Chronic Kidney Disease can be defined as structural or functional kidney damage for ³ 3 months with or without decreased Glomerular Filtration Rate (GFR). For my colleagues in the medical profession, it can be define as GFR <60mls/min/1.73m2 for³ 3 or more months with or without Kidney damage.
Chronic Kidney Disease (CKD) is under diagnosed and under recognized all over the world. Over 50 million individuals have progressive CKD worldwide, and well over a million of them are on renal replacement therapy.
The attention being paid globally to chronic kidney disease is attributable to five factors; the rapid increase in its prevalence, the enormous cost of treatment, recent data indicating that overt disease is the tip of an iceberg of covert disease, an appreciation of its major role in increasing the risk of cardiovascular disease, and the discovery of effective measures to prevent its progression.
Classification of CKD
STAGE DESCRIPTION GFR (MLS/MIN/1.73M2 )
1 Kidney damage with normal or Decreased GFR ³ 90
2 Kidney damage with mild Decrease in GFR 60 – 89
3 Moderate Decrease in GFR 30 – 59
4 Severe Decrease in GFR 15 – 29
5 Kidney Failure < 15 (or dialysis)
Signs and symptoms
Patients with CKD stages 1-3 are generally asymptomatic. Typically, it is not until stages 4-5 that endocrine/metabolic derangements or disturbances in water or electrolyte balance become clinically manifest.
Signs of metabolic acidosis in stage 5 CKD include the following:
• Protein-energy malnutrition
• Loss of lean body mass
• Muscle weakness
Signs of alterations in the way the kidneys are handling salt and water in stage 5 include the following:
• Peripheral edema
• Pulmonary edema
Anemia in CKD is associated with the following:
• Reduced exercise capacity
• Impaired cognitive and immune function
• Reduced quality of life
• Development of cardiovascular disease
• New onset of heart failure or the development of more severe heart failure
• Increased cardiovascular mortality
Other manifestations of uremia include the following:
• Pericarditis: Can be complicated by cardiac tamponade, possibly resulting in death
• Encephalopathy: Can progress to coma and death
• Peripheral neuropathy
• Restless leg syndrome
• Gastrointestinal symptoms: Anorexia, nausea, vomiting, diarrhea
• Skin manifestations: Dry skin, pruritus, ecchymosis
• Fatigue, increased somnolence, failure to thrive
• Erectile dysfunction, decreased libido, amenorrhea
• Platelet dysfunction with tendency to bleed
Risk Factors for Chronic Kidney Disease
The incidence of renal disease is known to increase with age.
End Stage Renal Disease is commoner in males. The majority of studies also suggest a faster rate of decline in GFR in males.
In the USA, the incidence and prevalence of diabetic and hypertensive renal diseases are higher in African Americans and Hispanics compared to Caucasians.
Diabetic and non diabetic nephropathies cluster in families.
Many studies point to proteinuria as an important prognostic factor in the progression of kidney disease.
Strong evidence links the progression of Chronic Kidney Disease (CKD) to systemic hypertension.
While there is little doubt that poor glycaemic control is a major factor in the initiation of CKD in susceptible diabetic patients, the evidence for a role for hyperglycaemia in the progression of diabetic nephropathy is conflicting.
This has been implicated in the pathogenesis of glomerulosclerosis and tubulointerstitial fibrosis. A number of studies have confirmed by multivariate analysis that dyslipidaemia is a risk factor for a faster rate of progression.
Excessive body weight and a raised body mass index have been linked to a faster rate of progression of CKD in patients with IgA nephropathy.
Hyperuricaemia has been associated with systemic hypertension, cardiovascular and renal diseases.
Cigarette smoking causes an increase in systemic blood pressure and affects renal haemodynamics. In diabetic and non-diabetic patients, there is evidence that smoking is associated with a faster rate of decline of CKD.
Some evidence links heavy alcohol consumption to progressive renal insufficiency, perhaps through the hypertensive effect of alcohol.
Patients with CKD consuming more than two drinks a day had an increased odds ratio for developing ESRD compared to those drinking less.
Coffee drinking (five or more cups a day) was associated with a small increase in blood pressure in a study in US medical students. 52 Experimental data also suggest that excessive caffeine intake is associated with elevated blood pressure, increased proteinuria and more severe tubulointerstitial scarring in a susceptible strain of obese rats.52
A case control study in the general population conducted in the USA showed that recreational drugs are risk factors for the development of ESRD.
Non Steroidal Anti-Inflammatory Drugs (NSAIDS)
Some studies have linked consumption of analgesics especially paracetamol and non-steroidal anti-inflammatory agent egfeldin, Ibuprofen etcwith a higher risk of developing CKD.
To fully investigate the underlying cause of kidney damage, various forms of medical imaging, blood tests, and often renal biopsy (removing a small sample of kidney tissue) are employed to find out if a reversible cause for the kidney malfunction is present. Aim is to look for and quantify the parameters above
Management of Chronic Kidney Disease
The management of chronic kidney disease (CKD) patients before and after starting dialysis remains highly fragmented resulting in sub optimal clinical outcomes and high costs, creating a high burden of disease on patients and the healthcare system. For CKD patient not yet on dialysis, the major goals of management are:
(1) Early identification of CKD patient and intervention to slow the progression of CKD.
(2) Identification and management of the complications of CKD.
(3) Identification and management of the complications of co-morbid conditions, and
(4) Smooth transition to renal replacement therapy (RRT).
For those CKD patients on dialysis,focused attention on avoidable hospitalizations is a key to a successful disease management programme.Multi disciplinary collaboration among physicians(nephrologist,primary care physicians,cardiologist,endocrinologist,vascular surgeons and transplant physicians)and participating caregivers(nurse,pharmacist,social workers and dietician) is critical as well.
Interventions To Slow The Progression Of CKD
Lifestyle modifications such as weight reduction, exercise and dietary manipulations can be effective, as shown in clinical trials in which the incidence of type 2 diabetes in overweight individuals with impaired glucose tolerance was substantially lowered by these means.
Approaches to control hypertention by means of dietary salt restrictions and diet rich in fruit and vegetables and low in saturated fat have been recommended.
Improved health education with reduction of excessive body weight, regular exercise and dietary approaches should lead in the longterm to a reduction in the incresing numbers of people with diabetes and hypertension who constitute the major future pool of CKD cases.
SecondaryPrevention Of Progression
In patients with established CKD,there is a wide range of interventions that offer the possibility of slowing progression.
Control of hypertention is the single most effective intervention. In patients with CKD,target blood pressure should be less than 130/80mmHg in the absence of diabetes or substantial proteinuria(<1g in 24hours)
and less than 125/75mmHg in diabetic patients and those with protein excretion in excess of 1g in 24hours.These recommendations and guidelines are based on observations made in several clinical studies of diabetic and non-diabetic nephropathies. A pooled analysis of many of these studies suggested that the lower the mean arterial pressure, the slower the progression of CKD.
The three most common causes of CKD are diabetes mellitus, hypertension, and glomerulonephritis. Together, these cause about 75% of all adult cases. Others are Polycystic Kidneys, Bilateral Renal Artery Stenosis and Chronic Renal Failure. Therefore, life style modification will help in preventing the development of the aforementioned risk factors hence CKD.