RU2407440C1 - Method of ultrasonic diagnostics of visceral obesity - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to field of medicine and can be used for diagnostics of visceral obesity in patients with metabolic syndrome. Before carrying out ultrasonic examination peroral contrasting of stomach with 200 ml of degassed liquid is performed. Thickness of visceral fat layer - S (mm) is determined by formula: S=l-h, where l is distance between white line of abdomen and anterior wall of aorta, and h is distance between stomach walls. If S>30 mm, visceral obesity is diagnosed.

EFFECT: method allows to increase accuracy of visceral obesity diagnostics.

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Description

The invention relates to medicine and can be used to diagnose visceral obesity in patients with metabolic syndrome.

Known methods for the diagnosis of visceral obesity (VO) by radiation research methods. The most accurate is computed tomography (CT), it provides a good visualization of visceral adipose tissue, but its disadvantage is radiation exposure to the patient [1]. Magnetic resonance imaging (MRI) does not carry radiation, makes it possible to visualize anatomical structures well, but due to the high cost and duration of the study, it cannot be a screening method [2].

Closest to the technical nature of the present invention is a method for the diagnosis of visceral obesity by ultrasound examination of the abdominal cavity using a linear sensor with a frequency of 3.5 MHz. [3]. In this case, the distance between the white line of the abdomen and the anterior wall of the aorta is estimated. According to foreign authors (Kuczmarski RJ et al.), A distance of more than 100 mm is regarded as a manifestation of visceral obesity, which determines a high risk of developing cardiovascular complications. In a similar way, other authors diagnosed visceral obesity [4, 5, 6]. However, the known method is not accurate enough, because the stomach is included in the determined distance, the degree of filling of which varies, which reduces the accuracy of this technique and can lead to false-positive results in relation to the diagnosis of visceral obesity and, accordingly, insufficiently adequate appointment of therapeutic measures.

A new technical problem is to increase the accuracy of the method.

To solve the problem in a method for determining visceral obesity, which consists in conducting an ultrasound examination with subsequent measurement of the distance that the visceral fat occupies 5 cm down from the xiphoid process along the midline of the body, which, in addition to the study, conduct oral contrasting of the stomach with 200 ml of degassed liquid and determine the thickness of the visceral fat layer S (mm) by the formula S = lh, where l is the distance between the white line of the abdomen and the anterior wall of the aorta, and h is p the distance between the walls of the stomach, and at S> 30, visceral obesity is diagnosed.

The method is as follows.

The study is carried out in the morning, on an empty stomach. Immediately 1-2 minutes before the study, oral contrasting of the stomach is carried out by taking 200 ml of degassed liquid by the patient. The patient's position during the study is horizontal. Scanning is performed transversely to the body axis along the midline at the level of 5 cm down from the xiphoid process. A 3.5 MHz linear sensor using gel for ultrasonography is used. During ultrasound, subcutaneous adipose tissue is a hypoechoic structure with hyperechoic connective tissue interlobular septa. The rectus abdominis muscles are visualized as hypoechoic formations with hyperechoic strips. The white line of the abdomen is represented by a hyperechoic strip between the rectus muscles, 1-3 mm thick. Due to the introduction of a degassed fluid, the stomach becomes hypoechoic, its walls differentiate well against the background of surrounding tissues and become hyperechoic 2-4 mm thick. The thickness of the visceral fat layer (S) in mm is determined by the formula

S = l-h,

where l is the distance in mm between the white line of the abdomen and the anterior wall of the aorta,

h is the distance in mm between the front and rear walls of the stomach, previously contrasted with a degassed liquid. Visceral obesity (VO) is diagnosed with S values greater than 30 mm.

The criteria of the proposed method are selected based on the analysis of the results of a clinical study of 23 patients: 15 women and 8 men aged 15 to 71 years (average age 40 ± 20 years), with obesity of varying severity and metabolic syndrome being treated in the endocrinology department of clinics Siberian State Medical University, an endocrinological clinic, as well as outpatients with this syndrome. At the examination stage, all patients underwent ultrasound with contrasting the stomach with a degassed liquid in a volume of 200 ml according to the proposed method. VO was diagnosed with a fat thickness of more than 30 mm. At the same time, magnetic resonance imaging was performed on the same patients, where the area occupied by visceral fat on axial sections at the level of L _{4-5 was} determined. With an area of more than 130 cm ² , visceral obesity was determined in patients. Statistical analysis showed a high degree of correlation between the results of ultrasound and magnetic resonance imaging (r = 0.95; p <0.001).

The performance indicators of the proposed method for the diagnosis of visceral obesity were: sensitivity - 92%, specificity - 98%, accuracy - 90%.

Example 1

Patient S., 37 years old, is undergoing treatment for type 2 diabetes mellitus in the endocrinology clinic of SibSMU. Body weight 108 kg, height 168 cm, BMI = 39 (obesity 2 degrees), anthropometric indicators correspond to visceral obesity (OT / OB = 0.96). Ultrasound scanning using the proposed method, the distance between the aorta and the white line of the abdomen (1) was 89 mm, the distance between the walls of the contrasted stomach (h) was 74 mm, the thickness of visceral fat (S) was determined by the formula S = l-h and amounted to 15 mm. The thickness of subcutaneous fat at this level was 32 mm, at the navel 54 mm. Adipose tissue is located mainly in the subcutaneous fat. VO is not diagnosed.

A magnetic resonance study was carried out, in which the area of visceral fat was 89 cm ² , which also corresponded to normal values.

Example 2

A 24-year-old woman, M., turned to the endocrinology clinic with complaints of overweight. An anthropometric study revealed: body weight 82 kg, height 171 cm, BMI = 28 (overweight), OT / OB = 0.91, which corresponds to the anthropometric criteria for visceral obesity. An ultrasound study was performed. Ultrasound examination without contrasting the stomach, the depth of the aorta was 63 mm.

When ultrasound scanning using contrasting the stomach with a degassed liquid according to the proposed method, the thickness of visceral fat was 39 mm The thickness of subcutaneous fat at this level was 49 mm. Diagnosed with VO, which was further confirmed by the results of MRI: the area of VLT was 149 cm ² , with a norm of 130 cm ² .

Thus, the proposed method has the following advantages: the absence of radiation exposure, the possibility of repeated studies to monitor the dynamics of the process, ultrasound scanning allows you to visualize the early signs of visceral obesity in patients with metabolic syndrome, timely adjust treatment and carry out a set of preventive measures aimed at preventing cardiac vascular complications of the metabolic syndrome. The ultrasonic method is widely used in clinical practice to diagnose a wide range of pathologies, including when examining the abdominal organs. Ultrasound is safe for the patient, and the speed and low cost of the study allow the use of this method for screening.

Information sources

1. L. Sjostrom, H. Kvist, A. Cederblad, U. Tylen Determination of total adipose tissue and body fat in women by computed tomography, 40K, and tritium // Obesity Research - 1997. - Vol. 5. - P.519-530.

2. Kooy K, Seidell JC. Techniques for the measurement of visceral fat: a practical guide. Int J Obes 1993; 17: 187-196.

3. Weits T. Comparison of ultrasound and skinfold caliper measurement of subcutaneous fat tissue. Int J Obes 1986; 10: 161-168 (prototype).

4. Borkan GA. Comparison of computed tomography, skinfolds and ultrasound in assessment of subcutaneous fat thickness. In: Norgan NG, ed. Euro Nut Conference Series: Human body composition and fat distribution. The Hague: CIP gegevens Koninklijke Bibliotheek, 1987: 129-141.

5. Hayes PA, Sowood PJ. Subcutaneous fat thickness measured by magnetic resonance imaging, ultrasound, and calipers. Med Sci Sports Exerc 1988; 20: 303-309.

Claims (1)

The method of ultrasound diagnosis of visceral obesity, which consists in conducting an ultrasound examination followed by measuring the distance that the visceral fat occupies 5 cm down from the xiphoid process along the midline of the body, characterized in that, before conducting the study, an oral contrast of the stomach with 200 ml of degassed liquid is carried out, the thickness of the visceral fat layer - S (mm) is determined by the formula: S = lh, where l is the distance between the white line of the abdomen and the anterior wall of the aorta, h is the -being between the walls of the stomach, and when S> 30 mm diagnose visceral obesity.