Film on urine (white, iridescent): causes

Urine is a natural biological fluid secreted by the kidneys as a result of the breakdown of unnecessary metabolic products. The kidneys normalize the water and electrolyte balance of the body, help maintain normal blood pressure, cleanse the blood of waste, toxins, microbes, etc.

The importance of kidney function cannot be overestimated. In 24 hours they pump up to 200 liters of blood, completely purifying it. Therefore, it is extremely important to constantly monitor the normal functioning of organs and do urine tests at least 3-4 times a year.

But even without a clinical laboratory, we can independently ensure that urine is always normal, which means that the kidneys continue to function normally.

Visual assessment of urine

The analysis requires the first portion of morning urine. Before taking the test, you need to wash thoroughly, preferably with potassium permanganate, and the test vessel must be clean. The first thing you need to pay attention to is the color. The urine of an adult healthy person is straw-yellow in color.

But remember that urine changes color due to some medications, food and the amount of liquid you drank the day before. For example, carrots turn them orange, and beets turn them reddish-brown.

Next is transparency. There should be no sediment, mucus, flakes, etc. in the fluid. Usually, crystalline sediment indicates the presence of sand or kidney stones.

How do laboratories detect lipemia?

Lipemia can be seen with the naked eye. The blood of such patients appears cloudy. This method is not reliable. Lipemia can be noticed only if the concentration of triglycerides is very high: in the supernatant - more than 3.4 mmol/L, in whole blood - more than 11.3 mmol/L. This is very subjective; not every laboratory technician can examine the changes that are recorded using special tests.

Many laboratories test for triglyceride concentrations. This method makes it possible to indirectly judge the presence of lipemia and, in combination with determining the L-index (more about it below), judge its cause. But this study has two shortcomings:

The content of triglycerides in different types of lipoproteins varies: for example, in VLDL it is about 50%, in chylomicrons – up to 85–90%.
In most of these assays, triglyceride concentration is inferred from the oxidation of glycerol to dihydroxyacetone phosphate. The more triglycerides, the faster glycerol oxidizes. If there is a lot of glycerol in the sample, a false positive result will be obtained. Such cases are known in patients with certain genetic disorders, among lovers of beer that contains glycerin.

Currently, automatic determination of the L-index is most often used. The essence of the method is that a blood sample is diluted in saline or a special buffer solution and the absorption spectrum of light of a certain wavelength (300–700 nm) is measured. The more lipids in a sample, the more it absorbs light.

Automatic determination of the L-index is a fast, inexpensive and fairly accurate method for detecting lipemia. But it also has some disadvantages. You can get a false positive result when the blood plasma is cloudy due to the content of other substances, for example, paraprotein (an “incorrect” immunoglobulin protein that appears in the blood in some diseases), contrast dyes that are used during some medical procedures.

Test systems for automatically determining the L-index are produced by different manufacturers; there is no single standard, and this makes it difficult to interpret the analysis results. Thus, errors are also possible when using this method, although they are rare.

Film on urine

If a fatty film is clearly visible on top of the urine, this indicates a large amount of fatty food eaten. This is especially clear in children's analyses. In this case, the diet should be adjusted so as not to complicate the functioning of the liver and kidneys.

Sometimes a rainbow film forms on the urine. Its appearance can be due to two reasons: infection by parasites. It has been proven that every third adult carries parasites in their body without knowing it. And also the presence of acetone in the urine gives a rainbow effect.

Important: if parasites are present, the urine changes not only its color, but also its smell. The smell becomes pungent and unpleasant, and the urine darkens and various impurities appear in it.

Oily urine is observed in people who have a body weight that is much higher than normal, high cholesterol, and sometimes it appears in patients with diabetes.

Why does lipemia occur?

The most common reason is improper patient preparation. After eating a meal, especially a fatty one, the content of chylomicrons in the blood increases for several hours. Often, doctors simply say that you need to show up for tests in the morning on an empty stomach. Everyone can understand this in their own way. For example, a person can have dinner very late, then sleep a little and come to the clinic in the morning without breakfast, but the required interval will not be maintained. In emergency situations, when analysis needs to be done immediately, there is often no time to find out when the patient last ate.

This is why doctors at the Center for Immunology and Reproduction tell patients in such detail how to properly prepare for tests. It is important to strictly follow these recommendations.

Other possible causes of lipemia:

Recent introduction of fat emulsions for parenteral (intravenous) nutrition. They are usually used in intensive care units and in patients who cannot feed themselves or are unable to feed through a tube. These are drugs such as Intralipid, SMOFlipid, Lipofundin, Lipovenoz.
Primary lipemia is a hereditary disorder of lipid metabolism.
Secondary lipemia is a condition that is a symptom of other diseases, such as non-alcoholic fatty liver disease, diabetes mellitus, HIV infection, and renal dysfunction.
Excessive alcohol consumption, alcoholism.
Taking certain medications: antiretroviral drugs, glucocorticosteroids, non-selective beta-adrenergic receptor antagonists.
There is evidence that ketogenic diets increase blood cholesterol and triglyceride levels.

Reasons for the appearance of white film

A short time after the test, a white film forms on the surface, or a cloudy sediment appears in the urine. There are several physiological reasons for this phenomenon:

Increased physical activity, fatigue recently,
Constant and prolonged hypothermia of the body,
Chronic alcoholism,
Prolonged stay in the sauna, overheating of the body,
Taking medications containing phosphorus or calcium
Prolonged stress state
Neglect of intimate hygiene rules

But if the appearance of a white film repeats from time to time, then it is better to consult a doctor and get tested to rule out a serious disease.

If there is an inflammatory process in your kidneys - pyelonephritis, or this disease was protracted and took on chronic forms, then such a deviation from the norm as a white film or cloudiness in the urine may indicate the presence of phosphate stones in the kidneys.

Men suffering from inflammation of the prostate gland may experience a white film in their urine. Women can also have this feature with inflammation of the female genital organs.

How does lipemia interfere with testing?

Lipemia can interfere with blood tests in several ways:

Increases light absorption. Because of this, the results of spectrophotometric analysis, which are used during biochemical blood tests, are distorted. The accuracy of studies that use light with a short wavelength suffers especially severely. The device determines the concentrations of some substances, for example, ALT, AST, bilirubin, incorrectly.
Lipoproteins prevent antibodies from binding to antigens. As a result, the results of immunological tests are distorted. Depending on the nature of the reaction, they can turn out to be false positive and false negative.
Distorts the results of studies in which the method of capillary electrophoresis of whey proteins is used. For example, it was noted that when analyzing blood with lipemia, the alpha-2-globulin fraction changes.
Leads to heterogeneity of plasma and serum after centrifugation. In a centrifuge, VLDL, due to its low density, accumulates in the upper layer. Accordingly, there will be very few substances that are soluble in water. During analysis, their concentration will be incorrectly determined as low. At the same time, steroid hormones and some drugs accumulate in the upper lipid layer, and their concentration will be low in the lower part of the tube.
Leads to the effect of volume displacement. Normal blood plasma consists of 92% water and 8% lipids. With lipemia, these figures can be 75% and 25%, respectively. But electrolytes are dissolved only in plasma, they are not in lipids. If the laboratory uses methods that determine the level of electrolytes in the total volume (indirect potentiometry, flame photometry), then their concentration will be lower than it actually is.
With lipemia, hemolysis occurs more strongly - the destruction of red blood cells and the release of hemoglobin from them. This also interferes with the analysis and affects its accuracy. It is not entirely clear why lipids lead to this effect; it is believed that they act on the wall of red blood cells during the processing and centrifugation of blood as detergents (surfactants).

How to establish an accurate diagnosis of the disease?

An accurate diagnosis can only be made in a clinical laboratory. To do this, all the urine per day is taken. A week before the test, you need to adjust your diet: you should not eat anything smoked, spicy, salty, exclude alcohol, carbonated drinks and chocolate.

Starting at 6 a.m., all the urine excreted by the body is collected in one container, which is immediately tightly sealed with a lid and put away in a cool place. A day later, i.e. at 6 am the next day, all the liquid is carefully mixed, the volume is measured and recorded, and 100 g of liquid is sent to the laboratory for testing.

Interesting fact

Making a diagnosis by analyzing biological fluids was known back in Ancient Greece and Ancient Egypt. To obtain an accurate diagnosis, milk from a woman who had just given birth was used. A few drops of milk were poured into the urine of a seriously ill person. If the milk froze at the bottom in the form of sediment, they concluded that the patient would soon die. If the milk remained in the middle of the vessel, then the illness will be long-lasting, but the result is still unknown. If the milk floats to the surface, the person will soon recover.

Modern medicine explains this phenomenon by changes in the density of urine during severe inflammatory processes, with glomerulonephritis, pyelonephritis or tuberculous kidney infection.

Accurate diagnosis

To obtain detailed data on the functioning of the urinary system, a daily urine test is performed, since it is the daily excretion of salts by the kidneys that is limited. Since its chemical composition directly depends on the food consumed, spicy, smoked, sweet, carbonated and alcoholic drinks and canned food are prohibited a week before the procedure. Urine is collected throughout the day in one container, starting at 6 a.m., each time the container is tightly closed with a lid to prevent oxidation, and it is put away in a dark, cool place. The last collection of material is done no later than 6 a.m. of the next day, after which the urine is shaken, 100 ml is poured into another clean jar and sent to the laboratory as quickly as possible. The accompanying note should indicate the total volume of daily urine.

If phosphates were detected in a random analysis, the doctor is obliged to inform the patient about the dangers of salts in the urine. Phosphorus is necessary for the body for normal metabolism, muscle and brain function. Its level increases with frequent consumption of foods containing phosphates. With their excess, the body poorly absorbs magnesium, calcium and iron. Phosphaturia therapy is the prevention of stone formation and chronic inflammation of the urinary system. To prevent the precipitation of insoluble salts, a special diet is prescribed, which restores the acidity of urine, and in an acidic environment, phosphorus-calcium sediment does not form.