C-peptide as a key risk factor for non-alcoholic fatty liver disease in the United States population

Effect of Cytokeratin-18, C-peptide, MHR, and MACK-3 Biomarkers in Metabolic Dysfunction-Associated Fatty Liver Disease After Laparoscopic Sleeve Gastrectomy

Background

Laparoscopic sleeve gastrectomy (LSG) has emerged as a valuable treatment for various metabolic disorders, including metabolic dysfunction-associated fatty liver disease (MAFLD) in patients with obesity. Consequently, there is a pressing need to develop noninvasive biomarkers for diagnosing and monitoring disease progression.

Objectives

This study aimed to evaluate specific biomarkers, including Cytokeratin-18 (CK-18), C-peptide, monocyte to HDL cholesterol ratio (MHR), and MACK-3, in patients with obesity with MAFLD undergoing LSG.

Design

A prospective cohort study on patients with obesity before and 6 months after the LSG procedure.

Methods

70 patients with obesity with confirmed MAFLD, determined by Transient Elastography (TE), were pre- and 6 months postoperatively tested. Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), lipid profile, ghrelin, leptin, peptide YY, GLP-1, and liver fibrosis scores, including AST/ALT ratio (AAR), Fibrosis-4 index (FIB-4), and BARD Score were tested.

Results

BMI significantly decreased in all participants, with a % excess weight loss of 62.0% ± 15.4%. TE measurements revealed a significant postoperative reduction from 100% to 87.1% (P = .006). All selected biomarkers showed significant postoperative improvement-a significant association of CK-18 with MAFLD markers, including AAR, FIB-4, and BARD score, were found. MACK-3 had positive associations with FIB-4. C-peptide and MHR showed no association with MAFLD markers. Furthermore, there was a positive correlation between CK-18 and MACK-3 tests and between C-peptide and CK-18 and MACK-3. Additionally, a receiver operating characteristic (ROC) curve was constructed, with CK-18 performing the best, with an estimated area under the curve of 0.863.

Conclusion

Serum CK-18 outperformed other selected biomarkers in predicting and monitoring MAFLD in patients with obesity, suggesting its prospective utility in clinical practice. Further studies are needed to validate the accuracy of the MACK-3 test.

Circulating total and H-specific GDF15 levels are elevated in subjects with MASLD but not in hyperlipidemic but otherwise metabolically healthy subjects with obesity

BACKGROUND

Growth differentiation factor 15 (GDF15) is a mitokine, the role of which, total or H-specific, in modulating energy metabolism and homeostasis in obesity-related diseases, such as metabolic dysfunction associated steatotic liver disease (MASLD), has not been fully elucidated in adult humans. We aimed to investigate the fasting and stimulated levels of GDF15, total and H-specific, glucose-dependent insulinotropic polypeptide (GIP) and C-peptide, in two physiology interventional studies: one focusing on obesity, and the other on MASLD.

METHODS

Study 1 investigated individuals with normal weight or with obesity, undergoing a 3-h mixed meal test (MMT); and study 2, examined adults with MASLD and controls undergoing a 120-min oral glucose tolerance test (OGTT). Exploratory correlations of total and H-specific GDF15 with clinical, hormonal and metabolomic/lipidomic parameters were also performed.

RESULTS

In study 1, 15 individuals were included per weight group. Fasting and postprandial total and H-specific GDF15 were similar between groups, whereas GIP was markedly higher in leaner individuals and was upregulated following a MMT. Baseline and postprandial C-peptide were markedly elevated in people with obesity compared with lean subjects. GIP was higher in leaner individuals and was upregulated after a MMT, while C-peptide and its overall AUC after a MMT was markedly elevated in people with obesity compared with lean subjects. In study 2, 27 individuals were evaluated. Fasting total GDF15 was similar, but postprandial total GDF15 levels were significantly higher in MASLD patients compared to controls. GIP and C-peptide remained unaffected. The postprandial course of GDF15 was clustered among those of triglycerides and molecules of the alanine cycle, was robustly elevated under MASLD, and constituted the most notable differentiating molecule between healthy and MASLD status. We also present robust positive correlations of the incremental area under the curve of total and H-specific GDF15 with a plethora of lipid subspecies, which remained significant after adjusting for confounders.

CONCLUSION

Serum GDF15 levels do not differ in relation to weight status in hyperlipidemic but otherwise metabolically healthy individuals. In contrast, GDF15 levels are significantly increased in MASLD patients at baseline and they remain significantly higher compared to healthy participants during OGTT, pointing to a role for GDF15 as a mitokine with important roles in the pathophysiology and possibly therapeutics of MASLD. Trial registration ClinicalTrials.gov NCT03986684, NCT04430946.

The metabolic profiles and body composition of non-obese metabolic associated fatty liver disease

Background/purpose

Metabolic-associated fatty liver disease (MAFLD) is a major cause of chronic liver disease worldwide and is generally thought to be closely related to obesity and diabetes. However, it also affects non-obese individuals, particularly in Asian cultures.

Methods

Healthy physical examination subjects and MAFLD patients were included in the endocrinology department of Jiangsu Provincial Hospital of Traditional Chinese Medicine. MAFLD was defined as fatty liver in imaging without virus infection, drug, alcohol, or other known causes of chronic liver disease. Non-obese MAFLD was defined as MAFLD in non-obese subjects (BMI<25 kg/m2).

Results

The final analysis comprised 1047 participants in total. Of 946 MAFLD patients, 162 (17.12%) were diagnosed with non-obese MAFLD. Non-obese MAFLD patients were older, had lower alanine aminotransferase (ALT), triglyceride, and waist circumference, but had higher high density lipoprotein cholesterol (HDL-c) than obese MAFLD patients. Compared with non-obese healthy controls, non-obese MAFLD patients had higher BMI, ALT, gamma-glutamyl transferase (GGT), uric acid (UA), triglycerides (TG), and low density lipoprotein cholesterol (LDL-c). In terms of body composition, body fat mass (BFM), waist-hip ratio (WHR), percent body fat (PBF), visceral fat area (VFA), and fat mass index (FMI) were lower in non-obese healthy controls than non-obese MAFLD patients. A binary logistic regression analysis revealed that non-obese MAFLD was linked with lower GGT and higher HDL-c.

Conclusion

In this study cohort, non-obese MAFLD was present at a prevalence of 13.90%. In contrast to non-obese healthy controls, non-obese MAFLD patients exhibited different metabolic profiles, but they also had different body compositions.

A novel antisense lncRNA, ARBAG harboring an RNA destabilizing GWAS variant for C-peptide dictates the transcript isoforms of GABRA6 in cerebellum

Human disease-associated genetic variations often map to long non-coding RNA (lncRNA) genes; however, elucidation of their functional impact is challenging. We previously identified a new genetic variant rs4454083 (A/G) residing in exon of an uncharacterized lncRNA ARBAG that strongly associates with plasma levels of C-peptide, a hormone that regulates insulin bioavailability. On the opposite strand, rs4454083 also corresponds to an intron of a cerebellum-specific GABA receptor subunit gene GABRA6 that mediates strengthening of inhibitory synapses by insulin. Here, we show that alleles of rs4454083 modulate transcript levels of the antisense gene, ARBAG, which then controls the expression of the sense gene, GABRA6. Predisposing to low C-peptide, GG (a minor allele genotype across ethnicities) stabilizes ARBAG lncRNA causing higher transcript levels in cerebellum. ARBAG lncRNA abundance leads to cleavage of GABRA6 mRNA at the complementary region, resulting in a dysfunctional GABRA6 protein that would not be recruited for synapse strengthening. Together, our findings in human cerebellar cell-line and induced Pluripotent Stem Cells (iPSCs) demonstrate biological role of a novel lncRNA in determining the ratio of mRNA isoforms of a protein-coding gene and the ability of an embedded variant in modulating lncRNA stability leading to inter-individual differences in protein expression.

Blood C-peptide concentration as a proxy marker of cardiovascular disease: An observational cross-sectional study

Background and Aims

Cardiovascular diseases (CVDs) are among the leading causes of disability and early death in sub-Saharan Africa. Most of the current blood tests for CVD diagnosis involve performing about three test profiles; often at additional cost to patients. C-peptide, a cleavage product of proinsulin, is a promising marker that has the potential to serve as a proxy marker for diagnosing CVDs in resource-poor settings.

Methodology

The study was an observational cross-sectional one and involved 127 consenting persons diagnosed with CVD and 127 individuals without CVD. The socio-demographic and clinical characteristics of participants were obtained. Blood levels of C-peptide, fasting plasma glucose (FPG), total creatinine kinase (CK), creatine kinase myocardial bound (CKMB), lactate dehydrogenase (LDH), propeptide of brain natriuretic peptide (PBNP), Troponin T, lipids, and biomarkers of kidney and liver function were analyzed using ELISA and an automated analyzer. Insulin resistance was computed using the modified homeostatic model assessment (HOMA-IR).

Results

The CVD Group had significantly higher levels of C-peptide, CK, CKMB, troponin T, PBNP, FPG, HOMA-IR, and several selected kidney, liver, and lipid parameters compared to the non-CVD Group (p < 0.05 for all). Troponin T recorded a positive correlation (r = 0.34, p < 0.001) with C-peptide among the CVD Group. The sensitivity and specificity of C-peptide in identifying CVD were 96.1% and 91.3% respectively (area under the curve = 0.938, p < 0.001).

Conclusion

C-peptide levels were higher in the CVD Group and appeared to be a valuable (high sensitivity and specificity) biomarker in detecting CVD.

Association of dietary insulinemic and inflammatory potential with risk of liver cancer and chronic liver disease mortality in postmenopausal women: a prospective cohort study

BACKGROUND

Low diet quality, diabetes, and chronic inflammation are risk factors of liver cancer and chronic liver disease (CLD), but the extent to which insulinemic and inflammatory diets are independently associated with risk of liver cancer and CLD mortality is unknown.

METHODS

We conducted a prospective cohort analysis among 78,356 postmenopausal women in the Women's Health Initiative Observational Study. Two validated dietary indices, the empirical dietary index for hyperinsulinemia (EDIH) and the empirical dietary inflammation pattern (EDIP), were estimated from a food-frequency questionnaire. Incident cases of liver cancer and CLD mortality were adjudicated via review of medical records and linkage to National Death Index. Multivariable hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using Cox proportional hazards models, adjusted for age, diabetes, body mass index, and other covariates.

RESULTS

During a median 22.1 y of follow-up, we documented 176 primary liver cancer cases and 156 CLD mortality cases. EDIH was positively associated with incident liver cancer (HRQuartile 4 vs. Quartile 1 = 1.68; 95% CI: 1.00, 2.83; P-trend = 0.05) and CLD mortality (HRQ4 vs. Q1 = 2.28; 95% CI: 1.25, 4.15; P-trend = 0.02) in the multivariable model. EDIP was also positively associated with liver cancer (HRQ4 vs. Q1 = 1.88; 95% CI: 1.17, 3.03; P-trend = 0.009) and CLD mortality (HRQ4 vs. Q1 = 1.85; 95% CI: 1.09, 3.15; P-trend = 0.007). Estimates remained significant and robust in sensitivity analyses. Further analyses indicated positive associations for refined grains, processed meat, sugary beverages, and eggs, and inverse associations for coffee/tea and poultry.

CONCLUSIONS

Dietary insulinemic and inflammatory potentials were independently associated with higher risk of liver cancer and CLD mortality in U.S. postmenopausal women. These findings suggest a potential role for diet modification to reduce risk of liver cancer and CLD.

Association of serum C-peptide with all-cause and cardiovascular disease mortality in ultrasound-defined nonalcoholic fatty liver disease

OBJECTIVE

To determine the prognostic value of C-peptide in long-term nonalcoholic fatty liver disease (NAFLD) mortality.

METHODS

A total of 4670 participants with NAFLD were enrolled in this study. Multivariable Cox regression models evaluated the links between C-peptide levels and all-cause and cardiovascular disease (CVD) mortality risk using adjusted hazard ratios (aHR). In addition, a two‑piecewise Cox model with penalized splines was adapted to investigate the nonlinear relationships between C-peptide and mortality.

RESULTS

After a mean follow‑up period of 20 years, 1714 deaths from all causes were recorded. In an adjusted Cox regression analysis, using the low C-peptide group as the reference (quartile 1), higher C-peptide (quartile 4) was notably associated with increased all-cause mortality (aHR =1.39; 95% CI: 1.18-1.65) and CVD death (aHR = 1.97; 95% CI: 1.41-2.76). Spline analyses demonstrated that the association between C-peptide levels and all-cause mortality was U-shaped, with a threshold value of 0.41 nmol/L. Below the threshold, every one-unit increment in C-peptide had a 70% reduced risk of all-cause death (aHR = 0.30, 95% CI: 0.1-0.7). Above the threshold, the C-peptide levels were associated with a higher probability of all-cause death (aHR = 1. 3, 95% CI:1.2-1.4).

CONCLUSIONS

In the US NAFLD population defined by ultrasound, a U-shaped association was detected between baseline serum C-peptide level and all-cause mortality.

Insulin-Like Growth Factor-I Might be a Predictor for Severe Non-Alcoholic Fatty Liver Disease in Morbidly Obese Patients

The aim of the study was to compare the IGF-1 levels, metabolic and clinical parameters among the ultrasonographically classified non-alcoholic fatty liver disease (NAFLD) groups and determine the factors that may predict the NAFLD severity in patients with morbid obesity. This study was conducted on 316 morbidly obese patients (250 F/66 M). The data of patients before and 1st-year after bariatric surgery were recorded. According to the ultrasonographically NAFLD screening, patients with normal hepatic features were classified as Group 1(n=57), with mild and moderate NAFLD were classified as Group 2(n=219), and with severe NAFLD were classified as Group 3(n=40). IGF-1 standard deviation scores (SDSIGF1) were calculated according to age and gender. Parameters that could predict the presence and severity of NAFLD were evaluated. IGF-1 levels were significantly associated with Group 3 than Group 1(p=0.037), and the significance remained between the same groups when IGF-1 levels were standardized as SDSIGF1(p=0.036). Decreased levels of SDSIGF1 explained 5% of severe NAFLD than the normal group (p=0.036). Liver Diameter, FPG, ALT, AST, and GGT were also found as significant predictors for severe NAFLD. There were significant differences between pre-and postop values in all groups (p<0.001). This study showed that IGF-1 might be considered a sgnificant predictor of severe NAFLD in morbidly obese patients. It is crucial in clinical practice to determine predictive factors of NAFLD that could support the diagnosis accompanied by non-invasive imaging methods.

Simple surrogate equations to predict controlled attenuation parameter values for screening non-alcoholic fatty liver disease in a Chinese population

Objective

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease. The controlled attenuation parameter (CAP) obtained by FibroScan reflects the level of liver steatosis in patients with obesity. Our study aimed to construct a simple equation to predict the CAP, to facilitate the screening and monitoring of patients at high risk for NAFLD.

Methods

A total of 272 subjects were randomly divided into derivation and validation cohorts at a ratio of 1:2. The derivation set was used for constructing a multiple linear regression model; the validation set was used to verify the validity of the model.

Results

Several variables strongly correlated with the CAP were used to construct the following equation for predicting CAP values:CAP1 = 2.4 × BMI + 10.5 × TG+ 3.6 × NC + 10.3 × CP +31.0, where BMI is body mass index, TG is triglyceride, NC is neck circumference and CP is C-peptide. The CAP1 model had an R2 of 0.764 and adjusted R2 of 0.753. It was then simplified to derive CAP2 included only simple anthropometric parameters: CAP2 = 3.5 × BMI + 4.2 × NC + 20.3 (R2 = 0.696, adjusted R2 = 0.689). The data were well fitted by both models. In the verification group, the predicted (CAP1 and CAP2) values were compared to the actual CAP values. For the CAP1 equation, R2 = 0.653, adjusted R2 = 0.651. For the CAP2 equation, R2 = 0.625, adjusted R2 = 0.623. The intra-class correlation coefficient (ICC) values were 0.781 for CAP1 and 0.716 for CAP2 (p &lt; 0.001). The actual CAP and the predicted CAP also showed good agreement in Bland-Altman plot.

Conclusion

The equations for predicting the CAP value comprise easily accessible variables, and showed good stability and predictive power. Thus, they can be used as simple surrogate tools for early screening and follow-up of NAFLD in the Chinese population.

Machine learning models for predicting non-alcoholic fatty liver disease in the general United States population: NHANES database

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, affecting over 30% of the United States population. Early patient identification using a simple method is highly desirable.

AIM

To create machine learning models for predicting NAFLD in the general United States population.

METHODS

Using the NHANES 1988-1994. Thirty NAFLD-related factors were included. The dataset was divided into the training (70%) and testing (30%) datasets. Twenty-four machine learning algorithms were applied to the training dataset. The best-performing models and another interpretable model (i.e., coarse trees) were tested using the testing dataset.

RESULTS

There were 3235 participants (n = 3235) that met the inclusion criteria. In the training phase, the ensemble of random undersampling (RUS) boosted trees had the highest F1 (0.53). In the testing phase, we compared selective machine learning models and NAFLD indices. Based on F1, the ensemble of RUS boosted trees remained the top performer (accuracy 71.1% and F1 0.56) followed by the fatty liver index (accuracy 68.8% and F1 0.52). A simple model (coarse trees) had an accuracy of 74.9% and an F1 of 0.33.

CONCLUSION

Not every machine learning model is complex. Using a simpler model such as coarse trees, we can create an interpretable model for predicting NAFLD with only two predictors: fasting C-peptide and waist circumference. Although the simpler model does not have the best performance, its simplicity is useful in clinical practice.

Decreased plasma n6 : n3 polyunsaturated fatty acids ratio interacting with high C-peptide promotes non-alcoholic fatty liver disease in type 2 diabetes patients

AIMS/INTRODUCTION

To explore relationships between polyunsaturated fatty acids (PUFA) and non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes, and whether insulin action has an interactive effect with PUFA on NAFLD progression.

MATERIALS AND METHODS

We extracted clinical and omics data of 482 type 2 diabetes patients from a tertiary hospital consecutively from April 2018 to April 2019. NAFLD was estimated by ultrasound at admission. Plasma fasting n3 and n6 fatty acids were quantified by liquid chromatography-tandem mass spectrometry analysis. Restricted cubic spline nested in binary logistic regression was used to select the cut-off point, and estimate odds ratios and 95% confidence intervals. Additive interactions of the n6 : n3 ratio with insulin action for NAFLD were estimated using relative excess risk due to interaction, attributable proportion due to interaction and synergy index. Relative excess risk due to interaction >0, attributable proportion due to interaction >0 or synergy index >1 indicates biological interaction. Spearman correlation analysis was used to obtain partial correlation coefficients between PUFA and hallmarks of NAFLD.

RESULTS

Of 482 patients, 313 were with and 169 were without NAFLD. N3 ≥800 and n6 PUFA ≥8,100 μmol/L were independently associated with increased NAFLD risk; n6 : n3 ratio ≤10 was associated with NAFLD (odds ratio 1.80, 95% confidence interval 1.20-2.71), and the effect size was amplified by high C-peptide (odds ratio 8.89, 95% confidence interval 4.48-17.7) with significant interaction. The additive interaction of the n6 : n3 ratio and fasting insulin was not significant.

CONCLUSION

Decreased n6 : n3 ratio was associated with increased NAFLD risk in type 2 diabetes patients, and the effect was only significant and amplified when there was the co-presence of high C-peptide.

Prevalence and risk factor analysis for the nonalcoholic fatty liver disease in patients with type 2 diabetes mellitus

Although non-alcoholic fatty liver disease (NAFLD) is strongly associated with type 2 diabetes mellitus (T2DM), the diagnosis of NAFLD for T2DM patients remains a challenge.This study aimed to investigate the prevalence and risk factors for the NAFLD in T2DM outpatients.This is a retrospective, cross-sectional study that included 2405 T2DM patients treated and admitted for glucose control into the Endocrinology Department of our hospital from April 2017 to March 2019. Using strict exclusion criteria, the target patients were screened and divided into two groups: NAFLD patients (study group) and non-NAFLD patients (control group). Subsequently, 34 factors were compared between the two groups. Furthermore, multivariate analysis of the NAFLD risk factors was performed using logistic regression. Finally, the diagnostic significance of individual biochemical predictors, as well as the combined predictive indicator (CPI), for NAFLD was estimated using receiver operating characteristic (ROC) curve analysis.In this study, the overall prevalence of NAFLD in T2DM patients was 58.67%. Of the target patients, 17 factors were identified by univariate analysis to be associated with NAFLD, and 8 factors were found to be significant predictors for NAFLD using binary logistic regression modeling. Furthermore, the CPI and C-Peptide represent high diagnostic value for NAFLD in T2DM patients.This study provides a more comprehensive risk factor analysis for NAFLD in T2DM patients. These data can be used to provide timely diagnosis and effective management of NAFLD.

Association of dietary insulinaemic potential and odds of non-alcoholic fatty liver disease among adults: A case-control study

BACKGROUND

Hyperinsulinaemia is considered as a major risk factor for the development of a myriad of chronic diseases. We examined the association between the dietary insulinaemic potential and the odds of non-alcoholic fatty liver disease (NAFLD) among Iranian adults.

METHODS

After being subjected to a liver ultrasound, 166 patients with NAFLD and 200 controls were included in the study. The dietary intakes and the physical activity levels of the participants were evaluated using a validated semi-quantitative food frequency questionnaire and the International Physical Activity Questionnaire (short IPAQ), respectively. The insulinaemic potential of the diet was assessed by computing the scores of the Empirical Dietary Index for Hyperinsulinemia (EDIH) and the Empirical Dietary Index for Insulin Resistance (EDIR).

RESULTS

Compared with the control subjects, patients with NAFLD were significantly older; had higher values for body mass index, fasting blood sugar, triglycerides, low-density lipoprotein cholesterol, total cholesterol and alanine transaminase; and were more likely to smoke. Moreover, NAFLD patients had significant lower levels of high-density lipoprotein cholesterol and were less likely to perform physical activity. The risk of NAFLD was higher in the individuals in the highest tertile of the EDIH (odds ratio [OR] = 2.79; 95% confidence interval [CI] = 1.32-5.90; p value for trend < 0.05) and EDIR (OR = 2.42; 95% CI = 1.22-4.79; p value for trend < 0.05) compared to those in the lowest tertile of these scores.

CONCLUSIONS

Our study indicates that a higher dietary insulinaemic potential is associated with an increased risk of NAFLD.

Free Triiodothyronine Is Independently Associated with Nonalcoholic Fatty Liver Disease in Hospitalized Type 2 Diabetes Mellitus Patients

OBJECTIVE

Free triiodothyronine (FT3) is an independent risk factor for nonalcoholic fatty liver disease (NAFLD) in patients with euthyroid. However, whether FT3 has an independent effect on NAFLD in a population of type 2 diabetes remains unknown. The purpose of this study was to identify the potential role of FT3 in NAFLD with T2DM.

DESIGN

A cross-sectional study. Patient. A total of 859 T2DM patients who met the inclusion criteria were included. There were 506 T2DM patients without NAFLD and 353 T2DM patients with NAFLD.

METHODS

The independent samples t-test or Wilcoxon rank sum test were used for continuous variables of different distribution types, while the chi-square test was used for categorical variables. Pearson correlation analysis and linear regression were used to analyze the correlation between FT3 and clinical measurements and biochemical indicators. Multivariate logistic regression analysis was used to determine independent predictors.

RESULTS

Patients with NAFLD had higher BMI, SBP, and DBP, longer duration of T2DM, and higher islet function index, blood glucose index, liver function index, renal function index, blood lipid index, and FT3. We also found that FT3 was affected by other five indicators, including ALT, CR, GGT, TC, and LDL-C only in the NAFLD group but not in the non-NAFLD group. FT3 was significantly associated with NAFLD in T2DM patients, and the prevalence of NAFLD increased gradually from the lowest FT3 tertile to the highest FT3 tertile (P for trend < 0.001).

CONCLUSION

FT3 is independently associated with NAFLD in hospitalized T2DM patients after rigorous adjustment for various metabolic parameters.

Burden of Disease due to Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the most common liver disease in both Western populations and other parts of the world. This review discusses the prevalence and incidence of NAFLD in various regions around the world. The methodology used to identify the epidemiology and classify the stages of the disease is described. The impact of the disease on individuals, looking at both liver-related and extrahepatic consequences of the disease, is then discussed. Finally, the economic and societal impact of the disease is discussed.

C-peptide is associated with NAFLD inflammatory and fibrotic progression in type 2 diabetes

BACKGROUND

A higher prevalence of nonalcoholic steatohepatitis (NASH) and advanced stages of fibrosis was observed in type 2 diabetes. We aim to investigate whether C-peptide is associated with nonalcoholic fatty liver disease (NAFLD) progression in type 2 diabetic adults.

METHODS

A total of 4937 diabetic participants were enrolled from China in 2018. Liver steatosis was detected by ultrasound. Subjects with NAFLD were categorized into simple NAFLD and probable NASH by the concurrent presence of metabolic syndrome. NAFLD fibrosis score was used to identify patients with probable advanced fibrosis.

RESULTS

Individuals with a longer history of type 2 diabetes had a lower C-peptide level and a lower prevalence of probable NASH but a higher prevalence of advanced fibrosis. C-peptide was positively associated with simple NAFLD and probable NASH, with odds ratios (ORs) of 4.55 [95% confidence interval (CI) 3.16, 6.55] and 5.28 (95% CI 3.94, 7.09), respectively, comparing quartile 4 with quartile 1 (both p for trend <0.001). However, C-peptide quartiles were negatively associated with the probable presence of advanced fibrosis (Q4 vs. Q1, OR 0.59, 95% CI 0.36, 0.97, p for trend <0.05). A 1-SD increment of ln(C-peptide) was also significantly associated with inflammatory and fibrotic progression (OR 1.34, 95% CI 1.27, 1.41; OR 0.88, 95% CI 0.79, 0.98, respectively).

CONCLUSIONS

Significant but opposite associations between C-peptide and inflammatory and fibrotic progression of NAFLD were observed. Understanding islet hormone changes during type 2 diabetes and differentiating the stage of NAFLD may help to personalize treatment strategies for NAFLD patients with type 2 diabetes.

C-Peptide: A Mediator of the Association Between Serum Uric Acid to Creatinine Ratio and Non-Alcoholic Fatty Liver Disease in a Chinese Population With Normal Serum Uric Acid Levels

BACKGROUND

The data on the relationship between normal-ranged serum uric acid (SUA), β-cell function, and non-alcoholic fatty liver disease (NAFLD) are complicated and insufficient. Moreover, uric acid is excreted by kidney, and SUA levels may be affected by renal function. Thus, we introduced a renal function-normalized index [serum uric acid to creatinine ratio (SUA/Cr)] into the study and explored the association between SUA/Cr, C-peptide and NAFLD in a Chinese population with normal SUA levels by a cross-sectional analysis.

MATERIALS AND METHODS

A total of 282 individuals with normal SUA levels and different glucose tolerance status from a diabetes project were included in the study (mean age = 53.7± 10.5 years; women = 64.50%). NAFLD was diagnosed by abdominal ultrasonography (NAFLD, n=86; without NAFLD, n=196). Trapezoid formula was used to calculate area under the curve of C-peptide (AUC_CP) from 4 points (including 0, 30,60, and 120min) during 2-h oral glucose tolerance test. Spearman correlation analysis was used to explore the correlation between SUA/Cr, AUC_CP and NAFLD risk factors. Multiple logistic regression analysis was used to explore the association between SUA/Cr or AUC_CP and NAFLD. Mediation analysis was used to explore whether AUC_CP mediated the association between SUA/Cr and NAFLD.

RESULTS

Individuals with NAFLD had significantly higher SUA/Cr and AUC_CP than those without NAFLD(P<0.05). Spearman correlation analysis showed that both SUA/Cr and AUC_CP were significantly associated with many NAFLD risk factors, and SUA/Cr was positively correlated with AUC_CP (P<0.05). Multiple logistic regression analysis indicated that SUA/Cr and AUC_CP were positively associated with NAFLD incidence (P<0.05). Medication analysis indicated that SUA/Cr had a significant direct effect on NAFLD (β =0.5854, 95% CI: 0.3232-0.8966), and AUC_CP partly mediated the indirect effect of SUA/Cr on NAFLD incidence (β =0.1311, 95% CI: 0.0168-0.4663).

CONCLUSIONS

SUA/Cr was positively associated with NAFLD incidence, and AUC_CP partly mediated the association in a Chinese population with normal SUA levels. Thus, we should pay more attention to high-normal SUA and C-peptide levels due to their predictive power in NAFLD incidence.

Risk factors for non-alcoholic fatty liver disease-associated hepatic fibrosis in type 2 diabetes patients

AIMS

In patients with type 2 diabetes, non-alcoholic fatty liver disease (NAFLD) and liver fibrosis is frequent and presumably associated with increased cardiovascular disease risk and mortality. The objective was to investigate risk factors associated with hepatic fibrosis in patients with type 2 diabetes and NAFLD to provide a basis for the prevention and treatment.

METHODS

Liver stiffness measurements (LSM) expressed in kilopascals (kPa) and controlled attenuation parameter (CAP) expressed in dB/m were diagnosed by transient elastography. Hepatic steatosis and significant fibrosis were defined as having a CAP score ≥ 260 dB/m and an LSM score ≥ 8 kPa, respectively. Associations between fibrosis categories with anthropometric and metabolic variables were determined; then, variables with statistical significance in the univariate analysis were included in multivariate model.

RESULTS

A total of 108 participant with type 2 diabetes and NAFLD (mean age: 44.69 ± 5.57 years; mean duration of diabetes 4.68 ± 4.24 years) were recruited. In these patients, body mass index, obesity, fat mass, waist circumferences, resting energy expenditure, CAP score, fasting insulin, C-peptide, HbA1C, hs-CRP as well as liver enzymes and systolic blood pressure and diastolic blood pressure were positively associated with fibrosis (all p < 0.05). Using multivariate logistic regression, serum aspartate aminotransferase (OR 1.12; 95% CI 1.06-1.19), waist circumferences (odds ratio [OR] 1.15; 95% CI 1.05-1.25) and C-peptide (OR 3.81; 95% CI 1.5-9.7) remained as independently associated with liver fibrosis.

CONCLUSION

For participants with type 2 diabetes with coexisting NAFLD, stratification by independent risk factors for fibrosis could have important prognostic value.