How do I know I have kidney disease?
What is Proteinuria
The kidneys function as master chemist of the body keeping it chemically balanced and healthy. The three important functions of the healthy kidneys are to remove waste from our body, regulation of electrolytes and water balance, and production of various hormones for blood production, healthy bones and blood pressure control. Chronic kidney disease (CKD) is a term the doctors use to categorise whatever disease process that can potentially damage the kidneys. When the kidneys are damaged progressively over a period time, they are unable to perform the various vital functions optimally; this condition is termed chronic kidney failure. Most diseases attack both kidneys simultaneously and hence when kidney failure is confirmed via blood testing, it usually means both kidneys are affected.
In a report published recently, 26 million Americans adults (1 in 9) have CKD. More than 367,000 patients are currently dependent on dialysis for survival. Every two hours, one person waiting for a kidney transplant dies. For every patient who is on dialysis, there are 200 more patients with moderate stage of CKD and more than 5000 with early stages of CKD. Many more millions of Americans are at increased risk for developing CKD, but most do not even know it. In the 6th Report of the Singapore Renal Registry 2005/2006, 990 and 1111new patients were diagnosed to have advanced kidney failure requiring initiation of dialysis support in 2005 and 2006 respectively. Similar to the United States, there are probably thousands of Singaporeans who are suffering from CKD or are at risk of developing CKD in the future.
In chronic kidney failure, the damage often occurs very gradually over the years Thus, there may not be any obvious symptoms and most CKD patients do not have any symptoms early in the disease. Most of them feel well until their kidney disease are in the advanced stage of kidney failure. Even if they experience symptoms, majority of the symptoms for CKD are rather non-specific and these include :
- feel more tired, fatigue and have less energy
- have trouble concentrating
- decrease in appetite and lost of weight
- not sleeping well
- persistent generalized dry and itchy skin
- frequent muscle cramps at night
- swelling of the feet and ankles (see picture 1)
- puffiness of eyes, especially in the morning
- passing out bloody, cloudy or tea-coloured urine (see picture 2)
- excessive foaming of the urine that indicates the presence of protein (see picture3)
- need to urinate more often, especially at night
- decrease in urine output or difficulty in passing urine over a period of time
- high blood pressure (hypertension)
Such symptoms are due to the lost of the vital kidney functions and hence resulting in the build up of toxins and excessive water in the body as urination decreases. Some patients may develop symptoms and sighs related to the complications associated with kidney failure such as hypertension (headache, visual disturbances, nausea) and anemia (giddiness, tiredness, shortness of breath).
The main cause of kidney failure in Singapore is diabetes mellitus which accounts for more than 50% of the cases. Other common causes that may affect the kidneys are :
- Glomerulonephritis (chronic inflammation and scaring of the kidneys)
- Hypertension
- Inherited kidney diseases, such as polycystic kidney disease
- Urinary tract obstruction caused by problems such as kidney stones, enlarged prostate in elderly males
- Recurrent urinary tract infections
CKD can affects people of all ages. Prevention and early identification of CKD with early appropriate treatment can significantly increase the chances of retarding and reversing the deterioration process. By understanding the common causes of CKD, we can now appreciate that some people are more likely than others to develop kidney disease. You may have an increase risk for CKD if you:
- have diabetes
- have hypertension
- have a positive family history of CKD
- are elderly
In general, every adults should have a screening test done for CKD, especially those who are at risk for CKD. The screening process is simple and only require three easy tests :
- blood pressure measurement
- urine analysis for protein and blood
- blood test for creatinine level
Such tests should be preformed at the first instance the underlying disease (e.g. diabetes mellitus) is diagnosed and subsequently on an annual basis.
Once CKD is detected, the goal of therapy is to retard or halt the otherwise relentless progression of CKD to advanced kidney. Control of blood pressure and treatment of underlying disease (e.g. diabetes mellitus), whenever feasible, are the broad principles of management in CKD.
Similar to the management of all chronic diseases (CKD is a chronic disease), healthy lifestyle plays a pivotal role in the prevention and management of CKD. Reduction in the daily intake of salt (sodium) and protein in our diet are important steps to preserve the kidney function. Studies have proven that excessive salt intake may result in fluid retention and uncontrolled hypertension thus leading to further insult on the kidneys. Many studies show that a reduction in sodium intake to 2300 mg/day can lower systolic blood pressure by about 5-6 mmHg and diastolic pressure by 1-2 mmHg among hypertensive individuals. Moreover, many who are not yet on blood pressure medication respond nicely to sodium reduction, particularly in those whose blood pressure is the high normal range. Too much protein can make the already malfunctioned kidneys work too hard in removing the protein and toxic metabolites. Excessive protein when excreted in the urine can cause further kidney damage. Smoking cessation is also an important step in the management of CKD. Smoking not only damages the kidneys directly, it also increases the blood pressure and interferes with the medication used to treat hypertension.
Controlling the blood sugar level to the recommended target level is of paramount importance in those diabetic patients. Uncontrolled diabetes not only predisposes a diabetic patient to risk of developing CKD, it also accelerates the rate of worsening of the kidney function in diabetic patients with CKD.
As high blood pressure can lead to progression of CKD, it is important to lower the blood pressure to around 130/80mmHg as recommended by various international guidelines. Generally, all classes of anti-hypertensive agents are effectively in controlling blood pressure; however, in CKD patients, two classes of anti-hypertensive agents are preferred as first line blood pressure medicine. These are the Angiotensin converting enzymes inhibitors(ACE-inhibitors) and Angiotensin II receptor blockers (ARBs). These 2 classes of anti-hypertensive agents not only can effectively lower blood pressure, they have added functions of reducing protein in the urine and renal function preservation.
CKD can cause other associated complications such as high lipids, anemia and kidney bones disease. Medications may be required to treat these associated complications in CKD patients.
In summary, CKD is a common disease and is associated with various serious complications, morbidity and mortality. Early detection through screening (especially in those people who are at risk) with early institution of appropriate medications are of extreme importance in the management and prevention of CKD.
Dr Roger Tan
Consultant Nephrologist
Roger Kidney Clinic
Gleneagles Medical Centre