Dysregulated Neurovascular Control Underlies Declining Microvascular Functionality in People With Non-alcoholic Fatty Liver Disease (NAFLD) at Risk of Liver Fibrosis

Global epidemiology of type 2 diabetes in patients with NAFLD or MAFLD: a systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and metabolic-associated fatty liver disease (MAFLD) shares common pathophysiological mechanisms with type 2 diabetes, making them significant risk factors for type 2 diabetes. The present study aimed to assess the epidemiological feature of type 2 diabetes in patients with NAFLD or MAFLD at global levels.

METHODS

Published studies were searched for terms that included type 2 diabetes, and NAFLD or MAFLD using PubMed, EMBASE, MEDLINE, and Web of Science databases from their inception to December 2022. The pooled global and regional prevalence and incidence density of type 2 diabetes in patients with NAFLD or MAFLD were evaluated using random-effects meta-analysis. Potential sources of heterogeneity were investigated using stratified meta-analysis and meta-regression.

RESULTS

A total of 395 studies (6,878,568 participants with NAFLD; 1,172,637 participants with MAFLD) from 40 countries or areas were included in the meta-analysis. The pooled prevalence of type 2 diabetes among NAFLD or MAFLD patients was 28.3% (95% confidence interval 25.2-31.6%) and 26.2% (23.9-28.6%) globally. The incidence density of type 2 diabetes in NAFLD or MAFLD patients was 24.6 per 1000-person year (20.7 to 29.2) and 26.9 per 1000-person year (7.3 to 44.4), respectively.

CONCLUSIONS

The present study describes the global prevalence and incidence of type 2 diabetes in patients with NAFLD or MAFLD. The study findings serve as a valuable resource to assess the global clinical and economic impact of type 2 diabetes in patients with NAFLD or MAFLD.

The sympathetic nervous system in the 21st century: Neuroimmune interactions in metabolic homeostasis and obesity

The sympathetic nervous system maintains metabolic homeostasis by orchestrating the activity of organs such as the pancreas, liver, and white and brown adipose tissues. From the first renderings by Thomas Willis to contemporary techniques for visualization, tracing, and functional probing of axonal arborizations within organs, our understanding of the sympathetic nervous system has started to grow beyond classical models. In the present review, we outline the evolution of these findings and provide updated neuroanatomical maps of sympathetic innervation. We offer an autonomic framework for the neuroendocrine loop of leptin action, and we discuss the role of immune cells in regulating sympathetic terminals and metabolism. We highlight potential anti-obesity therapeutic approaches that emerge from the modern appreciation of SNS as a neural network vis a vis the historical fear of sympathomimetic pharmacology, while shifting focus from post- to pre-synaptic targeting. Finally, we critically appraise the field and where it needs to go.

Risk of Heart Failure in Patients With Nonalcoholic Fatty Liver Disease: JACC Review Topic of the Week

Heart failure (HF) and nonalcoholic fatty liver disease (NAFLD) are 2 conditions that have become important global public health problems. Emerging evidence supports a strong and independent association between NAFLD and the risk of new-onset HF, and there are multiple potential pathophysiological mechanisms by which NAFLD may increase risk of new-onset HF. The magnitude of this risk parallels the underlying severity of NAFLD, especially the level of liver fibrosis. Patients with NAFLD develop accelerated coronary atherosclerosis, myocardial alterations (mainly cardiac remodeling and hypertrophy), and certain arrhythmias (mainly atrial fibrillation), which may precede and promote the development of new-onset HF. This brief narrative review aims to provide an overview of the association between NAFLD and increased risk of new-onset HF, discuss the underlying mechanisms that link these 2 diseases, and summarize targeted pharmacological treatments for NAFLD that might also reduce the risk of HF.

Fatty liver index and hypertension-mediated organ damage in never-treated hypertensive patients without diabetes mellitus

BACKGROUND

We investigated whether fatty liver index (FLI), a surrogate marker of nonalcoholic fatty liver disease (NAFLD), is associated with hypertension-mediated organ damage (HMOD) in never-treated hypertensive patients without diabetes mellitus.

METHODS

We performed both clinic and ambulatory blood pressure (BP) measurements, and calculated the FLI for all participants. A FLI of no less than 60 indicates a high-risk of underlying NAFLD, whereas a FLI of less than 60 indicates lower risk. We evaluated left ventricular mass (LVM) by echocardiography, arterial stiffness by carotid--femoral pulse wave velocity (PWV), capillary rarefaction by nailfold capillaroscopy, as well as urinary albumin-to-creatinine ratio (ACR). HMOD was defined according to the categorical thresholds for each domain, except for capillary rarefaction in which case the categorization of patients was made by the median.

RESULTS

We included 146 hypertensive patients (men, 43.8%; mean age, 56.6 ± 10.8 years; BMI, 30.3 ± 4.9 kg/m2; FLI, 57.2 ± 27.7; office, systolic/diastolic, and 24-h BP, 153.5 ± 15.8/94.7 ± 9.8 mmHg, and 140.5 ± 9.9/83.8 ± 9 mmHg, respectively). Patients with FLI at least 60 (n = 76) were younger, with higher BMI and 24-h SBP, compared with patients with FLI less than 60 (n = 70). FLI was associated with HMOD after adjustment (LVM indexed to height, P = 0.004; PWV, P = 0.047; reduced capillary density, P = 0.001; and logACR, P = 0.003). High-risk FLI phenotype and FLI z scores increased the likelihood of any HMOD by 3.8 (95% confidence interval, 1.6-7.1) and 5.4 (95% confidence interval, 2.3-15.0) times, respectively. However, the increased number of HMOD domains has progressively stopped being determined by the FLI z scores (P = 0.65).

CONCLUSION

High-risk FLI pattern was associated with various HMOD, and may re-classify never-treated hypertensive patients without diabetes mellitus into a higher cardiovascular risk level.

Association between non-alcoholic fatty liver disease and impaired cardiac sympathetic/parasympathetic balance in subjects with and without type 2 diabetes-The Cooperative Health Research in South Tyrol (CHRIS)-NAFLD sub-study

BACKGROUND AND AIMS

Cardiovascular disease (CVD) is the leading cause of death in patients with non-alcoholic fatty liver disease (NAFLD), both with and without type 2 diabetes mellitus (T2DM). Cardiac autonomic dysfunction is a risk factor for CVD morbidity and mortality. The aim of this pilot study was to assess whether there is an association between NAFLD and impaired cardiac autonomic function.

METHODS AND RESULTS

Among the first 4979 participants from the Cooperative Health Research in South Tyrol (CHRIS) study, we randomly recruited 173 individuals with T2DM and 183 age- and sex-matched nondiabetic controls. Participants underwent ultrasonography and vibration-controlled transient elastography (Fibroscan®, Echosens) to assess hepatic steatosis and liver stiffness. The low-to-high-frequency (LF/HF) power ratio and other heart rate variability (HRV) measures were calculated from a 20-min resting electrocardiogram (ECG) to derive a measure of cardiac sympathetic/parasympathetic imbalance. Among the 356 individuals recruited for the study, 117 had NAFLD and T2DM, 56 had T2DM alone, 68 had NAFLD alone, and 115 subjects had neither condition. Individuals with T2DM and NAFLD (adjusted odds ratio [OR] 4.29, 95% confidence intervals [CI] 1.90-10.6) and individuals with NAFLD alone (adjusted OR 3.41, 95% CI 1.59-7.29), but not those with T2DM alone, had a substantially increased risk of having cardiac sympathetic/parasympathetic imbalance, compared with those without NAFLD and T2DM. Logistic regression models were adjusted for age, sex, body mass index (BMI), hypertension, dyslipidemia, insulin resistance, hemoglobin A1c (HbA1c), C-reactive protein (CRP), and Fibroscan®-measured liver stiffness.

CONCLUSIONS

NAFLD was associated with cardiac sympathetic/parasympathetic imbalance, regardless of the presence or absence of T2DM, liver stiffness, and other potential confounding factors.