Diagnostic technique for clinically latent hypercorticoidism in patients suffering from stype 2 diabetes mellitus or obesity

FIELD: medicine.

SUBSTANCE: first stage comprises a night suppressive test with dexamethasone 1 mg with a test considered to be positive, if plasma cortisol measured at 8.00 in the next morning exceeds 50 nmole/l. If the first stage has a positive result, the second stage is performed 1-2 days later. At the second stage, blood plasma cortisol at 24.00, daily urine free cortisol, a coefficient of circadian rhythm of cortisol secretion are determined on the same day. If at least two of the three test results are above normal: plasma cortisol at 24.00 is more than 207 nmole/l, daily urine free cortisol is more than 180 mcg/day, coefficient of circadian rhythm of cortisol secretion is more than 50%, hypercorticoidism syndrome is diagnosed. The presented technique provides higher accuracy and simplifies diagnosing of the given disease.

EFFECT: technique enables well-timed adequate therapeutic approach, prevents the disease transformation into manifestative hypercorticoidism with developing severe disabling complications.

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The invention relates to medicine, endocrinology, can be used for the diagnosis of clinically latent hypercortisolism in patients with diabetes type 2 diabetes or obesity.

According to current data, the prevalence of clinically latent hypercortisolism among patients with diabetes type 2 diabetes or obesity higher than that among patients without diabetes and obesity. As expected, clinically hidden hypercortisolism can be either a single disease, so be preclinical stage of overt Cushing's syndrome is a condition with severe disabling complications.

It is known that after identifying clinically latent hypercortisolism and medical interventions, statistically significantly improved glycemic, blood pressure, lipid metabolism - major triad in the treatment of diabetes. Given the prevalence of patients with type 2 diabetes, severe disabling complications as hypercortisolism, and diabetes, diagnosis of clinically latent endogenous hypercortisolism is the actual problem.

However, to date, for the diagnosis of clinically latent hypercortisolism tests used with both low sensitivity and low specificity, which leads to a significant number of cases the EB as a false positive, and false-negative diagnosis.

Currently, a widely used screening method clinically latent hypercortisolism is night suppressive test with 1 mg of dexamethasone with determination of plasma cortisol the next morning at 08.00 described in The Diagnosis of Cushing''s Syndrome. An Endocrine Society Clin Pract Guideline. J. Clin. Endocrinol. Metab. 2008;(93):1526-1540. Protocol test: taking 1 mg of dexamethasone at 2300-2400, 08.00-09.00 hours the next morning produce blood cortisol. The result of plasma cortisol in excess of 50 nmol/l, with high probability, indicates the presence in varying degrees of Autonomous hyperproductive cortisol. The test has a high sensitivity with low specificity and requires further investigation.

Also apply the test with determination of free cortisol in saliva at 23.00 described there, in The Diagnosis of Cushing''s Syndrome. An Endocrine Society Clin Pract Guideline. J. Clin. Endocrinol. Metab. 2008;(93): 1526-1540. Protocol: sample can be collected at home in a special container, which contains a cotton swab that you want to chew on for 1-2 minutes. Normal levels of cortisol in saliva at 2300-2400 not exceed 145 ng/DL (4 nmol/l) using enzyme-linked immunosorbent assay (ELISA) or mass spectrometry.

The described method has the same disadvantages as the previous one, and additionally requires twice the distribution which significantly increases the cost of diagnostic testing. In addition, at present, the method of determination of free cortisol in saliva is not standardized, not determined normal values, and, most importantly, is not widely available due to expensive equipment. Both are described diagnostic methods require additional examination.

At the moment there are no strict recommendations, what test to use to confirm/exclude clinically latent syndrome hypercortisolism. There are three strategies of diagnosis: the use of algorithm for diagnosis of overt Cushing's syndrome, the use of algorithm for diagnosis of subclinical syndrome hypercortisolism and various combinations of all available tests for diagnosing syndrome hypercortisolism.

Nieman LK. as a confirmatory test proposes to use a two-fold determination of free cortisol in urine daily, if the first test was used suppressive test with 1 mg of dexamethasone. Method of test: the first portion of urine after waking up not going, and going all subsequent, including the morning portion of the second day. Required calculate the average values of free cortisol in the two samples. The result is regarded as positive, in case of exceeding the upper value the Oia rules the proposed laboratory for The Diagnosis of Cushing''s Syndrome. An Endocrine Society Clin Pract Guideline. J. Clin. Endocrinol. Metab. 2008;(93): 1526-1540).

One drawback of the test is the need twofold analysis, in other words, the urine within 2 days. This reduces the patient's quality of life and increases the cost of the examination. In addition, the test has a high sensitivity in relation to clinically overt syndrome hypercortisolism, but not in relation to the clinically latent syndrome hypercortisolism.

Terzolo M, Pia A, Reimondo G serves as a supporting use a combination of tests from the definition of free cortisol in daily urine and the level of adrenocorticotropic hormone in the plasma in the morning (Subclinical Cushing''s syndrome: definition and management. Clinical Endocrinology. 2012;(76): 12-18.). In addition to the above drawback associated with the determination of free cortisol in urine daily, this combination of tests can be effective only in the case of adrenal nature clinically latent hypercortisolism. Thus, some patients with pituitary nature clinically latent hypercortisolism remain outside the purview of physicians.

There is a method of assessing the state of the pituitary-adrenal and insular systems of the human body (patent RF№2123186, running from 10.12.1998) concentrations adrenocorticotropin (ACTH), growth hormone (STH), aldosterone (ALD), the court is ash (CDF) and insular apparatus of the pancreas (UGGG) concentration of immunoreactive insulin (IRI) in the blood plasma of people based on gender, age, wecaretoo Quetelet index (IR) and the data correlation analysis of relationships between measured anthropometric and hormonal indicators. The state of the GIE and IAPI was estimated using radioimmunoassay studies of blood plasma by gender, age (group 1 - 20-24 years, 2 group of 25-29 years, group 3 - 30-34 years), IR and the presence of correlations between the studied parameters. If there is a negative feedback between the pairs of indices of "shifts" of the values of the indicators relative to corresponding averages must be multidirectional, if there is a positive correlation between the studied indicators of the value of one of the estimated "paired" indicators compared with its average value should be combined with higher values of another indicator, located on the first correlation, other deviations from the normal values indicate the presence of pathological process.

The disadvantages of this method are the complexity, the need to identify a large number of indicators and the relationships between them.

The prototype of the invention is a diagnostic method with holding suppressive test with 1 mg of dexamethasone (threshold cortisol plasma 60 nmol/l) as the screening of hypercorticism the mA and holding a combination of tests as confirmatory stage. This combination consists of determining the level of adrenocorticotropic hormone at 08.00, free cortisol in urine daily (twice), plasma cortisol at 24 : 00 with the calculation of the coefficient of the circadian rhythm of secretion of cortisol and conduct suppressive test with 4 mg dexamethasone. The technique is generally 1-2 weeks (Catargi B, Rigalleau V, A Poussin, Ronci-Chaix N, Milestones V, Vergnot V, Gin H, Roger P, Tabarin A. Occult Cushing''s syndrome in type-2 diabetes. J. Clin. Endocrinol. Metab. 2003;(88):5808-5813).

The disadvantage of this technique are: 1) high threshold of plasma cortisol after suppressive test with 1 mg of dexamethasone, 60 nmol/l, which entails a reduction in the sensitivity of the initial test; 2) carrying out a large number of tests confirming step that increases the cost of the survey; 3) the use of tests with a high sensitivity only in the case of adrenal nature of hypercortisolism; 4) the use of tests (suppressive test with 4 mg dexamethasone), significantly increases the risk of uncontrolled hypertension and hyperglycemia.

The objective of the invention is the development of more accurate and simple method for the diagnosis of clinically latent endogenous hypercortisolism in patients with diabetes type 2 diabetes or obesity.

This object is achieved in part what about if the level of plasma cortisol after suppressive test with 1 mg of dexamethasone greater than 50 nmol/l, then one day by the method of enzyme-enhanced chemiluminescence carry out the determination of the level of plasma cortisol at 24.00, free cortisol in daily urine, the ratio of circadian rhythm of secretion of cortisol, and if at least two of the three tests above normal: the level of plasma cortisol at 24 : 00 207 nmol/l, free cortisol in daily urine above 180 mg/day, the ratio of circadian rhythm of secretion of cortisol over 50%, diagnose the syndrome hypercortisolism.

The technical result of the invention is to improve the accuracy and reduce the time of diagnosis of clinically latent hypercortisolism in patients with diabetes type 2 diabetes or obesity through two stages consistently for 3-4 days, namely a two-stage diagnostic methods, including as a screening test - suppressive test with 1 mg of dexamethasone (threshold cortisol 50 nmol/l), as supporting a combination of tests: determination of cortisol in blood plasma at 24.00, free cortisol in daily urine once, the calculation of the coefficient of the circadian rhythm of secretion of cortisol. Determination of the concentrations of all hormones carried out by the method of enzyme-enhanced chemiluminescence. The result is the detection of the disease at an early stage, reducing the FOB is cnyh effects on the diagnostic techniques the shortening of the diagnostic examination, the reduction of financial expenses.

The use of cortisol plasma 50 nmol/l after suppressive test with 1 mg of dexamethasone can improve the sensitivity of the test to 98%, which will reduce the number of false-negative test results. And, as a consequence, virtually no patient with a clinically latent syndrome hypercortisolism will not be skipped.

Use in one day combination of tests from the determination of cortisol in blood plasma at 24.00, free cortisol in urine daily and calculate the circadian rhythm of secretion of cortisol will allow you to differentiate the cause of hypercortisolism. Functional hypercortisolism level of free cortisol in daily urine increased, however, the rhythm of secretion saved. Pathological hypercortisolism level of free cortisol can be both normal and elevated, but the rhythm of secretion will be broken. Thus, through the use of tests in one day potentially be reduced the number of false-positive results and, as a consequence, the number of unnecessary and expensive tests. In other words, will increase the specificity of diagnosis.

Use once a combination of tests in one day, compared with the conventional serial twofold performing each TES is and has greater accuracy, reduces costs and days of the survey.

Detailed description of the method and examples of its specific implementation.

Diagnosis of clinically latent hypercortisolism in patients with diabetes type 2 diabetes or obesity is carried out in 2 stages. Determination of the concentrations of all hormones carried out by the method of enzyme-enhanced chemiluminescence, test kits Siemens, USA, use an indoor analyzer Immulite 2000 Siemens Healthcare Diagnostics (USA-Germany).

Preparatory activities prior to the screening test: all patients eliminate the use of drugs that affect the levels of cortisol in the blood and changes the results of pharmacological tests. Namely: combined oral contraceptives, phenobarbital, phenytoin, carbamazepine, rifabutin, rifampicin, ethosuximide, pioglitazone, Itraconazole, ritonavir, fluoxetine, diltiazem, cimetidine, mitotane, fenofibrate, carbenoxolone, drugs licorice and licorice.

In the case of combined oral contraceptives - test 1 month after their withdrawal, the other listed drugs - 1 to 2 a week.

As a screening test used suppressive test with 1 mg of dexamethasone. The patient is taking 1 mg of dexamethasone at 23.00, then at 08.00 the next morning make a determination of the level of plasma cortisol. When carrying out the AI test does not require the definition of the original morning point cortisol for comparison.

Interpretation of results: the test is considered positive if the level of plasma cortisol after the test exceeds 50 nmol/L.

In the case of a positive test result after 1-2 days is a combination of confirmatory tests.

The patient collects daily urine for analysis of free cortisol: the first portion of urine after waking up not going, and going all subsequent, including the first morning portion of the next day. On the day of collecting daily urine 24.00 also determine the level of plasma cortisol and calculate the coefficient of circadian rhythm of secretion of cortisol.

Interpretation of results

Syndrome hypercortisolism exclude, if all test results are normal, namely: the level of plasma cortisol at 24.00 less than 207 nmol/l, free cortisol in daily urine below 180 mg/day, the ratio of circadian rhythm of secretion of cortisol less than 50%.

Syndrome hypercortisolism is confirmed if at least two of the three tests above normal: the level of plasma cortisol at 24 : 00 207 nmol/l, free cortisol in daily urine above 180 mg/day, the ratio of circadian rhythm of secretion of cortisol more than 50%.

The performance of the proposed method is confirmed by the following clinical examples.

Example 1. P-Ko OP, 1959, entered 5/03/2012 with complaints of excessive weight, the fat in the back, ineffecti the efficiency of diets and physical exercise, the increase of pressure, pain in knee joints, shortness of breath. From history: 50 years began to notice a rapid increase in body mass (after menopause), for 2 years, recovered by 25 kg on the background of normal power mode. To reduce weight daily completed charging, went before going to sleep for about 40 minutes, 3 times per week visited the pool - no effect. Objectively: body mass index - 48 kg/m waist circumference - 136 cm; striae, plethora face; there is a black acanthosis and symptom dirty elbows". Despite the absence of classical signs of hypercortisolism (characteristic striae, the plethora of the face, weakness of the proximal muscles of the limbs), it was decided to conduct the laboratory diagnosis of the syndrome hypercortisolism.

Stage I: suppressive test with 1 mg of dexamethasone: 425 nmol/l (normal less than 50 nmol/l). Given the result above normal, the patient were performed diagnostic tests of the second stage to confirm syndrome hypercortisolism.

Stage II:

cortisol plasma 24.00 - 419 nmol/l (normal less than 207 nmol/l), free cortisol in daily urine: 165 µg/day (normal range up to 180 mcg/day), the coefficient of the circadian rhythm of secretion of cortisol: 95% (normal less than 50%).

Considering the obtained results and the absence of specific signs of hypercortisolism, the patient was diagnosed clinically latent syndrome hypercorticism the mA. After further examination, aimed at establishing the causes of hypercortisolism, it was discovered the formation of the left adrenal gland of 3.4×3,5×4,2 see In the future was performed surgery (left adrenalectomy), with the development of adrenal insufficiency in the early postoperative period, which is the final confirmation of the presence of the syndrome hypercortisolism. Three months later, the patient lost 10 kg, the levels of blood pressure are normal and will not accept any medicines.

Example 2.

Patient-To-b IV, 1959, received 12/12/2011 complaining overweight, elevated blood pressure, lack of compensation of carbohydrate metabolism, in spite of adherence to diet and adequate glucose-lowering therapy. From the anamnesis: my entire adult life had a higher body mass; type 2 diabetes was diagnosed 2 years ago, when they began to be troubled by a dry mouth and thirst. Heredity for type 2 diabetes are not burdened by the weight of children at birth less than 4000, Objectively: body mass index of 34 kg/m²the waist circumference - 116 cm; striae, plethora, proximal muscle weakness no. The patient was decided to conduct the laboratory diagnosis of the syndrome hypercortisolism due to lack of family history and the history of life in type 2 diabetes and decompensation of carbohydrate metabolism, however the adequate measures.

Stage I: suppressive test with 1 mg of dexamethasone: 71,2 nmol/l (normal less than 50 nmol/l). Given the result above normal, the patient were performed diagnostic tests of the second stage to confirm syndrome hypercortisolism.

Stage II:

cortisol plasma 24.00 - 654 nmol/l (normal less than 207 nmol/l);

free cortisol in daily urine: 234,1 µg/day (normal range up to 180 mcg/day);

the coefficient of circadian rhythm of secretion of cortisol: 43,5% (rate less than 50%).

According to the research results of the second stage of the diagnosis of the syndrome hypercortisolism was confirmed. After further examination, aimed at establishing the causes of hypercortisolism, was discovered pituitary adenoma. Was later performed surgery (transnasal adenomectomy) with the development of adrenal insufficiency in the early postoperative period, which is the final confirmation of the presence of the syndrome hypercortisolism. After six months of blood pressure within normal limits without medication, the data for the carbohydrate at the time of inspection, was not found.

Example 3.

Patient s M.V., born in 1947, he entered 19/09/2011 with complaints about excessive weight, lack of compensation of carbohydrate metabolism despite appropriate hypoglycemic therapy. From the anamnesis: heredity for type 2 diabetes not otagos is on. Objectively: body mass index 30 kg/m²the waist circumference - 110 cm; stretch marks pink color on the anterior abdominal wall. To the patient it was decided to conduct laboratory diagnosis of the syndrome hypercortisolism due to lack of family history for type 2 diabetes and decompensation of carbohydrate metabolism, despite adequate measures.

Stage I: suppressive test with 1 mg of dexamethasone: 56 nmol/l (normal less than 50 nmol/l). Given the result above normal, the patient were performed diagnostic tests of the second stage to confirm syndrome hypercortisolism.

Stage II:

cortisol plasma 24.00 - 102 nmol/l (normal less than 207 nmol/l);

free cortisol in daily urine: 100,1 µg/day (normal range up to 180 mcg/day);

the coefficient of circadian rhythm of secretion of cortisol: 30% (rate less than 50 %).

According to the results of the second stage of the diagnosis of the syndrome hypercortisolism was excluded. When more detailed history revealed that the patient is suffering from a depressive disorder, which is generally characterized by hyperactivation of the hypothalamic-pituitary-adrenal axis. After adjustment of status re-examinations for signs of hypercortisolism were within normal limits.

We conducted a survey of the proposed diagnostic method in two groups: group I - 134 patient with diabetes mellitus type 2 and obesity, group II - 60 obese patients without diabetes. No patient had no specific signs of hypercortisolism. All patients underwent a suppressive test with 1 mg of dexamethasone. A positive result (cortisol plasma more than 50 nmol/l) had 19 patients of group I, 6 patients from group II. A positive result made by the combination of confirmatory tests: 13 patients of group I, 4 patients of group II. All examinations took no more than 3-4 days.

In further conducted research aimed at determining the nature of hypercortisolism (definition of adrenocorticotropic hormone, computed tomography of the adrenal glands, magnetic resonance imaging of the brain). Of the 13 patients of group I 4 was verified diagnosis of hypercortisolism pituitary origin, 4 - adrenal origin. Of the 4 patients of group II in one patient verified diagnosis of hypercortisolism pituitary origin, one - adrenal origin.

It is important to note that all patients with a negative result of a combination of confirmatory tests were also performed imaging methods and determination of adrenocorticotropic hormone. None of the patients has not been verified hypercortisolism. In other words, not missed a single case of syndrome hypercortisolism.

Thus, the proposed diagnosis the definition method improves the accuracy of diagnosis of clinically latent hypercortisolism and failed to apply adequate therapeutic tactics, preventing the transfer of disease to overt hypercortisolism with severe disabling complications, and reduce the time of diagnostic testing and financial costs.

Method for the diagnosis of clinically latent hypercortisolismatpatients with diabetes type 2 diabetes or obesity, comprising the suppressive test with 1 mg of dexamethasone, determination of plasma cortisol at 24.00, free cortisol in daily urine, coefficient of circadian rhythm of secretion of cortisol,characterized in that if the level of plasma cortisol after suppressive test with 1 mg of dexamethasone greater than 50 nmol/l in one day by the method of enzyme-enhanced chemiluminescence carry out the determination of the level of plasma cortisol at 24.00, free cortisol in daily urine, the ratio of circadian rhythm of secretion of cortisol, and if at least two of the three tests above normal: the level of plasma cortisol at 24 : 00 207 nmol/l, free cortisol in daily urine above 180 mg/day, the ratio of circadian rhythm of secretion of cortisol over 50%, diagnose the syndrome hypercortisolism.