Non alcoholic fatty liver disease and risk of incident diabetes in subjects who are not obese

Influence of MAFLD and NAFLD on arterial stiffness: A longitudinal cohort study

BACKGROUND AND AIMS

This cohort study investigated associations of nonalcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated fatty liver disease (MAFLD) with risk of increase in arterial stiffness (AS), measured as brachial-ankle pulse wave velocity (baPWV).

METHODS AND RESULTS

Participants who had health examinations between 2006 and 2019 were analyzed for fatty liver and increased baPWV using liver ultrasonography and automatic volume plethysmography device. Participants were classified based on presence of MAFLD or NAFLD and further divided into subgroups: no fatty liver disease (reference), NAFLD-only, MAFLD-only, and both NAFLD and MAFLD. Subgroups were additionally stratified by sex. Cox proportional hazard model was utilized to analyze the risk of developing baPWV ≥1400 cm/s in participants without baseline elevation of the baPWV. The NAFLD and MAFLD groups exhibited higher risks of increased baPWV (NAFLD: adjusted hazard ratio (aHR), 1.35 [95% CI, 1.29-1.42]; MAFLD: aHR, 1.37 [95% CI, 1.31-1.43]) compared to group without the conditions. Incidence of NAFLD or MAFLD were higher in men than in women but aHR of developing the increase in AS was higher in women. In subgroup analysis, the MAFLD-only group presented the strongest associations with increase in AS (aHR, 1.53 [95% CI, 1.43-1.64]), with the trend more pronounced in women than in men (Women, aHR, 1.63 [95% CI, 1.08-2.46]; Men, aHR 1.45 [95% CI, 1.35-1.56]).

CONCLUSIONS

Both NAFLD and MAFLD are significantly associated with elevated AS. These associations tended to be stronger in MAFLD than in NAFLD, in women than in men.

NAFLD Is Associated With Quiescent Rather Than Active Crohn's Disease

BACKGROUND AND AIMS

Crohn's disease (CD) confers an increased risk of nonalcoholic fatty liver disease (NAFLD), but the pathogenesis remains poorly understood. We determined if active intestinal inflammation increases the risk of NAFLD in patients with CD.

METHODS

Two cohorts (2017/2018 and 2020) with CD and no known liver disease were enrolled consecutively during staging magnetic resonance enterography. We quantified proton density fat fraction, MaRIA (Magnetic Resonance Index of Activity), and visceral adipose tissue. NAFLD was diagnosed when proton density fat fraction ≥5.5%. Synchronous endoscopy was graded by the Simple Endoscopic Score for CD and Rutgeerts score, while clinical activity was graded by the Harvey-Bradshaw index. Cytokine profiling was performed for the 2020 cohort. Transient elastography and liver biopsy were requested by standard of care.

RESULTS

NAFLD was diagnosed in 40% (n = 144 of 363), with higher prevalence during radiographically quiescent disease (odds ratio, 1.7; P = .01), independent of body mass index/visceral adipose tissue (adjusted odds ratio, 7.8; P = .03). These findings were corroborated by endoscopic disease activity, but not by aggregate clinical symptoms. Circulating interleukin-8 was independent of body mass index to predict NAFLD, but traditional proinflammatory cytokines were not. NAFLD subjects had similar liver stiffness estimates regardless of CD activity. Definitive or borderline steatohepatitis was present in most patients that underwent liver biopsy.

CONCLUSIONS

Quiescent CD is associated with risk of NAFLD. These findings suggest potentially distinct pathogenic mechanisms of NAFLD in patients with CD compared with the prevailing leaky gut hypothesis proposed for individuals without inflammatory bowel disease. Future validation and mechanistic studies are needed to dissect these distinct disease modifying factors.

Association of sex-specific body mass index and waist circumference trajectories with non-alcoholic fatty liver disease incidence based on growth mixture modeling

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease. The relationship between the trajectories of obesity indicators and incident NAFLD is unknown. Therefore, this study aims to explore the sex-specific association between the trajectories of obesity indicators and the incidence of NAFLD.

METHODS AND RESULTS

In total, 9067 participants were recruited for this longitudinal study. Obesity indicators use body mass index (BMI) and waist circumference (WC). The trajectory of obesity indicators was analyzed using the growth mixture modeling. The multivariate logistic regression model was used to analyze the association between obesity indicators' trajectories and incident NAFLD. Over a median follow-up of 1.82 years, 1013 (11.74%) participants developed NAFLD. We identified BMI and WC change trajectories as the stable group, increasing group, and decreasing group. After adjusting for baseline level and other confounders, multivariate logistic regression analysis showed that compared with stable group of BMI, the increasing group, and decreasing group odds ratio and 95% confidence interval of NAFLD were 2.10 (1.06-4.15), and 0.25 (0.09-0.67) in men, and 1.82 (1.08-3.04) and 0.32 (0.16-0.64) in women. Compared with stable group of WC, the increasing group was 2.57 (1.39-4.74) in men, the increasing group, and decreasing group were 2.29 (1.70-3.10) and 0.28 (0.12-0.64) in women. Sensitivity analysis showed that the results were stable.

CONCLUSION

The BMI and WC changing trajectories are significantly associated with the incidence of NAFLD in men and women. Populations of real-world health examinations can be categorized based on obesity indicator changes to prevent NAFLD.

Lean Nonalcoholic Fatty Liver Disease and Risk of Incident Type 2 Diabetes mellitus: A Literature Review and Meta-analysis

OBJECTIVE

There is limited data regarding the risk of incident type 2 diabetes mellitus(T2DM) among lean nonalcoholic fatty liver disease (NAFLD) individuals. We performed a meta-analysis of relevant studies. Research design and methods We collected data using PubMed, Scopus, Cochrane and Web of Science from the databases' inception until December 2022. We included cohort studies in which lean NAFLD was diagnosed through imaging methods or biopsy. Eligible studies were selected according to predefined keywords and clinical outcomes.

RESULTS

A total of 16 observational studies with 304,975 adult individuals (7.7% with lean NAFLD) and nearly 1300 cases of incident diabetes followed up over a median period of 5.05 years were included in the final analysis. Patients with lean NAFLD had a greater risk of incident diabetes than those without NAFLD (random-effects hazard ratio [HR] 2.72, 95% CI 1.56-4.74; I2 = 93.8%). Compared with the lean without NAFLD group, the adjusted HRs (95% CIs) of incident diabetes for participants in the overweight/obese without NAFLD and overweight/obese with NAFLD groups were 1.32 (0.99- 1.77) and 2.98(1.66-5.32). It appeared to be even greater among NAFLD patients with advanced high NAFLD fibrosis score (random-effects HR 3.48, 95% CI 1.92-6.31). Sensitivity analyses and publication bias did not alter these findings.

CONCLUSIONS

Lean NAFLD is significantly associated with at least twofold increased risk of incident diabetes in non-overweight subjects. This risk parallels the underlying severity of NAFLD. The presence of NAFLD in non-overweight individuals had a more significant impact on the development of diabetes than being overweight itself.

Comparison of cardiovascular mortality between MAFLD and NAFLD: A cohort study

BACKGROUND AND AIMS

A new diagnostic criterion of metabolic dysfunction-associated fatty liver disease (MAFLD) has been proposed. However, only few studies have shown that MAFLD predicts cardiovascular disease (CVD) mortality better than non-alcoholic fatty liver disease (NAFLD). Therefore, a cohort study was conducted to assess this relationship.

METHODS AND RESULTS

Health examination data from health care centers in South Korea were assessed after excluding participants with missing covariates and cancer history (n = 701,664). Liver ultrasonography reports, laboratory and anthropometric data were extracted. Diagnoses of NAFLD and MAFLD were performed according to standard definitions. Participants were categorized based on the presence of NAFLD and MAFLD. In addition, participants were classified into five categories: no fatty liver disease (no FLD), NAFLD-only, MAFLD-only, both FLDs, and alcoholic FLD (AFLD) and non-MAFLD. Multivariable regression modeling was performed. The median follow-up duration was 8.77 years, and 52.56% of participants were men. After stratifying the cohort into no-MAFLD and MAFLD groups, MAFLD was associated with increased CVD mortality (adjusted HR 1.14, 95% CI 1.02-1.28). When participants were divided into no-NAFLD and NAFLD groups, there was a non-significant trend towards an increase in CVD mortality in NAFLD group (adjusted HR 1.07, 95% CI 0.95-1.21). When participants were divided into five categories, MAFLD-only group showed increased CVD mortality (adjusted HR 1.35, 95% CI 1.07-1.70) while NAFLD-only group showed no significant association with CVD mortality (adjusted HR 0.67, 95% CI 0.38-1.19).

CONCLUSIONS

In conclusion, MAFLD is associated with increased CVD mortality in a relatively young Korean population.

Comparative Associations of Nonalcoholic Fatty Liver Disease and Metabolic Dysfunction-Associated Fatty Liver Disease With Coronary Artery Calcification: A Cross-Sectional and Longitudinal Cohort Study

BACKGROUND

In cross-sectional and retrospective cohort studies, we examined comparative associations between nonalcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated fatty liver disease (MAFLD) and risk of having or developing coronary artery calcification (CAC).

METHODS

Participants who had health examinations between 2010 and 2019 were analyzed. Liver ultrasonography and coronary artery computed tomography were used to diagnose fatty liver and CAC. Participants were divided into a MAFLD and no-MAFLD group and then NAFLD and no-NAFLD groups. Participants were further divided into no fatty liver disease (reference), NAFLD-only, MAFLD-only, and both NAFLD and MAFLD groups. Logistic regression modeling was performed. Cox proportional hazard model was used to examine the risk of incident CAC in participants without CAC at baseline and who had at least two CAC measurements.

RESULTS

In cross-sectional analyses, 162 180 participants were included. Compared with either the no-NAFLD or no-MAFLD groups, the NAFLD and MAFLD groups were associated with a higher risk of prevalent CAC (NAFLD: adjusted odds ratio [OR], 1.34 [95% CI, 1.29-1.39]; MAFLD: adjusted OR, 1.44 [95% CI, 1.39-1.48]). Among the 4 groups, the MAFLD-only group had the strongest association with risk of prevalent CAC (adjusted OR, 1.60 [95% CI, 1.52-1.69]). Conversely, the NAFLD-only group was associated with a lower risk of prevalent CAC (adjusted OR, 0.76 [95% CI, 0.66-0.87]). In longitudinal analyses, 34 233 participants were included. Compared with either the no-NAFLD or no-MAFLD groups, the NAFLD and MAFLD groups were associated with a higher risk of incident CAC (NAFLD: adjusted hazard ratio, 1.68 [95% CI, 1.43-1.99]; MAFLD: adjusted hazard ratio, 1.82 [95% CI, 1.56-2.13]). Among these 4 groups, the MAFLD-only group had the strongest associations with risk of incident CAC (adjusted hazard ratio, 2.03,[95% CI, 1.62-2.55]). The NAFLD-only group was not independently associated with risk of incident CAC (adjusted hazard ratio, 0.88 [95% CI, 0.44-1.78]) Conclusions: Both NAFLD and MAFLD are significantly associated with an increased prevalence and incidence of CAC. These associations tended to be stronger for MAFLD.

Metabolic status indicators and influencing factors in non-obese, non-centrally obese nonalcoholic fatty liver disease

Non-obese nonalcoholic fatty liver disease (NAFLD) is characterized by metabolic disorders and related complications. This study aimed to provide an integrated description of clinical, metabolic, and influencing factors for a specific category of patients with non-obese NAFLD. A total of 36 participants with body mass index (BMI) < 28 kg/m2 and visceral adipose tissue < 100 cm2 were classified into 2 groups: the non-obese, non-centrally obese control group (n = 17) and non-obese, non-centrally obese NAFLD group (n = 19). Hypertriglyceridemia, impaired fasting glucose, low high-density lipoprotein cholesterol levels, and hypertension were used to determine whether participants were metabolically abnormal. Based on a logistic regression model, odds ratios for the factors influencing NAFLD with 95% confidence intervals were calculated. Insulin resistance (IR) and fasting plasma glucose (FPG) levels were higher in the NAFLD group than in the control group (P < .05). The NAFLD group had a higher metabolic abnormality rate than the healthy control group (36.84% vs 5.88%, P = .044). Correlation analysis showed that IR was positively correlated with FPG and triglyceride (P < .05). BMI was the main influencing factor of NAFLD (regression coefficient β = 0.631; odds ratio = 1.879; 95% confidence interval, 1.233-2.863). NAFLD patients with a BMI < 28 kg/m2 and visceral adipose tissue < 100 cm2 had more apparent IR, higher FPG, and a higher metabolic abnormality rate. IR may be affected by FPG and triglyceride. Even in non-obese and non-centrally obese individuals, BMI should be controlled to avoid NAFLD.

Sex-specific metabolic risk factors and their trajectories towards the non-alcoholic fatty liver disease incidence

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease. This study examined sex-specific associations between NAFLD and metabolic factors and investigated the trajectory of risk factors.

METHODS

We retrospectively investigated 16,140 individuals from Beijing Health Management Cohort. Univariate and multivariate time-dependent Cox regression analyses were performed to identify independent risk factors for new-onset NAFLD. The trajectory of risk factors was investigated using the latent growth curve model and growth mixture model.

RESULTS

Over a median follow-up of 3.15 years, 2,450 (15.18%) participants developed NAFLD. The risk factors for NAFLD in men were increased body mass index (BMI); waist circumference (WC); triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), haemoglobin (Hb), and serum uric acid (SUA) levels; and platelet (PLT) count and decreased serum creatinine-to-body weight (sCr/bw) and high-density lipoprotein cholesterol (HDL-C) levels. In women, the risk factors were increased BMI, WC, and fasting plasma glucose (FPG), TG, LDL-C, SUA, white blood cell (WBC), and PLT and decreased sCr/bw and HDL-C levels. In addition, BMI, LDL-C, sCr/bw and PLT changing trajectories were associated with NAFLD in men; BMI, WC, TG, LDL-C, SUA and sCr/bw trends was associated with NAFLD risk in women.

CONCLUSIONS

Development of NAFLD is associated with BMI, LDL-C, sCr/bw and PLT changing trajectories in men; BMI, WC, TG, LDL-C, SUA and sCr/bw trends are associated an increased risk of NAFLD in women. Deterioration of metabolic risk factors status can be a predictor of NAFLD many years before its occurrence.

Comparative Burden of Metabolic Dysfunction in Lean NAFLD vs Non-lean NAFLD - A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is traditionally associated with obesity. However, there is a subtype of NAFLD, namely NAFLD in lean, that occurs without obesity. However, a recent call to redefine NAFLD to metabolic-associated fatty liver disease focuses on obesity and metabolic dysfunction. Criticism has arisen from the perceived over emphasis on systemic comorbidities, which may disadvantage the lean. The current analysis seeks to quantify the degree of metabolic dysfunction in NAFLD in lean and compare with NAFLD in overweight and obese and non-NAFLD.

METHODS

Medline and Embase databases were searched from inception to March 3, 2022. The inclusion criteria were articles with NAFLD in lean patients presenting with baseline metabolic parameters. Comparisons were conducted with subgroup analysis.

RESULTS

Eighty-five articles were included in the meta-analysis. NAFLD in lean accounted for 13.11% (95% confidence interval [CI], 10.26%-16.62%) of the global population and 14.55% (95% CI, 11.32%-18.51%) in Asia. The degree of metabolic dysfunction was weight dependent with significantly less metabolic dysfunction in NAFLD in lean subjects as compared with NAFLD in overweight counterparts. For NAFLD in lean, only 19.56% (95% CI, 15.28%-24.69%) of the subjects were diabetic, whereas 45.70% (95% CI, 35.01%-56.80%) of obese subjects with NAFLD had diabetes (P < .01). Fasting blood glucose and systolic and diastolic blood pressure values were significantly lower in subjects with NAFLD in lean than in overweight and obese.

CONCLUSION

The current analysis highlights the weight-dependent nature of metabolic dysfunction in NAFLD. Lean subjects with NAFLD were significantly less metabolically unhealthy than were obese and overweight persons with NAFLD. An overreliance on metabolic dysfunction in defining fatty liver will be a flaw in potentially excluding previously characterized NAFLD.

Combined evaluation of Fibrosis-4 index and fatty liver for stratifying the risk for diabetes mellitus

Aims/Introduction

To investigate whether the Fibrosis‐4 index can help stratify the risk of diabetes mellitus in patients with fatty liver disease.

Materials and Methods

Based on fatty liver disease and Fibrosis‐4 index (cut‐off value 1.3), we retrospectively divided 9,449 individuals, who underwent at least two annual health checkups, into four groups stratified by sex: normal; high Fibrosis‐4 index without fatty liver disease; low Fibrosis‐4 index with fatty liver disease; and high Fibrosis‐4 index with fatty liver disease.

Results

Onset rates for diabetes mellitus in the normal, high Fibrosis‐4 index without fatty liver disease, low Fibrosis‐4 index with fatty liver disease and high Fibrosis‐4 index with fatty liver disease groups were 1.6%, 4.3%, 6.8% and 10.2%, respectively, in men, and 0.6%, 0.9%, 5.3% and 7.0%, respectively, in women. Compared with the normal group, the high Fibrosis‐4 index without fatty liver disease, low Fibrosis‐4 index with fatty liver disease and high Fibrosis‐4 index with fatty liver disease groups were at a significant risk for diabetes mellitus onset in both male and female participants. Furthermore, in both sexes, high Fibrosis‐4 index with fatty liver disease remained a significant risk factor on multivariate analysis (high fibrosis‐4 index with fatty liver disease group: adjusted hazard ratio 4.03, 95% confidence interval 2.19–7.42 [men] and adjusted hazard ratio 6.40, 95% confidence interval 1.77–23.14 [women]).

Conclusions

Individuals with fatty liver disease and high Fibrosis‐4 index had a higher risk of diabetes mellitus onset. Therefore, Fibrosis‐4 index can help stratify the risk of diabetes mellitus in patients with fatty liver disease and identify patients requiring intervention.

Fatty liver index as a predictive marker for the development of diabetes: A retrospective cohort study using Japanese health check-up data

Background & aims

Fatty liver is associated with incident diabetes, and the fatty liver index (FLI) is a surrogate marker for non-alcoholic fatty liver disease (NAFLD). We aimed to determine whether or not FLI was associated with incident diabetes in relation to obesity and prediabetic levels in the general Japanese population.

Methods

This was a retrospective study using the Japanese health check-up database of one health insurance from FY2015 to FY2018. This study included 28,991 individuals with prediabetes. First, we stratified all participants into two groups: “high-risk,” comprising patients with HbA1c >6.0%, and “standard,” comprising the rest. Subsequently, we divided them into four groups according to FLI (<30 or not) and obesity (BMI <25 kg/m² or not). Subsequently, the incidence rate of diabetes was compared among the groups after 3 years of follow-up using multiple logistic regression models after adjusting for potential confounders.

Results

After 3 years of follow-up, 1,547 new cases of diabetes were found, and the cumulative incidence was 2.96% for the standard group and 26.1% for the high-risk group. In non-obese individuals, odds ratios (95% confidence interval) for FLI ≥30 versus FLI <30 were: 1.44 (1.09–1.92) for the standard group and 1.42 (0.99–2.03) for the high-risk group. In the high-risk group, obesity (BMI ≥25 kg/m²) but FLI <30 was not a risk factor for developing diabetes.

Conclusion

Although high FLI is generally considered to be a risk factor for developing diabetes, obesity might have been a confounding factor. However, the present study showed that high FLI is a risk factor for the development of diabetes, even in non-obese individuals. Our results include suggestion to develop a screening tool to effectively identify people at high risk of developing diabetes from the population (especially non-obese prediabetes) who are apparently at low health risk and are unlikely to be targeted for health guidance.

1-year outcomes for lung transplantation recipients with non-alcoholic fatty liver disease

Advanced hepatic fibrosis and cirrhosis are absolute contraindications to lung transplantation. [ 1] However, whether fatty liver disease with mild–moderate fibrosis contributes to increased adverse outcomes post-lung transplantation remains unknown.

 We present a retrospective analysis of patients transplanted at Brigham and Women's Hospital between 2015 and 2017 to identify whether patients with mild–moderate non-alcoholic fatty liver disease (NAFLD) experience increased short-term complications compared to patients with normal liver architecture. Patients with advanced (F3–F4) fibrosis and/or cirrhosis were considered non-suitable transplant candidates, a priori. This study was powered for a difference in index hospital-free days within the first 30 days of 25% (α=0.05, β=0.8). Secondary outcomes included index intensive care unit (ICU)-free days within the first 10 days post-transplant, perioperative blood product transfusion, incidence of index hospitalisation arrhythmias and delirium, need for insulin on discharge post-transplant, tacrolimus dose required to maintain a trough of 8–12 ng·mL⁻¹ at index hospital discharge, and 1-year post-transplant incidence of insulin-dependent diabetes, acute kidney injury, acute cellular rejection, unplanned hospital readmissions and infection.

 150 patients underwent lung transplantation between 2015 and 2017 and were included in the analysis; of these patients 40 (27%) had evidence of NAFLD. Median index hospital-free days for patients with NAFLD were non-inferior to those without (16 days, IQR 10.5–19.5 versus 12 days, IQR 0–18.0, p=0.03). Regarding secondary outcomes, both index hospitalisation and 1-year outcomes were non-inferior between patients with NAFLD and those with normal liver architecture.

 This study demonstrates that mild–moderate severity NAFLD may not be a contraindication to lung transplantation.

In this single-centre, retrospective analysis of lung transplant recipients, we identified that mild–moderate non-alcoholic fatty liver disease is associated with acceptable perioperative and 1-year outcomeshttps://bit.ly/36WNzhi

Association of liver enzymes with incident diabetes in US Hispanic/Latino adults

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) has been associated with increased risk of incident diabetes. But such evidence is lacking in the Hispanic/Latino population, which has high prevalence of obesity and NAFLD.

METHODS

We conducted a prospective cohort study of 6,928 adults of Hispanic/Latino background who had no diabetes, did not report excessive alcohol use, and no hepatitis B and C infection at baseline (2008-2011). We estimated risk ratios (RR) for incident diabetes, identified from visit 2 examination by glucose measurements or antidiabetic medication use, with baseline liver enzymes (alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT)).

RESULTS

A total of 738 adults developed diabetes during 6 years of follow-up. After adjusting for participant characteristics at baseline, versus the lowest quartile, highest quartiles of ALT and GGT were associated with risks for incident diabetes (RR for ALT: 1.51 [95% CI 1.03-2.22], p-trend = 0.006; RR for GGT: 2.39 [1.60-3.55], p-trend = 0.001). Higher GGT levels predicted increased risk of incident diabetes even among those with ALT or AST below the median levels. The associations of ALT and GGT with incident diabetes were similar among most Hispanic background but were not seen among Dominicans (p for interaction <0.05). The association of AST with incident diabetes was found only among light-to-moderate alcohol drinkers (RR = 1.50 [1.20-1.86]) but not abstainers (RR = 0.91 [0.69-1.20], p for interaction = 0.006).

CONCLUSION

Higher ALT and GGT levels are associated with increased risk of developing diabetes among Latinos. Liver enzyme tests might aid in diabetes prevention by identifying high-risk individuals.

A review of non-alcoholic fatty liver disease in non-obese and lean individuals

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of hepatic disorders. It represents a wide range of chronic liver diseases in patients with no history of significant alcohol consumption, starting with simple steatosis and progressing towards non-alcoholic steatohepatitis, cirrhosis, and ultimately hepatocellular carcinoma. NAFLD is usually associated with type 2 diabetes mellitus, dyslipidemia, metabolic syndrome, and obesity. This disease has mostly been studied in obese individuals; however, it has been widely reported and studied among the lean/non-obese population in recent years. The pathogenesis of NAFLD in non-obese patients is associated with various genetic predispositions, particularly a patatin-like phospholipase domain-containing protein 3 G allele polymorphism, which results in the accumulation of triglyceride in the liver and resistance to insulin. Additionally, dietary factors such as high fructose consumption seem to play a substantial role in the pathology of non-obese NAFLD. Although there is not enough evidence on the treatment of NAFLD in non-obese patients, the standard approach is to advise altering one's lifestyle in order to diminish visceral adiposity. Dietary modification, weight loss, and increased physical activity are highly recommended. We aimed to review and summarize the existing information on the prevalence, pathogenesis, genetic predispositions, diagnosis, and treatment of NAFLD in non-obese patients according to the latest literature.

Non-alcoholic fatty liver disease and risk of incident diabetes mellitus: an updated meta-analysis of 501 022 adult individuals

OBJECTIVE

Follow-up studies have shown that non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of incident diabetes, but currently, it is uncertain whether this risk changes with increasing severity of NAFLD. We performed a meta-analysis of relevant studies to quantify the magnitude of the association between NAFLD and risk of incident diabetes.

DESIGN

We systematically searched PubMed, Scopus and Web of Science databases from January 2000 to June 2020 using predefined keywords to identify observational studies with a follow-up duration of at least 1 year, in which NAFLD was diagnosed by imaging techniques or biopsy. Meta-analysis was performed using random-effects modelling.

RESULTS

33 studies with 501 022 individuals (30.8% with NAFLD) and 27 953 cases of incident diabetes over a median of 5 years (IQR: 4.0-19 years) were included. Patients with NAFLD had a higher risk of incident diabetes than those without NAFLD (n=26 studies; random-effects HR 2.19, 95% CI 1.93 to 2.48; I2 =91.2%). Patients with more 'severe' NAFLD were also more likely to develop incident diabetes (n=9 studies; random-effects HR 2.69, 95% CI 2.08 to 3.49; I2 =69%). This risk markedly increased across the severity of liver fibrosis (n=5 studies; random-effects HR 3.42, 95% CI 2.29 to 5.11; I2=44.6%). All risks were independent of age, sex, adiposity measures and other common metabolic risk factors. Sensitivity analyses did not alter these findings. Funnel plots did not reveal any significant publication bias.

CONCLUSION

This updated meta-analysis shows that NAFLD is associated with a ~2.2-fold increased risk of incident diabetes. This risk parallels the underlying severity of NAFLD.

Derivation and Validation of a Prediction Model for Predicting the 5-Year Incidence of Type 2 Diabetes in Non-Obese Adults: A Population-Based Cohort Study

PURPOSE

The aim of this study was to derivate and validate a nomogram based on independent predictors to better evaluate the 5-year risk of T2D in non-obese adults.

PATIENTS AND METHODS

This is a historical cohort study from a collection of databases that included 12,940 non-obese participants without diabetes at baseline. All participants were randomised to a derivation cohort (n = 9651) and a validation cohort (n = 3289). In the derivation cohort, the least absolute shrinkage and selection operator (LASSO) regression model was used to determine the optimal risk factors for T2D. Multivariate Cox regression analysis was used to establish the nomogram of T2D prediction. The receiver operating characteristic (ROC) curve, C-index, calibration curve, and decision curve analysis were performed by 1000 bootstrap resamplings to evaluate the discrimination ability, calibration, and clinical practicability of the nomogram.

RESULTS

After LASSO regression analysis of the derivation cohort, it was found that age, fatty liver, γ-glutamyltranspeptidase, triglycerides, glycosylated hemoglobin A1c and fasting plasma glucose were risk predictors, which were integrated into the nomogram. The C-index of derivation cohort and validation cohort were 0.906 [95% confidence interval (CI), 0.878-0.934] and 0.837 (95% CI, 0.760-0.914), respectively. The AUC of 5-year T2D risk in the derivation cohort and validation cohort was 0.916 (95% CI, 0.889-0.943) and 0.829 (95% CI, 0.753-0.905), respectively. The calibration curve indicated that the predicted probability of nomogram is in good agreement with the actual probability. The decision curve analysis demonstrated that the predicted nomogram was clinically useful.

CONCLUSION

Our nomogram can be used as a reasonable, affordable, simple, and widely implemented tool to predict the 5-year risk of T2D in non-obese adults. With this model, early identification of high-risk individuals is helpful to timely intervene and reduce the risk of T2D in non-obese adults.

Nonalcoholic Fatty Liver Disease (NAFLD) for Primary Care Providers: Beyond the Liver

Abstract::

Nonalcoholic fatty liver disease (NAFLD) has consolidated as a major public health problem, affecting ~25% of the global population. This percentage is significantly higher in the setting of obesity and/or type 2 diabetes. Presence of NAFLD is associated with severe liver complications, such as nonalcoholic steatohepatitis (NASH; i.e., presence of inflammation and necrosis), cirrhosis and hepatocellular carcinoma. However, the majority of these patients die of cardiovascular disease. For this reason, management of this condition requires a multidisciplinary team, where primary care providers are at center stage. However, important misconceptions remain among primary care providers, preventing them from appropriately approach these patients. Nonalcoholic fatty liver disease should be understood as part of a systemic disease, characterized for abnormal accumulation of fat in tissues other than the adipose tissue. This, in turn, produces dysfunction of those organs or tissues (process sometimes referred to as lipotoxicity). Therefore, due to the systemic nature of this condition, it should not surprise that NAFLD is closely related to other metabolic conditions. In this review, we will focus on the extrahepatic manifestations of NAFLD and its metabolic and cardiovascular implications. We believe these are the most important issues primary care providers should understand, in order to effectively manage these complicated patients. In addition, we have provided a simple and straightforward approach to the diagnosis and treatment of patients with NAFLD and/or NASH. We hope this review will serve as a guide for primary care providers to approach their patients with NAFLD.

Human and molecular genetics shed lights on fatty liver disease and diabetes conundrum

The causal role of abdominal overweight/obesity, insulin resistance and type 2 diabetes (T2D) on the risk of fatty liver disease (FLD) has robustly been proven. A consensus of experts has recently proposed the novel definition of 'metabolic dysfunction-associated fatty liver disease, MAFLD' instead of 'nonalcoholic fatty liver disease, NAFLD', emphasizing the central role of dysmetabolism in the disease pathogenesis. Conversely, a direct and independent contribution of FLD per se on risk of developing T2D is still a controversial topic. When dealing with FLD as a potential risk factor for T2D, it is straightforward to think of hepatic insulin resistance as the most relevant underlying mechanism. Emerging evidence supports genetic determinants of FLD (eg PNPLA3, TM6SF2, MBOAT7, GCKR, HSD17B13) as determinants of insulin resistance and T2D. However, recent studies highlighted that the key molecular mechanism of dysmetabolism is not fat accumulation per se but the degree of hepatic fibrosis (excess liver fat content-lipotoxicity), leading to reduced insulin clearance, insulin resistance and T2D. A consequence of these findings is that drugs that will ameliorate liver fat accumulation and fibrosis in principle may also exert a beneficial effect on insulin resistance and risk of T2D in individuals with FLD. Finally, initial findings show that these genetic factors might be directly implicated in modulating pancreatic beta-cell function, although future studies are needed to fully understand this relationship.

FIB-4 index is a marker for a subsequent decrease in insulin secretion in a non-diabetic Japanese population

Non-alcoholic fatty liver disease (NAFLD) is associated with a high risk of type 2 diabetes (DM), therefore, early diagnosis of NAFLD is important to prevent incident DM. FIB-4 index, a biomarker, often used to evaluate severity of NAFLD, may be useful to evaluate risk for incident DM in ordinary clinical setting. Here, we determined the association of FIB-4 index with changes in indices representing glucose metabolism with aging in a non-diabetic population. From among the participants of the population-based Iwaki study of Japanese people conducted during 2014-2017, 1,268 non-diabetic individuals with complete data sets (age: 51.4 ± 15.9 years; men/women: 485/773) were enrolled in a cross-sectional study. In addition, of the participants, 439 who attended consecutive appointments between 2014 and 2017 were enrolled in a longitudinal study that aimed to evaluate the changes in insulin secretion and resistance with aging (age: 53.1 ± 13.7 years; men/women: 178/261). The cross-sectional study showed significant correlations of FIB-4 index with homeostasis model of assessment (HOMA) indices, even after adjustment for multiple factors (HOMA-β: β =  - 0.254, p < 0.001; HOMA-R: β =  - 0.247, p < 0.001). The longitudinal study showed a significant association between FIB-4 index and the change in HOMA-β (p < 0.001) but not HOMA-R (p = 0.639) during the 3-year study period. Use of the optimal cut-off value of the FIB-4 index for the prediction of decreased insulin secretion (HOMA-β < 30), determined using receiver operating characteristic analysis (1.592), showed that individuals at risk had a hazard ratio of 2.22 (confidence interval 1.17-4.06) for decreased insulin secretion, after adjustment for confounders. FIB-4 index may represent a useful predictor of a subsequent decrease in insulin secretion, at least in a non-diabetic Japanese population.

Significant fibrosis predicts new-onset diabetes mellitus and arterial hypertension in patients with NASH

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) could play a catalytic role in the development of metabolic comorbidities, although the magnitude of this effect in metabolically healthy patients with NAFLD remains unclear. We assessed the role of biopsy-proven NAFLD on the risk of developing type 2 diabetes mellitus (T2DM) and other metabolic comorbidities (arterial hypertension [AHT], and dyslipidemia) in metabolically healthy patients.

METHODS

We included 178 metabolically healthy-defined by the absence of baseline T2DM, AHT, dyslipidemia-patients with biopsy-proven NAFLD from the HEPAmet Registry (N = 1,030). Hepamet fibrosis score (HFS), NAFLD fibrosis score, and Fibrosis-4 were calculated. Follow-up was computed from biopsy to the diagnosis of T2DM, AHT, or dyslipidemia.

RESULTS

During a follow-up of 5.6 ± 4.4 years, T2DM occurred in 9% (16/178), AHT in 8.4% (15/178), low HDL in 9.6% (17/178), and hypertriglyceridemia in 23.6% (42/178) of patients. In multivariate analysis, significant fibrosis predicted T2DM and AHT. Independent variables related to T2DM appearance were significant fibrosis (HR 2.95; 95% CI 1.19-7.31; p = 0.019), glucose levels (p = 0.008), age (p = 0.007) and BMI (p = 0.039). AHT was independently linked to significant fibrosis (HR 2.39; 95% CI 1.14-5.10; p = 0.028), age (p = 0.0001), BMI (p = 0.006), glucose (p = 0.021) and platelets (p = 0.050). The annual incidence rate of T2DM was higher in patients with significant fibrosis (4.4 vs. 1.2 cases per 100 person-years), and increased in the presence of obesity, similar to AHT (4.6 vs. 1.1 cases per 100 person-years). HFS >0.12 predicted the risk of T2DM (25% [4/16] vs. HFS <0.12 4.5% [4/88]; logRank 6.658, p = 0.010).

CONCLUSION

Metabolically healthy patients with NAFLD-related significant fibrosis were at greater risk of developing T2DM and AHT. HFS >0.12, but not NAFLD fibrosis score or Fibrosis-4, predicted the occurrence of T2DM.

LAY SUMMARY

Patients with biopsy-proven non-alcoholic fatty liver disease and significant fibrosis were at risk of developing type 2 diabetes mellitus and arterial hypertension. The risk of metabolic outcomes in patients with significant fibrosis was increased in the presence of obesity. In addition to liver biopsy, patients at intermediate-to-high risk of significant fibrosis by Hepamet fibrosis score were at risk of type 2 diabetes mellitus.

Sexual Dimorphism of NAFLD in Adults. Focus on Clinical Aspects and Implications for Practice and Translational Research

Nonalcoholic fatty liver disease (NAFLD) embraces the clinico-pathological consequences of hepatic lipotoxicity and is a major public health problem globally. Sexual dimorphism is a definite feature of most human diseases but, under this aspect, NAFLD lags behind other medical fields. Here, we aim at summarizing and critically discussing the most prominent sex differences and gaps in NAFLD in humans, with emphasis on those aspects which are relevant for clinical practice and translational research. Sexual dimorphism of NAFLD is covered with references to the following areas: disease prevalence and risk factors, pathophysiology, comorbidities, natural course and complications. Finally, we also discuss selected gender differences and whether sex-specific lifestyle changes should be adopted to contrast NAFLD in men and women.

Hepatic Steatosis in Lean Patients: Risk Factors and Impact on Mortality

BACKGROUND

The prognostic impact of liver steatosis in obese patients is well established. Limited data on the risk factors for and impact of hepatic steatosis in lean patients are available.

AIMS

Assess risk factors for liver steatosis in lean patients and investigate its impact on survival.

METHODS

Patients without viral hepatitis and with a BMI ≤ 25 kg/m² undergoing liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) by transient elastography were retrospectively identified. Clinical characteristics and laboratory test results were obtained at the time of LSM/CAP measurement. National death registry data were obtained in order to assess survival.

RESULTS

Among n = 218 lean patients, n = 97 (34.5%) showed significant liver steatosis (CAP ≥ 268 dB/m), while n = 184 (65.5%) had no or just mild steatosis (CAP < 268 dB/m). Patients with steatosis had higher GGT (238.0(± 450.3) vs. 112.1(± 180.0) IU/mL; p = 0.013), AST (63(± 67.4) vs. 38.5(± 32.9) IU/mL; p = 0.001), ALT (59.1(± 58.8) vs. 44.3(± 52.7) IU/mL; p = 0.048) and triglyceride levels (120.1(± 80.3) vs. 96.1(± 58.2) mg/dL; p = 0.014), and showed a trend toward more severe fibrosis (LSM 15.6(± 19.5) vs. 12.0(± 15.7) kPa; p = 0.115). In multivariate binary logistic regression analysis, only serum uric acid levels were independently associated with liver steatosis (odds ratio 1.43 per unit mg/dL; 95% CI 1.001-2.054; p = 0.049). During a mean follow-up of 38.9(± 10.6) months, n = 14 patients (5.0%) died. In the absence of advanced fibrosis, survival after 1 year was similar in patients without (98.7%) and with (98.6%) significant steatosis. Patients with advanced fibrosis had worse 1-year survival without concomitant significant steatosis (84.8%) than patients with steatosis (95.8%; log-rank p < 0.001).

CONCLUSIONS

High serum uric acid levels increase the risk of liver steatosis in lean patients. Liver fibrosis but not hepatic steatosis is a risk factor for impaired survival in lean patients.

Management of Diabetes Mellitus in Patients with Chronic Liver Diseases

Diabetes mellitus (DM) is a common chronic disease affecting humans globally. During the last few years, the incidence of diabetes has increased and has received more attention. In addition to growing DM populations, DM complications are involving injuries to more organs, such as the heart and cerebral vessel damage. DM complications can reduce quality of life and shorten life spans and eventually also impede social and economic development. Therefore, effective measures to curb the occurrence and development of diabetes assist in improving patients' quality of life, delay the progression of DM in the population, and ease a social burden. The liver is regarded as an important link in the management and control of DM, including the alleviation of glucose metabolism and lipid metabolism and others via glucose storage and endogenous glucose generation from glycogen stored in the liver. Liver cirrhosis is a very common chronic disease, which often lowers the quality of life and decreases life expectancy. According to a growing body of research, diabetes shows a close correlation with hepatitis, liver cirrhosis, and liver cancer. Moreover, coexistence of liver complications would accelerate the deterioration of patients with diabetes. Liver cirrhosis and diabetes influence each other. Thus, in addition to pharmacological treatments and lifestyle interventions, effective control of cirrhosis might assist in a better management of diabetes. When it comes to different etiologies of liver cirrhosis, different therapeutic methods, such as antiviral treatment, may be more effective. Effective control of cirrhosis might be a strategy for better management of diabetes.