Unfortunately, diabetes often gives complications to the kidneys, and they are very dangerous. Kidney damage in diabetes mellitus gives the patient a huge problem. Because for the treatment of renal failure, it is necessary to regularly carry out dialysis procedures. If you are lucky to find a donor, then a kidney transplant is performed. Diabetic kidney disease often causes painful death for patients.
If diabetes is good at controlling blood sugar, then kidney complications can be avoided.
The good news is that if you keep your blood sugar close to normal, you will almost certainly be able to prevent kidney damage. For this you need to actively engage in their health.
You will also be pleased that measures to prevent kidney disease at the same time serve to prevent other complications of diabetes.
How diabetes causes kidney damage
In each kidney a person has hundreds of thousands of so-called “glomeruli”. These are filters that clean the blood of waste and toxins. The blood passes under pressure through the small capillaries of the glomeruli and at the same time filtered. The main part of the fluid and normal blood components returns to the body. And waste with a small amount of fluid passes from the kidneys to the bladder. Then they are removed outside through the urethra.
In diabetes, blood with a high sugar content passes through the kidneys. Glucose pulls a lot of fluid, which causes an increased pressure inside each glomerulus. Therefore, glomerular filtration rate is the most important indicator of the quality of kidney function, and often increases in the early stage of diabetes. The glomeruli are surrounded by a tissue called the glomerular basement membrane. And this membrane is abnormally thickened, like other tissues that adjoin it. As a result, the capillaries inside the glomeruli are gradually replaced. The less active glomeruli remain, the worse the kidneys filter the blood. Since there is a significant reserve of glomeruli in the human kidneys, the process of blood purification continues.
In the end, the kidneys are so depleted that they appear symptoms of renal failure:
- skin itches;
- metallic taste in the mouth;
- bad breath, like the smell of urine;
- shortness of breath, even with minimal physical exertion and rest;
- leg cramps and cramps, especially in the evenings, before bedtime;
- loss of consciousness, coma.
This usually occurs after 15–20 years of diabetes, if the blood sugar was elevated, that is, the diabetes was poorly treated. Uricaemia occurs - the accumulation of nitrogenous waste in the blood, which the affected kidneys can no longer filter.
Analyzes and examinations of the kidneys in diabetes mellitus
To check your kidneys for diabetes, you need to pass the following tests.
- blood test for creatinine;
- urine analysis for albumin or microalbumin;
- Creatinine urine test.
Knowing the level of creatinine in the blood, it is possible to calculate the glomerular filtration rate of the kidneys. Also find out whether there is microalbuminuria or not, and calculate the ratio of albumin and creatinine in the urine. Read more about all these analyzes and kidney performance, see “What tests to pass to check the kidneys” (opens in a separate window).
The earliest sign of kidney problems in diabetes is microalbuminuria. Albumin is a protein whose molecules have a small diameter. Healthy kidneys pass a very small amount of it into the urine. As soon as their work worsens a little, albumin in the urine becomes larger.
Diagnostic indicators of albuminuria
|Albuminuria in the morning urine, mcg / min||Albuminuria per day, mg||The concentration of albumin in the urine, mg / l||The ratio of albumin / creatinine urine, mg / mol|
|Normoalbuminuria||< 20||< 30||< 20||<2.5 for men and <3.5 for women|
|Microalbuminuria||20-199||30-299||20-199||2.5-25.0 for men and 3.5-25.0 for women|
|Macroalbuminuria||>= 200||>= 300||>= 200||> 25|
You should know that an increased amount of albumin in the urine may be not only due to kidney damage. If yesterday there was significant exercise, today albuminuria may be above normal. This should be considered when planning the day of testing. Also increase albuminuria: high-protein diet, fever, urinary tract infections, heart failure, pregnancy. The ratio of albumin to creatinine in the urine is a much more reliable indicator of kidney problems. Read more about it here (opens in a separate window)
If a patient has been diagnosed with diabetes and microalbuminuria has been confirmed several times, this means that he has an increased risk of not only renal failure, but also cardiovascular diseases. If not treated, then later the filtration ability of the kidneys weakens even more, and other proteins, larger in size, appear in the urine. This is called proteinuria.
The worse the kidneys work, the more creatinine accumulates in the blood. After the glomerular filtration rate has been calculated, it is possible to determine at what stage the kidney damage is in the patient.
Stages of chronic kidney disease, depending on glomerular filtration rate
Stage of kidney damage
|Glomerular filtration rate (GFR), ml / min / 1.73 m2|
|> 90, with analyzes showing evidence of kidney problems|
|60-90 - minor kidney dysfunction|
|45-59 - moderate kidney damage|
|30-44 - moderate kidney damage|
|15-29 - pronounced renal dysfunction|
|<15 or dialysis - chronic renal failure|
Notes to the table. Evidence of kidney problems that show tests and examinations. It can be:
- proteinuria (the presence in the urine of large protein molecules);
- blood in the urine (after excluding all other causes);
- structural abnormalities, which showed kidney ultrasound;
- glomerulonephritis, which was confirmed by a biopsy of the kidney.
As a rule, symptoms begin to appear only at the 4th stage of chronic kidney disease. And all the earlier stages proceed without external manifestations. If it turns out to detect kidney problems at an early stage and start treatment on time, then the development of kidney failure is often prevented. Once again, we strongly recommend that you regularly take tests at least once a year, as described in the section “Which tests to pass, in order to check the kidneys”. At the same time, you can also check the levels of urea and uric acid in the blood.
Tablets for type 2 diabetes, which are allowed to use at different stages of kidney disease
Stages of kidney damage, on which it is allowed to apply
|Metformin (Siofor, Glyukofazh)|
|Glibenclamide, including micronized (Manin)|
|Gliclazide and Gliclazide MB (Glidiab, Aktos)|
|Glipizid, including prolonged (Movogleken, Glibens retard)|
|Repaglinide (NovoNorm, Diagninid)|
Note to the table.
* At 4-5 stages of kidney damage, you need to adjust the dose of the drug. Also, as the progression of kidney disease slows down the breakdown of insulin in the body. This increases the risk of hypoglycemia. Therefore, the dosage of insulin needs to be adjusted downward.
Patients who are at risk of developing renal failure.
|Categories of patients||How often should be checked|
|Patients with diabetes mellitus type 1 who become ill in early childhood or after puberty||After 5 years from the onset of diabetes, then - annually|
|Patients with diabetes mellitus type 1 who become ill during puberty||Immediately at the time of diagnosis, then - annually|
|Patients with diabetes type 2||Immediately at the time of diagnosis, then - annually|
|Pregnant women with diabetes mellitus or patients with gestational diabetes||1 time per trimester|
Prevention of kidney damage in diabetes
Chronic kidney disease develops in approximately 1/3 of patients with type 1 and type 2 diabetes, that is, not all patients. How likely it is that you have symptoms of kidney failure depends on the test results that we described in the previous section. Pass the tests and discuss their results with your doctor.
What you can do to prevent kidney damage in diabetes:
- keep blood sugar close to normal - that’s the most important thing
- read the article "Diet for the kidneys in diabetes";
- regularly measure blood pressure at home with a tonometer (how to do it correctly, so that the result is accurate);
- your blood pressure should be normal, below 130/80;
- take tests that check the work of the kidneys, at least once a year;
- perform everything you need to control sugar, blood pressure, cholesterol and fat in the blood, including taking medications prescribed by a doctor;
- adhere to the correct diet for diabetes (in this issue, the "official" recommendations are very different from ours, read below in this article);
- exercise regularly physical therapy, try home exercises with light dumbbells, which are absolutely safe for the kidneys;
- drink alcohol "purely symbolic", never get drunk;
- stop smoking;
- find a good doctor who will “lead” your diabetes and go to him regularly.
Studies have convincingly shown that smoking in itself is a significant factor that increases the risk of developing renal failure in diabetes. Quitting smoking is not a formal recommendation, but an urgent need.
The doctor prescribes kidney treatment for diabetes, depending on what stage is their defeat. The main responsibility for the implementation of appointments is the patient himself. Something depends on his family members.
We list the main directions of treatment of kidney disease in diabetes:
- intensive blood sugar control;
- lowering blood pressure to a target level of 130/80 mm Hg. Art. and below;
- maintaining an optimal diet for diabetic kidney problems;
- control of cholesterol and triglycerides (fats) in the blood;
- kidney transplant.
In the article “Diabetic nephropathy,” the issue of treating kidneys in diabetes is discussed in great detail. Read also "Diet for the kidneys in diabetes."
Diabetes and the kidneys: what you need to remember
If there are problems with the kidneys, then blood tests for creatinine and urine for microalbuminuria allow them to be detected early. If you start treatment in time, this greatly increases the chances of success. Therefore, the analyzes that are described here (opens in a separate window), you need to regularly take 1 time a year. Consider using a low-carb diet to normalize your blood sugar. Read more in the article "Diet for the kidneys in diabetes."
Many diabetics who have high blood pressure, in addition to medication, can help limit salt in the diet. Try to reduce the intake of sodium chloride, i.e. table salt, and evaluate what results you get. Each person has their own individual sensitivity to salt.
Another complication, diabetic neuropathy, can damage the nerves that control the bladder. In this case, the function of emptying the bladder is impaired. In the urine, which remains all the time, infection that can damage the kidneys can multiply. At the same time, in diabetics who have managed to normalize their sugar in the blood, neuropathy is often reversible, that is, it goes away completely.
If you have difficulty urinating or other signs of a urinary tract infection, consult a doctor immediately. These problems can seriously accelerate the development of renal complications in diabetes.