Non-alcoholic fatty liver disease, sleep behaviors, and incident type 2 diabetes

Prophylactic effects of nutrition, dietary strategies, exercise, lifestyle and environment on nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease and its prevalence has risen sharply. However, whether nutrition, dietary strategies, exercise, lifestyle and environment have preventive value for NAFLD remains unclear.

METHODS

Through searching 4 databases (PubMed, Web of Science, Embase and the Cochrane Library) from inception to January 2025, we selected studies about nutrition, dietary strategies, exercise, lifestyle and environment in the prevention of NAFLD and conducted a narrative review on this topic.

RESULTS

Reasonable nutrient intake encompassing macronutrients and micronutrients have an independent protective relationship with NAFLD. Besides, proper dietary strategies including mediterranean diet, intermittent fasting diet, ketogenic diet, and dietary approaches to stop hypertension diet have their inhibitory effects on the developmental process of NAFLD. Moreover, right exercises including walking, jogging, bicycling, and swimming are recommended for the prevention of NAFLD because they could effectively reduce weight, which is an important risk factor for NAFLD, and improve liver function. In addition, embracing a healthy lifestyle including reducing sedentary behavior, not smoking, sleeping well and brushing teeth regularly is integral since it not only could reduce the risk of NAFLD but also significantly contribute to overall prevention and control. Finally, the environment, including the social and natural environments, plays a potential role in NAFLD prevention.

CONCLUSION

Nutrition, dietary strategies, exercise, lifestyle and environment play an important role in the prevention of NAFLD. Moreover, this review offers comprehensive prevention recommendations for people at high risk of NAFLD.

Newly identified single-nucleotide polymorphism associated with the transition from nonalcoholic fatty liver disease to liver fibrosis: results from a nested case-control study in the UK biobank

BACKGROUND

Genetic factors may have a significant influence on the likelihood of liver fibrosis in individuals with nonalcoholic fatty liver disease (NAFLD). The present study was conducted to explore how single-nucleotide polymorphism (SNP) impacts the development of fibrosis in those suffering from NAFLD.

MATERIALS AND METHODS

Utilizing the UK Biobank dataset, we conducted a nested case-control analysis among NAFLD participants, defining the case group as those with liver fibrosis and cirrhosis during follow-up. For our in vitro investigations, we employed the LX-2 human hepatic stellate cell line. Our procedures included cultivating these cells, employing SAMM50-rs2073080 plasmid techniques to enhance the expression of recently discovered SNPs, and conducting biochemical assays. To quantify gene expression, we used real-time PCR with fluorescence detection.

RESULTS

The study analyzed data from 5467 participants (1094 cases and 4373 controls). Genome-wide association analysis identified nine significant loci, including the novel rs2073080 variant, strongly associated with NAFLD-associated hepatic fibrosis. In vitro TGF-β modeling revealed significant upregulation of α-SMA and COL1A1, confirming model effectiveness. Oxidative stress markers like elevated malondialdehyde (MDA) and reduced catalase (CAT) and superoxide dismutase (SOD) levels indicated liver damage in the TGF-β group. SAMM50-rs2073080 was upregulated in the NAFLD-associated fibrosis model. In vitro experiments on LX-2 cells showed that SAMM50-rs2073080 overexpression led to increased fibrosis, as indicated by higher cellular MDA levels and lower CAT and SOD levels, compared to the vector group.

CONCLUSION

Our research highlights a significant association of SAMM50-rs2073080 with the progression of NAFLD to hepatic fibrosis, and the in vitro experiments further corroborated these findings.

The association between insomnia (related symptoms) and glycaemic control: a systematic review and meta-analysis

Background

Insomnia characterised by difficulties in falling asleep and maintaining sleep, and early awaking, is a prevalent worldwide sleep disorder. While previous studies have suggested an association between insomnia and adverse glycaemic control, the evidence remains inconclusive. Therefore, this meta-analysis aims to explore this association.

Methods

Insomnia was assessed based on defined criteria, including related symptoms such as poor sleep quality and low sleep efficiency. Glycaemic control was evaluated using indicators such as fasting plasma glucose, haemoglobin A1c, and the presence of diabetes. A literature search was performed in PubMed, Web of Science, and Scopus. The quality of the included studied was assessed using The Newcastle-Ottawa Scale. Effect sizes, including odds ratio, relative risk, mean difference, and standard mean difference, were chosen based on data type. Forest plots visually displayed pooled effect sizes and corresponding 95% confidence intervals, while the I2 test calculated heterogeneity. Meta-regression and subgroup analysis explored potential sources of heterogeneity. Leave-one-out sensitivity analysis assessed result robustness, and Begg's and Egger's tests evaluated publication bias.

Results

Ninety-one articles, comprising 84 are cross-sectional studies, (five are case-control studies, and two are cohort studies) with 2 217 521 participants, were included. Ten separate meta-analyses were conducted based on variable type (binary/continuous), study design (cross-sectional, case-control, or cohort), and measurement of exposures/outcomes. All meta-analyses indicated a positive association between insomnia (related symptoms) and adverse glycaemic control. However, three meta-analyses showed significant heterogeneity, and three lacked robustness. No publication bias was detected across any of the analyses.

Conclusions

Insomnia is likely associated with adverse glycaemic control. As the included studies are observational, future research should prioritise diverse methodologies and robust study designs to further explore this complex relationship.

Keywords

insomnia, insomnia related symptoms, glycaemic control, systematic review, meta-analysis.

Registration

PROSPERO CRD42024491688.

Sleep risk factors modify the association between c-reactive protein and type 2 diabetes: A prospective cohort study

OBJECTIVE

To investigate the prospective association between serum CRP levels and T2D incidence and explore whether such association was modified by sleep risk factors.

METHODS

The study included 366 746 participants without diabetes and exhibited CRP measures at baseline from the UK Biobank. Sleep risk factors included sleep duration, insomnia, snoring, chronotype, and daytime sleepiness. Cox proportional hazards model was used to estimate the hazard ratio (HR), and 95 % confidence interval (CI) of T2D associated with CRP levels. Interactions between CRP and sleep risk factors were also tested.

RESULTS

During a median follow-up of 10.4 years, 14 200 T2D cases were identified. The HRs (95 % CIs) of T2D were 1.31 (1.21-1.43), 1.62 (1.50-1.75), 1.98 (1.83-2.13), and 2.38 (2.21-2.57), respectively, in higher quintile groups of CRP levels compared with the lowest group (p-value for trend <0.001). There were interactions of CRP levels with self-reported sleep duration, snoring, and daytime sleepiness (p-value for interaction = 0.002, 0.0002, and 0.0001). The associated risks between T2D and the elevation in CRP were more evident among participants with high-risk sleep factors.

CONCLUSIONS

Our study indicates that the elevation in serum CRP levels is associated with a higher T2D incidence; and such relation is modified by sleep risk factors including sleep duration, snoring, and daytime sleepiness.

Disease Modules Associated with Unfavorable Sleep Patterns and Their Genetic Determinants: A Prospective Cohort Study of the UK Biobank

Despite the established associations between sleep-related traits and major diseases, comprehensive assessment on affected disease modules and their genetic determinants is lacking. Using multiple correspondence analysis and the k-means clustering algorithm, 235,826 eligible participants were clustered into distinct unfavorable sleep patterns [short sleep duration (n = 10,073), snoring (22,419), insomnia (102,771), insomnia and snoring (62,909)] and favorable sleep pattern groups (37,654). The associations of unfavorable sleep patterns with 134 diseases were estimated using Cox regression models; and comorbidity network analyses were applied for disease module identification. Genetic determinants associated with each disease module were identified by genome-wide association studies (GWAS). During an average follow-up of 10.80 years, unfavorable sleep patterns featured by 'short sleep duration', 'snoring', 'insomnia', and 'insomnia and snoring' were associated with increased risk of 0, 9, 10, and 19 diseases, respectively. Furthermore, comorbidity network analyses categorized these affected diseases into three disease modules, characterized by predominant diseases related to digestive system, circulatory and endocrine systems (snoring-related patterns only), and musculoskeletal system (insomnia-related patterns only). Using the number of affected diseases, as an index of a person's susceptibility to each disease module [i.e., susceptible score (SS)], GWAS analyses identified five, one, and three significant loci associated with the residual SS of these aforementioned disease modules, respectively, which mapped to several potential biological pathways, including those related to hormone regulation and catecholamine uptake. In conclusion, individuals with unfavorable sleep patterns, particularly snoring and insomnia, had increased risk of multiple diseases. The identification of three major disease modules with their relevant genetic determinants may facilitate strategy development for precision prevention of future health decline.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-023-00144-8.

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.

Associations of Sugar-Sweetened Beverages, Artificially Sweetened Beverages, and Pure Fruit Juice With Nonalcoholic Fatty Liver Disease: Cross-sectional and Longitudinal Study

OBJECTIVE

We aimed to test the associations of sugar-sweetened beverages (SSB), artificially sweetened beverages (ASB), and pure fruit juice (PJ) consumption with the risk of nonalcoholic fatty liver disease (NAFLD).

METHODS

Data for 136 277 UK Biobank participants who completed the dietary questionnaire and did not have a history of liver disease were included. Logistic regression was used for the cross-sectional setting where NAFLD was defined by a fatty liver index (FLI) ≥60. Cox proportional hazard regression was used for the longitudinal setting where hospitalized NAFLD was defined as hospital admission with Internationl Classification of Diseases-10 codes K76.0 and K75.8.

RESULTS

Compared with 0 L/wk for corresponding beverages, multivariate-adjusted odds ratios (95% confidence intervals) for NAFLD in consumption ≤1, 1 to 2, and >2 L/wk were 1.06 (1.02-1.10), 1.24 (1.19-1.29), and 1.42 (1.35-1.49) for SSB; 1.43 (1.37-1.50), 1.73 (1.65-1.82), and 2.37 (2.25-2.50) for ASB, and 0.87 (0.84-0.89), 0.91 (0.88-0.94), and 1.07 (1.02-1.13) for PJ, respectively. Consumption of SSB and ASB were both positively correlated with FLI (P for line < .001). During a median follow-up of 10.2 years, 1043 cases of hospitalized NAFLD were recorded. ASB consumption of 1 to 2 and >2 L/wk was associated with a 22% (0.99-1.50) and 35% (1.11-1.65) increased risk of hospitalized NAFLD, respectively (P for trend = .002). However, the associations of SSB and PJ with the risk of hospitalized NAFLD were not significant.

CONCLUSIONS

Consumption of SSB, ASB, and PJ were all related to the risk of NAFLD. Excessive consumption of ASBs was associated with an increased risk of incident hospitalized NAFLD.

Associations between Periodontal Status and Liver Function in the Japanese Population: A Cross-Sectional Study

A relationship between periodontitis and liver function has been suggested. Indeed, patients with severe periodontal disease have been found to be more prone to liver dysfunction. The periodontal inflammatory surface area (PISA) has been shown to be a useful indicator of periodontal and systemic diseases. However, little information is available regarding whether the PISA is associated with liver function markers, such as gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). This study aimed to clarify relationship between liver function markers, AST, ALT, and GGT, and PISA level in a cross-sectional study. The subjects were recruited between 2018 and 2021 at the Medical and Dental Collaboration Center of Kanagawa Dental College Hospital. A periodontal clinical examination was performed, and the PISA was calculated. Peripheral blood samples were collected, and serum levels of liver function markers were measured. The levels of liver function markers were examined in different values of PISA. Participants with high PISA scores were more likely to have increased GGT levels while AST and ALT were not changed with PISA. Increased GGT was found in 10.8% and 29.4% (p = 0.0056), increased AST in 48.2% and 52.9% (p = 0.62), and increased ALT in 35.2% and 47.0% (p = 0.20) among <300 mm² and ≧300 mm² PISA groups, respectively. It was found that males with a PISA of 300 mm² or higher had an elevated level of serum GGT. In conclusion, elevated GGT was found in the high PISA group, particularly in males, while AST and ALT did not differ by PISA.

Non-Alcoholic Fatty Liver Disease or Type 2 Diabetes Mellitus—The Chicken or the Egg Dilemma

In clinical practice, we often deal with patients who suffer from non-alcoholic fatty liver disease (NAFLD) concurrent with type 2 diabetes mellitus (T2DM). The etiopathogenesis of NAFLD is mainly connected with insulin resistance (IR) and obesity. Similarly, the latter patients are in the process of developing T2DM. However, the mechanisms of NAFLD and T2DM coexistence have not been fully elucidated. Considering that both diseases and their complications are of epidemic proportions and significantly affect the length and quality of life, we aimed to answer which of these diseases appears first and thereby highlight the need for their diagnosis and treatment. To address this question, we present and discuss the epidemiological data, diagnoses, complications and pathomechanisms of these two coexisting metabolic diseases. This question is difficult to answer due to the lack of a uniform procedure for NAFLD diagnosis and the asymptomatic nature of both diseases, especially at their beginning stages. To conclude, most researchers suggest that NAFLD appears as the first disease and starts the sequence of circumstances leading ultimately to the development of T2DM. However, there are also data suggesting that T2DM develops before NAFLD. Despite the fact that we cannot definitively answer this question, it is very important to bring the attention of clinicians and researchers to the coexistence of NAFLD and T2DM in order to prevent their consequences.