Factors independently associated with cardiorespiratory fitness in patients with non-alcoholic fatty liver disease

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Relationship between Health-Related Fitness and Quality of Life in Nonalcoholic Fatty Liver Disease

BACKGROUND

It is well known that patients with nonalcoholic fatty liver disease (NAFLD) suffer from impaired quality of life (QoL) and decreased health-related fitness. Studies on the relationship between them have been scarce.

METHODS

A cross-sectional survey was performed in 104 NAFLD patients. Liver fat content and fibrosis were assessed using transient elastography. Health-related fitness was measured by fitness test. VO₂max was determined by YMCA submaximal cycle ergometer test. Body composition was tested by bioimpedance analysis. QoL was evaluated using the 36-item Short Form Health Survey Questionnaire (SF-36).

RESULTS

Most patients had severe liver steatosis without significant fibrosis. Most of them exhibited poor health-related fitness. Multiple linear regression analyses demonstrated that body compositions (waist circumference, hip circumference, percent body fat, percent skeletal muscle, visceral fat area) dependently contributed to QoL (health transition, role limitation due to physical problem, general health, physical functioning and vitality). VO₂max was positively related with physical functioning.

CONCLUSION

For NAFLD patients, decreased health-related fitness was associated with impaired QoL both in the physical and mental dimension. Our results indicate that visceral fat together with muscle mass and VO₂max could serve as individual exercise intervention targets to improve QoL.

Low cardiopulmonary fitness is associated with higher liver fat content and higher gamma-glutamyltransferase concentrations in the general population - "The Sedentary's Liver"

BACKGROUND

We investigated the association between low cardiorespiratory fitness and liver fat content (LFC) in the general population.

MATERIALS AND METHODS

We evaluated data from 2151 adults (51.1% women) from two population-based cohorts of the Study of Health in Pomerania (SHIP-2 and SHIP-TREND-0). We analysed the cross-sectional associations of peak oxygen uptake (VO_2peak ) with LFC, assessed by magnetic resonance imaging proton density fat fraction, as well as serum gamma-glutamyltransferase (GGT) and aminotransferase concentrations by multivariable regression models.

RESULTS

We observed significant inverse associations of VO_2peak with LFC and serum GGT, but not with serum aminotransferase levels. Specifically, a 1 L/min lower VO_2peak was associated with a 1.09% (95% confidence interval [CI]: 0.45-1.73; P = .002) higher LFC and a 0.18 μkatal/L (95% CI: 0.09-0.26; P < .001) higher GGT levels. The adjusted odds ratio (OR) for the risk of prevalent hepatic steatosis (HS) by a 1 L/min decrease in VO_2peak was 1.61 (95% CI: 1.22-2.13; P = .001). Compared to subjects with high VO_2peak , obese and overweight individuals with low VO_2peak had 1.78% (95% CI: 0.32-3.25; P = .017) and 0.94% (95% CI: 0.15-1.74; P = .021) higher mean LFC, respectively. Compared to those with high VO_2peak , low VO_2peak was independently associated with a higher risk of prevalent HS in the obese (adjusted-OR 2.29, 95% CI=1.48-3.56; P < .001) and overweight (adjusted OR 1.57, 95% CI=1.16-2.14; P = .04) groups.

CONCLUSIONS

Lower VO_2peak was significantly associated with greater LFC and higher serum GGT levels in a population-based cohort of adult individuals. Our results suggest that low VO_2peak might be a risk factor for HS.

Non-alcoholic fatty liver disease-related risk of cardiovascular disease and other cardiac complications

BACKGROUND/AIM

Non-alcoholic fatty liver disease (NAFLD) affects approximately 25% of the global adult population. The aim of this narrative review is to describe the associations between NAFLD and cardiovascular disease (CVD), arrhythmias, cardiac conduction defects, myocardial remodelling and heart failure. We also discuss the potential mechanisms that mediate or attenuate the strength of these associations, and briefly summarize the effect of treatments that both ameliorate NAFLD and decrease risk of CVD.

METHODS

Searches of PubMed were performed by the two authors using the terms listed in Appendix. We limited the timeframe to the last decade due to the vast amount of research in the field (up to April 2021) for meta-analyses, reviews and original papers. Only articles published in English were considered.

RESULTS

NAFLD is associated with an increased risk of fatal/non-fatal CVD events and other cardiac and arrhythmic complications (left ventricular hypertrophy, aortic-valve sclerosis and certain arrhythmias), independently of common CVD risk factors. There are probably several underlying mechanisms, including hepatic/systemic insulin resistance, atherogenic dyslipidaemia, hypertension and pro-atherogenic, pro-coagulant and pro-inflammatory mediators released from the steatotic/inflamed liver that may be involved. Some genetic polymorphisms, such as PNPLA3 (rs738409 C>G) and TM6SF2 (rs58542926 C>T), may worsen the liver disease, but also attenuate the strength of the association between NAFLD and CVD, possibly via their effects on lipoprotein metabolism. Of the currently tested drugs for treating NAFLD that also benefit the vasculature, pioglitazone and GLP-1 receptor agonists are the most promising.

CONCLUSIONS

The complex interplay between the liver and cardiometabolic risk factors contributes to CVD, arrhythmias and cardiac disease in NAFLD. There is an urgent need for a multidisciplinary approach to manage both liver disease and cardiometabolic risk, and to test the cardiovascular and cardiac effects of new drugs for NAFLD.

NAFLD, and cardiovascular and cardiac diseases: Factors influencing risk, prediction and treatment

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD), affecting up to around 30% of the world's adult population, causes considerable liver-related and extrahepatic morbidity and mortality. Strong evidence indicates that NAFLD (especially its more severe forms) is associated with a greater risk of all-cause mortality, and the predominant cause of mortality in this patient population is cardiovascular disease (CVD). This narrative review aims to discuss the strong association between NAFLD and increased risk of cardiovascular, cardiac and arrhythmic complications. Also discussed are the putative mechanisms linking NAFLD to CVD and other cardiac/arrhythmic complications, with a brief summary of CVD risk prediction/stratification and management of the increased CVD risk observed in patients with NAFLD.

RESULTS

NAFLD is associated with an increased risk of CVD events and other cardiac complications (left ventricular hypertrophy, valvular calcification, certain arrhythmias) independently of traditional CVD risk factors. The magnitude of risk of CVD and other cardiac/arrhythmic complications parallels the severity of NAFLD (especially liver fibrosis severity). There are most likely multiple underlying mechanisms through which NAFLD may increase risk of CVD and cardiac/arrhythmic complications. Indeed, NAFLD exacerbates hepatic and systemic insulin resistance, promotes atherogenic dyslipidaemia, induces hypertension, and triggers synthesis of proatherogenic, procoagulant and proinflammatory mediators that may contribute to the development of CVD and other cardiac/arrhythmic complications.

CONCLUSION

Careful assessment of CVD risk is mandatory in patients with NAFLD for primary prevention of CVD, together with pharmacological treatment for coexisting CVD risk factors.