Chronic kidney disease

Most people would associate chronic kidney disease (CKD) with kidney failure requiring dialysis or kidney transplantation. However, CKD is not just about kidney failure. There are 5 stages of CKD, namely, stage 1 – glomerular filtration rate (GFR) ≥ 90 ml/min/1.73 m2 with proteinuria (protein in the urine), stage 2 – GFR 60 – 89 ml/min/1.73 m2 with proteinuria, stage 3 – GFR 30 – 59 ml/min/1.73 m2, stage 4 – GFR 15 – 29 ml/min/1.73 m2 and stage 5 – GFR < 15 ml/min/1.73 m2. Patients with stage 4 or 5 CKD are having end stage kidney disease. Most patients with CKD would have died from other causes before they reached the dialysis state. While there are ample information on the prevalence of end-stage renal disease in the general population, information on national prevalence of CKD is not widely available.

A recent study from the National Health Research Institutes of Taiwan looked at the prevalence of CKD in a cohort of 462, 293 individuals older than 20 years who participated in a standard medical screening programme since 1994 (Lancet 2008; 371: 2173 – 2182). They were observed for 13 years with a median follow-up of 7.5 years. CKD in this cohort was determined by GFR (estimated from a formula based on serum creatinine) and urinary protein. From this cohort of participants, the national prevalence of CKD was determined. The national prevalence of CKD in Taiwan was 11.93%. The prevalence of CKD differs according to the socioeconomic status of the individual. In the low socioeconomic status population, the prevalence of CKD was 19.87% as compared to 7.33% in the high status group. Cohort participants with CKD had an 83% higher risk of dying from all causes of death compared to those without CKD. The risk of dying from cardiovascular diseases was 100% higher for those with CKD. In the whole study population, 10.3% of deaths were attributable to CKD but in the low socioeconomic status population, 17.5% of deaths were attributable to CKD. Thirty nine percent of people with CKD who died did so before the age of 65. Another interesting fact that came out of this study was that regular users of Chinese herbal medicines had a 20% increased risk of developing CKD.

People with stage 1 to stage 3 CKD are usually asymptomatic. Unless you measure the GFR (either by actual measurement or from estimation with a formula based on serum creatinine), you will not know there is a problem with your kidneys. Unless you test your urine for protein, you will not know you have proteinuria. Testing urine for the presence of protein is not a laborious or difficult task. All it involves is dipping a test strip into some urine and comparing the colour changes on the strip against a chart. The test strip will not only tell you whether you have protein in the urine but also if you have blood, white cells and bacteria in the urine.

The use of Chinese herbal medicines by the Chinese population is unavoidable. However one should be mindful that injudicious use can damage your internal organs such as the kidneys or the liver. If CKD does not kill you immediately, it will certainly increase your risk of dying from other causes at a relatively young age of below 65.

For those who could not afford a full medical health check, just having a simple urine dip stick test can give your doctor very valuable information on the status of your kidneys. The good thing about urine dip stick is – its very cheap!