Sugar in the urine. What does it mean?

What is the renal threshold?

Sugar in the human body comes with food products, which include carbohydrates. The name "sugar" combines two carbohydrates - glucose and fructose. However, speaking of it as a laboratory indicator, only glucose is always considered. Why does sugar appear in the urine with various diseases? How to regard it? What is Glucosuria? Let's talk about this in more detail.

Normally, glucose in the intestine is absorbed into the blood, enters the cells of the body and penetrates into them through the action of insulin. It is used as a source of energy and as a plastic material.

Excess glucose is partially deposited in the liver in the form of glycogen. The other part of the blood vessels enters the kidneys and is filtered in their glomeruli into the so-called primary urine. Primary urine from the glomeruli enters the proximal renal tubules. There, sugar is absorbed by means of special carrier proteins and enters the bloodstream again. While the blood sugar does not exceed a certain amount, called the renal threshold, it is completely reabsorbed from the primary urine. Therefore, in the urine of a healthy person there should be no sugar. The renal threshold is an individual value, but on the average it is equal to 10 mmol / l. In children and pregnant women it is lower - about 7 mmol / l.

If blood sugar exceeded 10 mmol / l, then, after getting into the primary urine, it can not completely reabsorb. Its too much. Some part of it gets into the final urine and is removed along with it from the body. Thus, sugar appears in the urine, which is determined by laboratory tests.

Normally, there can be only traces of sugar in the urine. This concentration is not more than 0.2 mmol / l. It is not detected by conventional methods. The determination of sugar from urine determined by laboratory methods is called glucosuria. It is physiological and pathological.

At what conditions does sugar appear in the urine?

At what diseases and conditions does sugar appear in the urine? What does it mean? Physiological glucosuria may be associated with increased blood sugar in stress, exercise, taking certain drugs, for example, steroidal anti-inflammatory drugs; At pregnancy, at the use in a plenty of sweets, honey. It does not last long, it is not high, and when the blood sugar decreases, it disappears.

Pathological glucosuria happens:

1. Not dependent on the state of the kidneys,
2. Caused by a violation of the reabsorption or filtration function of the kidneys.

In the first case, sugar in the urine with diabetes is the most frequent example of glucosuria. In this disease, blood sugar is increased because of a lack of insulin or the inability of cells to respond to it. If the blood glucose exceeds the renal threshold, sugar will appear in the urine in an obligatory manner.

Increase in blood glucose in diseases such as Isenko-Cushing's disease, pheochromocytoma, thyrotoxicosis can also lead to an increase in blood glucose. It can also be caused by severe chronic liver diseases, in which its function of glucose storage is impaired. In all these cases, the appearance of sugar in the urine is a sign that there is too much of it in your blood.

With glycosuria of the second type, sugar in the blood can be normal, and the appearance of it in the urine is due to the fact that the kidneys are impaired. In this case, both renal filtration and reabsorption can be increased.

How to pass urine to the analysis?

Determine the sugar in the urine collected per day. The first, usually morning, portion of urine for analysis is not taken. All the following during the day, including the morning portion the next day, collected in a jar. The bank should be kept in the refrigerator, otherwise part of the sugar will collapse, and the result of the analysis will be understated. For example, you collect urine from 7 o'clock in the morning to 7 o'clock tomorrow. The urine should be measured as accurately as possible and recorded, what is its daily amount.

Then the urine must be mixed, poured a little into a small jar and taken to the laboratory. To find out how much sugar a person spends per day, you need to increase the amount of sugar in 1 liter by the daily amount of urine, which is usually done by laboratory assistants themselves.