Chronic kidney disease, or reduced kidney function, is extremely common and usually associated with no symptoms at all – until it is in its very advanced stages. CKD is present in around 14% of the adult population, with 1/3rd of the population being at risk. Importantly, the presence of CKD is associated with a 10-20 times increased risk of death from heart disease. Some sufferers will progress to chronic kidney failure and require dialysis if they are eligible.
Good management of CKD reduces cardiovascular risk by 50%.
Kidney function declines with age, reducing by around 1% each year from the mid 30s. Kidney disease is detected by the persistent presence of protein in the urine and a reduced eGFR (effective glomerular filtration rate – how much blood/urine is filtered by the kidneys each minute). eGFR is assessed routinely on a common biochemistry blood test – it takes into account the blood creatinine level and the age and gender of the person. There are a number of factors which have an effect on the result (including dehydration, race, muscle mass etc) and which need to be taken into account when evaluating a result. In adults less than 70 years of age an eGFR persistently less than 60 ml/min reflects early kidney disease, particularly if there is also raised protein levels in the urine. An eGFR less than 30 ml/min is an indication of severe CKD.
For people over 70 years of age an eGFR of less than 45 is indicative of early CKD.
The most common causes of CKD are *diabetes, chronic glomerulonephritis, hypertension and polycystic kidney disease (polycystic kidneys and some forms of glomerulonephritis are inherited).
At most risk of developing CKD, and who should have annual checks are those with
- age more than 50 years
- diabetes
- hypertension
- smokers
- obesity
- family history of CKD
- ATSI background
The complications and treatment goals for CKD, heart disease and diabetes are very similar. The most important treatment strategy to slow the progression of CKD is to reduce blood pressure to quite low levels.
Management Goals for CKD:
1 Control Blood Pressure – goal BP < 130/80 or < 125/75 if diabetic or there is significant protein in the urine (more than 1gm/24 hours). Using an ‘ACE’ or ‘ARB’ medication is usually advised as these have a renal protective effect as well as reducing blood pressure.
2 Reduce Protein in urine – using blood pressure reducing strategies
3 Control Cholesterol – goal total cholesterol < 4 mm, LDL cholesterol < 2.5 mm
4 Excellent control of Diabetes – HbA1c < 7
5 Cease Smoking
6 Weight Control – BMI < 25
7 Regular Exercise – 30 minutes walking per day
8 Low Salt Diet
9 No more than 1-2 Alcohol drinks per day
10 Annual influenza vaccine (and Pneumovax immunisation)
In more advanced stages of CKD other complications often arise, including
- anaemia
- mineral and bone disorders, including high phosphate levels and secondary hyperparathyroidism
- high potassium levels
- restless leg syndrome (very common)
- sleep apnoea
- depression
- general itching
- loss of appetite and nausea
- frequent voiding during the night
- secondary gout
These complications require specific dietary modifications and medication.
Medication and CKD:
Many medications are excreted from the body by the kidneys and when the kidneys are not functioning adequately these medications can accumulate in the body and have adverse effects. These medications either have to be taken in a reduced dose or avoided altogether in CKD, especially when it is more advanced. The more common include:
- some diabetic medications : sulfonylureas, metformin, glibenclamide, glimepiride (Glimel)
- Allopurinol and colchicine – gout treatments
- *Anti-inflammatory medications – for arthritis
- Digoxin
- Beta blockers : sotalol and atenolol ( metoprolol is an alternate)
- *Radiographic contrast media
- *Lithium
- Gabapentin
- *Aminoglycosides including Gentamicin
- Antivirals (Zovirax, Famvir, Valtrex)
- Diamox
- *Combination of NSAID anti-inflammatory + diuretic + ACE
* these medications can cause further kidney damage.
(In advanced kidney failure a low potassium diet may be advised - see a low potassium diet.)
Good management of CKD reduces cardiovascular risk by 50%.
Kidney function declines with age, reducing by around 1% each year from the mid 30s. Kidney disease is detected by the persistent presence of protein in the urine and a reduced eGFR (effective glomerular filtration rate – how much blood/urine is filtered by the kidneys each minute). eGFR is assessed routinely on a common biochemistry blood test – it takes into account the blood creatinine level and the age and gender of the person. There are a number of factors which have an effect on the result (including dehydration, race, muscle mass etc) and which need to be taken into account when evaluating a result. In adults less than 70 years of age an eGFR persistently less than 60 ml/min reflects early kidney disease, particularly if there is also raised protein levels in the urine. An eGFR less than 30 ml/min is an indication of severe CKD.
For people over 70 years of age an eGFR of less than 45 is indicative of early CKD.
The most common causes of CKD are *diabetes, chronic glomerulonephritis, hypertension and polycystic kidney disease (polycystic kidneys and some forms of glomerulonephritis are inherited).
At most risk of developing CKD, and who should have annual checks are those with
- age more than 50 years
- diabetes
- hypertension
- smokers
- obesity
- family history of CKD
- ATSI background
The complications and treatment goals for CKD, heart disease and diabetes are very similar. The most important treatment strategy to slow the progression of CKD is to reduce blood pressure to quite low levels.
Management Goals for CKD:
1 Control Blood Pressure – goal BP < 130/80 or < 125/75 if diabetic or there is significant protein in the urine (more than 1gm/24 hours). Using an ‘ACE’ or ‘ARB’ medication is usually advised as these have a renal protective effect as well as reducing blood pressure.
2 Reduce Protein in urine – using blood pressure reducing strategies
3 Control Cholesterol – goal total cholesterol < 4 mm, LDL cholesterol < 2.5 mm
4 Excellent control of Diabetes – HbA1c < 7
5 Cease Smoking
6 Weight Control – BMI < 25
7 Regular Exercise – 30 minutes walking per day
8 Low Salt Diet
9 No more than 1-2 Alcohol drinks per day
10 Annual influenza vaccine (and Pneumovax immunisation)
In more advanced stages of CKD other complications often arise, including
- anaemia
- mineral and bone disorders, including high phosphate levels and secondary hyperparathyroidism
- high potassium levels
- restless leg syndrome (very common)
- sleep apnoea
- depression
- general itching
- loss of appetite and nausea
- frequent voiding during the night
- secondary gout
These complications require specific dietary modifications and medication.
Medication and CKD:
Many medications are excreted from the body by the kidneys and when the kidneys are not functioning adequately these medications can accumulate in the body and have adverse effects. These medications either have to be taken in a reduced dose or avoided altogether in CKD, especially when it is more advanced. The more common include:
- some diabetic medications : sulfonylureas, metformin, glibenclamide, glimepiride (Glimel)
- Allopurinol and colchicine – gout treatments
- *Anti-inflammatory medications – for arthritis
- Digoxin
- Beta blockers : sotalol and atenolol ( metoprolol is an alternate)
- *Radiographic contrast media
- *Lithium
- Gabapentin
- *Aminoglycosides including Gentamicin
- Antivirals (Zovirax, Famvir, Valtrex)
- Diamox
- *Combination of NSAID anti-inflammatory + diuretic + ACE
* these medications can cause further kidney damage.
(In advanced kidney failure a low potassium diet may be advised - see a low potassium diet.)
