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Serum CTRP3 level is inversely associated with nonalcoholic fatty liver disease: A 3-y longitudinal study
Clinica Chimica Acta 479 (2018) 79–83
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Clinica Chimica Acta journal homepage: www.elsevier.com/locate/cca
Serum CTRP3 level is inversely associated with nonalcoholic fatty liver disease: A 3-y longitudinal study Wenjing Zhou1, Yuming Wang1, Yue Wu, Ji Yang, Liqian Xu, Yunmei Yang
T
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Department of Geriatrics, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang Province, China
A R T I C L E I N F O
A B S T R A C T
Keywords: C1q Tumor necrosis factor-Related Protein 3 (CTRP3) Biomarker Adipokine Nonalcoholic fatty liver disease (NAFLD) Longitudinal study
Background: CTRP3, a novel adipokine, has been linked with a variety of physiological functions, including adipokines secretion, energy metabolism, through an endocrine mean. This study evaluated the role of serum CTRP3 levels in the development of nonalcoholic fatty liver disease (NAFLD). Methods: The hospital-based longitudinal study recruited urban residents who took health examination. Serum CTRP3 levels were evaluated by an enzyme-linked immunosorbent assay. The adjusted odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the relationship between baseline serum CTRP3 and incidence of NAFLD at follow-up. Results: Of the 814 participants at baseline, 313 subjects were included at follow-up. At baseline, serum CTRP3 level was lower in subjects with NAFLD (283.3 [159.6–375.0] ng/ml) than it in non-NAFLD subjects (295.0 [184.0–398.0] ng/ml) (p = 0.006). Meanwhile, serum CTRP3 level was inversely correlated with body mass index, waist-to-hip ratio, triglycerides and fasting plasma glucose. After a 3-y follow-up, the CTRP3 concentrations decreased from the baseline (206.7 [136.3–322.6] ng/ml) to the follow-up (177.4 [112.1–295.5] ng/ ml, p < 0.001) in the subjects who developed NAFLD (n = 55). Compared with the 1st Quartile of baseline serum CTRP3, the subjects in the 3rd Quartile and 4th Quartile indicated lower risks of NAFLD progression at 3-y (adjusted OR = 0.451, 95% CI [0.270–0.755], p = 0.002 and adjusted OR = 0.468, 95% CI [0.310–0.707], p < 0.001). Conclusion: Serum level of CTRP3 was inversely associated with the progress of NAFLD independently at 3-y.
1. Introduction Non-alcoholic fatty liver disease (NAFLD), one of the most prevalent chronic liver diseases, covers a spectrum of diseases ranging from simple hepatic steatosis, to steatohepatitis, fibrosis and finally cirrhosis [1,2]. Current evidence suggests that NAFLD closely associates with obesity and insulin resistance, and now is regarded as hepatic manifestation of the metabolic syndrome [3]. Adipose tissue was conventionally thought to be a reservoir for energy storage, however recent advance supports its role as an endocrine organ [4,5]. The discovery of various adipocyte-derived hormones, i.e. adipokines, revealed their critical roles in metabolic functions [6,7]. The previous studies reported a novel family of adipokines and named Complement C1q Tumor necrosis factor-Related Proteins (CTRPs) [8,9]. Several of these proteins show essential roles in regulating energy metabolism [9,10].
Previous reports revealed that CTRP3, a novel adipokine, has been linked with a variety of physiological functions, including adipokines secretion, energy metabolism, inflammation, cellular differentiation and development, through an endocrine mean [10–14]. Besides, a series of population/hospital-based studies have been conducted [15,16]. A case-control study of Deng et al. [16] found that the serum CTRP3 levels in the subjects with obesity or hypertension were lower than those in the control. It suggested CTRP3 was an independent factor in regulating blood pressure and insulin resistance. Wolf et al. [15] also showed that serum CTRP3 decreased in the subjects with obesity, not in subjects with coronary artery disease, while its level depended on body mass index (BMI). However, Fadaei et al. [17] revealed that decreased serum levels of CTRP3 were associated with increased risk of type 2 diabetes and coronary artery disease. Tan et al. [18] found a decreased concentration of CTRP3 in women with polycystic ovary syndrome, which is an endocrine disorder closely associated with obesity and
Abbreviations: CTRP, Complement C1q Tumor necrosis factor-Related Protein; DBP, Diastolic Blood Pressure; FPG, fasting plasma glucose; HOMA-IR, Homeostasis model assessment of insulin resistance; IFG, impaired fasting glucose; IGT, impaired glucose tolerance; NAFLD, Non-alcoholic fatty liver disease; SBP, Systolic Blood Pressure; WHR, waist-to-hip ratio ⁎ Corresponding author. E-mail address: [email protected] (Y. Yang). 1 W. Zhou and Y. Wang contribute equally. https://doi.org/10.1016/j.cca.2018.01.003 Received 29 October 2017; Received in revised form 2 January 2018; Accepted 2 January 2018 Available online 03 January 2018 0009-8981/ © 2018 Elsevier B.V. All rights reserved.
Clinica Chimica Acta 479 (2018) 79–83
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dyslipidemia. Ban et al. [19] reported that serum CTRP3 decreased in patients with newly diagnosed type 2 diabetes, and furthermore, it positively correlated with serum leptin level, while negatively correlated with glucose and C reactive protein. These data suggested that serum CTRP3 might be a practical biomarker in the clinical management of obesity and its associated diseases. Recent advance links obesity and metabolic syndrome to NAFLD. It reveals a complex interaction between the liver and adipose tissue via the secretion of adipokines. As a novel adipokine, CTRP3 may play a beneficial role in NAFLD. 2. Methods 2.1. Study design and patients The hospital-based longitudinal study recruited the subjects who took the annual health examination at the First Affiliated Hospital, College of Medicine, Zhejiang University from January to November 2013. From February to December 2016, the subjects were invited for follow-up assessments. Of the 814 subjects who initially participated in at baseline, 313 were ultimately enrolled in the follow-up study. Subjects with the following medical conditions were excluded: viral/ drug-induced/autoimmune liver diseases, pregnancy, excessively alcoholic consumption (> 140 g/w men, > 70 g/w women), malignant tumor, severe cardiopulmonary disorders, renal dysfunction, severe inflammatory and endocrine diseases, and used estrogens or steroids. This study was approved by the Ethics Committee of the First Affiliated Hospital of Zhejiang University, in accordance with the Helsinki Declaration of 1964. All subjects gave written informed consent before participation. 2.2. Examinations Fig. 1. Flow chart of the study population.
Fasting blood samples were collected and frozen for the further measurement of serum CTRP3 levels by using enzyme-linked immunosorbent assay. The intra and inter assay CVs of serum CTRP3 measurement were 5.2% and 10.7%, respectively. Besides, routine blood chemistry analyses and anthropometric exam were performed in our hospital, as reported before [20]. NAFLD and its ultrasonographic degrees were diagnosed based on the guidelines for diagnosis and treatment of NAFLD issued by Fatty Liver and Alcoholic Liver Disease Study Group of the Chinese Liver Disease Association [21–23].
Table 1 Baseline characteristics of subjects by NAFLD.
2.3. Statistical methods Normally distributed variables were presented as mean ± standard deviation; variables with a skewed distribution underwent a lg(x) transformation to achieve a normal distribution and were presented as median value (interquartile range). Normality of distribution was tested with the Kolmogorov-Smirnov test. The Student's t-test or MannWhitney U test for continuous variables, and χ2 test for categorical variables were used to compare the parameters between two groups. Comparisons among three NAFLD groups (mild, moderate and severe) used Kruskal–Wallis test. The χ2 test was used for testing the difference of NAFLD within the quartiles of serum CTRP3. Wilcoxon matchedpairs signed rank test was used for comparison between baseline and follow-up. To assess the relationship between baseline serum CTRP3 and incidence of NAFLD at follow-up, we calculated the adjusted odds ratio (OR) and 95% confidence interval (CI) with a multivariable binary logistic regression model. Correlation between serum CTRP3 and the anthropometric/biomedical parameters were performed using partial correlation coefficients. All statistical analyses were performed using SPSS (version 21.0). Power of sample size (post hoc) was calculated by G*Power (version 3.1, Heinrich-Heine-Universität Düsseldorf, Germany) [24]. A 2-sided p < 0.05 was considered significant.
Parameter
Non-NAFLD
NAFLD
p
No. of subjects Age (y) Male, n (%) IFG&IGT, n (%) Hypertension, n (%) SBP (mm Hg) DBP (mm Hg) BMI (kg/m2) WHR CTRP3 (ng/ml) ALT (U/l) AST (U/l) GGT (U/l) TG (mmol/l) HDL-C (mmol/l) LDL-C (mmol/l) FPG (mmol/l) Insulin (mU/l) HbA1c (%) HOMA-IR C peptide (ng/ml) UA (μmol/l)
537 53.9 ± 12.8 185, 34.5% 138, 25.7% 117, 21.8% 111.8 ± 22.3 73.8 ± 16.2 22.7 ± 3.3 0.82 ± 0.09 295.0 [184.0–398.0] 20.0 [13.0–32.0] 18.0 [15.0–25.0] 33.0 [23.0–49.0] 1.10 [0.82–1.77] 1.15 ± 0.36 2.29 ± 0.90 3.91 [3.05–5.70] 12.5 [8.4–18.3] 6.28 [5.20–8.96] 2.30 [1.40–3.56] 1.13 ± 0.68 322.6 ± 86.7
277 54.3 ± 13.5 101, 36.5% 79, 28.5% 99, 35.7% 121.0 ± 23.0 79.3 ± 16.6 23.4 ± 3.5 0.87 ± 0.09 283.3 [159.6–375.0] 22.0 [15.0–34.0] 22.0 [17.0–29.0] 32.0 [23.0–52.0] 1.39 [1.02–2.04] 1.17 ± 0.36 2.52 ± 0.89 4.40 [3.71–5.88] 12.5 [9.2–18.4] 6.20 [5.20–9.00] 2.59 [1.71–3.98] 1.12 ± 0.69 313.0 ± 85.4
NS NS NS < 0.001 < 0.001 < 0.001 0.003 < 0.001 0.006 0.017 < 0.001 NS < 0.001 NS 0.001 < 0.001 NS NS 0.007 NS NS
Data are mean ± SD or median (interquartile range). p values indicated the comparisons between non-NAFLD (n = 537) and NAFLD (n = 277) at baseline. HOMA-IR, Homeostasis model assessment of insulin resistance; IFG, impaired fasting glucose; IGT, impaired glucose tolerance; LDL-C, low-density lipoprotein cholesterol; SBP, Systolic Blood Pressure; WHR, waist-to-hip ratio. Status of bold applies when p value lesses than .05.
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Fig. 2. Comparisons of serum CTRP3. Data represent the median (interquartile range). A) baseline in 2013: control vs. NAFLD (p = 0.006); B) baseline in 2013: mild, moderate, severe (p < 0.001); C) follow-up in 2016: not developed in 3 y vs. developed in 3 y (p < 0.001); D) NAFLD developed in 3 y: baseline levels vs. follow-up levels (p < 0.001).
Table 2 Partial correlations of serum CTRP3 with various parameters among all participants at baseline. Parameter
r value
p
SBP DBP BMI WHR ALT AST GGT TG HDL-C LDL-C FPG Insulin HbA1c HOMA-IR C peptide UA
0.003 0.064 −0.160 −0.104 −0.068 −0.044 −0.009 −0.134 0.012 0.004 −0.136 −0.017 0.029 −0.063 −0.031 0.011
NS NS < 0.001 0.003 NS NS NS < 0.001 NS NS < 0.001 NS NS NS NS NS
Fig. 3. Incidence rate of NAFLD in the 3-y follow-up by quartile of CTRP3 levels at baseline: the 1st Quartile 30.8%, the 2nd Quartile 17.9%, the 3rd Quartile 12.8% and the 4th Quartile 8.9% (p = 0.002, linear-by-linear association, p < 0.001).
All correlation coefficients were calculated after adjustment for age, sex, diabetes, and hypertension. Variables with a skewed distribution underwent a lg(x) transformation to achieve a normal distribution before analysis. ALT, Alanine transaminase; AST, Aspartate transaminase; HOMA-IR, Homeostasis model assessment of insulin resistance; WHR, waist-to-hip ratio. Status of bold applies when p value lesses than .05.
serum CTRP3 Levels and the numbers of subjects, the power of the sample size at baseline was 0.839 (effect size d = 0.218). Among the subjects with NAFLD, the mild subjects (316.3 [395.7–175.6] ng/ml) presented higher levels of CTRP3 than the severe subjects (183.5 [233.2–118.6] ng/ml) (p < 0.001, Fig. 2B). Among all subjects, as Table 2 indicated, serum CTRP3 level was inversely correlated with BMI (r = − 0.160, p < 0.001), waist-to-hip ratio (WHR) (r = − 0.104, p = 0.003), triglycerides (r = −0.134, p < 0.001) and fasting plasma glucose (FPG) (r = −0.136, p < 0.001). After a follow-up of 3 y, a total of 313 subjects without NAFLD at baseline completed the reassessment in 2016. Fifty-five subjects developed NAFLD, while 258 subjects did not. As shown in Fig. 2C and D, the CTRP3 concentration was
3. Results Of the 814 participants at baseline, 313 subjects were included at follow-up, as shown in Fig. 1. At baseline, the prevalence of NAFLD was 34.0% (277/814). NAFLD incidence rate at this 3-y follow-up was 17.6% (55/313). The annual incidence rate was 5.9%. Table 1 indicated the baseline characteristics of the participants. Serum CTRP3 level was lower in subjects with NAFLD (n = 277, 283.3 [159.6–375.0] ng/ml) than it in non-NAFLD subjects (n = 537, 295.0 [184.0–398.0] ng/ml) (p = 0.006), as shown in Fig. 2A. Given the 81
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Table 3 Baseline serum CTRP3 predictive of development of NAFLD at 3 y. Reference Quartile 1 (75.3–195.3 ng/ml)
Quartile 2 (195.4–299.9 ng/ml) Quartile 3 (300.8–396.9 ng/ml) Quartile 4 (399.2–533.8 ng/ml)
Adjustment
Odds ratio
95% confidence interval
p
Model Model Model Model Model Model
0.975 1.018 0.517 0.451 0.510 0.468
0.535–1.775 0.504–2.056 0.342–0.781 0.270–0.755 0.366–0.711 0.310–0.707
NS NS 0.002 0.002 < 0.001 < 0.001
1 2 1 2 1 2
Model 1: unadjusted. Model 2: adjusted for age, sex, IFG&IGT, hypertension, SBP, DBP, BMI, WHR, ALT, AST, GGT, TG, HDL-C, LDL-C, HbA1c, FPG, Insulin, HOMA-IR, C peptide and UA. HOMA-IR, Homeostasis model assessment of insulin resistance; IFG, impaired fasting glucose; IGT, impaired glucose tolerance; WHR, waist-to-hip ratio. Status of bold applies when p value lesses than .05.
Previous epidemiological studies have reported that serum CTRP3 levels decreased in obesity and its related diseases, e.g. hypertension, type 2 diabetes, and polycystic ovary syndrome [15,16,18]. However, most of the studies failed to investigate the cause-and-effect association between serum levels of CTRP3 and diseases owing to the cross-sectional or case-control design. In this hospital-based longitudinal study, we firstly reported that serum CTRP3 level was inversely associated with the development of NAFLD. Some limitations merit comment. Firstly, the golden standard for NAFLD is liver biopsy rather than ultrasonography that was chosen to define the degrees of NAFLD in the study [22,28]. Secondly, our study population was enrolled at one urban academic center. Thus, it might be potential selection bias, and the results should be interpreted with caution. Besides, a 3-y follow-up witnessed a high dropout rate of 41.7%. Most of them (23.5%) were due to medical conditions, including excessive alcoholic consumption, other liver diseases, malignant tumor and etc., which may related with the population enrolled (elder urban residents). In conclusion, we reported serum level of CTRP3 was inversely associated with the progress of NAFLD independently at 3 y. Further large population-based cohort studies are needed to evaluate if CTRP3 is qualified as a practical biomarker of NAFLD. The advance of the crosstalk between adipose and liver, via the regulation of adipokines, might promote the clinical management of NALFD.
significantly lower in subjects who had progressed to NAFLD (177.4 [112.1–295.5] ng/ml), compared with subjects who did not develop (321.5 [214.2–415.2] ng/ml at follow-up) (p < 0.001). At follow-up, the power of the sample size was 0.999 (effect size d = 0.781). The comparison between the baseline and the follow-up CTRP3 levels revealed a significant decrease in subjects who developed NAFLD (p < 0.001). In Fig. 3, when stratified by quartile of baseline serum CTRP3, subjects in the 1st Quartile had an incidence rate of 30.8% after the 3-y follow-up. Remarkably, the incidence rates of NAFLD decreased from the 2nd Quartile 17.9%, the 3rd Quartile 12.8% to the 4th Quartile 8.9% (p = 0.002, linear-by-linear association p < 0.001). Furthermore, serum levels of CTRP3 at baseline were significantly associated with the lower incidence of NAFLD after the 3-y follow-up (the 3rd Quartile: adjusted OR = 0.451, 95% CI [0.270–0.755], p = 0.002; the 4th Quartile: adjusted OR = 0.468, 95% CI [0.310–0.707], p < 0.001), compared with the 1st Quartile, as shown in Table 3. 4. Discussion This study showed that at baseline, the subjects with NAFLD presented a decreased serum level of CTRP3, compared with the nonNAFLD. Furthermore, in the NAFLD group, it was lower in the subjects with severe NAFLD than it in the mild. Besides, CTRP3 inversely correlated with BMI, WHR, triglycerides and FPG. After a 3-y follow-up, the CTRP3 levels were significantly lower in subjects who had developed to NAFLD, compared with subjects who did not progress. And among the subjects who developed, the CTRP3 concentrations decreased at follow-up, compared with those at baseline. Furthermore, serum levels of CTRP3 at baseline were found to be inversely associated with the development of NAFLD at 3 y. Previous findings showed that CTRP3, a secreted circulating hormone of the C1q family, plays a role in various physiological functions, e.g. lipid and glucose metabolism. The in vitro and in vivo study by Peterson et al. [11] found Recombinant CTRP3 lowered glucose levels in wild-type and ob/ob mice, which involves the Akt signaling pathway to down-regulate hepatic gluconeogenic gene expression. The insulinindependent glucose-lowering effect could be also observed in cultured hepatocytes. Further, Peterson et al. [10] also found in the rodent study that CTRP3 involves in regulating liver lipid metabolism and might be a potential spot in the future management of hepatic steatosis. Besides, via the ctrp3-KO mice and high-fat diet model, Wolf et al. [25] reported that CTRP3 is essential for metabolic homeostasis and plays a role in modulating liver size. Recent advance supported AMP-activated protein kinase (AMPK) as a downstream of CTRP3, which can be activated by phosphorylation [26]. Besides, CTRP3 was found to promote the gene expression and protein secretion of the other adipokines, e.g. leptin, apelin, which protects from insulin resistance [27]. The mechanism above might relate to the role of CTRP3 in the development of NAFLD [13].
Acknowledgement This study was funded by National Natural Science Foundation of China (No. 81771498) and Foundation of Zhejiang Provincial Department of Health (2015KYB158). References [1] e.e.e. European Association for the Study of the Liver. Electronic address, D. European Association for the Study of, O. European Association for the Study of, EASL-EASD-EASO Clinical Practice Guidelines for the management of non-alcoholic fatty liver disease, J. Hepatol. 64 (6) (2016) 1388–1402. [2] J.Z. Zhu, Y.N. Dai, Y.M. Wang, Q.Y. Zhou, C.H. Yu, Y.M. Li, Prevalence of nonalcoholic fatty liver disease and economy, Dig. Dis. Sci. 60 (11) (2015) 3194–3202. [3] A.L. Birkenfeld, G.I. Shulman, Nonalcoholic fatty liver disease, hepatic insulin resistance, and type 2 diabetes, Hepatology 59 (2) (2014) 713–723. [4] P.E. Scherer, Adipose tissue: from lipid storage compartment to endocrine organ, Diabetes 55 (6) (2006) 1537–1545. [5] E.D. Rosen, B.M. Spiegelman, Adipocytes as regulators of energy balance and glucose homeostasis, Nature 444 (7121) (2006) 847–853. [6] Y. Zhang, R. Proenca, M. Maffei, M. Barone, L. Leopold, J.M. Friedman, Positional cloning of the mouse obese gene and its human homologue, Nature 372 (6505) (1994) 425–432. [7] J. Zhu, X. Wan, Y. Wang, K. Zhu, C. Li, C. Yu, Y. Li, Serum fetuin B level increased in subjects of nonalcoholic fatty liver disease: a case-control study, Endocrine 56 (1) (2017) 208–211. [8] G.W. Wong, J. Wang, C. Hug, T.S. Tsao, H.F. Lodish, A family of Acrp30/adiponectin structural and functional paralogs, Proc. Natl. Acad. Sci. U. S. A. 101 (28) (2004) 10302–10307. [9] L. Shapiro, P.E. Scherer, The crystal structure of a complement-1q family protein suggests an evolutionary link to tumor necrosis factor, Curr. Biol. 8 (6) (1998) 335–338.
82
Clinica Chimica Acta 479 (2018) 79–83
W. Zhou et al.
[10] J.M. Peterson, M.M. Seldin, Z. Wei, S. Aja, G.W. Wong, CTRP3 attenuates dietinduced hepatic steatosis by regulating triglyceride metabolism, Am. J. Physiol. Gastrointest. Liver Physiol. 305 (3) (2013) G214–24. [11] J.M. Peterson, Z. Wei, G.W. Wong, C1q/TNF-related protein-3 (CTRP3), a novel adipokine that regulates hepatic glucose output, J. Biol. Chem. 285 (51) (2010) 39691–39701. [12] G.W. Wong, S.A. Krawczyk, C. Kitidis-Mitrokostas, T. Revett, R. Gimeno, H.F. Lodish, Molecular, biochemical and functional characterizations of C1q/TNF family members: adipose-tissue-selective expression patterns, regulation by PPARgamma agonist, cysteine-mediated oligomerizations, combinatorial associations and metabolic functions, Biochem. J. 416 (2) (2008) 161–177. [13] Y. Yang, Y. Li, Z. Ma, S. Jiang, C. Fan, W. Hu, D. Wang, S. Di, Y. Sun, W. Yi, A brief glimpse at CTRP3 and CTRP9 in lipid metabolism and cardiovascular protection, Prog. Lipid Res. 64 (2016) 170–177. [14] Y. Li, G.L. Wright, J.M. Peterson, C1q/TNF-related protein 3 (CTRP3) function and regulation, Compr. Physiol. 7 (3) (2017) 863–878. [15] R.M. Wolf, K.E. Steele, L.A. Peterson, T.H. Magnuson, M.A. Schweitzer, G.W. Wong, Lower circulating C1q/TNF-related protein-3 (CTRP3) levels are associated with obesity: a cross-sectional study, PLoS One 10 (7) (2015) e0133955. [16] W. Deng, C. Li, Y. Zhang, J. Zhao, M. Yang, M. Tian, L. Li, Y. Zheng, B. Chen, G. Yang, Serum C1q/TNF-related protein-3 (CTRP3) levels are decreased in obesity and hypertension and are negatively correlated with parameters of insulin resistance, Diabetol. Metab. Syndr. 7 (2015) 33. [17] R. Fadaei, N. Moradi, M. Baratchian, H. Aghajani, M. Malek, A.A. Fazaeli, S. Fallah, Association of C1q/TNF-related protein-3 (CTRP3) and CTRP13 serum levels with coronary artery disease in subjects with and without type 2 diabetes mellitus, PLoS One 11 (12) (2016) e0168773. [18] B.K. Tan, J. Chen, J. Hu, O. Amar, H.S. Mattu, R. Adya, V. Patel, M. Ramanjaneya, H. Lehnert, H.S. Randeva, Metformin increases the novel adipokine cartonectin/ CTRP3 in women with polycystic ovary syndrome, J. Clin. Endocrinol. Metab. 98 (12) (2013) E1891–900. [19] B. Ban, B. Bai, M. Zhang, J. Hu, M. Ramanjaneya, B.K. Tan, J. Chen, Low serum
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
83
cartonectin/CTRP3 concentrations in newly diagnosed type 2 diabetes mellitus: in vivo regulation of cartonectin by glucose, PLoS One 9 (11) (2014) e112931. Y.N. Dai, J.Z. Zhu, Z.Y. Fang, D.J. Zhao, X.Y. Wan, H.T. Zhu, C.H. Yu, Y.M. Li, A case-control study: association between serum neuregulin 4 level and non-alcoholic fatty liver disease, Metab. Clin. Exp. 64 (12) (2015) 1667–1673. G.C. Farrell, S. Chitturi, G.K. Lau, J.D. Sollano, N. Asia-Pacific Working Party on, Guidelines for the assessment and management of non-alcoholic fatty liver disease in the Asia-Pacific region: executive summary, J. Gastroenterol. Hepatol. 22 (6) (2007) 775–777. M.D. Zeng, J.G. Fan, L.G. Lu, Y.M. Li, C.W. Chen, B.Y. Wang, Y.M. Mao, D. Chinese National Consensus Workshop on Nonalcoholic Fatty Liver, Guidelines for the diagnosis and treatment of nonalcoholic fatty liver diseases, J. Dig. Dis. 9 (2) (2008) 108–112. M. Graif, M. Yanuka, M. Baraz, A. Blank, M. Moshkovitz, A. Kessler, T. Gilat, J. Weiss, E. Walach, P. Amazeen, C.S. Irving, Quantitative estimation of attenuation in ultrasound video images: correlation with histology in diffuse liver disease, Investig. Radiol. 35 (5) (2000) 319–324. F. Faul, E. Erdfelder, A. Buchner, A.G. Lang, Statistical power analyses using G*Power 3.1: tests for correlation and regression analyses, Behav. Res. Methods 41 (4) (2009) 1149–1160. R.M. Wolf, X. Lei, Z.C. Yang, M. Nyandjo, S.Y. Tan, G.W. Wong, CTRP3 deficiency reduces liver size and alters IL-6 and TGFbeta levels in obese mice, Am. J. Physiol. Endocrinol. Metab. 310 (5) (2016) E332–45. D. Wu, H. Lei, J.Y. Wang, C.L. Zhang, H. Feng, F.Y. Fu, L. Li, L.L. Wu, CTRP3 attenuates post-infarct cardiac fibrosis by targeting Smad3 activation and inhibiting myofibroblast differentiation, J. Mol. Med. (Berl.) 93 (12) (2015) 1311–1325. X. Li, L. Jiang, M. Yang, Y.W. Wu, S.X. Sun, J.Z. Sun, CTRP3 modulates the expression and secretion of adipokines in 3T3-L1 adipocytes, Endocr. J. 61 (12) (2014) 1153–1162. E.K. Spengler, R. Loomba, Recommendations for diagnosis, referral for liver biopsy, and treatment of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis, Mayo Clin. Proc. 90 (9) (2015) 1233–1246.
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Serum CTRP3 level is inversely associated with nonalcoholic fatty liver disease: A 3-y longitudinal study Wenjing Zhou1, Yuming Wang1, Yue Wu, Ji Yang, Liqian Xu, Yunmei Yang
T
⁎
Department of Geriatrics, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang Province, China
A R T I C L E I N F O
A B S T R A C T
Keywords: C1q Tumor necrosis factor-Related Protein 3 (CTRP3) Biomarker Adipokine Nonalcoholic fatty liver disease (NAFLD) Longitudinal study
Background: CTRP3, a novel adipokine, has been linked with a variety of physiological functions, including adipokines secretion, energy metabolism, through an endocrine mean. This study evaluated the role of serum CTRP3 levels in the development of nonalcoholic fatty liver disease (NAFLD). Methods: The hospital-based longitudinal study recruited urban residents who took health examination. Serum CTRP3 levels were evaluated by an enzyme-linked immunosorbent assay. The adjusted odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the relationship between baseline serum CTRP3 and incidence of NAFLD at follow-up. Results: Of the 814 participants at baseline, 313 subjects were included at follow-up. At baseline, serum CTRP3 level was lower in subjects with NAFLD (283.3 [159.6–375.0] ng/ml) than it in non-NAFLD subjects (295.0 [184.0–398.0] ng/ml) (p = 0.006). Meanwhile, serum CTRP3 level was inversely correlated with body mass index, waist-to-hip ratio, triglycerides and fasting plasma glucose. After a 3-y follow-up, the CTRP3 concentrations decreased from the baseline (206.7 [136.3–322.6] ng/ml) to the follow-up (177.4 [112.1–295.5] ng/ ml, p < 0.001) in the subjects who developed NAFLD (n = 55). Compared with the 1st Quartile of baseline serum CTRP3, the subjects in the 3rd Quartile and 4th Quartile indicated lower risks of NAFLD progression at 3-y (adjusted OR = 0.451, 95% CI [0.270–0.755], p = 0.002 and adjusted OR = 0.468, 95% CI [0.310–0.707], p < 0.001). Conclusion: Serum level of CTRP3 was inversely associated with the progress of NAFLD independently at 3-y.
1. Introduction Non-alcoholic fatty liver disease (NAFLD), one of the most prevalent chronic liver diseases, covers a spectrum of diseases ranging from simple hepatic steatosis, to steatohepatitis, fibrosis and finally cirrhosis [1,2]. Current evidence suggests that NAFLD closely associates with obesity and insulin resistance, and now is regarded as hepatic manifestation of the metabolic syndrome [3]. Adipose tissue was conventionally thought to be a reservoir for energy storage, however recent advance supports its role as an endocrine organ [4,5]. The discovery of various adipocyte-derived hormones, i.e. adipokines, revealed their critical roles in metabolic functions [6,7]. The previous studies reported a novel family of adipokines and named Complement C1q Tumor necrosis factor-Related Proteins (CTRPs) [8,9]. Several of these proteins show essential roles in regulating energy metabolism [9,10].
Previous reports revealed that CTRP3, a novel adipokine, has been linked with a variety of physiological functions, including adipokines secretion, energy metabolism, inflammation, cellular differentiation and development, through an endocrine mean [10–14]. Besides, a series of population/hospital-based studies have been conducted [15,16]. A case-control study of Deng et al. [16] found that the serum CTRP3 levels in the subjects with obesity or hypertension were lower than those in the control. It suggested CTRP3 was an independent factor in regulating blood pressure and insulin resistance. Wolf et al. [15] also showed that serum CTRP3 decreased in the subjects with obesity, not in subjects with coronary artery disease, while its level depended on body mass index (BMI). However, Fadaei et al. [17] revealed that decreased serum levels of CTRP3 were associated with increased risk of type 2 diabetes and coronary artery disease. Tan et al. [18] found a decreased concentration of CTRP3 in women with polycystic ovary syndrome, which is an endocrine disorder closely associated with obesity and
Abbreviations: CTRP, Complement C1q Tumor necrosis factor-Related Protein; DBP, Diastolic Blood Pressure; FPG, fasting plasma glucose; HOMA-IR, Homeostasis model assessment of insulin resistance; IFG, impaired fasting glucose; IGT, impaired glucose tolerance; NAFLD, Non-alcoholic fatty liver disease; SBP, Systolic Blood Pressure; WHR, waist-to-hip ratio ⁎ Corresponding author. E-mail address: [email protected] (Y. Yang). 1 W. Zhou and Y. Wang contribute equally. https://doi.org/10.1016/j.cca.2018.01.003 Received 29 October 2017; Received in revised form 2 January 2018; Accepted 2 January 2018 Available online 03 January 2018 0009-8981/ © 2018 Elsevier B.V. All rights reserved.
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dyslipidemia. Ban et al. [19] reported that serum CTRP3 decreased in patients with newly diagnosed type 2 diabetes, and furthermore, it positively correlated with serum leptin level, while negatively correlated with glucose and C reactive protein. These data suggested that serum CTRP3 might be a practical biomarker in the clinical management of obesity and its associated diseases. Recent advance links obesity and metabolic syndrome to NAFLD. It reveals a complex interaction between the liver and adipose tissue via the secretion of adipokines. As a novel adipokine, CTRP3 may play a beneficial role in NAFLD. 2. Methods 2.1. Study design and patients The hospital-based longitudinal study recruited the subjects who took the annual health examination at the First Affiliated Hospital, College of Medicine, Zhejiang University from January to November 2013. From February to December 2016, the subjects were invited for follow-up assessments. Of the 814 subjects who initially participated in at baseline, 313 were ultimately enrolled in the follow-up study. Subjects with the following medical conditions were excluded: viral/ drug-induced/autoimmune liver diseases, pregnancy, excessively alcoholic consumption (> 140 g/w men, > 70 g/w women), malignant tumor, severe cardiopulmonary disorders, renal dysfunction, severe inflammatory and endocrine diseases, and used estrogens or steroids. This study was approved by the Ethics Committee of the First Affiliated Hospital of Zhejiang University, in accordance with the Helsinki Declaration of 1964. All subjects gave written informed consent before participation. 2.2. Examinations Fig. 1. Flow chart of the study population.
Fasting blood samples were collected and frozen for the further measurement of serum CTRP3 levels by using enzyme-linked immunosorbent assay. The intra and inter assay CVs of serum CTRP3 measurement were 5.2% and 10.7%, respectively. Besides, routine blood chemistry analyses and anthropometric exam were performed in our hospital, as reported before [20]. NAFLD and its ultrasonographic degrees were diagnosed based on the guidelines for diagnosis and treatment of NAFLD issued by Fatty Liver and Alcoholic Liver Disease Study Group of the Chinese Liver Disease Association [21–23].
Table 1 Baseline characteristics of subjects by NAFLD.
2.3. Statistical methods Normally distributed variables were presented as mean ± standard deviation; variables with a skewed distribution underwent a lg(x) transformation to achieve a normal distribution and were presented as median value (interquartile range). Normality of distribution was tested with the Kolmogorov-Smirnov test. The Student's t-test or MannWhitney U test for continuous variables, and χ2 test for categorical variables were used to compare the parameters between two groups. Comparisons among three NAFLD groups (mild, moderate and severe) used Kruskal–Wallis test. The χ2 test was used for testing the difference of NAFLD within the quartiles of serum CTRP3. Wilcoxon matchedpairs signed rank test was used for comparison between baseline and follow-up. To assess the relationship between baseline serum CTRP3 and incidence of NAFLD at follow-up, we calculated the adjusted odds ratio (OR) and 95% confidence interval (CI) with a multivariable binary logistic regression model. Correlation between serum CTRP3 and the anthropometric/biomedical parameters were performed using partial correlation coefficients. All statistical analyses were performed using SPSS (version 21.0). Power of sample size (post hoc) was calculated by G*Power (version 3.1, Heinrich-Heine-Universität Düsseldorf, Germany) [24]. A 2-sided p < 0.05 was considered significant.
Parameter
Non-NAFLD
NAFLD
p
No. of subjects Age (y) Male, n (%) IFG&IGT, n (%) Hypertension, n (%) SBP (mm Hg) DBP (mm Hg) BMI (kg/m2) WHR CTRP3 (ng/ml) ALT (U/l) AST (U/l) GGT (U/l) TG (mmol/l) HDL-C (mmol/l) LDL-C (mmol/l) FPG (mmol/l) Insulin (mU/l) HbA1c (%) HOMA-IR C peptide (ng/ml) UA (μmol/l)
537 53.9 ± 12.8 185, 34.5% 138, 25.7% 117, 21.8% 111.8 ± 22.3 73.8 ± 16.2 22.7 ± 3.3 0.82 ± 0.09 295.0 [184.0–398.0] 20.0 [13.0–32.0] 18.0 [15.0–25.0] 33.0 [23.0–49.0] 1.10 [0.82–1.77] 1.15 ± 0.36 2.29 ± 0.90 3.91 [3.05–5.70] 12.5 [8.4–18.3] 6.28 [5.20–8.96] 2.30 [1.40–3.56] 1.13 ± 0.68 322.6 ± 86.7
277 54.3 ± 13.5 101, 36.5% 79, 28.5% 99, 35.7% 121.0 ± 23.0 79.3 ± 16.6 23.4 ± 3.5 0.87 ± 0.09 283.3 [159.6–375.0] 22.0 [15.0–34.0] 22.0 [17.0–29.0] 32.0 [23.0–52.0] 1.39 [1.02–2.04] 1.17 ± 0.36 2.52 ± 0.89 4.40 [3.71–5.88] 12.5 [9.2–18.4] 6.20 [5.20–9.00] 2.59 [1.71–3.98] 1.12 ± 0.69 313.0 ± 85.4
NS NS NS < 0.001 < 0.001 < 0.001 0.003 < 0.001 0.006 0.017 < 0.001 NS < 0.001 NS 0.001 < 0.001 NS NS 0.007 NS NS
Data are mean ± SD or median (interquartile range). p values indicated the comparisons between non-NAFLD (n = 537) and NAFLD (n = 277) at baseline. HOMA-IR, Homeostasis model assessment of insulin resistance; IFG, impaired fasting glucose; IGT, impaired glucose tolerance; LDL-C, low-density lipoprotein cholesterol; SBP, Systolic Blood Pressure; WHR, waist-to-hip ratio. Status of bold applies when p value lesses than .05.
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Fig. 2. Comparisons of serum CTRP3. Data represent the median (interquartile range). A) baseline in 2013: control vs. NAFLD (p = 0.006); B) baseline in 2013: mild, moderate, severe (p < 0.001); C) follow-up in 2016: not developed in 3 y vs. developed in 3 y (p < 0.001); D) NAFLD developed in 3 y: baseline levels vs. follow-up levels (p < 0.001).
Table 2 Partial correlations of serum CTRP3 with various parameters among all participants at baseline. Parameter
r value
p
SBP DBP BMI WHR ALT AST GGT TG HDL-C LDL-C FPG Insulin HbA1c HOMA-IR C peptide UA
0.003 0.064 −0.160 −0.104 −0.068 −0.044 −0.009 −0.134 0.012 0.004 −0.136 −0.017 0.029 −0.063 −0.031 0.011
NS NS < 0.001 0.003 NS NS NS < 0.001 NS NS < 0.001 NS NS NS NS NS
Fig. 3. Incidence rate of NAFLD in the 3-y follow-up by quartile of CTRP3 levels at baseline: the 1st Quartile 30.8%, the 2nd Quartile 17.9%, the 3rd Quartile 12.8% and the 4th Quartile 8.9% (p = 0.002, linear-by-linear association, p < 0.001).
All correlation coefficients were calculated after adjustment for age, sex, diabetes, and hypertension. Variables with a skewed distribution underwent a lg(x) transformation to achieve a normal distribution before analysis. ALT, Alanine transaminase; AST, Aspartate transaminase; HOMA-IR, Homeostasis model assessment of insulin resistance; WHR, waist-to-hip ratio. Status of bold applies when p value lesses than .05.
serum CTRP3 Levels and the numbers of subjects, the power of the sample size at baseline was 0.839 (effect size d = 0.218). Among the subjects with NAFLD, the mild subjects (316.3 [395.7–175.6] ng/ml) presented higher levels of CTRP3 than the severe subjects (183.5 [233.2–118.6] ng/ml) (p < 0.001, Fig. 2B). Among all subjects, as Table 2 indicated, serum CTRP3 level was inversely correlated with BMI (r = − 0.160, p < 0.001), waist-to-hip ratio (WHR) (r = − 0.104, p = 0.003), triglycerides (r = −0.134, p < 0.001) and fasting plasma glucose (FPG) (r = −0.136, p < 0.001). After a follow-up of 3 y, a total of 313 subjects without NAFLD at baseline completed the reassessment in 2016. Fifty-five subjects developed NAFLD, while 258 subjects did not. As shown in Fig. 2C and D, the CTRP3 concentration was
3. Results Of the 814 participants at baseline, 313 subjects were included at follow-up, as shown in Fig. 1. At baseline, the prevalence of NAFLD was 34.0% (277/814). NAFLD incidence rate at this 3-y follow-up was 17.6% (55/313). The annual incidence rate was 5.9%. Table 1 indicated the baseline characteristics of the participants. Serum CTRP3 level was lower in subjects with NAFLD (n = 277, 283.3 [159.6–375.0] ng/ml) than it in non-NAFLD subjects (n = 537, 295.0 [184.0–398.0] ng/ml) (p = 0.006), as shown in Fig. 2A. Given the 81
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Table 3 Baseline serum CTRP3 predictive of development of NAFLD at 3 y. Reference Quartile 1 (75.3–195.3 ng/ml)
Quartile 2 (195.4–299.9 ng/ml) Quartile 3 (300.8–396.9 ng/ml) Quartile 4 (399.2–533.8 ng/ml)
Adjustment
Odds ratio
95% confidence interval
p
Model Model Model Model Model Model
0.975 1.018 0.517 0.451 0.510 0.468
0.535–1.775 0.504–2.056 0.342–0.781 0.270–0.755 0.366–0.711 0.310–0.707
NS NS 0.002 0.002 < 0.001 < 0.001
1 2 1 2 1 2
Model 1: unadjusted. Model 2: adjusted for age, sex, IFG&IGT, hypertension, SBP, DBP, BMI, WHR, ALT, AST, GGT, TG, HDL-C, LDL-C, HbA1c, FPG, Insulin, HOMA-IR, C peptide and UA. HOMA-IR, Homeostasis model assessment of insulin resistance; IFG, impaired fasting glucose; IGT, impaired glucose tolerance; WHR, waist-to-hip ratio. Status of bold applies when p value lesses than .05.
Previous epidemiological studies have reported that serum CTRP3 levels decreased in obesity and its related diseases, e.g. hypertension, type 2 diabetes, and polycystic ovary syndrome [15,16,18]. However, most of the studies failed to investigate the cause-and-effect association between serum levels of CTRP3 and diseases owing to the cross-sectional or case-control design. In this hospital-based longitudinal study, we firstly reported that serum CTRP3 level was inversely associated with the development of NAFLD. Some limitations merit comment. Firstly, the golden standard for NAFLD is liver biopsy rather than ultrasonography that was chosen to define the degrees of NAFLD in the study [22,28]. Secondly, our study population was enrolled at one urban academic center. Thus, it might be potential selection bias, and the results should be interpreted with caution. Besides, a 3-y follow-up witnessed a high dropout rate of 41.7%. Most of them (23.5%) were due to medical conditions, including excessive alcoholic consumption, other liver diseases, malignant tumor and etc., which may related with the population enrolled (elder urban residents). In conclusion, we reported serum level of CTRP3 was inversely associated with the progress of NAFLD independently at 3 y. Further large population-based cohort studies are needed to evaluate if CTRP3 is qualified as a practical biomarker of NAFLD. The advance of the crosstalk between adipose and liver, via the regulation of adipokines, might promote the clinical management of NALFD.
significantly lower in subjects who had progressed to NAFLD (177.4 [112.1–295.5] ng/ml), compared with subjects who did not develop (321.5 [214.2–415.2] ng/ml at follow-up) (p < 0.001). At follow-up, the power of the sample size was 0.999 (effect size d = 0.781). The comparison between the baseline and the follow-up CTRP3 levels revealed a significant decrease in subjects who developed NAFLD (p < 0.001). In Fig. 3, when stratified by quartile of baseline serum CTRP3, subjects in the 1st Quartile had an incidence rate of 30.8% after the 3-y follow-up. Remarkably, the incidence rates of NAFLD decreased from the 2nd Quartile 17.9%, the 3rd Quartile 12.8% to the 4th Quartile 8.9% (p = 0.002, linear-by-linear association p < 0.001). Furthermore, serum levels of CTRP3 at baseline were significantly associated with the lower incidence of NAFLD after the 3-y follow-up (the 3rd Quartile: adjusted OR = 0.451, 95% CI [0.270–0.755], p = 0.002; the 4th Quartile: adjusted OR = 0.468, 95% CI [0.310–0.707], p < 0.001), compared with the 1st Quartile, as shown in Table 3. 4. Discussion This study showed that at baseline, the subjects with NAFLD presented a decreased serum level of CTRP3, compared with the nonNAFLD. Furthermore, in the NAFLD group, it was lower in the subjects with severe NAFLD than it in the mild. Besides, CTRP3 inversely correlated with BMI, WHR, triglycerides and FPG. After a 3-y follow-up, the CTRP3 levels were significantly lower in subjects who had developed to NAFLD, compared with subjects who did not progress. And among the subjects who developed, the CTRP3 concentrations decreased at follow-up, compared with those at baseline. Furthermore, serum levels of CTRP3 at baseline were found to be inversely associated with the development of NAFLD at 3 y. Previous findings showed that CTRP3, a secreted circulating hormone of the C1q family, plays a role in various physiological functions, e.g. lipid and glucose metabolism. The in vitro and in vivo study by Peterson et al. [11] found Recombinant CTRP3 lowered glucose levels in wild-type and ob/ob mice, which involves the Akt signaling pathway to down-regulate hepatic gluconeogenic gene expression. The insulinindependent glucose-lowering effect could be also observed in cultured hepatocytes. Further, Peterson et al. [10] also found in the rodent study that CTRP3 involves in regulating liver lipid metabolism and might be a potential spot in the future management of hepatic steatosis. Besides, via the ctrp3-KO mice and high-fat diet model, Wolf et al. [25] reported that CTRP3 is essential for metabolic homeostasis and plays a role in modulating liver size. Recent advance supported AMP-activated protein kinase (AMPK) as a downstream of CTRP3, which can be activated by phosphorylation [26]. Besides, CTRP3 was found to promote the gene expression and protein secretion of the other adipokines, e.g. leptin, apelin, which protects from insulin resistance [27]. The mechanism above might relate to the role of CTRP3 in the development of NAFLD [13].
Acknowledgement This study was funded by National Natural Science Foundation of China (No. 81771498) and Foundation of Zhejiang Provincial Department of Health (2015KYB158). References [1] e.e.e. European Association for the Study of the Liver. Electronic address, D. European Association for the Study of, O. European Association for the Study of, EASL-EASD-EASO Clinical Practice Guidelines for the management of non-alcoholic fatty liver disease, J. Hepatol. 64 (6) (2016) 1388–1402. [2] J.Z. Zhu, Y.N. Dai, Y.M. Wang, Q.Y. Zhou, C.H. Yu, Y.M. Li, Prevalence of nonalcoholic fatty liver disease and economy, Dig. Dis. Sci. 60 (11) (2015) 3194–3202. [3] A.L. Birkenfeld, G.I. Shulman, Nonalcoholic fatty liver disease, hepatic insulin resistance, and type 2 diabetes, Hepatology 59 (2) (2014) 713–723. [4] P.E. Scherer, Adipose tissue: from lipid storage compartment to endocrine organ, Diabetes 55 (6) (2006) 1537–1545. [5] E.D. Rosen, B.M. Spiegelman, Adipocytes as regulators of energy balance and glucose homeostasis, Nature 444 (7121) (2006) 847–853. [6] Y. Zhang, R. Proenca, M. Maffei, M. Barone, L. Leopold, J.M. Friedman, Positional cloning of the mouse obese gene and its human homologue, Nature 372 (6505) (1994) 425–432. [7] J. Zhu, X. Wan, Y. Wang, K. Zhu, C. Li, C. Yu, Y. Li, Serum fetuin B level increased in subjects of nonalcoholic fatty liver disease: a case-control study, Endocrine 56 (1) (2017) 208–211. [8] G.W. Wong, J. Wang, C. Hug, T.S. Tsao, H.F. Lodish, A family of Acrp30/adiponectin structural and functional paralogs, Proc. Natl. Acad. Sci. U. S. A. 101 (28) (2004) 10302–10307. [9] L. Shapiro, P.E. Scherer, The crystal structure of a complement-1q family protein suggests an evolutionary link to tumor necrosis factor, Curr. Biol. 8 (6) (1998) 335–338.
82
Clinica Chimica Acta 479 (2018) 79–83
W. Zhou et al.
[10] J.M. Peterson, M.M. Seldin, Z. Wei, S. Aja, G.W. Wong, CTRP3 attenuates dietinduced hepatic steatosis by regulating triglyceride metabolism, Am. J. Physiol. Gastrointest. Liver Physiol. 305 (3) (2013) G214–24. [11] J.M. Peterson, Z. Wei, G.W. Wong, C1q/TNF-related protein-3 (CTRP3), a novel adipokine that regulates hepatic glucose output, J. Biol. Chem. 285 (51) (2010) 39691–39701. [12] G.W. Wong, S.A. Krawczyk, C. Kitidis-Mitrokostas, T. Revett, R. Gimeno, H.F. Lodish, Molecular, biochemical and functional characterizations of C1q/TNF family members: adipose-tissue-selective expression patterns, regulation by PPARgamma agonist, cysteine-mediated oligomerizations, combinatorial associations and metabolic functions, Biochem. J. 416 (2) (2008) 161–177. [13] Y. Yang, Y. Li, Z. Ma, S. Jiang, C. Fan, W. Hu, D. Wang, S. Di, Y. Sun, W. Yi, A brief glimpse at CTRP3 and CTRP9 in lipid metabolism and cardiovascular protection, Prog. Lipid Res. 64 (2016) 170–177. [14] Y. Li, G.L. Wright, J.M. Peterson, C1q/TNF-related protein 3 (CTRP3) function and regulation, Compr. Physiol. 7 (3) (2017) 863–878. [15] R.M. Wolf, K.E. Steele, L.A. Peterson, T.H. Magnuson, M.A. Schweitzer, G.W. Wong, Lower circulating C1q/TNF-related protein-3 (CTRP3) levels are associated with obesity: a cross-sectional study, PLoS One 10 (7) (2015) e0133955. [16] W. Deng, C. Li, Y. Zhang, J. Zhao, M. Yang, M. Tian, L. Li, Y. Zheng, B. Chen, G. Yang, Serum C1q/TNF-related protein-3 (CTRP3) levels are decreased in obesity and hypertension and are negatively correlated with parameters of insulin resistance, Diabetol. Metab. Syndr. 7 (2015) 33. [17] R. Fadaei, N. Moradi, M. Baratchian, H. Aghajani, M. Malek, A.A. Fazaeli, S. Fallah, Association of C1q/TNF-related protein-3 (CTRP3) and CTRP13 serum levels with coronary artery disease in subjects with and without type 2 diabetes mellitus, PLoS One 11 (12) (2016) e0168773. [18] B.K. Tan, J. Chen, J. Hu, O. Amar, H.S. Mattu, R. Adya, V. Patel, M. Ramanjaneya, H. Lehnert, H.S. Randeva, Metformin increases the novel adipokine cartonectin/ CTRP3 in women with polycystic ovary syndrome, J. Clin. Endocrinol. Metab. 98 (12) (2013) E1891–900. [19] B. Ban, B. Bai, M. Zhang, J. Hu, M. Ramanjaneya, B.K. Tan, J. Chen, Low serum
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
83
cartonectin/CTRP3 concentrations in newly diagnosed type 2 diabetes mellitus: in vivo regulation of cartonectin by glucose, PLoS One 9 (11) (2014) e112931. Y.N. Dai, J.Z. Zhu, Z.Y. Fang, D.J. Zhao, X.Y. Wan, H.T. Zhu, C.H. Yu, Y.M. Li, A case-control study: association between serum neuregulin 4 level and non-alcoholic fatty liver disease, Metab. Clin. Exp. 64 (12) (2015) 1667–1673. G.C. Farrell, S. Chitturi, G.K. Lau, J.D. Sollano, N. Asia-Pacific Working Party on, Guidelines for the assessment and management of non-alcoholic fatty liver disease in the Asia-Pacific region: executive summary, J. Gastroenterol. Hepatol. 22 (6) (2007) 775–777. M.D. Zeng, J.G. Fan, L.G. Lu, Y.M. Li, C.W. Chen, B.Y. Wang, Y.M. Mao, D. Chinese National Consensus Workshop on Nonalcoholic Fatty Liver, Guidelines for the diagnosis and treatment of nonalcoholic fatty liver diseases, J. Dig. Dis. 9 (2) (2008) 108–112. M. Graif, M. Yanuka, M. Baraz, A. Blank, M. Moshkovitz, A. Kessler, T. Gilat, J. Weiss, E. Walach, P. Amazeen, C.S. Irving, Quantitative estimation of attenuation in ultrasound video images: correlation with histology in diffuse liver disease, Investig. Radiol. 35 (5) (2000) 319–324. F. Faul, E. Erdfelder, A. Buchner, A.G. Lang, Statistical power analyses using G*Power 3.1: tests for correlation and regression analyses, Behav. Res. Methods 41 (4) (2009) 1149–1160. R.M. Wolf, X. Lei, Z.C. Yang, M. Nyandjo, S.Y. Tan, G.W. Wong, CTRP3 deficiency reduces liver size and alters IL-6 and TGFbeta levels in obese mice, Am. J. Physiol. Endocrinol. Metab. 310 (5) (2016) E332–45. D. Wu, H. Lei, J.Y. Wang, C.L. Zhang, H. Feng, F.Y. Fu, L. Li, L.L. Wu, CTRP3 attenuates post-infarct cardiac fibrosis by targeting Smad3 activation and inhibiting myofibroblast differentiation, J. Mol. Med. (Berl.) 93 (12) (2015) 1311–1325. X. Li, L. Jiang, M. Yang, Y.W. Wu, S.X. Sun, J.Z. Sun, CTRP3 modulates the expression and secretion of adipokines in 3T3-L1 adipocytes, Endocr. J. 61 (12) (2014) 1153–1162. E.K. Spengler, R. Loomba, Recommendations for diagnosis, referral for liver biopsy, and treatment of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis, Mayo Clin. Proc. 90 (9) (2015) 1233–1246.