Dr. Vijay Kher

Early detection and prevention of Chronic Kidney Disease

Chronic kidney disease (CKD) is progressive and irreversible deterioration of kidney function and represents a significant health problem worldwide both in terms of magnitude of the disease as well as the financial implications it involves.

In USA it has been found that about 1 person in 10 in the general population has some form of kidney disease which when extrapolated to India would suggest that at least 100 million people in INDIA if not more, have some form CKD (Table I).  Globally more than 500 million individuals have some degree of chronic kidney disease.

The common causes of CKD in India and globally are Diabetes, hypertension, chronic glomerulonephritis and chronic interstitial diseases. CKD is a slowly progressive disorder and is categorized into 5 stages depending on the degree of loss of kidney function (estimated as glomerular filtration rate (GFR) (Table 1).  Stage V is the stage when kidney function falls less than 15 % (estimated GFR < 15 ml/min [normal GFR 90-100 ml/min] and is called kidney failure when a patient requires dialysis or kidney transplant / renal replacement therapy. Uncontrolled diabetes and hypertension, two commonest cause of CKD usually take 10-15 years to cause kidney failure. Thus there is huge scope for prevention of kidney disease in these conditions if kidney disease is diagnosed / detected early and intervened effectively.

Strategies for early detection and prevention

Screen subjects at high risk for chronic kidney disease. These are

  • Patients with diabetes mellitus and hypertension
  • Patients with history of kidney disease
  • Obese individuals or those who smoke.
  • Individuals above 60 years of age
  • Individuals with family h/o diabetes, hypertension and kidney disease

What should you do in these high risk subjects?

  • Spot urine albumin protein to creatinine ratio – which will pick up individuals with microalbuminuria (30 – 300 mg /gm of creatinine); overt albuminuria (> 300 mgms /gm creatinine); serum creatinine and estimate GFR, and if need be imaging tests.
  • Those with microalbuminuria or overt albuminuria and early CKD especially with diabetes & hypertension should be given ACE inhibitor’s or ARB’s (specific type of anti hypertensive medicines) and monitored regularly to achieve target blood pressure levels of less than 130/80 mmHg, glycosylated hemoglobin (HbA1c) of < 7 % (measures 3 months average blood sugars). The dose of ARB’s or ACEI’s should be targeted to decrease or normalization of proteinuria / or microalbuminuria and target blood pressure levels. These strategies have reduced the burden of disease from cardiovascular disease, diabetes, hypertension & CKD at relatively less expense.
  • Thus it is possible to detect & diagnose early CKD with easy to do tests in the clinic and institute cost effective preventive therapies so that need for more expensive therapeutic modalities for kidney failure is lessened.
  • Early detection is possible with doing simple laboratory tests in the high-risk individuals like urinalysis, spot urine protein / albumin to creatinine ratio and serum creatinine and estimate GFR using MDRD or cockroft & Gault formula.
  • The consequences of undetected CKD is progressive loss of kidney function leading to kidney failure and need for dialysis & transplantation which are expensive treatment modalities. The other important consequence is premature death due to cardiovascular events. The mortality of a patient on dialysis is more than 100 times than in the general population. A 25 year old person in general population on dialysis has similar mortality to an eighty year old person. What has been very striking is that even in early stages of CKD like GFR < 70 ml/min vs > 90 ml ml/min the relative risk of death is 1.68. This is at a stage when serum creatinine level may not be higher than in the normal range. Mortality rates even among the subjects with urinary protein levels more than 300 mg/dl vs < 30 mg/dl are six times higher.
  • These revealing data during the last five years have highlighted that even small increases in serum creatinine levels suggesting minimal deterioration of kidney function either in form of proteinuria or deterioration of GFR have a huge impact on cardiovascular mortality. Kidney function has been emphasized by these data to the most important factor determining cardiovascular events. Thus a need for early detection and possible prevention.
  • The costs of end stage kidney disease are escalating worldwide. More than 1.5 million people are currently alive through either hemo or peritoneal dialysis or transplantation. Over the next decade the cost is predicted to exceed to more than one trillion dollars. The economic burden could strain healthcare budgets worldwide, more so in the developing countries. For lower income countries it is impossible to meet such costs. With epidemics of diabetes and hypertension worldwide, the greatest growth and impact of these is likely to be in the developing world, thus greater need for early detection and prevention in these countries and as much important for India.
  • “Diabetes and hypertension are developing in epidemic proportions in our country and kidney disease consequent to these will have a huge financial impact unless we introduce a national programme for prevention of kidney disease along with control and prevention of diabetes & hypertension.
  • 12th March 2009 is going to be celebrated as world kidney day and we intend to educate public about kidney disease, its prevention and also management.

Table 1

Stages of Chronic Kidney Disease

Stage Description GFR Estimated burden in India
1. Kidney damage with normal or  GFR > 90 28 million (2.8 %)
2. Kidney damage with mild ¯ GFR 60 – 89 28 million (2.8 %)
3. Moderate ¯ GFR 30 – 59 37 million (3.7 %)
4. Severe ¯ GFR 15 – 29 1.3 million (0.13 %)
5. Kidney Failure < 15 (or dialysis) 2 million (0.2 %)