To diagnose diabetes mellitus, assess the severity and state of disease compensation, determining fasting blood sugar and re-determining it during the day, studying daily and fractional glycosuria in separate portions, determining the content of ketone bodies in urine and blood, studying the dynamics of glycemia are of paramount importance. with various forms of glucose tolerance test.
The study of blood sugar can be carried out by various methods, which must be indicated for the correct interpretation of the test results. One of the most accurate methods that determine the true glucose content in the blood is glucose oxidase.
The fasting blood sugar level by these methods in healthy individuals is from 3.3 to 5.5 mmol / L (from 60 to 100 mg in 100 ml of blood), during the day it does not exceed 7.7 mmol / L (140 mg%)
The fasting blood sugar level in healthy individuals is from 3.3 to 5.5 mmol / L, during the day it does not exceed 7.7 mmol / L.
To date, some laboratories still use the titrimetric method based on the restoring properties of glucose. Since other reducing substances are also detected, the blood sugar according to this method is 10% higher than its level determined by other methods. The norm of fasting blood sugar according to the Hagedorn-Jensen method is 80-120 mg%, or 4.44-6.66 mmol / L.
It should be remembered that capillary (mixed) blood from a finger contains 100 ml per 1.1 mmol (20 mg) of glucose more than venous, and the level of glucose in plasma or serum is 10-15% higher than the determined level of glucose in capillary blood. This is significant when evaluating a glucose tolerance test. Detection of glycosuria can be qualitative and quantitative. Qualitative determination is made either using reagents or special, indicator papers such as glucose test. Indicator strips and tablets are very sensitive (detect glucose concentrations from 0, 1 to 0.25%), with their help it is also possible to quantify sugar in urine up to 2%.
Quantitative determination of sugar in urine is carried out using a polarimeter or other methods.
In the presence of characteristic clinical symptoms (polydipsia, polyuria, nocturia) in combination with glycemia and glycosuria, the diagnosis of diabetes is not difficult.
Obvious diabetes is established based on the detection of sugar in the blood and urine.
Obvious diabetes is established based on the detection of sugar in the blood and urine. Lab analysis is examined on an empty stomach. Glycosuria is determined in daily urine or daily, or in a portion of urine collected 2 hours after a meal. Examination of morning urine alone is not indicative, since with mild forms of diabetes in the urine collected on an empty stomach, glycosuria is usually not detected. With a slight increase in fasting blood sugar, a diagnosis is possible only if you get repeatedly unequivocal results, supported by the detection of glycosuria in daily urine or in separate portions of urine. The determination of the diagnosis in such cases helps the determination of glycemia during the day based on the food received by the patient. In cases of untreated obvious diabetes mellitus, the blood sugar level during the day exceeds 10 mmol / L (180 mg%), which serves as the basis for the appearance of glycosuria, since the renal permeability threshold for glucose is 9.5 mmol / L (170-180 mg% )
Glycosuria is often the first symptom of diabetes detected in the laboratory. It should be remembered that the presence of sugar in the urine is a more common phenomenon than its detection in the blood. Various variants of sensitivity of the permeability threshold for glucose can be observed, for example, renal diabetes, in which the excretion of sugar with urine is observed during physiological fluctuations in glycemia, as well as various nephropathies, in which tubular glucose reabsorption is reduced. However, all patients with glycosuria should be carefully examined in terms of diagnosing latent diabetes mellitus.