Relationship of liver fat content with systemic metabolism and chronic complications in patients with type 2 diabetes mellitus

Exploring the heterogeneity of hepatic and pancreatic fat deposition in obesity: implications for metabolic health

Objective

This retrospective observational study investigates the heterogeneity of hepatic and pancreatic fat deposition and its implications for metabolic health in individuals with obesity.

Methods

A total of 706 patients with obesity underwent an MRI to quantify liver and pancreatic fat. Patients were classified into four groups based on fat deposition: no fat (None), fatty pancreas only (NAFPD), fatty liver only (NAFLD), and both conditions (NAFLD+NAFPD). Biochemical profiles, insulin resistance (Homeostatic Model Assessment for Insulin Resistance, HOMA-IR), and β-cell function were analyzed. A series of multiple linear regressions were used to investigate the independent effects of characteristics on glucose, insulin, and C-peptide at 0h. Another multiple linear regression was performed to evaluate the effects of basic characteristics on average liver fat, mean pancreatic fat, and visceral fat.

Results

The majority (76.63%) exhibited both NAFLD and NAFPD, highlighting the heterogeneity of fat deposition among individuals with obesity. Groups with fatty liver displayed significantly higher fasting glucose, insulin, C-peptide, and HOMA-IR levels than those without fatty liver (P < 0.01). Fatty pancreas alone did not significantly influence these metabolic parameters (P > 0.05). This underscores the greater metabolic impact of hepatic fat compared to pancreatic fat.

Conclusions

The study confirms the complex heterogeneity of fat deposition in obesity, with the fatty liver being a more influential factor in metabolic disturbances than the fatty pancreas. The prevalent co-occurrence of NAFLD and NAFPD in this population underscores the need for targeted management strategies focusing on hepatic fat reduction to mitigate metabolic risk.

Quantitative assessment of renal steatosis in patients with type 2 diabetes mellitus using the iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification sequence imaging: repeatability and clinical implications

Background

Fatty kidney disease is linked to renal function damage, but there is no noninvasive tool for monitoring renal fat accumulation. This study aimed to explore the repeatability of the iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification (IDEAL-IQ) sequence imaging in quantifying renal fat deposition and to assess the differences observed in patients with type 2 diabetes mellitus (T2DM).

Methods

A total of 26 healthy participants underwent two IDEAL-IQ scans without repositioning, and the repeatability of the imaging technique was assessed with Bland-Altman analysis. Additionally, 96 patients with T2DM underwent a single IDEAL-IQ scan for the examination of renal fat deposition. The patients with T2DM were classified into three groups based on their estimated glomerular filtration rate (eGFR). One-way analysis of variance was used to analyze the differences of renal fat depositions between the groups. Receiver operating characteristic curve analysis was used to assess the diagnostic performance of IDEAL-IQ.

Results

Bland-Altman analyses showed narrower limits of agreement and a significant correlation (r=0.81; P<0.05) between the two IDEAL-IQ scans. Statistically significant differences between the healthy volunteers and patients with T2DM, diabetic kidney disease (DKD) I-II, and or DKD III-IV were found in renal parenchymal proton-density fat fraction (PDFF) values (P<0.001). Renal parenchymal PDFF was negatively correlated with eGFR (r=-0.437; P<0.001) and positive correlated with serum creatinine level (µmol/L) (r=0.421; P<0.001). The area under the curve of IDEAL-IQ in discriminating between the healthy volunteers and patients with T2DM was 0.857. For discriminating T2DM from DKD I-II and DKD III-IV, the IDEAL-IQ had an area under the curve of 0.689 and 0.823, respectively.

Conclusions

IDEAL-IQ is a promising and reproducible technique for the assessment of renal fat deposition and identification of risk of DKD in patients with T2DM. Moreover, IDEAL-IQ imaging is expected to improve the sensitivity and specificity of early renal function damage and staging assessment of patients with T2DM.

"Adjusting internal organs and dredging channelon" electroacupuncture glycolipid metabolism disorders in NAFLD mice by mediating the AMPK/ACC signaling pathway

To investigate the effect mechanism of electroacupuncture based on the AMP-activated protein kinase (AMPK) /acetyl-CoA carboxylase (ACC) signaling pathway to improve glycolipid metabolism disorders in db/db mice. 10 db/m mice with normal genotype were used as the normal control group without diabetes (Con), and 30 db/db mice were divided randomly into three groups: Pathological model mice (Mod), Acupuncture + ACC antagonist group (Acu + ACC), and Acupuncture + AMPK antagonist group (Acu + AMPK). Con and Mod did not receive any special treatment, only as a control observation. The latter two groups of mice received electroacupuncture treatment for 4 weeks. Mouse triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol(LDL-C), and cholesterin(CHO) levels were detected by colorimetric assay. Enzyme-linked immunoassay (ELISA) was used to detect insulin(INS) levels. Liver histopathologic changes and hepatic glycogen synthesis were observed by HE and PAS staining. The mRNA and protein expression of insulin receptor substrate-1(IRS1), Phosphatidylinositol 3-kinase(PI3K), protein kinase B (AKT), AMPK, and ACC were detected by Western blot and qRT-PCR.The results show that compared with Mod, TG, LDL, CHO, and INS levels of Acu + AMPK and Acu + ACC mice were significantly reduced (P < 0.05), and the HDL levels were significantly increased (P < 0.05), the steatotic degeneration of mice hepatocytes was reduced to different degrees, and the hepatocyte glycogen particles were increased, and the latter two groups had a decrease in AKT, ACC mRNA expression was reduced (P < 0.05), PI3K protein expression was increased, and AKT and ACC protein expression was reduced (P < 0.05), in addition, protein expression of AMPK was increased and IRS1 protein expression was reduced in Acu + ACC (P < 0.05). The study showed that electroacupuncture improves glucose-lipid metabolism disorders in db/db mice, and this mechanism is related to the AMPK/ACC signaling pathway.

Non-Invasive Diagnostic of NAFLD in Type 2 Diabetes Mellitus and Risk Stratification: Strengths and Limitations

The progressive potential of liver damage in type 2 diabetes mellitus (T2DM) towards advanced fibrosis, end-stage liver disease, and hepatocarcinoma has led to increased concern for quantifying liver injury and individual risk assessment. The combination of blood-based markers and imaging techniques is recommended for the initial evaluation in NAFLD and for regular monitoring to evaluate disease progression. Continued development of ultrasonographic and magnetic resonance imaging methods for accurate quantification of liver steatosis and fibrosis, as well as promising tools for the detection of high-risk NASH, have been noted. In this review, we aim to summarize available evidence regarding the usefulness of non-invasive methods for the assessment of NAFLD in T2DM. We focus on the power and limitations of various methods for diagnosis, risk stratification, and patient monitoring that support their implementation in clinical setting or in research field.

Global prevalence of non-alcoholic fatty liver disease in type 2 diabetes mellitus: an updated systematic review and meta-analysis

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease, with type 2 diabetes mellitus (T2DM) as a major predictor. Insulin resistance and chronic inflammation are key pathways in the pathogenesis of T2DM leading to NAFLD and vice versa, with the synergistic effect of NAFLD and T2DM increasing morbidity and mortality risks. This meta-analysis aims to quantify the prevalence of NAFLD and the prevalence of clinically significant and advanced fibrosis in people with T2DM.

METHODS

MEDLINE and Embase databases were searched from inception until 13 February 2023. The primary outcomes were the prevalence of NAFLD, non-alcoholic steatohepatitis (NASH) and fibrosis in people with T2DM. A generalised linear mixed model with Clopper-Pearson intervals was used for the analysis of proportions with sensitivity analysis conducted to explore heterogeneity between studies.

RESULTS

156 studies met the inclusion criteria, and a pooled analysis of 1 832 125 patients determined that the prevalence rates of NAFLD and NASH in T2DM were 65.04% (95% CI 61.79% to 68.15%, I2=99.90%) and 31.55% (95% CI 17.12% to 50.70%, I2=97.70%), respectively. 35.54% (95% CI 19.56% to 55.56%, I2=100.00%) of individuals with T2DM with NAFLD had clinically significant fibrosis (F2-F4), while 14.95% (95% CI 11.03% to 19.95%, I2=99.00%) had advanced fibrosis (F3-F4).

CONCLUSION

This study determined a high prevalence of NAFLD, NASH and fibrosis in people with T2DM. Increased efforts are required to prevent T2DM to combat the rising burden of NAFLD.

PROSPERO REGISTRATION NUMBER

CRD42022360251.

Hepatic MR imaging using IDEAL-IQ sequence: Will Gd-EOB-DTPA interfere with reproductivity of fat fraction quantification?

BACKGROUND

Iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification sequence (IDEAL-IQ) is based on chemical shift-based water and fat separation technique to get proton density fat fraction. Multiple studies have shown that using IDEAL-IQ to test the stability and repeatability of liver fat is acceptable and has high accuracy.

AIM

To explore whether Gadoxetate Disodium (Gd-EOB-DTPA) interferes with the measurement of the hepatic fat content quantified with the IDEAL-IQ and to evaluate the robustness of this technique.

METHODS

IDEAL-IQ was used to quantify the liver fat content at 3.0T in 65 patients injected with Gd-EOB-DTPA contrast. After injection, IDEAL-IQ was estimated four times, and the fat fraction (FF) and R2* were measured at the following time points: Pre-contrast, between the portal phase (70 s) and the late phase (180 s), the delayed phase (5 min) and the hepatobiliary phase (20 min). One-way repeated-measures analysis was conducted to evaluate the difference in the FFs between the four time points. Bland-Altman plots were adopted to assess the FF changes before and after injection of the contrast agent. P < 0.05 was considered statistically significant.

RESULTS

The assessment of the FF at the four time points in the liver, spleen and spine showed no significant differences, and the measurements of hepatic FF yielded good consistency between T1 and T2 [95% confidence interval: -0.6768%, 0.6658%], T1 and T3 (-0.3900%, 0.3178%), and T1 and T4 (-0.3750%, 0.2825%). R2* of the liver, spleen and spine increased significantly after injection (P < 0.0001).

CONCLUSION

Using the IDEAL-IQ sequence to measure the FF, we can obtain results that will not be affected by Gd-EOB-DTPA. The high reproducibility of the IDEAL-IQ sequence makes it available in the scanning interval to save time during multiphase examinations.

Retinal Vascular Lesions in Patients with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Background: This systematic review and meta-analysis aimed to summarize and compare data on retinal vascular lesions between patients with nonalcoholic fatty liver disease (NAFLD) and individuals without the disease. Methods: Search was performed in PubMed, Scopus and Cochrane Library, complemented by handsearching (PROSPERO ID: CRD42022345558). Thirty-six studies comprising 24,985 individuals (12,387 NAFLD patients and 12,598 controls) were selected for the meta-analysis. Results: Apart from retinopathy, no study with a different type of retinal vascular lesion was retrieved. Overall, there was no significant difference in the presence of retinopathy in NAFLD patients compared to controls (Odds Ratio (OR) = 1.20; 95% Confidence Interval (CI): 0.91-1.59). Heterogeneity among studies was high (I² = 93%; p < 0.00001), while Egger's test revealed no publication bias (p = 0.60). However, subgroup analysis showed positive association between retinopathy and NAFLD in type 1 diabetes mellitus (T1DM) (OR = 2.35; 95% CI: 1.53-3.60), but not in type 2 diabetes mellitus patients. Meta-regression analysis exploring potential confounders revealed no significant association. Conclusions: The presence of retinopathy was not overall different between individuals with and without NAFLD; however, T1DM patients with NAFLD had higher rates of retinopathy compared to T1DM patients without NAFLD, a finding warranting further research to show whether NAFLD may predict retinopathy in T1DM patients.

The mediating role of HbA1c in the association between elevated low-density lipoprotein cholesterol levels and diabetic peripheral neuropathy in patients with type 2 diabetes mellitus

BACKGROUND

Increased levels of low-density lipoprotein cholesterol (LDL-C) have been identified as one potential risk factor for diabetic peripheral neuropathy (DPN) in patients. The current study seeks to clarify the link between LDL-C, hyperglycemia, and DPN in patients with type 2 diabetes mellitus (T2DM).

METHODS

Here, a total of 120 T2DM individuals were recruited. These volunteers with T2DM were divided into 2 groups, based on the presence or absence of peripheral neuropathy. Additionally, their baseline characteristics were compared. Association among LDL-C and glycosylated hemoglobin (HbA1c) levels and DPN, particularly with respect to specific nerve conduction velocity were analyzed. To identify factors influencing DPN, regression was performed. Furthermore, mediation analysis was employed to evaluate the indirect, direct and total effects of LDL-C on specific nerve conduction velocity, with HbA1c serving as a mediator.

RESULTS

Compared to 55 patients without DPN, 65 patients with DPN demonstrated elevated levels of LDL-C and HbA1c. Both LDL-C and HbA1c have been found to be associated with reduced the motor fiber conduction velocities of Ulnar (or the Common peroneal) nerve in diabetic patients. HbA1c is one of the known risk factors for DPN in individuals with T2DM. Further mediation analysis revealed that the effect of LDL-C on the Ulnar (or the Common peroneal) nerve motor fiber conduction velocities are fully mediated by HbA1c in patients with T2DM.

CONCLUSIONS

The impact of elevated LDL-C levels upon the Ulnar (or the Common peroneal) nerve motor fiber conduction velocities in patients with T2DM was found to be entirely mediated by increased HbA1c levels.