KIDNEY WORK WHEN EVIL - Chronic kidney disease is a serious, often ignored by patients themselves because, unlike other diseases, it can silently progress to an advanced stage.


The kidneys have many functions, the most important of which is the removal of nitrogenous wastes from the body. But they also regulate the concentration of minerals - or electrolytes - such as calcium, sodium or potassium in the blood, acid-base balance and the amount of fluid in the body. They also play an essential role in regulating blood pressure; they also produce erythropoietin, essential for the production of red blood cells. Finally, they host the final stage of the chemical conversion of vitamin D, essential for bone particular. (See also Kidneys, precise as clockwork)

What is kidney failure?

Kidney filtered through the glomeruli daily by 180 liters of liquid which are then largely reabsorbed by the renal tubule to finally form 1 to 2 liters of final urine. Kidney function is measured by glomerular filtration rate which normal values are between 80 and 120 ml / min depending on age, sex, weight and ethnicity.

The function of elimination of nitrogenous waste is measured by blood urea (waste from food) and creatinine (waste product of muscle metabolism). These two products are eliminated in the urine. If urea and creatinine accumulate in the blood, it shows a decrease in glomerular filtration rate, thus kidney failure, described according to five stages of severity. Less than 15 ml / min (stage 5), the inability of the kidneys is almost complete: we must quickly consider dialysis or organ transplantation. Less than 60 ml / min (stage 3), the first symptoms of kidney failure appear.

Kidney failure is called chronic when the disease is installed, with a very low reversibility of luck. But it can also suffer from acute renal failure, however, has a very high recovery potential. About 5% of the population in industrialized countries have chronic kidney disease, the most moderate (stage 3), the percentage associated with severe renal impairment is still low (0.4%). In Switzerland, about 350 000 people were affected, including 30,000 with severe disease.

Causes ...

Chronic renal failure is the result of a disease affecting both kidneys, whatever its origin. The main causes of chronic renal failure - those of acute renal failure are very different ... it must now include:

  • hypertension (31%) and diabetes (15%): these diseases are often integrated into a table where others suffer organs, like the heart, blood vessels or the brain;
  • glomerulonephritis (15%) and interstitial nephritis (14%), affected more specific;
  • polycystic disease (cysts, sometimes very large, gradually developing in the kidney) alone accounts for over 11% of cases.

Note that these percentages are calculated for the Swiss French-speaking population on dialysis. The proportion of chronic kidney disease less severe, is linked to hypertension or diabetes, is probably more important in the general population, but less well identified.
It should also be noted that acute pyelonephritis (infection or kidney) and renal colic (caused by kidney stones), two common diseases and very "noisy", very seldom the cause of chronic kidney failure, thanks to easy identification and the many treatments available.

... And consequences

Chronic renal failure causes:

  • hypertension (very frequently, since it may also be the cause);
  • anemia;
  • bone disorders;
  • water, electrolyte disorders, including a salt retention that can form edema, and potassium retention which can be dangerous for heart function.

Unlike other diseases such as heart failure, kidney failure can progress silently until a relatively advanced stage. Indeed, hypertension is often the first clinical manifestation objectified, but she herself is known is often silent. Furthermore, early clinical symptoms (fatigue, loss of appetite, shortness of breath ...), when present, are nonspecific and may be due to many other causes.

The kidneys can lose more than 80-90% of the service before lead to decreased urine production. When we get to this point, the need for dialysis is often required in a short time and the chances of recovery are very low. This situation concerns 30 to 40% of patients before start of dialysis.



Early detection is key

The search for the last twenty years has helped to clarify the mechanisms of progression and better assess the impact of chronic renal failure. We now know that, even if kidney disease is halted, continuous renal progress through mechanisms independent of the underlying disease, following the loss of kidney tissue. The kidney tissue unharmed must somehow work in "overdrive" to accomplish its physiological tasks and this excess load causes an "accelerated aging" irretrievably going to a decline in function.

Chronic kidney disease first requires early identification, in order to stop or treat as early as possible the responsible disease and preserve as much healthy kidney tissue. Furthermore, recent studies show that one can curb effectively the decrease in function by different measures that save the work of the kidneys. By identifying more precisely the mechanisms involved in this accelerated aging, we will have more effective therapeutic tools for slow or even stop it.

Epidemiological research has enabled better assess the importance of chronic renal failure and measure its impact on the world in life expectancy and quality of life. Based on the increase in diseases such as diabetes and hypertension, especially in less industrialized countries, and the aging of the population, we should expect more cases in the coming years or, at the world population, a real public health problem. Studies have shown that even moderate (stage 3), most of the time hidden, kidney failure has a negative influence on survival and promotes the appearance of other cardiovascular diseases such as heart failure.

An effort is underway to early identification of patients with kidney failure and inform them of the significance of the diagnosis and the possible consequences. This involves a control of blood pressure, a blood test for the determination of creatinine and a urinalysis. This first step is essential, because screening is not enough. Informed patients must improve: surveys estimate that only 20% of patients know they have chronic renal insufficiency. This is not to alarm patients but to make them aware of the problem and precautions.

good and low blood pressure lifestyle are key to treatment

If there is no specific treatment, many measures have proved effective, either to curb the deterioration of kidney function, or to avoid or reduce cardiovascular consequences:

Maintaining a lower blood pressure than usual standards is one of the most important elements (the aim should be 130/80 on average). Some classes of antihypertensive drugs appear to provide an additional protective effect. However, despite the numerous drugs available, the goal is difficult to achieve and often requires multiple medications, with the risk of side effects, frequent monitoring and prescribing a low-salt diet.

A second measure, very important, is the correction of cardiovascular risk factors, since kidney failure is, somehow, a cardiovascular disease. It optimizes the treatment of high cholesterol, diabetes, and it is also recommended to patients to quit smoking and practicing regular physical exercise. Chronic kidney disease causes abnormal blood calcium and phosphorus that have not only on bones consequences, but also the vessels that can calcify, preventing proper circulation and worsening atherosclerosis. The correction of these anomalies is difficult. We must reduce the absorption of dietary phosphate, administer vitamin D active and compensate for the lack of bicarbonates and be restricted to the food level.

A dietary approach is in fact inseparable from the management, its importance increasing as renal failure progresses. Besides salt, it may be necessary to reduce the intake of protein, phosphate and potassium.

In conclusion, chronic renal failure is a very little manifesto first syndrome: it must be detected earlier. Among the measures for identification, the measurement of blood pressure, a measurement of creatinine and urinalysis tests are the first to perform. In about 50% of cases, chronic renal failure is the result of a general disease such as hypertension or diabetes. In the absence of specific treatment, the highlight must be accompanied by an optimization of the treatment of systemic disease (eg diabetes control), the introduction of measures to protect the kidneys (such as continued a lower blood pressure), dietary precautions and correction associated biological abnormalities