Lean non-alcoholic fatty liver disease and development of diabetes: a cohort study

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.

Longitudinal Outcomes Associated With Metabolic Dysfunction-Associated Steatotic Liver Disease: A Meta-analysis of 129 Studies

BACKGROUND & AIMS

The progression of metabolic dysfunction-associated steatotic liver disease (MASLD) has been found to manifest in a series of hepatic and extrahepatic complications. A comprehensive meta-analysis of the longitudinal outcomes associated with MASLD has yet to be conducted.

METHODS

To investigate the longitudinal outcomes associated with MASLD, Medline and Embase databases were searched to identify original studies that evaluated the longitudinal risks of incident clinical outcomes among MASLD patients compared with non-MASLD individuals. DerSimonian Laird random-effects meta-analysis was performed. Pooled effect estimates were calculated, and heterogeneity among studies was evaluated.

RESULTS

One hundred twenty-nine studies were included in the meta-analysis. Meta-analysis revealed a significant increase in the risk of cardiovascular outcomes (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.27-1.60; P < .01), various metabolic outcomes such as incident hypertension (HR, 1.75; 95% CI, 1.46-2.08; P < .01), diabetes (HR, 2.56; 95% CI, 2.10-3.13; P < .01), pre-diabetes (HR, 1.69; 95% CI, 1.22-2.35; P < .01), metabolic syndrome (HR, 2.57; 95% CI, 1.13-5.85; P = .02), chronic kidney disease (HR, 1.38; 95% CI, 1.27-1.50; P < .01), as well as all cancers (HR, 1.54; 95% CI, 1.35-1.76; P < .01) among MASLD patients compared with non-MASLD individuals. By subgroup analysis, MASLD patients with advanced liver disease (HR, 3.60; 95% CI, 2.10-6.18; P < .01) were also found to be associated with a significantly greater risk (P = .02) of incident diabetes than those with less severe MASLD (HR, 1.63; 95% CI, 1.0-2.45; P = .02) when compared with non-MASLD.

CONCLUSIONS

The present study emphasizes the association between MASLD and its clinical outcomes including cardiovascular, metabolic, oncologic, and other outcomes. The multisystemic nature of MASLD found in this analysis requires treatment targets to reduce systemic events and end organ complications.

Triglycerides Mediate the Influence of Body Mass Index on Non-Alcoholic Fatty Liver Disease in a Non-Obese Chinese Population with Normal Low-Density Lipoprotein Cholesterol Levels

INTRODUCTION

Over 25% of the world's population has non-obese or lean non-alcoholic fatty liver disease (NAFLD), and the prevalence is higher than average in Asia. The present study focused on the relationship between body mass index (BMI) and non-obese NAFLD in non-overweight people in China, particularly the influence of triglycerides (TG) in the pathogenesis of non-obese NAFLD. The findings suggest new treatments for NAFLD patients with normal BMI, as well as provide an early warning system for the understanding and prevention of NAFLD in non-obese patients.

METHODS

This cross-sectional study enrolled 159,959 Chinese subjects with BMI <24 kg/m2 and normal levels of low-density lipoprotein cholesterol (LDL-c). The average age was 40.21 ± 13.88 years, and males accounted for 45.7%. A total of 15,907 (9.94%) patients with NAFLD were diagnosed by ultrasonography. Biochemical indicators were measured using an automated analyzer (Abbott AxSYM). The BMI (kg/m2) was calculated from the weight (kg)/height in square meters (m2). The BMI quartile was used as the column-stratified variable to determine the baseline distribution, and logistic regression analysis was used to assess the relationship between NAFLD and its risk factors, with multiple logistic regression used to assess the relationships between BMI or TG and NAFLD and multivariate linear regression used to analyze the association between BMI and TG, while mediation analysis was used to assess the mediation effect of TG.

RESULTS

After adjustment of all covariates, the odds ratios were 1.788 (95% CI: 1.749-1.829; p < 0.00001) and 1.491 (95% CI: 1.451-1.532; p < 0.00001) for the association between BMI and TG with NAFLD incidence. The multivariate linear regression coefficient of BMI and TG was β = 0.027 (95% CI: 0.023-0.030; p < 0.00001). Mediation analysis showed that BMI contributed to 10.81% of lean NAFLD with a mediation effect of 2.98%.

CONCLUSION

In a Chinese population with BMI <24 kg/m2 and normal LDL-c levels, BMI and TG were found to be independent predictors of NAFLD. The direct effect of BMI on non-obese NAFLD was 10.41%. The TG level was found to partially mediate the association.

Nonalcoholic fatty liver disease without overlapping metabolic-associated fatty liver disease and the risk of incident type 2 diabetes

BACKGROUND AND AIMS

Re-classifying NAFLD as metabolic-associated fatty liver (MAFLD) has been proposed. While some people fulfil criteria for NAFLD, they do not have MAFLD; and whether NAFLD-only subjects have increased the risk of type 2 diabetes remains unknown. We compared risk of incident T2D in individuals with: (a) NAFLD-only; and (b) MAFLD, to individuals without fatty liver, considering effect modification by sex.

METHODS

246 424 Koreans without diabetes or a secondary cause of ultrasound-diagnosed hepatic steatosis were studied. Subjects were stratified into: (a) NAFLD-only status and (b) NAFLD that overlapped with MAFLD (MAFLD). Cox proportional hazards models with incident T2D as the outcome were used to estimate hazard ratios (HRs) for: (a) and (b). Models were adjusted for time-dependent covariates, and effect modification by sex was analysed in subgroups.

RESULTS

A total of 5439 participants had NAFLD-only status and 56 839 met MAFLD criteria. During a median follow-up of 5.5 years, 8402 incident cases of T2D occurred. Multivariable-adjusted HRs (95% CI) for incident T2D comparing NAFLD-only and MAFLD to the reference (neither condition) were 2.39 (1.63-3.51) and 5.75 (5.17-6.36) (women), and 1.53 (1.25-1.88) and 2.60 (2.44-2.76) (men), respectively. The increased risk of T2D in the NAFLD-only group was higher in women than in men (p for interaction by sex <0.001) and consistently observed across all subgroups. Risk of T2D was increased in lean participants regardless of metabolic dysregulation (including prediabetes).

CONCLUSIONS

NAFLD-only participants without metabolic dysregulation and the criteria for MAFLD are at increased risk of developing T2D. This association was consistently stronger in women than in men.

Impact of body mass index on disease progression and outcomes in patients with nonalcoholic fatty liver disease

BACKGROUND

The relationship between body mass index (BMI) and outcomes in patients with nonalcoholic fatty liver disease (NAFLD) is not well defined. This study aimed to assess the presentations, outcomes, and development of liver-related events (LREs) and non-LREs in patients with NAFLD stratified by BMI.

METHODS

Records of NAFLD patients from 2000-2022 were reviewed. Patients were categorized as lean (18.5-22.9 kg/m2), overweight (23-24.9 kg/m2), and obese (>25 kg/m2) based on BMI. Stage of steatosis, fibrosis, and NAFLD activity score were noted in the patients undergoing liver biopsy in each group.

RESULTS

Out of 1051 NAFLD patients, 127 (12.1%) had normal BMI, 177 (16.8%) and 747 (71.1%) were overweight and obese, respectively. Median [interquartile range] BMI was 21.9 [20.6-22.5], 24.2 [23.7-24.6], and 28.3 [26.6-30.6] kg/m2 in each group, respectively. Prevalence of metabolic syndrome and dyslipidemia were significantly higher in the obese. Obese patients had significantly higher median [interquartile range] liver stiffness (6.4 [4.9-9.4] kPa) than overweight and lean subjects. A higher proportion of obese patients had significant and advanced liver fibrosis. At follow-up, there were no significant differences in the progression of liver disease, new LREs, coronary artery disease, or hypertension across the BMI groups. Overweight and obese patients were more likely to develop new-onset diabetes by follow-up. The mortality rates in the three groups were comparable (0.47, 0.68, and 0.49 per 100 person-years, respectively), with similar causes of death (liver-related vs non-liver-related).

CONCLUSIONS

Patients with lean NAFLD have similar disease severity and rates of progression as the obese. BMI is not a reliable determinant of outcomes in NAFLD patients.

KEY MESSAGES

Comparison of cardiometabolic risk factors between obese and non-obese patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is closely associated with cardiometabolic abnormalities. This association could be partly influenced by weight, but not entirely. This study aimed to compare the cardiometabolic risk factors between obese and non-obese NAFLD patients, and explored the relationship between adiposity and severity of fatty liver. This cross-sectional study included 452 patients with Fibroscan-proven NAFLD. Anthropometric measurements, metabolic components and hepatic histological features were evaluated. The risk of metabolic syndrome in each body mass index (BMI) category was analyzed using logistic regression. The prevalence of metabolic syndrome was 10.2%, 27.7%, and 62.1% in normal-weight, overweight and obese participants. Regression analysis showed that the risk of metabolic syndrome in overweight and obese NAFLD patients was 3.74 and 4.85 times higher than in patients with normal weight, respectively. Waist circumference (β = 0.770, P < 0.001) and serum concentration of fasting blood glucose (β = 0.193, P = 0.002) and triglyceride (β = 0.432, P < 0.001) were the determinants of metabolic syndrome occurrence in NAFLD patients. Metabolic abnormalities were similar in obese and non-obese NAFLD patients, although, the increase in BMI was associated with an increased risk of metabolic syndrome in patients.

Regression of nonalcoholic fatty liver disease is associated with reduced risk of incident diabetes: A longitudinal cohort study

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is potentially reversible. However, whether improvement of NAFLD leads to clinical benefits remains uncertain. We investigated the association between regression of NAFLD and the risk of incident diabetes in a longitudinal way.

METHODS

A cohort of 11,260 adults who had NAFLD at in an initial exam, had the second evaluation for NAFLD status at 1~2 years from an initial exam were followed up for incident diabetes from 2001 and 2016. NAFLD was diagnosed with abdominal ultrasound.

RESULTS

At baseline, NAFLD was regressed in 2,559 participants (22.7%). During 51,388 person-years of follow-up (median 4 years), 1,768 participants developed diabetes. The fully adjusted hazard ratio (HR) for incident diabetes in participants with regressed NAFLD compared to those with persistent NAFLD was 0.81 [95% confidence interval (CI) 0.72-0.92]. When assessed by NAFLD severity, among participants with a low NAFLD fibrosis score (NFS) (< -1.455), participants with regressed NAFLD had a lower risk of incident diabetes than those with persistent NAFLD (HR 0.77, 95% CI 0.68-0.88). However, in participants with an intermediate to high NFS (≥ -1.455), the risk of incident diabetes was not different between NAFLD regression and persistence groups (HR 1.12, 95% CI 0.82-1.51).

CONCLUSIONS

Regression of NAFLD was associated with decreased risk of incident diabetes compared to persistent NAFLD. However, the benefit was evident only for NAFLD patients with low NFS. This suggests that early intervention for NAFLD, before advanced fibrosis is present, may maximize the metabolic benefit from NAFLD regression.

Long-term outcomes in lean and non-lean NAFLD patients: a systematic review and meta-analysis

BACKGROUND

Although nonalcoholic fatty liver disease (NAFLD) commonly occurs in overweight or obese individuals, it is increasingly being identified in the lean population. The association between lean and an increased risk of all-cause mortality among patients with NAFLD remains controversial. We aimed to perform a systematic review and meta-analysis of the literature to evaluate this association and compare the long-term outcomes of lean NAFLD patients and non-lean NAFLD patients.

METHODS

For this systematic review and meta-analysis, we searched PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Wan Fang, and Chinese Biomedical Literature Database (CBM) from inception to October 15, 2021, for relevant original research articles without any language restrictions. Our primary outcome was to compare the all-cause mortality in lean NAFLD patients and non-lean NAFLD patients by qualitative synthesis. Relative risks (RRs) and corresponding 95% confidential intervals (CIs) were pooled with a random effect model. Heterogeneity was evaluated using I-squared (I²) statistics while publication bias was determined using Egger's tests. Subgroup and sensitivity analyses were performed. As for secondary outcomes, we estimated total, cardiovascular, and liver-related mortality, as well as the incidence of diabetes, hypertension, cirrhosis, and cancer in lean and non-lean individuals with NAFLD by quantitative synthesis. Person-years of follow-up were used as the denominator to estimate the mortality and incidence.

RESULTS

We identified 12 studies (n = 26,329), 7 of which (n = 7924) were used to evaluate the risk of all-cause mortality between lean and non-lean NAFLD patients. Lean patients with NAFLD were found to be at an elevated risk of death compared to non-lean patients (RR = 1.39, 95% CI 1.08-1.82, heterogeneity: I² = 43%). Among the lean NAFLD population, all-cause mortality was 13.3 (95% CI: 6.7-26.1) per 1000 person-years, 3.6 (95% CI: 1.0-11.7) for liver-related mortality, and 7.7 (95% CI: 6.4-9.2) for cardiovascular-related mortality. The incidence of new-onset diabetes was 13.7 (95% CI 8·2-22.7) per 1000 person-years, new-onset hypertension was 56.1 (95% CI: 40.2-77.9), cirrhosis was 2.3 (95% CI: 1.0-5.0), and cancer was 25.7 (95% CI: 20.3-32.4).

CONCLUSIONS

Lean patients with NAFLD had a higher risk of all-cause death than non-lean patients. Body mass index (BMI) should not be used as a criterion to determine whether further observation and therapy of patients with NAFLD are warranted.

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.

The change of non-alcoholic fatty liver disease is associated with risk of incident diabetes

Background & aims

The effect of change in non-alcoholic fatty liver disease (NAFLD) status on incident diabetes has not been well studied. We aimed to investigate the association of NAFLD development and remission with the risk of incident diabetes during a median of 3.5-year follow-up.

Methods

A total of 2690 participants without diabetes were recruited in 2011-2012 and assessed for incident diabetes in 2014. Abdominal ultrasonography was used to determine the change of NAFLD. 75 g oral glucose tolerance test (OGTT) was performed to determine diabetes. NAFLD severity was assessed using Gholam's model. The odds ratios (ORs) for incident diabetes were estimated by logistic regression models.

Results

NAFLD was developed in 580 (33.2%) participants and NAFLD remission occurred in 150 (15.9%) participants during a median of 3.5-year follow-up. A total of 484 participants developed diabetes during follow-up, including 170 (14.6%) in consistent non-NAFLD group, 111 (19.1%) in NAFLD developed group, 19 (12.7%) in NAFLD remission group, and 184 (23.2%) in sustained NAFLD group. The development of NAFLD increased the risk of incident diabetes by 43% (OR, 1.43; 95%CI, 1.10-1.86) after adjustment for multiple confounders. Compared with sustained NAFLD group, remission of NAFLD reduced the risk of incident diabetes by 52% (OR, 0.48; 95%CI, 0.29-0.80). The effect of NAFLD alteration on incident diabetes was not changed after adjustment for body mass index or waist circumference, change of body mass index or waist circumference. In NAFLD remission group, participants with non-alcoholic steatohepatitis (NASH) at baseline were more likely to develop diabetes (OR, 3.03; 95%CI, 1.01-9.12).

Conclusions

NAFLD development increases the risk of incident diabetes, whereas NAFLD remission reduces the risk of incident diabetes. Moreover, presence of NASH at baseline could attenuate the protective effect of NAFLD remission on incident diabetes. Our study suggests that early intervention of NAFLD and maintenance of non-NAFLD are important for prevention of diabetes.

Mechanisms of non-alcoholic fatty liver disease development in normal-weight individuals

While non-alcoholic fatty liver disease (NAFLD) without inflammation or fibrosis is considered a relatively 'benign' disease, non-alcoholic steatohepatitis (NASH), by contrast, is characterized by marked inflammation in addition to lipid accumulation, and may include fibrosis, progression to cirrhosis and hepatocellular carcinoma. Obesity and type II diabetes are frequently associated with NAFLD/NASH; however, a significant number of lean individuals may develop these diseases. Little attention has been paid to the causes and mechanisms contributing to NAFLD development in normal-weight individuals. One of the main causes of NAFLD in normal-weight individuals is the accumulation of visceral and muscular fat and its interaction with the liver. Myosteatosis (triglyceride accumulation in the muscle) induces a loss of muscle by reducing blood flow and insulin diffusion, contributing to NAFLD. Normal-weight patients with NAFLD exhibit higher serum markers of liver damage and C-reactive protein levels, as well as more pronounced insulin resistance, compared to healthy controls. Notably, increased levels of C-reactive protein and insulin resistance are strongly correlated with the risk of developing NAFLD/NASH. Gut dysbiosis has also been associated with NAFLD/NASH progression in normal-weight individuals. More investigation is required to elucidate the mechanisms leading to NAFLD in normal-weight individuals.

Nonalcoholic Fatty Liver Disease in Lean/Nonobese and Obese Individuals: A Comprehensive Review on Prevalence, Pathogenesis, Clinical Outcomes, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with an estimated prevalence of 25% globally. NAFLD is closely associated with metabolic syndrome, which are both becoming increasingly more common with increasing rates of insulin resistance, dyslipidemia, and hypertension. Although NAFLD is strongly associated with obesity, lean or nonobese NAFLD is a relatively new phenotype and occurs in patients without increased waist circumference and with or without visceral fat. Currently, there is limited literature comparing and illustrating the differences between lean/nonobese and obese NAFLD patients with regard to risk factors, pathophysiology, and clinical outcomes. In this review, we aim to define and further delineate different phenotypes of NAFLD and present a comprehensive review on the prevalence, incidence, risk factors, genetic predisposition, and pathophysiology. Furthermore, we discuss and compare the clinical outcomes, such as insulin resistance, dyslipidemia, hypertension, coronary artery disease, mortality, and progression to nonalcoholic steatohepatitis, among lean/nonobese and obese NAFLD patients. Finally, we summarize the most up to date current management of NAFLD, including lifestyle interventions, pharmacologic therapies, and surgical options.

Associations of physical activity domains and muscle strength exercise with non-alcoholic fatty liver disease: a nation-wide cohort study

It is unclear if various types and domains of exercise have an identical effect on non-alcoholic fatty liver disease (NAFLD). Thus, this study aimed to investigate associations of different physical activity domains and muscle strength exercise with NAFLD using a nation-wide cohort database. Adults aged 20-79 years who participated in the Korean National Health and Nutrition Examination Survey between 2014 and 2018 were analyzed. Hepatic steatosis index was used to identify NAFLD. Physical activity was assessed with the Global Physical Activity Questionnaire. Of 21,015 participants, 4942 (23.5%) had NAFLD. Participants with ≥ 150 min/week of total physical activity had a lower risk of NAFLD than those with < 150 min/week (the fully adjusted OR: 0.86, 95% CI 0.78-0.95). When the individual domain of physical activity was assessed, ≥ 150 min/week of recreation activity was associated with a reduced risk of NAFLD (OR: 0.77, 95% CI 0.67-0.88), whereas ≥ 150 min/week of travel or work activity was not. The fully adjusted OR for NAFLD comparing participants with ≥ 2/week to those with < 2/week of muscle strength exercise was 0.83 (95% CI 0.73-0.94). Muscle strength exercise ≥ 2/week showed a lower risk of NAFLD for all levels of total and each specific domains of physical activity except for ≥ 150 min/week of work activity. An increased level of physical activity and muscle strength exercise was associated with a reduced risk of NAFLD, albeit the effect varied depending on domains of physical activity. Thus, physical activity should be differentiated by domains for the management of NAFLD. Muscle strength exercise could also be a good option for individuals who could not perform moderate-to-vigorous physical activity.

Non-obese or lean non-alcoholic fatty liver disease was associated with increased risk of cancer in patients with type 2 diabetes mellitus

INTRODUCTION

Risk of non-obese or lean non-alcoholic fatty liver disease (NAFLD) for cancer in patients with type 2 diabetes mellitus (T2DM) is less known. We aimed to evaluate independent associations of NAFLD, especially non-obese or lean NAFLD, and body mass index (BMI) on risks of cancer in patients with T2DM.

RESEARCH DESIGN AND METHODS

Cross-sectional analyses of baseline information on a cohort of 233 patients with T2DM were conducted in Xiamen, China. NAFLD was identified by hepatic ultrasonography diagnosis of hepatic steatosis without excessive alcohol consumption, viral or autoimmune liver disease. Fibrosis-4 (FIB-4) score was calculated to quantify severity of hepatic fibrosis.

RESULTS

All types of cancers were diagnosed on 19 (8.2%) patients. Prevalence of cancer was significantly higher in those with NAFLD than those without (15.5% vs 4.0%, p=0.002), but were not significantly different among BMI categories (6.8%, 13.7% and 6.5% for those with underweight or normal weight (n=74), overweight (n=51) and obesity (n=108), respectively, p=0.258). With adjustment for potential confounding factors in the multivariable logistic regression models, NAFLD was significantly associated with increased risk of cancer with the adjusted OR (95% CI) of 5.969 (1.349 to 26.413, p=0.019). Stratified analyses across BMI categories found similar association of NAFLD with risk of cancer for those non-obese or lean (the adjusted OR (95% CI) 17.446 (1.690 to 180.095, p=0.016)) but not for those with either overweight (OR (95% CI) 11.642 (0.832 to 162.963, p=0.068) or obesity (OR (95% CI) 0.917 (0.170 to 4.954, p=0.920). FIB-4 score was not significantly associated with risk of cancer for all subjects or stratified across BMI categories. BMI was not significantly associated with risk of cancer for all patients or stratified by NAFLD.

CONCLUSIONS

NAFLD, even non-obese or lean NAFLD, was independently associated with increased risk of cancer in patients with T2DM. Screening and management of NAFLD, especially for those with underweight or normal weight, should be strengthened from the perspective of improving prevention and management of cancer in patients with T2DM.

Safe use of sodium glucose co-transporter 2 inhibitors in the management of type 2 diabetes

One class of oral medicines used in the management of type 2 diabetes is sodium glucose co-transporter 2 (SGLT2) inhibitors. Their mode of action is unique and is not dependent on beta-cell function or the degree of a person's insulin resistance. This article reviews the use of SGLT2 inhibitors in managing type 2 diabetes, explaining the potential benefits and side effects of these medicines. It also explains the role of healthcare professionals, including nurses, in ensuring these medicines are used safely and appropriately.

Predicting Factors for Metabolic Non-Response to a Complex Lifestyle Intervention-A Replication Analysis to a Randomized-Controlled Trial

BACKGROUND

T2DM heterogeneity affects responsiveness to lifestyle treatment. Beta-cell failure and nonalcoholic fatty liver disease (NAFLD) independently predict T2DM, but NAFLD inconsistently predicts metabolic response to lifestyle intervention.

AIM

We attempt to replicate a prediction model deducted from the Tübinger Lifestyle Intervention Program by assessing similar metabolic factors to predict conversion to normal glucose regulation (NGR) in a comparable lifestyle intervention trial.

METHODS

In the Optimal Fiber Trial (OptiFiT), 131 Caucasian participants with prediabetes completed a one-year lifestyle intervention program and received a fiber or placebo supplement. We compared baseline parameters for responders and non-responders, assessed correlations of major metabolic changes and conducted a logistic regression analysis for predictors of remission to NGR.

RESULTS

NGR was achieved by 33 participants, respectively. At baseline, for the placebo group only, 1 h and 2 h glucose levels, glucose AUC and Cederholm index predicted conversion to NGR. HOMA-beta, HOMA-IR or liver fat indices did not differ between responders and non-responders of the placebo or the fiber group. Changes in waist circumference or fatty liver index correlated with changes in glycemia and insulin resistance, but not with changes in insulin secretion. Insulin-resistant NAFLD did not predict non-response. Differences in compliance did not explain the results.

CONCLUSIONS

Higher post-challenge glucose levels strongly predicted the metabolic non-response to complex lifestyle intervention in our cohort. Depending on the specific intervention and the investigated cohort, fasting glucose levels and insulin sensitivity might contribute to the risk pattern. Beta-cell function did not improve in accordance with other metabolic improvements, qualifying as a potential risk factor for non-response. We could not replicate previous data suggesting that an insulin-resistant fatty liver is a specific risk factor for treatment failure. Replication studies are required.

Nonalcoholic Fatty Liver Disease Without Metabolic-associated Fatty Liver Disease and the Risk of Metabolic Syndrome

BACKGROUND & AIMS

Metabolic (dysfunction)-associated fatty liver disease (MAFLD) was proposed to replace nonalcoholic fatty liver disease (NAFLD). Some people fulfill diagnostic criteria of NAFLD but not MAFLD (NAFLD without MAFLD), but the clinical implications of NAFLD in these subjects is unknown.

METHODS

We followed cohort of 12,197 men and women 20 years of age or older without metabolic dysfunction (defined by MAFLD criteria), heavy alcohol use, chronic viral hepatitis, liver cirrhosis, or malignancy for their risk of incident metabolic syndrome defined by Adult Treatment Panel III criteria.

RESULTS

By design, none of the study participants had MAFLD at baseline. The prevalence of NAFLD among participants without metabolic dysfunction meeting MAFLD criteria and without significant alcohol intake was 7.6%. During 74,508 person-years of follow-up, 2179 participants developed metabolic syndrome. The fully adjusted hazard ratio for metabolic syndrome comparing participants with NAFLD to those without it was 1.61 (95% confidence interval, 1.42-1.83). The increased risk of incident metabolic syndrome associated with NAFLD persisted for all studied subgroups, and the association was stronger for those with increased waist circumference (P for interaction = .029) and those without elevated triglycerides levels (P for interaction = .047).

CONCLUSION

In this large cohort, participants with NAFLD without MAFLD were at higher risk of developing metabolic syndrome compared to participants with no NAFLD and no MAFLD. Using MAFLD criteria may miss opportunities for early intervention in these subjects.

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.

Lean non-alcoholic fatty liver disease (Lean-NAFLD) and the development of metabolic syndrome: a retrospective study

Lean NAFLD is a special phenotypic closely correlated with metabolic syndrome (MS). The aim of this study is to investigate the MS development and the gender differences in lean NAFLD population. Participants were divided into 4 groups by BMI and NAFLD status. Descriptive analysis was performed to characterize baseline information. A total of 18,395 subjects were participated, and 1524 incident cases of MS were documented. Then, Kaplan–Meier curves were used to present the MS outcomes in different groups, and the NAFLD was found to be a riskier factor than obesity for MS. Subgroup analysis showed significantly higher MS incidence in female than male among lean NAFLD group, which is different from other groups. Although with higher prevalence in male, lean NAFLD seems to be a more harmful phenotype for females according to the TG, ALT and GGT levels. The logistic regressive analysis was performed to show the impact of NAFLD status and BMI changes on MS risk. Lean non-NAFLD subjects merely developed to NAFLD with no BMI status changes exhibited highest MS risk (ORs = 1.879, 95% CI 1.610–2.292) than that with both BMI increase and NAFLD development (ORs = 1.669, 95% CI 1.325–2.104). It also suggests the metabolic specificity of this population.

Adherence to a vegetable dietary pattern attenuates the risk of non-alcoholic fatty liver disease in incident type 2 diabetes: The TCLSIH cohort study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a strong risk factor for type 2 diabetes. However, no study has investigated whether dietary intake can modify this effect. Therefore, we aimed to investigate the effect of dietary pattern modification on the association between NAFLD and type 2 diabetes.

METHODS

A large prospective cohort study (n = 24,602) was conducted in China. NAFLD was diagnosed using liver ultrasonography considering alcohol consumption. Dietary data were assessed using a validated self-administered food frequency questionnaire. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Following a 93,873 person-year follow-up, 787 (3.20%) participants developed type 2 diabetes. In a multivariable adjusted model, compared with participants without NAFLD, the HR (95% CI) of incident type 2 diabetes for NAFLD patients was 3.04 (2.51, 3.68). On subgroup analyses, the adjusted HRs (95% CIs) of incident type 2 diabetes for NAFLD patients with low (≤median score) and high (>median score) vegetable pattern intakes were 4.08 (3.05, 5.46) and 2.38 (1.85, 3.07) (p for interaction <0.01), respectively. Higher vegetable intake was also found to attenuate the risk effect of phenotype groups of NAFLD on incident type 2 diabetes, especially in the lean NAFLD group.

CONCLUSIONS

The present study demonstrated that NAFLD is a strong risk factor for type 2 diabetes in the Chinese population. Notably, adherence to a dietary pattern rich in vegetables can attenuate this risk, especially in lean NAFLD patients.

Beneficial Activities of Alisma orientale Extract in a Western Diet-Induced Murine Non-Alcoholic Steatohepatitis and Related Fibrosis Model via Regulation of the Hepatic Adiponectin and Farnesoid X Receptor Pathways

The hepatic adiponectin and farnesoid X receptor (FXR) signaling pathways play multiple roles in modulating lipid and glucose metabolism, reducing hepatic inflammation and fibrosis, and altering various metabolic targets for the management of non-alcoholic fatty liver disease (NAFLD). Alisma orientale (AO, Ze xie in Chinese and Taeksa in Korean) is an herbal plant whose tubers are enriched with triterpenoids, which have been reported to exhibit various bioactive properties associated with NAFLD. Here, the present study provides a preclinical evaluation of the biological functions and related signaling pathways of AO extract for the treatment of NAFLD in a Western diet (WD)-induced mouse model. The findings showed that AO extract significantly reversed serum markers (liver function, lipid profile, and glucose) and improved histological features in the liver sections of mice fed WD for 52 weeks. In addition, it also reduced hepatic expression of fibrogenic markers in liver tissue and decreased the extent of collagen-positive areas, as well as inhibited F4/80 macrophage aggregation and inflammatory cytokine secretion. The activation of adiponectin and FXR expression in hepatic tissue may be a major mechanistic signaling cascade supporting the promising role of AO in NAFLD pharmacotherapy. Collectively, our results demonstrated that AO extract improves non-alcoholic steatohepatitis (NASH) resolution, particularly with respect to NASH-related fibrosis, along with the regulation of liver enzymes, postprandial hyperglycemia, hyperlipidemia, and weight loss, probably through the modulation of the hepatic adiponectin and FXR pathways.

Diabetes mellitus: an overview of the types, symptoms, complications and management

The incidence of diabetes mellitus is rapidly increasing, and this condition often results in significant metabolic disease and severe complications. Nurses have a crucial role in monitoring, educating and supporting people with diabetes, as well as their families and significant others. This article provides an overview of the main types and common symptoms of diabetes, its acute and long-term complications and its management. It also outlines the nurse's role in diabetes care, which frequently includes assessing and empowering patients.

The Association Between Breastfeeding and Nonalcoholic Fatty Liver Disease in Parous Women: A Nation-wide Cohort Study

BACKGROUND AND AIMS

Breastfeeding has multiple effects on maternal health outcomes. However, the effect of breastfeeding on NAFLD in parous women remains unclear.

APPROACH AND RESULTS

A total of 6,893 Korean parous women aged 30-50 years who participated in the Korean National Health and Nutrition Examination Survey were assessed for the association between breastfeeding and NAFLD. Duration of lactation was calculated by dividing the total lactation period by the number of breastfed children. NAFLD was defined by the hepatic steatosis index. Of 6,893 women, 1,049 (15.2%) had NAFLD. Prevalence of NAFLD was 18.3%, 14.3%, 12.3%, 14.4%, and 15.8% in women with a breastfeeding period of <1, ≥1-<3, ≥3-<6, ≥6-<12, and ≥12 months, respectively. In a fully adjusted model, breastfeeding (≥1 month) was associated with reduced NAFLD prevalence (OR, 0.67; 95% CI, 0.51-0.89) after adjusting for metabolic, socioeconomic, and maternal risk factors. Fully adjusted ORs (95% CI) decreased with an increase of breastfeeding duration: 0.74 (0.49-1.11), 0.70 (0.47-1.05), 0.67 (0.48-0.94), and 0.64 (0.46-0.89) for women with ≥1-<3, ≥3-<6, ≥6-<12, and ≥12 months of breastfeeding duration, respectively, compared to women with <1 month of breastfeeding duration. Such an association was also observed in all predefined subgroups without interaction.

CONCLUSIONS

Breastfeeding showed a protective effect against NAFLD in later life of parous women, suggesting a maternal benefit of breastfeeding on NAFLD.

Non-Alcoholic Fatty Liver Disease in Lean and Non-Obese Individuals: Current and Future Challenges

Non-alcoholic fatty liver disease (NAFLD), which approximately affects a quarter of the world’s population, has become a major public health concern. Although usually associated with excess body weight, it may also affect normal-weight individuals, a condition termed as lean/non-obese NAFLD. The prevalence of lean/non-obese NAFLD is around 20% within the NAFLD population, and 5% within the general population. Recent data suggest that individuals with lean NAFLD, despite the absence of obesity, exhibit similar cardiovascular- and cancer-related mortality compared to obese NAFLD individuals and increased all-cause mortality risk. Lean and obese NAFLD individuals share several metabolic abnormalities, but present dissimilarities in genetic predisposition, body composition, gut microbiota, and susceptibility to environmental factors. Current treatment of lean NAFLD is aimed at improving overall fitness and decreasing visceral adiposity, with weight loss strategies being the cornerstone of treatment. Moreover, several drugs including PPAR agonists, SGLT2 inhibitors, or GLP-1 receptor agonists could also be useful in the management of lean NAFLD. Although there has been an increase in research regarding lean NAFLD, there are still more questions than answers. There are several potential drugs for NAFLD therapy, but clinical trials are needed to evaluate their efficacy in lean individuals.

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.

The Risk of Type 2 Diabetes and Coronary Artery Disease in Non-obese Patients With Non-alcoholic Fatty Liver Disease: A Cohort Study

Background: Non-alcoholic fatty liver disease (NAFLD) is not uncommon in non-obese subjects, referred to as non-obese NAFLD. It is not fully determined whether non-obese NAFLD is associated with increased risks of type 2 diabetes (T2D) and coronary artery disease (CAD) in Chinese. This study aimed to examine the association between NAFLD and risks of T2D and CAD in a non-obese Chinese population. Methods: The present cohort study included two stages. In the first cross-sectional study, 16,093 non-obese subjects with a body max index (BMI) < 25.0 kg/m² were enrolled from The Second Xiangya Hospital, China, from 2011 to 2014. Hepatic steatosis was evaluated by ultrasonography examination. Logistic regression analyses were used to examine the association of non-obese NAFLD with T2D and CAD at baseline. In the subsequent 5-year follow-up study, 12,649 subjects free of T2D and CAD at baseline were included, and the incidence of T2D and CAD were observed. Cox proportional hazard regression analyses were performed to determine the risk of incident T2D and CAD with NAFLD. Results: At baseline, the prevalence of NAFLD, T2D and CAD were 10.7% (1,717/16,093), 3.3% (529/16,093) and 0.7% (113/16,093), respectively. The univariate logistic regression analyses showed NAFLD associated with both T2D and CAD. Moreover, in a multivariate logistic regression model, NAFLD remained independently associated with T2D (OR: 2.7, 95% CI: 2.2-3.3, p < 0.001). However, no significant association was found between NAFLD and CAD by the multivariate logistic regression analyses (OR: 1.1, 95% CI: 0.6-1.8, p = 0.854). During a 5-year follow-up period, 177 (1.4%) patients developed T2D, and 134 (1.1%) developed CAD, respectively. In univariate Cox regression models, NAFLD associated with both T2D and CAD. Moreover, the multivariate Cox regression analysis revealed that NAFLD independently associated with an increased risk of T2D (HR: 2.3, 95% CI: 1.7-3.2, p < 0.001). However, the association between NAFLD and incident CAD was lost in the multivariate Cox regression analysis (HR = 1.5, 95% CI: 1.0-2.4, p = 0.059). Conclusions: NAFLD was an independent risk factor for T2D in non-obese subjects. However, no significant association was observed between non-obese NAFLD and incident CAD after adjusting other traditional cardiovascular risk factors, suggesting these factors might mediate the increased incidence of CAD in non-obese NAFLD patients.

Metabolic drivers of non-alcoholic fatty liver disease

BACKGROUND

The incidence of non-alcoholic fatty liver disease (NAFLD) is rapidly increasing worldwide parallel to the global obesity epidemic. NAFLD encompasses a range of liver pathologies and most often originates from metabolically driven accumulation of fat in the liver, or non-alcoholic fatty liver (NAFL). In a subset of NAFL patients, the disease can progress to non-alcoholic steatohepatitis (NASH), which is a more severe form of liver disease characterized by hepatocyte injury, inflammation, and fibrosis. Significant progress has been made over the past decade in our understanding of NASH pathogenesis, but gaps remain in our mechanistic knowledge of the precise metabolic triggers for disease worsening.

SCOPE OF REVIEW

The transition from NAFL to NASH likely involves a complex constellation of multiple factors intrinsic and extrinsic to the liver. This review focuses on early metabolic events in the establishment of NAFL and initial stages of NASH. We discuss the association of NAFL with obesity as well as the role of adipose tissue in disease progression and highlight early metabolic drivers implicated in the pathological transition from hepatic fat accumulation to steatohepatitis.

MAJOR CONCLUSIONS

The close association of NAFL with features of metabolic syndrome highlight plausible mechanistic roles for adipose tissue health and the release of lipotoxic lipids, hepatic de novo lipogenesis (DNL), and disruption of the intestinal barrier in not only the initial establishment of hepatic steatosis, but also in mediating disease progression. Human genetic variants linked to NASH risk to date are heavily biased toward genes involved in the regulation of lipid metabolism, providing compelling support for the hypothesis that NASH is fundamentally a metabolic disease.

Lean NAFLD: an underrecognized and challenging disorder in medicine

Classically, Non-Alcoholic Fatty Liver Disease (NAFLD) has been thought to be driven by excessive weight gain and obesity. The overall greater awareness of this disorder has led to its recognition in patients with normal body mass index (BMI). Ongoing research has helped to better understand potential causes of Lean NAFLD, the risks for more advanced disease, and potential therapies. Here we review the recent literature on prevalence, risk factors, severity of disease, and potential therapeutic interventions.

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.

Nonalcoholic fatty liver disease and the risk of atrial fibrillation stratified by body mass index: a nationwide population-based study

We evaluated the association between nonalcoholic fatty liver disease (NAFLD) and incident atrial fibrillation (AF) and analyzed the impact of NAFLD on AF risk in relation to body mass index (BMI). A total of 8,048,055 subjects without significant liver disease who were available fatty liver index (FLI) values were included. Subjects were categorized into 3 groups based on FLI: < 30, 30 to < 60, and ≥ 60. During a median 8-year of follow-up, 534,442 subjects were newly diagnosed as AF (8.27 per 1000 person-years). Higher FLI was associated with an increased risk of AF (hazard ratio [HR] 1.053, 95% confidence interval [CI] 1.046–1.060 in 30 ≤ FLI < 60, and HR 1.115, 95% CI 1.106–1.125 in FLI ≥ 60). In underweight subjects (BMI < 18.5 kg/m²), higher FLI raised the risk of AF (by 1.6-fold in 30 ≤ FLI < 60 and by twofold in FLI ≥ 60). In normal- and overweight subjects, higher FLI was associated with an increased risk of AF, but the HRs were attenuated. In obese subjects, higher FLI was not associated with higher risk of AF. NAFLD as assessed by FLI was independently associated with an increased risk of AF in nonobese subjects with BMI < 25 kg/m². The impact of NAFLD on AF risk was accentuated in lean subjects with underweight.

Nonalcoholic Fatty Liver Disease and Cardiovascular Diseases: The Heart of the Matter

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most frequent cause of liver disease worldwide, comprising a plethora of conditions, ranging from steatosis to end-stage liver disease. Cardiovascular disease (CVD) has been associated with NAFLD and CVD-related events represent the main cause of death in patients with NAFLD, surpassing liver-related mortality. This association is not surprising as NAFLD has been considered a part of the metabolic syndrome and has been related to numerous CVD risk factors, namely, insulin resistance, abdominal obesity, dyslipidemia, hyperuricemia, chronic kidney disease, and type 2 diabetes. Moreover, both NAFLD and CVD present similar pathophysiological mechanisms, such as increased visceral adiposity, altered lipid metabolism, increased oxidative stress, and systemic inflammation that could explain their association. Whether NAFLD increases the risk for CVD or these diagnostic entities represent distinct manifestations of the metabolic syndrome has not yet been clarified. This review focuses on the relation between NAFLD and the spectrum of CVD, considering the pathophysiological mechanisms, risk factors, current evidence, and future directions.

A Review of the Epidemiology, Pathophysiology, and Efficacy of Anti-diabetic Drugs Used in the Treatment of Nonalcoholic Fatty Liver Disease

In recent years, epidemiological studies have consistently demonstrated that the coexistence of nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) is strongly associated with increased mortality and morbidity related to hepatic- and extrahepatic causes. Indeed, compared with the general population, patients with T2DM are more likely to be diagnosed with more severe forms of NAFLD (i.e., nonalcoholic steatohepatitis (NASH) with liver fibrosis). There is an ongoing debate whether NALFD is a consequence of diabetes or whether NAFLD is simply a component and manifestation of the metabolic syndrome, since liver fat (steatosis) and even more advanced stages of liver fibrosis can occur in the absence of diabetes. Nevertheless, insulin resistance is a key component of the mechanism of NAFLD development; furthermore, therapies that lower blood glucose concentrations also appear to be effective in the treatment of NAFLD. Here, we will discuss the pathophysiological and epidemiological associations between NAFLD and T2DM. We will also review currently available anti-diabetic agents with their regard to their efficacy of NAFLD/NASH treatment.

Nonalcoholic fatty liver disease in lean subjects: Prognosis, outcomes and management

Nonalcoholic fatty liver disease (NAFLD) accounts for most cases of chronic liver disease worldwide, with an estimated global prevalence of approximately 25% and ranges from simple steatosis to nonalcoholic steatohepatitis and cirrhosis. NAFLD is strongly connected to metabolic syndrome, and for many years, fatty liver was considered to be an exclusive feature of obese patients. However, recent studies have highlighted the presence of NAFLD in non-obese subjects, with or without increased visceral fat or even in lean subjects without increased waist circumference. “Lean NAFLD” is a relatively new concept and there is significant scientific interest in understanding the differences in pathophysiology, prognosis and management compared with NAFLD in overweight/obese patients. In the present editorial, we discuss the clinical and metabolic profiles and outcomes of lean NAFLD compared with both obese NAFLD and lean healthy individuals from Asian and Western countries. Moreover, we shed light to the challenging topic of management of NAFLD in lean subjects since there are no specific guidelines for this population. Finally, we discuss open questions and issues to be addressed in the future in order to categorize NAFLD patients into lean and non-lean cohorts.

Effect of Adult Weight Gain on Non-Alcoholic Fatty Liver Disease and Its Association with Anthropometric Parameters in the Lean Japanese Population

Limited data are available on the prevalence of non-alcoholic fatty liver disease (NAFLD) and its association with adult weight gain (AWG) in the lean population. This study aimed to determine the prevalence of NAFLD and to investigate whether AWG is associated with NAFLD in the lean Japanese population. We retrospectively analyzed patients who underwent abdominal ultrasonography as part of the annual health checkup between January 2019 and December 2019. Participants were classified into two groups: those with AWG ≥ 10 kg (AWG group, n = 497), and those without gain (non-AWG group, n = 3006). To adjust for the confounding effects, we generated 482 pairs using 1:1 propensity score matching. The associations between AWG and NAFLD, anthropometric parameters and NAFLD were investigated using univariate logistic regression analysis. We identified NAFLD in 197 (5.6%) participants. AWG was significantly associated with NAFLD (odds ratio (OR), 1.81; p = 0.003). Waist circumference was significantly associated with NAFLD in both the AWG (OR, 1.24; p < 0.001) and non-AWG groups (OR, 1.17; p < 0.001). The association between body mass index and NAFLD existed in the former group (OR, 1.76; p < 0.001), but was not significant in the latter group. AWG is a risk factor for NAFLD even in the lean Japanese population, and associations between anthropometric parameters and NAFLD become stronger if AWG coexists.

Peri-transplant management of nonalcoholic fatty liver disease in liver transplant candidates

The incidence of non-alcoholic fatty liver disease (NAFLD) is rapidly growing, affecting 25% of the world population. Non-alcoholic steatohepatitis (NASH) is the most severe form of NAFLD and affects 1.5% to 6.5% of the world population. Its rising incidence will make end-stage liver disease (ESLD) due to NASH the number one indication for liver transplantation (LT) in the next 10 to 20 years, overtaking Hepatitis C. Patients with NASH also have a high prevalence of associated comorbidities such as type 2 diabetes, obesity, metabolic syndrome, cardiovascular disease, and chronic kidney disease (CKD), which must be adequately managed during the peritransplant period for optimal post-transplant outcomes. The focus of this review article is to provide a comprehensive overview of the unique challenges these patients present in the peritransplant period, which comprises the pre-transplant, intraoperative, and immediate postoperative periods.

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.