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27DOI:10.33667/2782-4101 -2022-2-12-16
NOVEL METHOD FOR QUANTIFYING HEPATIC STEATOSIS IN PATIENTS WITH METABOLICALLY ASSOCIATED FATTY LIVER DISEASE
Alexey Borsukov, Daria Venidiktova, Semen Borsukov
Fundamental research laboratory "Diagnostic researches and minimally invasive technologies" of Smolensk State Medical University, the Ministry of Health of the Russian Federation, Smolensk, Russia
SUMMARY
Introduction. The article presents an overview of novel complex algorithm based on methods of ultrasound steatometry, combined elastography and dual-energy X-ray absorbtiometry in "Whole body" mode in diagnostic and monitoring of metabolically associated fatty liver disease.
The purpose of the study: to assess the possibility of quantitative ultrasound steatometry using in the detection and monitoring of metabolically associated fatty liver disease.
Material and methods. 157 patients were examined. The main group consisted of 47 patients with liver steatosis; 45 patients with steatohepatitis and clinically insignificant liver fibrosis (F0-F1); 32 patients with steatohepatitis and clinically significant liver fibrosis (F2-F3); 33 patients with focal hepatic steatosis. We used complex algorithm based on methods of questionnaires, laboratory tests, ultrasound steatometry, combined elastography and dual-energy x-ray absorbtiometry in "Whole body" mode, liver biopsy. to determine the severity of steatosis, a scale was used: S0 - no steatosis; <2.19 dB/cm; S1, minimal steatosis, <5 % of hepatocytes with steatosis; 2.2-2.29 dB/cm; S2 - moderate steatosis, <6-32 % of hepatocytes with steatosis; 2.3-2.9 dB/cm; S3 - severe steatosis, <33-100 % of hepatocytes with steatosis; >2.9 dB/cm. Results and conclusion. It is possible to use quantitative ultrasound steatometry for metabolically associated fatty liver disease, as a reference method both for the initial detection of the disease and for monitoring non-drug treatment (sensitivity 90.7%, specificity 92.4 %). The optimal complex for the diagnosis and monitoring of non-drug treatment of metabolically associated fatty liver disease includes an assessment of the level of compliance, the use of quantitative ultrasound steatometry and dual-energy X-ray absorptiometry in the «Whole body» mode (sensitivity 92.8 %, specificity 92.3 %). KEYWORDS: metabolically associated fatty liver disease, ultrasound steatometry, liver biopsy, dual-energy X-ray absorbtiometry.
CONFLICT of INTEREST. The authors declare no conflict of interest.
Funding. Funding for the study was carried out from the personal funds of the authors.
Introduction
Currently, the term non-alcoholic fatty liver disease (NAFLD) is understood as an independent nosological unit, the pathogenesis of which is based on the phenomena of insulin resistance and hyperinsulinemia and which includes a spectrum of clinical and morphological changes in the liver parenchyma: hepatic steatosis, steatohepatitis, hepatic fibrosis, hepatic cirrhosis and its complications (including hepatocellular carcinoma) [1]. In 2020, a new adaptive concept was proposed - MAFLD (Metabolically Associated Fatty Liver Disease), which allows emphasizing the systemic and multifactorial nature of the pathogenesis of a unified lesion of the hepatic parenchyma and personalizing the volumes and directions of treatment and diagnostic care in various clinical variants of the disease [2].
In different countries, the incidence of MAFLD varies and averages 6.3-33 %, reaching a level of 62-93 % in obese patients [2]. In most countries of the world, MAFLD ranks first among liver diseases [3]. These data correspond to the prevalence of the metabolic syndrome and its components [4, 5, 6].
The prognosis of the disease and management tactics are determined primarily by the severity of liver steatosis [7-10], which further affects the timing of the progression of the underlying disease and determines the risk of complications [11-13].
The problem of diagnosing MAFLD remains quite relevant at the present stage of medicine, as well as further treatment and monitoring [14-16]. Consequently, the problem is complex, and therefore requires a meaningful algorithm for early diagnosis [17, 18]. The importance of an adequate and timely assessment of the severity of the pathological process in the liver is beyond doubt: it is necessary in clinical practice to determine the stage, prognosis of the disease and the ability to timely adjust the tactics of treating patients [19, 20]. The use of modern instrumental methods has significantly expanded the amount of information received on the detection rate, periods of early development of liver diseases [21-23].
Ultrasound steatometry is in special, yet little-studied niche in gastroenterology and ultrasound diagnostics, which confirms the growing interest and participation of specialists in various scientific forums dedicated to the possibilities of methods for detecting and assessing MAFLD [24-26]. A general methodological view on the role and place of ultrasonic steatometry in a multidisciplinary hospital has not yet been developed [27, 28].
As MAFLD progresses, the process of pathological changes proceeds sequentially through several stages: from steatosis, stromal inflammatory reaction, stepwise necrosis to the de-
velopment of fibrosis and, in the terminal stage, liver cirrhosis with the possibility of neoplasia in the form of hepatocellular carcinoma [29, 30]. It is known that the assessment of the severity of liver steatosis is important for determining the stage of non-alcoholic fatty liver disease and further prognosis [31].
A reliable method for diagnosing liver pathology is morphological verification, i.e. liver biopsy [32]. Unfortunately, this method is associated with many complications and technical difficulties, so the search for highly informative methods for early, non-invasive diagnosis of liver pathology is constantly being carried out [33]. One of these methods, which allows to assess the severity of liver steatosis, is ultrasound steatom-etry. This method is based on a quantitative assessment of the attenuation coefficient of an ultrasound wave in tissues in dB/ cm (or dB/cm/MHz) and has a number of advantages, such as the possibility of an informative assessment of diffuse and focal changes in the liver in real time, good patient tolerance, no complications, cost-effectiveness [34]. Currently, there is a limited number of works on the use of ultrasound quantitative steatometry in non-alcoholic fatty liver disease, despite the fact that this diagnostic method is promising due to the possibility of non-invasively, repeatedly and quantitatively assessing liver steatosis.
Purpose of the study: to assess the possibility of quantitative ultrasound steatometry using in the detection and monitoring of metabolically associated fatty liver disease.
Material and methods
157 people with metabolically associated fatty liver disease were examined based on the Fundamental Research Laboratory «Diagnostic research and minimally invasive technologies». The main group consisted of 47 patients with liver steatosis (MAFLD); 45 patients with steatohepatitis (MASH) and clinically insignificant liver fibrosis (LF) (F0-F1); 32 patients with steatohepatitis and clinically significant LF (F2-F3); 33 patients with focal hepatic steatosis (FLS). Data on the distribution of patients by sex and age are presented in Table 1.
Control group 1 (n=102) - patients with a normal level of adipose tissue in the body according to non-invasive bio-impedancemetry, and not suffering from damage to the liver tissue according to clinical, laboratory and instrumental research methods.
Control group 2 (n=44) - patients with MAFLD, who underwent the entire complex of clinical, laboratory and instrumental procedures used in this study, without including ultrasound quantitative steatometry.
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Fig. I. A. Window of results of ultrasound steatometry: 1 - liver, 2 - active zone of measurement, 3 - short-circuit indicator of the ultrasound wave. B. Window of results of combined elastography: 1 - liver, 2 - active zone of measurement of short-circuit ultrasound wave, 3 - indicator of short-circuit ultrasound wave, quantitative indicator of inflammatory activity (A-index), quantitative indicator of the severity of liver fibrosis (F-index).
The study of patients of the main group (n=157) included:
• Stage 1 - questionnaires (SF-36 V.2., CAGE, AUDIT, DEBQ, CLDQ-NAFLD, IPAQ)
• Stage 2 - clinical and biochemical blood tests (including coagulogram and lipidogram), general urinalysis.
• Stage 3 - liver ultrasound with a quantitative assessment of the ultrasound wave attenuation coefficient (dB/cm), combined elastography of the liver with a quantitative assessment of liver steatosis, activity of the inflammatory process, severity of LF. to determine the severity of steatosis, a scale was used: S 0 - no steatosis; <2.19 dB/cm; S 1, minimal steatosis, <5 % of hepatocytes with steatosis; 2.2-2.29 dB/cm; S 2 - moderate steatosis, <6-32 % of hepatocytes with steatosis; 2.3-2.9 dB/cm; S 3 - severe steatosis, <33100 % of hepatocytes with steatosis; >2.9 dB/cm.
The window of results and the main indicators evaluated during quantitative ultrasound steatometry are shown in Fig. 1.
Table 1
Distribution of patients by age and sex
Groups Total Men Women Average age, year
n % n % n %
1 gr. MAFLD (n=47) 47 29,9 24 15,3 23 14,6 34,69±1,97
2 gr. MASH with clinically insignificant LF (F0-F1) (n=45) 45 28,7 24 15,3 21 13,4 51,42±1,42
3 gr. MASH with clinically significant LF (F2-F3) (n=32) 32 20,4 18 11,5 14 8,9 49,34±1,91
4 gr. FLS (n=33) 33 21,0 17 10,8 16 10,2 43±2,64
Total (n=157) 157 100 83 52,9 74 47,1 44,62±1,07
Externa]
Emotiogcnic
Restrictive
1Z
29
33
a%
80%
100K
20% 40% 60%
■ Male ■ Female
Fig. 2. Distribution of patients according type of eating disorder (DEBQ).
• Stage 4 - determination of complex indices: fatty liver index (FLI), assessment of the state of the liver according to the fibrosis scale in NAFLD (NFS), fibrosis index-4 (FIB-4).
• Stage 5 - dual-energy X-ray absorbtiometry (DXA) in "Whole body" mode.
• Stage 6 - trepan-biopsy of the liver with ultrasound control, with the study of micropreparations on the SAF scale (n=49 (32,7 %).
Non-drug measures in all patients were taken according to the general principles of weight loss with its subsequent maintenance: teaching patients a proper lifestyle with a change in eating habits (with the participation of a general practitioner); hypocaloric diet; keeping a food diary; physical exercises.
Statistical processing of the research results was carried out in the Microsoft Excel 2017 database. Data analysis was carried out using descriptive statistics and comparison of samples (using parametric and nonparametric criteria). Pearson rank correlation analysis was used to assess the relationship between two variables. Coefficient r greater than 0 at p<0.05 was taken as reliable. Indicators of predictive value (sensitivity and specificity) were determined.
Results
The results of the interpretation of the SF-36 questionnaire at the first visit of patients to the research center showed the results of quality of life slightly below the average levels in the general population of the Russian population. All patients of the control group 1 showed results above the average levels (minimum values for the physical component of health - 79, for the psychological component of health - 72).
The CLDQ-NAFLD (Chronic Liver Disease Questionnaire - Non-Alcoholic Fatty Liver Disease) questionnaire assess the level of quality of life in patients with chronic liver diseases (in particular, NAFLD) on 6 factors: fatigue, anxiety, emotional function, abdominal symptoms, systemic symptoms, activity. Patients of all studied groups assess their physical and psychological state above the average value; high results are noted in groups 1 and 4, which is probably due to the absence of clinical manifestations of NAFLD in most representatives of this group of patients.
The distribution of patients in the main study groups according to the results of DEBQ questionnaire is presented in Fig. 2.
In groups of patients 1 and 4, no increase in liver enzymes was recorded. In groups 2 and 3, there was an increase in the level of hepatic transaminases with a predominance of ALT. Additionally, in group 3, there were also changes in the direction of growth of ALT, AST, alkaline phosphatase, total and direct bilirubin.
In patients 1, 2 and 4 of the main study groups, there were no deviations of the coagulogram parameters from normal values. In the majority of patients of the 3rd main study group, at the recruitment stage, a decrease in blood clotting ability (prolongation of prothrombin time) was revealed.
Glucose levels differed significantly in groups 1-4 due to the presence in each of the groups of patients with type 2 diabetes.
In the majority of patients of the main study groups (except for patients of groups 1 and 4), the lipid profile showed a decrease in HDL levels, an increase in TG and LDL. Some of them also had an increase in total cholesterol levels. Increased levels of total cholesterol and LDL have been considered as risk factors for diabetes mellitus and atherosclerosis. a slight increase in triglyceride levels was also detected in patients with type 2 diabetes.
The distribution of patients in the main study groups according to the results of quantitative ultrasound steatometry is presented in Table 2.
The coincidence of the data of liver ultrasound quantitative steatometry with the data of combined elastography with the determination of liver steatosis at degrees of liver steatosis S 0 and S 3 was revealed, in the intermediate intervals S 1-S 2 there was a discrepancy in the data per 1 patient in each of the groups. In this group of patients, there was a complete agreement between the data ob-
Table 2
Distribution of patients in the main study groups (n=157) according to the results of quantitative ultrasound steatometry
Liver steatosis (grade) 1 gr. (n=47) 2 gr. (n=45) 3 gr. (n=32) 4 gr.* (n=33) Total (n=157)
n % n % n % n % n %
S 1 27 57,45 18 40 13 40,62 19 57,58 77 49
S 2 13 27,66 16 35,56 10 31,25 13 39,39 52 33,1
S 3 7 14,89 11 24,44 9 28,13 1 3,03 28 17,8
* In group 4 quantitative ultrasound steatometry was performed in a preselected area of interest (in the focus of focal liver steatosis).
Fig. 3. The ratio of indicators of liver ultrasound steatometry with the determination of the attenuation coefficient of the ultrasound wave (dB/cm), combined elastography with the determination of liver steatosis (dB/cm/MHz) and histological examination of liver biopsy specimens according to the SAF scale in patients (n=17) who agreed to re-biopsy 36 months after the start of the study.
Table 3
Dynamics of changes in the severity of liver steatosis according to the histological examination of liver biopsy specimens (SAF scale) in patients of the main study groups 1-3
Table 4
Distribution of patients of the main group based on the fat mass index according to DXA data in the «Whole Body» mode
Proportion of patients (%) who agreed to a liver biopsy at baseline (n=49) Proportion of patients (%) who agreed to a liver biopsy at baseline (n=17)* Proportion of patients (%) who agreed to a liver biopsy at the end of the study (n=17)
Liver steatosis
S 0 2,04 0 5,88
S 1 32,65 29,41 58,82
S 2 38,78 41,18 17,65
S 3 26,53 29,41 17,65
Activity of theinflammatory process
AO 32,65 23,53 52,94
A1 14,29 17,65 23,53
A2 24,49 29,41 17,65
A3 16,33 23,53 5,88
A4 12,24 5,88 0
Liver fibrosis
F0 38,78 35,29 64,71
F1 20,41 23,53 5,88
F2 14,29 23,53 11,76
F3 14,29 11,76 11,76
Fat mass index 1 gr. (n=47) 2 gr. (n=45) 3 gr. (n=32) 4 gr. (n=33)
n % n % n % n %
Excess 13 27,66 13 28,89 8 25 19 57,58
Obesity 1 grade 16 34,04 18 40 9 28,13 12 36,36
Obesity 2 grade 14 29,79 13 28,89 14 43,75 2 6,06
Obesity 3 grade 4 8,51 1 2,22 1 3,12 0 0
Conclusions
1. It is possible to use quantitative ultrasound steatometry for metabolically associated fatty liver disease, as a reference method both for the initial detection of the disease and for monitoring non-drug treatment (sensitivity 90.7 %, specificity 92.4 %).
2. The optimal complex for the diagnosis and monitoring of non-drug treatment of metabolically associated fatty liver disease includes an assessment of the level of compliance, the use of quantitative ultrasound steatometry and dual-energy X-ray absorptiometry in the «Whole body» mode (sensitivity 92.8 %, specificity 92.3 %).
*The same patients who consented to repeat liver biopsy at the end of the study.
tained using ultrasound steatometry of the liver with the data obtained from the histological examination of biopsy specimens (Fig. 3).
The distribution of the results of liver biopsy of patients who consented to repeat biopsy according to the severity of steatosis (S 0-S 3), the activity of the inflammatory process (A0-A4) and fibrosis (F0-F3) are presented in Table 3.
Based on the results of the primary DXA study, the results shown in Table 4 were obtained.
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Received 26.06.2022 Revised 18.07.2022 Accepted 24.07.2022
INFORMATION ABOUT AUTHORS
Borsukov Alexey Vasilyevich, MD, Professor, the Head of Fundamental research laboratory "Diagnostic researches and minimally invasive technologies", Smolensk State Medical University, the Ministry of Health of the Russian Federation, 214019, Smolensk, 28 Krupskoy str., ORCID: 0000-0003-4047-7252. Tel. +79036492210; e-mail: bor55@yandex.ru
Venidiktova Daria Yuryevna, Junior scientist of Fundamental research laboratory "Diagnostic researches and minimally invasive technologies", Smolensk State Medical University, the Ministry of Health of the Russian Federation, 214019, Smolensk, 28 Krupskoy str., ORCID: 0000-0001-5497-1476. Tel. +79107850371; e-mail: 92darv@gmail.com
Borsukov Semen Alekseevich, the 5-th grade student of Smolensk State Medical University, the Ministry of Health of the Russian Federation, 214019, Smolensk, 28 Krupskoy str., ORCID: 0000-0002-5747-6048. Tel. +79056953120; e-mail: semen.borsukov99@gmail.com
