Serum Fetuin B Levels and Factors Influencing its Concentrations in Patients with Newly Diagnosed Type 2 Diabetes Mellitus
Xing Xie1,2, Zi Wang1, Shuchun Chen1*, Xing Wang3, Yang Liu1 and Zelin Li1
1 Department of Endocrinology, He Bei General Hospital, P.R. China
2Department of Endocrinology, Baoding NO.1 Central Hospital, P.R. China
3Department of Emergency, Children’s Hospital of Hebei Province, P.R. China
Submission: December 22, 2019; Published: January 10, 2020
*Corresponding author: Shuchun Chen, Department of Endocrinology, He Bei General Hospital. No. 348 Heping West Road, Xinhua District, Shijiazhuang, Hebei 050000, China
How to cite this article: Xing Xie, Zi Wang, Shuchun Chen, Xing Wang, Yang Liu, et al. Serum Fetuin B Levels and Factors Influencing its Concentrations in Patients with Newly Diagnosed Type 2 Diabetes Mellitus. Curre Res Diabetes & Obes J. 2020; 12(4): 555843. DOI: 10.19080/CRDOJ.2020.12.555843
Abstract
The objective of this study is to explore the serum fetuin B levels and factors influencing its concentrations in patients with newly diagnosed type 2 diabetes mellitus (T2DM) and to provide evidence for the prevention of T2DM and its complications. Two hundred three patients with newly diagnosed type 2 diabetes and 209 healthy controls were recruited. The serum fetuin B levels were measured using an ELISA, and the correlations between fetuin B levels and glycosylated hemoglobin levels, insulin resistance index (HOMA-IR), SOD levels, GSH-PX levels, MDA levels, nonalcoholic fatty liver disease and carotid atherosclerosis were analyzed. We obtained the following results: (1) A significantly higher serum fetuin B level was observed in the T2DM group than in the CON group (P < 0.001). (2) The serum fetuin B level positively correlated with the HOMA-IR, HbA1c, TG, APOB, and GSH-PX levels, but it negatively correlated with HDL-C and SOD levels. The multivariate linear stepwise regression analysis showed that HBA1c was an important factor influencing fetuin B levels. (3) According to the logistic regression analysis, fetuin B is a risk factor for T2DM. Finally, we drew several conclusions: 1. The influencing factors for type 2 diabetes mellitus and non-alcoholic fatty liver disease include increased the serum fetuin B level in patients with newly diagnosed type 2 diabetes mellitus and resulted in a much higher serum fetuin B level in the group complicated with NAFLD. 2. The glycosylated hemoglobin level is an important factor influencing fetuin B levels..
Keywords: Type 2 diabetes mellitus; Insulin resistance; Carotid atherosclerosis; Nonalcoholic fatty liver; Fetal globulin B
Abbreviations: CAD: Coronary Artery Disease; GDM: Gestational Diabetes Mellitus; T2DM: Type 2 Diabetes Mellitus; BMI: Body Mass Index; NAFLD: Nonalcoholic Fatty Liver Disease; VFI: Visceral Fat Index; LAP: Fat Accumulation Product; MDA: Malondialdehyde
Introduction
Fetal globulin B, the second member of the fetoglobulin family, is the first liver cytokine and was discovered in mammals in 2000. It is one of the members of the cysteinase inhibitor superfamily [1]. However, the specific pathophysiological mechanism and functions of fetal globulin-B remain unclear. According to Meex and colleges, fetuin B levels were increased in rats with hepatic steatosis and obesity, and its levels are related to a disruption in the glucose metabolism balance [2]. In addition, serum fetuin B levels were increased in patients with coronary artery disease (CAD) [3], gestational diabetes mellitus (GDM) [4] and NAFLD [5]. Inconsistent with the findings from the study by Meex that serum fetuin B levels are increased in patients with type 2 diabetes mellitus [2], Kralisch and colleagues [6] confirmed a decrease in serum fetuin B levels in patients with type 2 diabetes mellitus. Coronary heart disease is a common macrovascular complication of type 2 diabetes mellitus. It has been reported that serum fetuin B is increased in coronary heart disease and non-alcoholic fatty liver, and it plays an important role in inflammation, inflammation and oxidative stress, important factors associated with macrovascular complications in type 2 diabetes mellitus. Whether fetuin B plays an important role in oxidative stress, has not been determined. Therefore, the serum fetuin B level, influencing factors and mechanism in patients with newly diagnosed type 2 diabetes mellitus are unclear. The purpose of this study is to analyze the changes in serum fetuin B levels in patients with newly diagnosed type 2 diabetes mellitus, analyze the relationships between fetuin B levels and BMI, WC, FBG, HOMA-IR, blood lipids, UA, SOD, MDA, GSH-PX, NAFLD, AS and other indexes, and explore its role in the occurrence and development of type 2 diabetes mellitus to provide a new basis for interventions targeting the occurrence and development of type 2 diabetes mellitus and its complications.
Materials and Methods
Subjects
Two hundred three patients with type 2 diabetes were chosen who were initially diagnosed at the Endocrinology Department of Hebei Provincial People’s Hospital (T2DM group) in January 2017, and the average age was 49±11.50 years. According to the presence or absence of carotid atherosclerosis, The T2DM group was divided into two subgroups according to the presence or absence of carotid atherosclerosis: the AS subgroup (group A) and AS-free subgroup (group B). Patients with T2DM were divided into an NAFLD subgroup (group C) and NAFLD subgroup (group D). From January 2017 to February 2018, 209 urban residents who underwent a physical examination at the Hebei Provincial People’s Hospital Physical Examination Center were selected as the control group (CON group), with the average age of 46.05±9.47 years.
Exclusion criteria
Patients with liver diseases, a history of hepatic virus infection, severe liver and kidney injury (serum creatinine level > 200 ± mol/L or liver enzyme levels 3 times higher than the upper limit of normal value), severe blood system diseases, acute complications of diabetes mellitus (hyperosmotic hyperglycemia coma, ketoacidosis, and lactic acid poisoning), a recent history of severe infectious diseases, severe coronary heart disease, a history of cerebral blood vessel disease, used lipid-lowering drugs in the past three months, or a history of stress (surgery, trauma, or mental stimulation) in the past 3 months were excluded.
Methods
a) All subjects completed a questionnaire designed by professionals that included information about age, sex, past history and other general conditions. Height, weight and waist circumference were included in the measurements of human body parameters.
b) The body mass index (BMI): BMI= weight (kg) / height2 (m2) was calculated. The visceral fat index (VAI) [7] and fat accumulation product (LAP) [8] were calculated to evaluate the visceral fat content as a noninvasive alternative index: males: VAI= {WC/ (39.68 (1.88×BMI)} × (TG/1.03) × (1.31/HDL), female: VAI= {WC/ (36.58) (1.89 × BMI)} × (TG/0.81) × (1.52/HDL); Male: LAP= (WC- 65) × TG, female: LAP= (WC- 58) × TG.
c) Subjects were required to fast for 8 or 12 hours. Then, 4 ml of venous blood was collected from a vein in the elbow on the next morning and stored at-80°C until further analysis.
d) Biochemical indexes were measured using an automatic biochemical analyzer produced by Hitachi Company, Japan. Fasting serum insulin levels were detected using an electrochemiluminescence method, and glycosylated hemoglobin levels were measured using high-pressure liquid chromatography. Biochemical parameters were measured in fasting venous blood samples from the subjects, and the tests described above were completed by professional examiners. The activities of malondialdehyde (MDA), (SOD) and GSH-PX were determined using the TBA method, WST-1 method and colorimetric method, respectively. Serum fetuin B levels were measured using an ELISA.
Diagnostic criteria
A carotid ultrasound was performed by an experienced ultrasound physician using an ACUSONS2000 ultrasound instrument. The diagnostic criteria for nonalcoholic fatty liver disease (NAFLD) were based on the guidelines for the diagnosis and treatment of fatty liver disease and alcoholic fatty liver disease established by the Hepatology Branch of the Chinese Medical Association in 2010.
Statistical analysis
Statistical analyses were performed using SSPS 21.0 software. Data with a normal distribution are reported as the means ± standard deviations (x ± SD), and data with a non-normal distribution are reported as medians (interquartile ranges). If the mean values for two samples exhibited a normal distribution and uniform variance, the t test is used, otherwise, the nonparametric rank sum test was used. The chi-square test was used to determine differences between two or more total ratios or correlations between classified variables. A linear correlation analysis between the two variables was conducted. When the normal variance of the data distribution was homogeneous, the Pearson correlation coefficient was calculated, otherwise, the Spearman correlation coefficient was calculated. A multivariate linear stepwise regression analysis was used to conduct the multivariate regression analysis. A correlation analysis between the second classification variables and some influencing factors was performed using a logistic regression analysis. All results were statistically significant (P < 0.05).
Results
Comparison of indicators between the T2DM group and the CON group (Table 1)
The serum fetuin B level of the T2DM group [3571.1 (2626.9, 4852.1) pmol/mL] was significantly higher than the CON group [2007.4 (1522.2, 2646.6) pmol/mL] (P < 0.001).
Comparison of indicators between groups A and B (Tables 2 & 3)
A significant difference in serum fetuin B levels was not observed between subgroup A and subgroup B [(3831.5 ±1552.8 vs 3781.0 ±1373.8 pg/ml) (p>0.05).
Comparison of indicators between subgroups C and D (Table 3)
Higher serum fetuin B levels were recorded in subgroup C than in subgroup D [4256.6 ±1276.0 pg/ml vs 3044.57 ±1480.7 pg/ml] (P < 0.001, (Figure 3).
Analysis of the correlations between fetuin B levels and General parameters, biochemical Indexes and oxidative stress Indexes (Tables 4 & 5)
Spearman rank correlation coefficients were calculated for data with a nonnormal distribution to evaluate the correlations between serum fetuin B levels and BMI, WC, and biochemical indexes. The results are presented in Table 4. Furthermore, a multivariate linear stepwise regression analysis was performed to observe the effects of BMI, WC, FBG, HOMA-IR, TG, APOB, VAI, LAP, and GSH-PX levels on fetuin B levels. Glycosylated hemoglobin levels exerted the greatest effect on serum fetuin B levels, indicating that glycosylated hemoglobin was an important factor influencing fetuin B levels.
Correlations between various indicators and T2DM (Table 6)
The effects of BMI, HbA1c, FBG, HOMA-IR, TG, TC, HDLC, LDLC, and fetuin B levels on the T2DM population were examined using a logistic regression analysis. The P values for fetuin B, FBG, and GSHPX levels were 0.021, 0.006, and 0.031, respectively. The ORs were 1.001, 12.552, and 1.009, respectively. Thus, fetuin B, FBG and GSHPX were risk factors for T2DM.
Relationship between the serum fetuin B level and incidence of T2DM (Table 7)
All subjects were divided into four groups according to the quartiles of serum fetuin B levels. The incidence of T2DM in groups Q1-Q4 was 17.0%, 30.2%, 54.7% and 92.5%, respectively.
The incidence of T2DM in groups Q3 and Q4 was significantly higher than in group Q1 (P < 0.0001 and P < 0.001, respectively). Although the incidence of T2DM in group Q2 was higher than in group Q1, the difference was not statistically significant (P ≤ 0.109). In model 1, the incidence of T2DM was 0.999 in group Q3 (95% CI: 0.998-0.999) compared with group Q1. In model 2, after correcting for GSH-PX and HDL-C levels, the incidence of T2DM in group Q3 was still higher than in group Q1, and the OR was 0.999 (95% CI: 0.998-0.999). The incidence of T2DM in group Q4 was higher than group Q1 (OR = 0.999). After model 3 was further adjusted for the FBG level (95% CI: 0.998-0.999), the incidence of T2DM in group Q3was still higher than in group Q1 (OR: 0.999, 95% CI: 0.998-1.000), and the incidence of T2DM in group Q4 was higher than in group Q1, with an OR value of 0.999 (95% CI: 0.998-1.000).
Correlations between indicators and T2DM combined with NAFLD (group C) (Table 8)
A logistic regression analysis was applied to determine the effects of various indexes on patients with T2DM complicated with NAFLD. The ORs for fetuin B and BMI were 1.001 and 1.558, respectively, with P values <0.05. Logistic regression equation coefficient was 45.516, P <0.001; therefore, fetuin B and BMI were risk factors for T2DM combined with NAFLD.
Discussion
The incidence of diabetes is increasing annually. Ninety percent of patients with diabetes are diagnosed with T2DM. The main characteristics are insulin resistance and a relative insulin deficiency [2]. Fetuin B is the second member of the fetoglobin family and a member of the cysteinase inhibitor superfamily [1]. It shares 22% structural homology with fetuin A, but its pathophysiology and mechanism remain unclear. Factors secreted by hepatocytes are related to insulin resistance [9], leading to the occurrence and development of metabolic diseases such as T2DM. Recent studies have confirmed that serum fetuin B levels in patients with T2DM, NAFLD, CAD, GDM and other metabolic diseases may play an important role in the occurrence and development of metabolic diseases. The study by Meex reported higher serum fetuin B levels in the T2DM group than in the CON group. However, in another study, a lower serum fetuin B level was observed in patients with T2DM than in the CON group [4], inconsistent with the results reported by Meex and colleagues.
In the present study, a higher serum fetuin B level was observed in the newly diagnosed T2DM group than in the CON group, consistent with the results from the study by Meex et al. [2] All subjects were divided into four groups according to the quartiles of serum fetuin B levels to evaluate the correlation between the serum fetuin B levels and the incidence of T2DM. The incidence of T2DM gradually increased from Q1 to Q4. A significant difference in the incidence of T2DM was observed between groups Q3, Q4 and Q1, but there was no difference with group Q2. After adjusting for GSH-PX, HDL-C, and FBG levels, the incidence of T2DM in group Q4 was still significantly different from group Q1. A logistic regression analysis was subsequently conducted using T2DM as the dependent variable to determine the effects of BMI, HbA1c, FBG, HOMA-IR, TG, TC, HDL-C, LDL-C, fetuin B and other indexes on T2DM. Fetuin B may be a risk factor for T2DM; thus, it may play an important role in the occurrence and development of type 2 diabetes mellitus.
Jung et al analyzed serum fetuin B levels in patients with ACS [10]. Zhu et al. further studied the serum fetuin B levels in patients with CAD. Significantly higher serum fetuin B levels were observed in patients with CAD than in the control group, and significantly higher serum fetuin B levels were observed in patients with acute coronary syndrome than in patients with stable angina pectoris [3]. Thus, fetuin-B may be a new biomarker for the occurrence and development of CAD. However, the exact mechanism by which fetuin B regulates the occurrence and development of CAD is not clear. In the present study, the T2DM group was divided into subgroups A and B according to the presence or absence of AS. The serum Fetuin-B levels were compared between subgroups A and B, but a significant difference was not observed, which is a finding that was inconsistent with the study of patients with coronary atherosclerosis described above.
The causes were analyzed, and the subjects selected in this study were diagnosed with carotid atherosclerosis. The severity of atherosclerosis was less serious than coronary pulsating atherosclerosis. In addition, the sample size selected in this experiment was small, and the sample size should be increased and expanded to patients with a later stage of the disease to explore the changes in serum fetuin B levels and its mechanism in a population with carotid atherosclerosis.
In the present study, the T2DM group was divided into subgroups C and D according to the presence or absence of NAFLD. A higher serum fetuin B level was observed in the NAFLD group than in the non-NAFLD group, consistent with the results reported by Zhu et al. [3] in the case-control study of non-alcoholic fatty liver disease. However, the fetuin B levels in patients with newly diagnosed T2DM complicated with NAFLD were not analyzed in previous studies. A logistic regression analysis was subsequently performed to determine the effect of T2DM with NAFLD as the dependent variable on patients with T2DM complicated with NAFLD. Fetuin B was a risk factor for newly diagnosed T2DM complicated with NAFLD, consistent with the study by Hazem M of patients with T2DM and NAFLD [11]. Insulin resistance is closely related to the occurrence of NAFLD. According to Meex et al. [2] serum fetuin B levels are increased in patients with hepatic steatosis compared with patients without hepatic steatosis, and the serum fetuin B level positively correlates with insulin resistance [12], but they did not correlate with BMI, blood lipid levels and liver function.
Recent studies have reported positive correlations between fetuin B levels and the insulin resistance index and fasting insulin levels. Higher fetuin B levels are detected in people with NAFLD. Fetuin B stimulates insulin secretion, leading to insulin resistance and type 2 diabetes mellitus. Previous studies have confirmed that hepatic steatosis is an independent risk factor for type 2 diabetes mellitus, indicating that hepatic steatosis leads to insulin resistance [13-16]. Therefore, we speculate that liver steatosis increases the fetuin B level, and as a negative factor secreted by hepatocytes, it promotes the occurrence and development of metabolic diseases such as type 2 diabetes mellitus by inducing insulin resistance. Recent studies have shown positive correlations between fetuin B levels and the insulin resistance index and fasting insulin levels. Higher fetuin B levels are detected in patients with NAFLD, and a high level of fetuin B increases insulin levels, leading to insulin resistance and the occurrence and development of type 2 diabetes mellitus [17]. At the same time, a reduction in hepatic lipid accumulation and fetuin B secretion may reduce or delay the occurrence and development of T2DM, CAD and other diseases related to insulin resistance. The common characteristic of metabolic diseases such as type 2 diabetes mellitus, gestational diabetes mellitus and non-alcoholic fatty liver disease are insulin resistance. Meex et al. [2] administered different concentrations of fetuin B to obese mice with abnormal glucose tolerance and hepatic steatosis. Insulin-stimulated glucose metabolism was disrupted in mouse myotubule cells and primitive hepatocytes [2]. Jung et al. [10] confirmed a positive correlation between the TG content in hepatocytes and fetuin B levels [14], indicating that insulin resistance is mainly involved in the occurrence and development of metabolic diseases. However, obese mice treated with different concentrations of fetuin B were also used to evaluate insulin sensitivity with the high insulin clamp test. Insulin sensitivity is mainly caused by abnormal glucose metabolism and not changes in insulin sensitivity, findings that are inconsistent with the research described above on the role of fetuin B in insulin resistance [18].
In the present study, all indexes related to fetuin B were analyzed using a multivariate stepwise linear regression analysis, and glycosylated hemoglobin had the greatest effect on fetuin B levels, suggesting that fetuin B may play a role in glucose metabolism, but not insulin resistance. Meex et al. [2] decreased the serum fetuin B levels and the expression of fetuin B in the liver of obese mice by injecting adenoviruses. Compared with the control group, significant changes in body weight were not observed, but the glucose tolerance in the intervention group was significantly improved. Based on these data, a reduction in the circulating fetuin B level improves systemic glucose metabolism in obese mice. Thus, fetuin B may contribute to the mechanism underlying type 2 diabetes.
The specific mechanism of fetuin B in metabolic diseases is unclear. Meex et al. [2] did not observe changes in the levels of TNF-α and other inflammatory molecules in mouse muscle tubule and hepatocytes after the administration of the fetuin B intervention, indicating that fetuin B may not play modulate the release of pro-inflammatory molecules. Currently, no study has described the relationship between fetuin B levels and oxidative stress. Therefore, we analyzed whether fetuin B affects the occurrence or development of metabolic diseases by modulating oxidative stress. In the present study, we performed a multivariate stepwise regression analysis of fetuin B levels in patients with type 2 diabetes mellitus. SOD, GSH-PX, and MDA levels were not entered into the equation, indicating that oxidative stress did not affect fetuin B levels in the present study. Based on these results, the effect of fetuin B on T2DM may not be mediated by oxidative stress. Although the specific pathogenesis of fetuin B is unknown, fetuin B may not regulate the occurrence and development of metabolic diseases such as T2DM by modulating the inflammatory response and oxidative stress, according to the results from the present study and previous publications. Therefore, future studies should focus on determine the effects of fetuin B on glucose metabolism and the mechanism of insulin resistance to prevent T2DM.
Conclusions
In summary, our cross-sectional study reveals that increased serum fetuin B levels in patients with a primary diagnosis of type 2 diabetes are a risk factor for type 2 diabetes. Furthermore, the increased level of fetuin B in patients with type 2 diabetes complicated with nonalcoholic fatty liver disease is a risk factor for type 2 diabetes combined with nonalcoholic fatty liver disease. In the future, we will evaluate the serum fetuin B levels in a larger sample of patients with type 2 diabetes and even study the mechanism of action of fetuin B in animals.
Contributions
Xing Xie and Zi Wang contributed equally to this paper and performed the experiments and acquisition of the data and paper writing. Shuchun Chen analyzed and interpreted the data. Xing Wang help to carry out the execution of the study, Yang Liu and Zelin Li participated in its design and coordination and data analysis and paper revision.
References
- Olivier E, Soury E, Ruminy P, Husson A, Parmentier F, et al. (2000) Fetuin-B, a second member of the fetuin family in mammals. Biochem J 350(2): 589-597.
- Meex RC, Hoy AJ, Morris A, Brown RD, Lo JC, et al. (2015) Fetuin B Is a Secreted Hepatocyte Factor Linking Steatosis to Impaired Glucose Metabolism. Cell Metab 22(6): 1078-1089.
- Zhu K, Wang Y, Shu P, Zhou Q, Zhu J, et al. (2017) Increased serum levels of fetuin B in patients with coronary artery disease. Endocrine 58(1): 97-105.
- Kralisch S, Hoffmann A, Lossner U, Kratzsch J, Blüher M, et al. (2017) Regulation of the novel adipokines/ hepatokines fetuin A and fetuin B in gestational diabetes mellitus. Metabolism 68: 88-94.
- Zhu J, Wan X, Wang Y, Zhu K, Li C, et al. (2017) Serum fetuin B level increased in subjects of nonalcoholic fatty liver disease: a case-control study. Endocrine 56(1): 208 -211.
- Kralisch S, Hoffmann A, Kloting N, Bachmann A, Kratzsch J, et al. (2017) The novel adipokine /hepatokine fetuin-B in severe human and murine diabetic kidney disease. Diabetes Metab 43(5): 465-468.
- Mazzuca E, Battaglia S, Marrone O, Marotta AM, Castrogiovanni A, et al. (2014) Gender-specific anthropometric markers of adiposity, metabolic syndrome and visceral adiposity index (VAI) in patients with obstructive sleep apnea. J Sleep Res 23(1): 13-21.
- Ioachimescu AG, Brennan DM, Hoar BM, Hoogwerf BJ (2010) The lipid accumulation product and all-cause mortality in patients at high cardiovascular risk: A PreCIS database study. Obesity (Silver Spring) 18(9): 1836-1844.
- Stefan N, Haring H U (2013) The role of hepatokines in metabolism. Nat Rev Endocrinol 9(3): 144-152.
- Jung S H, Won K J, Lee K P, Kim HJ, Seo EH, et al. (2015) The serum protein fetuin-B is involved in the development of acute myocardial infarction. Clin Sci (Lond) 129(1): 27-38.
- El-Ashmawy HM, Ahmed AM (2019) Serum fetuin-B level is an independent marker for nonalcoholic fatty liver disease in patients with type 2 diabetes. Eur J Gastroenterol Hepatol 31(7): 859-864.
- Wang D, Liu Y, Liu S, Lin L, Liu C, et al. (2018) Serum fetuin-B is positively associated with intrahepatic triglyceride content and increases the risk of insulin resistance in obese Chinese adults: A cross-sectional study. J Diabetes 10(7): 581-588.
- PH Ducuzeau, J Boursier, S Bertrai, Dubois S, Gauthier A, et al. (2013) MRI measurement of liver fatcontent predicts the metabolic syndrome. Diabetes Metab 39(4): 314-321.
- Kotronen A, Laaksonen M A, Heliövaara M, Reunanen A, Tuomilehto J, et al. (2013) Fatty liver score and 15- year incidence of type 2 diabetes. Hepatol Int 7(2): 610–621.
- Park SK, Seo MH, Shin HC, Ryoo JH (2013) Clinical availability of nonalcoholic fatty liver disease as an early predictor of type 2 diabetes mellitus inKorean men: 5-year prospective cohort study. Hepatology 57(4): 1378-1383.
- Zelbersagi S, Lotan R, Shibolet O, Webb M, Buch A, et al. (2013) Non-alcoholic fatty liver disease independently predicts prediabetes during a 7-year prospective follow-up. Liver Int 33(9): 1406-1412.
- Zhibin Li, Mingzhu Lin, Changqin Liu, Wang D, Shi X, et al. (2018) Fetuin-B links nonalcoholic fatty liver disease to type 2 diabetes via inducing insulin resistance: Association and path analyses. Cytokine 108: 145-150.
- Leite NC, Salles GF, Araujo AL, Villela-Nogueira CA, Cardoso CR (2009) Prevalence and associated factors of non-alcoholic fatty liver disease in patients with type-2 diabetes mellitus. Liver Int 29(1): 113-119.