular filtration rate and reduce kidney injury.
• Women of childbearing age should be counseled about the effects of chronic kidney disease on the fertility rate. In case pregnancy occurs, the impact on the fetus can be dangerous. Most drugs used against chronic renal disease are also harmful to the fetus. Patient education, in that case, to cope with pregnancy and related issues is very important. 
•  Patients with renal disease should perform regular exercises. According to one study, resistance training and aerobics, especially in patients undergoing dialysis, improve the quality of life by a significant percentage.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 14, 2023. 

References

Chronic kidney disease - ScienceDirect

https://www.sciencedirect.com/science/article/abs/pii/S0140673621005195