Elevated Fatty Liver Index Is Independently Associated With New Onset of Hypertension During a 10-Year Period in Both Male and Female Subjects

Machine learning-based analyses of contributing factors for the development of hypertension: a comparative study

OBJECTIVES

Sufficient attention has not been given to machine learning (ML) models using longitudinal data for investigating important predictors of new onset of hypertension. We investigated the predictive ability of several ML models for the development of hypertension.

METHODS

A total of 15 965 Japanese participants (men/women: 9,466/6,499, mean age: 45 years) who received annual health examinations were randomly divided into a training group (70%, n = 11,175) and a test group (30%, n = 4,790). The predictive abilities of 58 candidates including fatty liver index (FLI), which is calculated by using body mass index, waist circumference and levels of γ-glutamyl transferase and triglycerides, were investigated by statistics analogous to the area under the curve (AUC) in receiver operating characteristic curve analyses using ML models including logistic regression, random forest, naïve Bayes, extreme gradient boosting and artificial neural network.

RESULTS

During a 10-year period (mean period: 6.1 years), 2,132 subjects (19.1%) in the training group and 917 subjects (19.1%) in the test group had new onset of hypertension. Among the 58 parameters, systolic blood pressure, age and FLI were identified as important candidates by random forest feature selection with 10-fold cross-validation. The AUCs of ML models were 0.765-0.825, and discriminatory capacity was significantly improved in the artificial neural network model compared to that in the logistic regression model.

CONCLUSIONS

The development of hypertension can be simply and accurately predicted by each ML model using systolic blood pressure, age and FLI as selected features. By building multiple ML models, more practical prediction might be possible.

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) Is an Independent Risk Factor for the Development of Ischemic Heart Disease - A 10-Year Cohort Study

Background

The association of each of the recently classified steatotic liver diseases (SLDs), including metabolic dysfunction-associated SLD (MASLD), MASLD and increased alcohol intake (MetALD), and alcohol-associated liver disease (ALD), with new development of ischemic heart disease (IHD) remains unclear.

Methods and Results

We investigated the associations of various SLDs with the development of IHD during a 10-year follow-up period in 13,815 Japanese individuals without a history of IHD (men/women 8,933/4,882; mean age 48 years) who underwent annual health checkups including an abdominal ultrasound examination. Among the participants, 4,639 (33.6%) subjects were diagnosed as having SLDs, and the proportions of subjects with MASLD, MetALD and ALD were 25.4%, 4.7% and 1.9%, respectively. During the follow-up period, 1,963 (16.2%; men/women 1,374 [17.2%]/589 [14.2%]) subjects had new development of IHD. Multivariable Cox proportional hazard model analysis after adjustment of age, sex, estimated glomerular filtration rate (eGFR), current smoking habit, diabetes, hypertension and dyslipidemia showed that the adjusted risk for new onset of IHD was significantly higher in subjects with MASLD (hazard ratio 1.20 [95% confidence interval 1.01-1.55]; P=0.042) than in those without SLD. Other SLDs were not selected as independent risk factors for the development of IHD.

Conclusions

The presence of MASLD, but not other SLDs, is an independent risk factor for new onset of IHD during a 10-year follow-up period.

Sex differences in predicting dyslipidemia using polygenic risk score with fatty liver index and fibrotic nonalcoholic steatohepatitis index

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are recognized risk factors for dyslipidemia. Current prediction models that rely solely on dyslipidemia polygenic risk score (PRS) have certain limitations. We aimed to validate simple indexes for NAFLD and NASH as predictors of dyslipidemia using the PRS. This study utilized cohort data from an urban population-based dataset comprising 48,263 South Koreans. The incidence of dyslipidemia was higher in men than in women (32.4% and 27.8%; p < 0.001). The PRS model predicted dyslipidemia more accurately in men (AUROC [95% confidence intervals]: 0.645 [0.636-0.754]). Notably, integrating the fatty liver index (FLI) and fibrotic NASH index (FNI) with the PRS model resulted in the highest accuracy in diagnosing dyslipidemia, particularly in men (AUROC [95% confidence intervals]: 0.704 [0.698-0.711]). In conclusion, a predictive model combining the PRS with FLI and FNI was validated. This model offers more accurate predictive value for diagnosing dyslipidemia, particularly in East Asian men. Thus, our study has the clinical potential for identifying high-risk individuals and determining preventive measures for dyslipidemia in a sex-specific manner.

Association between liver fat level and risk of hypertension: evidence from a Chinese health examination dataset

BACKGROUND

Hypertension development is predominantly influenced by inflammation, excessive fat deposition, and metabolic irregularities. Among these factors, liver fat accumulation is a critical metabolic disorder. However, the quantification of liver fat levels and its associated risk for hypertension incidence remain ambiguous. This project is designed to explore the association between liver fat levels and the risk of hypertension in a healthy population.

METHODS

This cross-sectional study involved 4955 participants from the Health Management Center at Henan Provincial People's Hospital who were surveyed between February 2020 and February 2023. Participants were categorized into four groups based on liver fat quartiles. Subgroup analyses, restricted cubic spline regression models, and logistic regression were utilized to assess the association between liver fat levels and hypertension risk. The relationships between liver fat levels and inflammatory markers were examined using multiple linear regression models. Additionally, a mediation analysis was conducted to explore the role of inflammatory factors in the relationship between liver fat and hypertension risk.

RESULTS

Participants with hypertension exhibited greater liver fat levels than did those without hypertension. An increased risk of hypertension was associated with elevated liver fat levels, even after adjusting for other covariates [Q4 vs. Q1 in model II: odds ratio (OR = 1.28), 95% confidence interval (CI) = 1.04-1.59, P  = 0.022; P for trend = 0.039]. A nonlinear relationship was observed between liver fat level and hypertension risk, with a notable increase in hypertension risk occurring at liver fat levels greater than 8.65%. Additionally, a positive correlation was found between inflammatory markers and liver fat levels. A mediation effect of 4.76% was noted, linking hypertension risk and liver fat levels through neutrophils.

CONCLUSION

Liver fat levels exceeding 8.65% significantly elevated the risk of hypertension. Inflammatory factors serve as crucial mediators of the relationship between liver fat and hypertension.

High Intraocular Pressure Is Independently Associated With New-Onset Systemic Hypertension Over a 10-Year Period

BACKGROUND

Systemic hypertension (HT) is associated with the development of increased intraocular pressure (IOP), a risk factor for glaucoma. However, it remains unclear whether high IOP is a risk factor for HT.

METHODS AND RESULTS

We investigated 7,487 Japanese individuals (4,714 men, 2,773 women; mean [±SD] age 49±9 years) who underwent annual health checkups in 2006. Over the 10-year follow-up period, 1,232 (24.3%) men and 370 (11.5%) women developed new-onset HT, defined as initiation of antihypertensive drug treatment or blood pressure ≥140/90 mmHg. After dividing IOP into tertiles (T1-T3), Cox proportional hazards analysis (adjusted for age, sex, systolic blood pressure, obesity, current smoking, alcohol consumption, family history of HT, estimated glomerular filtration rate, and diabetes and dyslipidemia diagnoses at baseline) revealed a significantly higher risk of newly developed HT in T3 (IOP ≥14 mmHg; hazard ratio 1.14; 95% confidence interval 1.01-1.29; P=0.038) using T1 (IOP ≤11 mmHg) as the reference group. There was no significant interaction between sex and IOP tertile (P=0.153). A restricted cubic spline model showed a gradual but robust increase in the hazard ratio for new-onset HT with increasing IOP.

CONCLUSIONS

High IOP is an independent risk factor for the development of HT over a 10-year period.

Effect of Statins for Primary Prevention of Cardiovascular Disease According to the Fatty Liver Index

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is associated with increased risk of cardiovascular disease (CVD). We investigated the primary preventive effect of statins on CVD according to the level of fatty liver index (FLI), which is a marker of NAFLD.

METHODS

We conducted a nested case-control study on the basis of a nationwide health screening cohort in Korea. The participants were divided into tertiles (T1, T2, and T3) according to their FLI score. Cases were defined as individuals who developed CVD (composite of myocardial infarction and stroke). Three controls were matched to each case and multivariable conditional logistic regression analysis was performed.

RESULTS

Within a cohort of 206,263 participants without prior CVD, 7044 individuals suffered the primary outcome. For the nested case-control study, we selected these 7044 cases along with their corresponding 20,641 matched controls. Individuals in the T3 tertiles of FLI had a higher risk of CVD than those in the T1 tertile [adjusted odds ratio (OR) 1.30; 95% confidence interval (CI) 1.20-1.40, P < 0.001]. In sub-analyses based on FLI tertiles, statin therapy was associated with a lower risk of CVD (adjusted OR 0.72; 95% CI 0.61-0.85, P < 0.001) in the T3 tertile but not in the T1 and T2 tertiles.

CONCLUSIONS

Statin therapy was associated with a reduced risk of CVD in individuals with high FLI but not in those with low FLI. Further research is needed to determine the pathophysiologic mechanism between statin and NAFLD.

Deciphering metabolic dysfunction-associated steatotic liver disease: insights from predictive modeling and clustering analysis

BACKGROUND AND AIM

New nomenclature of steatotic liver disease (SLD) including metabolic dysfunction-associated SLD (MASLD), MASLD and increased alcohol intake (MetALD), and alcohol-associated liver disease (ALD) has recently been proposed. We investigated clustering analyses to decipher the complex landscape of SLD pathologies including the former nomenclature of nonalcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

Japanese individuals who received annual health checkups including abdominal ultrasonography (n = 15 788, men/women: 10 250/5538, mean age: 49 years) were recruited.

RESULTS

The numbers of individuals with SLD, MASLD, MetALD, ALD, NAFLD, and MAFLD were 5603 (35.5%), 4227 (26.8%), 795 (5.0%), 324 (2.1%), 3982 (25.8%), and 4946 (31.3%), respectively. Clustering analyses using t-distributed stochastic neighbor embedding and K-means to visually represent interconnections in SLDs uncovered five cluster formations. MASLD and NAFLD mainly shared three clusters including (i) low alcohol intake with relatively low-grade obesity; (ii) obesity with dyslipidemia; and (iii) dysfunction of glucose metabolism. Both MetALD and ALD displayed one distinct cluster intertwined with alcohol consumption. MAFLD widely shared all of the five clusters. In machine learning-based analyses using algorithms of random forest and extreme gradient boosting and receiver operating characteristic curve analyses, fatty liver index (FLI), calculated by body mass index, waist circumference, and levels of γ-glutamyl transferase and triglycerides, was selected as a useful feature for SLDs.

CONCLUSIONS

The new nomenclature of SLDs is useful for obtaining a better understanding of liver pathologies and for providing valuable insights into predictive factors and the dynamic interplay of diseases. FLI may be a noninvasive predictive marker for detection of SLDs.

Prediction and Validation of Metabolic Dysfunction-Associated Fatty Liver Disease Using Fatty Liver-Related Indices in a Japanese Population

Background: Recently, metabolic dysfunction-associated fatty liver disease (MAFLD) has been proposed. It is uncertain how indices that predict fatty liver are associated with MAFLD in Japanese. Methods: Among subjects who underwent a health examination at our hospital, 1257 (men: 787, women: 474) subjects participated in fatty liver evaluation of the fatty liver index (FLI) and fatty liver predicting index (FLPI) were included in this cross-sectional study. The discriminatory ability of each index for MAFLD was tested using receiver operating characteristic curve analysis. The association between FLI, FLPI, and MAFLD was investigated using multiple logistic regression analysis. Results: FLI and FLPI had good discriminatory ability for identifying MAFLD in both men and women, with specific cutoff values. Both FLI and FLPI were significantly higher in subjects with MAFLD, and the odds of MAFLD were higher among those in the highest tertile relative to the lowest tertile in both men and women. FLI and FLPI were higher in subjects who met the criteria for both MAFLD and metabolic syndrome (MetS) compared to those who had MAFLD or MetS alone, and most of the examined parameters in subjects with both conditions indicated a high metabolic risk profile. Conclusions: The study suggests that FLI and FLPI are valuable tools for predicting MAFLD and are similarly correlated with the disease. Furthermore, the highest values of these indices were observed in subjects who met the criteria for both MAFLD and MetS, emphasizing the importance of considering both conditions when assessing metabolic risk.

Fatty liver index (FLI): more than a marker of hepatic steatosis

Fatty liver index (FLI) was developed as a simple and accurate marker of hepatic steatosis. FLI is derived from an algorithm based on body mass index, waist circumference, and levels of triglycerides and gamma-glutamyltransferase, and it is widely used in clinical and epidemiological studies as a screening tool for discriminating between healthy and nonalcoholic fatty liver disease (NAFLD) subjects. However, a systematic review of the literature regarding FLI revealed that this index has more extensive relationships with biochemical and physiological parameters. FLI is associated with key parameters of lipid, protein and carbohydrate metabolism, hormones, vitamins and markers of inflammation, or oxidative stress. FLI can be a predictor or risk factor for a number of metabolic and nonmetabolic diseases and mortality. FLI is also used as an indicator for determining the effects of health-related prevention interventions, medications, and toxic substances on humans. Although in most cases, the exact mechanisms underlying these associations have not been fully elucidated, they are most often assumed to be mediated by insulin resistance, inflammation, and oxidative stress. Thus, FLI may be a promising marker of metabolic health due to its multiple associations with parameters of physiological and pathological processes. In this context, the present review summarizes the data from currently available literature on the associations between FLI and biochemical variables and physiological functions. We believe that this review will be of interest to researchers working in this area and can provide new perspectives and directions for future studies on FLI.

Validation of non-invasive indicators in the screening of metabolic dysfunction-associated fatty liver disease: a cross-sectional study among Uighurs in rural Xinjiang

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the most common chronic liver disease in China. Our study aimed to evaluate the screening value of the fatty liver index (FLI), hepatic steatosis index (HSI), lipid accumulation product (LAP), visceral adiposity index (VAI), and Zhejiang University index (ZJU), as well as other single indicators for MAFLD. We aimed to find the optimal screening tool and its appropriate cut-off values for rural Uyghur adults.

METHODS

We completed a survey of 14,321 Uyghur adults in 51 groups in Kashgar, Xinjiang, in 2016 using a typical sampling method, with 12,794 patients ultimately included in statistical analyses. Fatty liver was diagnosed using ultrasonography.

RESULTS

The prevalence of fatty liver disease (FLD) and MAFLD was 16.73% and 16.55%, respectively, and the FLI, HSI, LAP, VAI, and ZJU were all independently associated with an increased risk of MAFLD. The areas under the receiver operating characteristic curves (AUCs) of the FLI for diagnosing MAFLD in men and women were 0.853 and 0.847, respectively. The AUCs of the body mass index (BMI) for diagnosing MAFLD in men and women were 0.850 and 0.852, respectively. Compared with other metabolic-related markers, FLI had the largest AUC. In men, the optimal cut-off values of FLI and BMI for diagnosing MAFLD were 45 (sensitivity 84.83%, specificity 69.57%) and 27.4 (sensitivity 78.47%, specificity 76.30%), respectively. In women, the optimal cut-off values of FLI and BMI for diagnosing MAFLD were 45 (sensitivity 80.11%, specificity 74.23%) and 28.0 (sensitivity 79.56%, specificity 75.41%), respectively. In men and women, an FLI score of < 30 ruled out MAFLD, while a score of ≥ 50 was a basis for diagnosis.

CONCLUSION

FLI and BMI had good screening ability for MAFLD and were superior to HSI, LAP, VAI, and ZJU in both sexes.

An increase in calculated small dense low-density lipoprotein cholesterol predicts new onset of hypertension in a Japanese cohort

A disorder of lipid metabolism is involved in cardiovascular diseases including hypertension. A high level of small dense low-density lipoprotein cholesterol (sdLDL-C) is a strong risk factor for atherosclerotic cardiovascular disease. However, the association between sdLDL-C and hypertension has not been fully investigated. We investigated the associations between the development of hypertension during a 10-year period and levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides (TG), and LDL-C and sdLDL-C calculated by using the Sampson equations in 28,990 Japanese subjects who received annual health examinations. After exclusion of subjects with missing data, those with hypertension, and those with TG ≥ 800 mg/dL at baseline, a total of 15,177 subjects (men/women: 9374/5803, mean age: 46 years) were recruited. During the 10-year period, 2379 men (25.4%) and 724 women (12.5%) had new onset of hypertension. Multivariable Cox proportional hazard model analyses showed that levels of HDL-C, non-HDL-C, TG and sdLDL-C, but not levels of TC and LDL-C, were independent risk factors for the development of hypertension after adjustment of age, sex, family history of hypertension, systolic blood pressure, obesity, current smoking habit, alcohol drinking habit, estimated glomerular filtration rate, diagnosis of diabetes mellitus and use of lipid-lowering drugs and that the adjusted risk of sdLDL-C (per 1-standard deviation) was highest (hazard ratio [95% confidence interval: 1.09 [1.05-1.13]). The addition of sdLDL-C to traditional risk factors for hypertension significantly improved the discriminatory capability, which was better than that of other lipid fractions. In conclusion, a high level of calculated sdLDL-C predicts the development of hypertension.

Which Comes First, Nonalcoholic Fatty Liver Disease or Arterial Hypertension?

Non-alcoholic fatty liver disease (NAFLD) and arterial hypertension (AH) are widespread noncommunicable diseases in the global population. Since hypertension and NAFLD are diseases associated with metabolic syndrome, they are often comorbid. In fact, many contemporary published studies confirm the association of these diseases with each other, regardless of whether other metabolic factors, such as obesity, dyslipidemia, and type 2 diabetes mellites, are present. This narrative review considers the features of the association between NAFLD and AH, as well as possible pathophysiological mechanisms.

Coexistence of Metabolic Dysfunction-Associated Fatty Liver Disease and Chronic Kidney Disease Is a More Potent Risk Factor for Ischemic Heart Disease

Background Metabolic dysfunction-associated fatty liver disease (MAFLD), defined as fatty liver with overweight/obesity, type 2 diabetes, or metabolic abnormalities, is a newly proposed disease. However, it remains unclear whether the coexistence of MAFLD and chronic kidney disease (CKD) is a more potent risk factor for ischemic heart disease (IHD). Methods and Results We investigated the risk of the combination of MAFLD and CKD for development of IHD during a 10-year follow-up period in 28 990 Japanese subjects who received annual health examinations. After exclusion of subjects without data for abdominal ultrasonography or with the presence of IHD at baseline, a total of 14 141 subjects (men/women: 9195/4946; mean age, 48 years) were recruited. During the 10-year period (mean, 6.9 years), 479 subjects (men/women, 397/82) had new onset of IHD. Kaplan-Meier survival curves showed significant differences in rates of the cumulative incidence of IHD in subjects with and those without MAFLD (n=4581) and CKD (n=990; stages 1/2/3/4-5, 198/398/375/19). Multivariable Cox proportional hazard model analyses showed that coexistence of MAFLD and CKD, but not MAFLD or CKD alone, was an independent predictor for development of IHD after adjustment for age, sex, current smoking habit, family history of IHD, overweight/obesity, diabetes, hypertension, and dyslipidemia (hazard ratio, 1.51 [95% CI, 1.02-2.22]). The addition of the combination of MAFLD and CKD to traditional risk factors for IHD significantly improved the discriminatory capability. Conclusions The coexistence of MAFLD and CKD predicts new onset of IHD better than does MAFLD or CKD alone.

Metabolic dysfunction-associated fatty liver disease predicts new onset of chronic kidney disease better than fatty liver or nonalcoholic fatty liver disease

BACKGROUND

Possible associations of chronic kidney disease (CKD) with fatty liver (FL) and nonalcoholic fatty liver disease (NAFLD) have recently been focused on. Metabolic dysfunction-associated fatty liver disease (MAFLD), defined as FL with overweight/obesity, type 2 diabetes mellitus or metabolic abnormalities, has been proposed as a new feature of chronic liver disease. However, the relationship between MAFLD and new onset of CKD has not been fully addressed.

METHODS

We investigated the associations of FL, NAFLD and MAFLD with the development of CKD, defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 or positive for urinary protein, over a 10-year period in 28 890 Japanese subjects who received annual health examinations. After exclusion of subjects with no data for abdominal ultrasonography and subjects with CKD at baseline, a total of 13 159 subjects (men 8581, women 4578; mean age 48 years) were recruited.

RESULTS

The prevalence of FL, NAFLD and MAFLD was 34.6% (men 45.1%, women 15.1%), 32.8% (men 42.7%, women 14.5%) and 32.3% (men 42.4%, women 13.4%), respectively. During the 10-year follow-up period, 2163 subjects (men 1475, women 688) had new onset of CKD. Multivariable Cox proportional hazards model analyses showed that MAFLD [hazard ratio 1.12 (95% confidence interval 1.02-1.26); P = .027] but not FL or NAFLD was an independent risk factor for new onset of CKD after adjustment of age, sex, eGFR, current smoking habit, ischemic heart disease, diabetes mellitus, overweight/obesity, hypertension and dyslipidemia. The addition of MAFLD [continuous net reclassification improvement (NRI) 0.154, integrated discrimination improvement (IDI) 0.0024] to traditional risk factors without metabolic abnormalities significantly improved the discriminatory capacity better than did the addition of FL (NRI 0.138, IDI 0.0018) or NAFLD (NRI 0.132, IDI 0.0017).

CONCLUSIONS

MAFLD is modestly and independently associated with new onset of CKD and predicts the risk for development of CKD better than FL or NAFLD.

Metabolic dysfunction-associated fatty liver disease is associated with an increase in systolic blood pressure over time: linear mixed-effects model analyses

Metabolic dysfunction-associated fatty liver disease (MAFLD), a new feature of fatty liver (FL) disease that is defined as FL with overweight/obesity, type 2 diabetes mellitus or metabolic dysregulation, has been reported to be associated with the development of diabetes mellitus, chronic kidney disease and cardiovascular disease. However, the association between MAFLD and hypertension remains unclear. We investigated the association between MAFLD and systolic blood pressure (SBP) over a 10-year period in 28,990 Japanese subjects who received annual health examinations. After exclusion of subjects without data for SBP and abdominal ultrasonography at baseline, a total of 17,021 subjects (men/women: 10,973/6048; mean age: 49 years) were recruited. Linear mixed-effects model analyses using diagnoses of FL, nonalcoholic fatty liver disease (NAFLD) or MAFLD and age, sex, SBP, use of anti-hypertensive drugs, levels of uric acid and estimated glomerular filtration rate, family history of hypertension and habits of current smoking and alcohol drinking at baseline as well as the duration of the observation period and the interaction between each covariate and the duration of the observation period showed that the significant association of change in SBP over time with diagnosis of MAFLD (estimate: 0.223 mmHg/year, P < 0.001) was greater than that with diagnoses of FL (estimate: 0.196 mmHg/year, P < 0.001) and NAFLD (estimate: 0.203 mmHg/year, P < 0.001). Furthermore, the rate of increase in SBP over time was higher in subjects with MAFLD than in subjects without FL and subjects with FL who had no MAFLD. In conclusion, MAFLD is significantly associated with an increase in SBP over time. The presence of metabolic dysfunction-associated fatty liver disease (MAFLD) is significantly associated with an increase in systolic blood pressure over time.

Fatty liver index predicts the development of hypertension in a Japanese general population with and without dysglycemia

Fatty liver has been suggested to be associated with the development of hypertension. However, whether this association is related to glycemia has not been elucidated. Therefore, we investigated whether the fatty liver index (FLI) predicts the development of hypertension among individuals with and without dysglycemia in a general Japanese population. A total of 3114 participants (1036 males and 2078 females) without hypertension who underwent a Specific Health Checkup in the fiscal year 2013 were followed up until 2018. The participants were divided into six groups based on FLI tertiles (low, moderate, or high) and whether they had dysglycemia. We estimated the hazard ratios (HRs) of each group by sex using the Cox proportional hazard model. Models were adjusted for age, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, smoking, and alcohol consumption and further adjusted for systolic blood pressure (SBP). During the mean follow-up period of 2.8 years, 160 of the 3114 participants developed hypertension. Using the low FLI group with normoglycemia as a reference, the HR for incident hypertension was increased in the high FLI group with and without dysglycemia in both sexes after adjusting for confounders, except SBP (HR [95% confidence interval]: male: 1.52 (1.06-2.17) in normoglycemia and 2.05 (1.43-2.92) in dysglycemia, and female: 1.86 (1.43-2.42) in normoglycemia and 2.98 (2.19-4.07) in dysglycemia). Furthermore, in females, this association was observed after adjusting for SBP. We concluded that FLI was independently associated with an increased risk of incident hypertension in individuals with and without dysglycemia.

Association of non-alcoholic fatty liver disease with left ventricular changes in treatment-naive patients with uncomplicated hypertension

Background and aims

Cardiac structural and functional changes have been demonstrated in patients with non-alcoholic fatty liver disease (NAFLD). Because of the frequent association of NAFLD with hypertension, we aimed to examine the relationship of liver steatosis with left ventricular (LV) changes in patients with hypertension.

Materials and methods

In a cross-sectional study, we included 360 untreated, essential hypertensive patients who were free of major cardiovascular and renal complications. Liver steatosis was assessed by three different biochemical scores (NAFLD Liver Fat Score, LFS; Fatty Liver Index, FLI; Hepatic Steatosis Index, HSI). Echocardiography was performed with standard B-mode and tissue-Doppler imaging.

Results

LV hypertrophy was present in 19.4% and LV diastolic dysfunction in 49.2% of patients who had significantly higher body mass index (BMI), blood pressure (BP), and homeostatic model assessment (HOMA) index and higher frequency of the metabolic syndrome and liver steatosis that was defined by presence of 2 or more positive scores. LV mass index increased progressively across patients who had none, 1, or 2 or more liver steatosis scores, with associated progressive worsening of LV diastolic function. LV mass index was significantly and positively correlated with age, BMI, BP, HOMA-index, LFS, and HSI. Logistic regression analysis showed that age, BP, and liver steatosis scores independently predicted LV hypertrophy and diastolic dysfunction. Liver steatosis independently predicted LV dysfunction but not LV hypertrophy even after inclusion in analysis of the HOMA-index.

Conclusion

NAFLD is associated with LV hypertrophy and diastolic dysfunction in untreated patients with hypertension. In hypertension, NAFLD could contribute to LV diastolic dysfunction with mechanisms unrelated to insulin resistance.

Nonalcoholic fatty liver disease and diabetes

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in the world and represents a clinical-histopathologic entity where the steatosis component may vary in degree and may or may not have fibrotic progression. The key concept of NAFLD pathogenesis is excessive triglyceride hepatic accumulation because of an imbalance between free fatty acid influx and efflux. Strong epidemiological, biochemical, and therapeutic evidence supports the premise that the primary pathophysiological derangement in most patients with NAFLD is insulin resistance; thus the association between diabetes and NAFLD is widely recognized in the literature. Since NAFLD is the hepatic manifestation of a metabolic disease, it is also associated with a higher cardio-vascular risk. Conventional B-mode ultrasound is widely adopted as a first-line imaging modality for hepatic steatosis, although magnetic resonance imaging represents the gold standard noninvasive modality for quantifying the amount of fat in these patients. Treatment of NAFLD patients depends on the disease severity, ranging from a more benign condition of nonalcoholic fatty liver to nonalcoholic steatohepatitis. Abstinence from alcohol, a Mediterranean diet, and modification of risk factors are recommended for patients suffering from NAFLD to avoid major cardiovascular events, as per all diabetic patients. In addition, weight loss induced by bariatric surgery seems to also be effective in improving liver features, together with the benefits for diabetes control or resolution, dyslipidemia, and hypertension. Finally, liver transplantation represents the ultimate treatment for severe nonalcoholic fatty liver disease and is growing rapidly as a main indication in Western countries. This review offers a comprehensive multidisciplinary approach to NAFLD, highlighting its connection with diabetes.

High fatty liver index is an independent predictor of ischemic heart disease during a 10-year period in a Japanese population

AIM

Fatty liver index (FLI), which is calculated by using body mass index, waist circumference and levels of γ-glutamyl transferase and triglycerides, is a validated surrogate marker of nonalcoholic fatty liver disease. We retrospectively investigated the relationship between FLI and the development of ischemic heart disease (IHD) during a 10-year period.

METHODS

Among subjects who received annual health checkups (n = 28 990), a total of 18 851 subjects (men/women: 11 659/7192) were enrolled after exclusion of subjects with missing data and those with IHD at baseline.

RESULTS

FLI at baseline was significantly higher in men than in women. During the 10-year period, 450 men (3.9%) and 123 women (1.7%) had new onset of IHD determined by a self-reported questionnaire survey. Multivariable Cox proportional hazard models with a restricted cubic spline showed that hazard risk (HR) for the development of IHD increased with a higher FLI at baseline after adjustment of age, sex, current smoking habit, family history of IHD and diagnosis of diabetes mellitus, hypertension, dyslipidemia and chronic kidney disease at baseline. There was no significant interaction between FLI and sex for the adjusted HR. When divided by tertiles of FLI at baseline (T1∼T3), the adjusted risk for development of IHD in the T3 group (HR [95% confidence interval]: 1.34 [1.05-1.71]) was significantly higher than that in the T1 group as the reference. The addition of FLI into traditional risk factors for IHD significantly improved the discriminatory capability.

CONCLUSIONS

A high level of FLI is an independent predictor of new onset of IHD during a 10-year period.

High fibrosis-4 index predicts the new onset of ischaemic heart disease during a 10-year period in a general population

Aims

The fibrosis-4 (FIB-4) index, calculated using age, platelet count, and levels of aspartate aminotransferase and alanine aminotransferase, is a non-invasive indicator for the detection of liver fibrosis. Advanced hepatic fibrosis is associated with morbidity and mortality in patients with non-alcoholic fatty liver disease. However, the relationship between liver fibrosis and the development of ischaemic heart disease (IHD) has not fully been addressed.

Methods and results

We investigated the association between the FIB-4 index and the new onset of IHD during a 10-year period in a general population of subjects who received annual health examinations (n = 28 990). After exclusion of subjects with missing data and those with a history of IHD at baseline, a total of 13 448 subjects (men/women: 8774/4674, mean age: 48 years) were included. During the 10-year period, 378 men (4.3%) and 77 women (1.6%) had a new onset of IHD. Multivariable Cox proportional hazard models with a restricted cubic spline showed that hazard risk for the development of IHD increased with a higher FIB-4 index at baseline after adjustment of age, sex, fatty liver (FL) determined by ultrasonography, estimated glomerular filtration rate, habits of current smoking and alcohol drinking, family history of IHD, and diagnosis of hypertension, diabetes mellitus and dyslipidaemia. When divided by FL, the FIB-4 index becomes an independent predictor for the development of IHD in subjects with FL but not in those without FL. The addition of the FIB-4 index to traditional risk factors for IHD significantly improved the discriminatory capability.

Conclusion

A high level of the FIB-4 index predicts the new onset of IHD during a 10-year period.

Prediction and validation of nonalcoholic fatty liver disease by fatty liver index in a Japanese population

Fatty liver index (FLI) calculated by using body mass index (BMI), waist circumference and levels of γ-glutamyl transferase and triglycerides is a non-invasive predictor of nonalcoholic fatty liver disease (NAFLD). The original study in Italy showed that the cutoff level for prediction of NAFLD was FLI ≥60. However, the sex difference in FLI was not taken into consideration, and it is unclear whether the cutoff value can be applied to other races. We investigated the cutoff value of FLI for prediction of NAFLD determined by abdominal ultrasonography using receiver operating characteristic curve analyses in 14,471 Japanese subjects (men/women: 9,240/5,231; mean age: 48 ± 9 years). There was a significant interaction between sex and FLI for detection of NAFLD (p < 0.001). The cutoff values of FLI in men and women were 35.1 (area under the curve [AUC]: 0.82) and 15.6 (AUC: 0.91), respectively. When the subjects were divided by the absence and presence of obesity (BMI ≥25), there was a significant interaction between FLI and obesity for detection of NAFLD in women (p < 0.001) but not in men (p = 0.679). The cutoff values of FLI in non-obese/obese men and women were 22.6/52.6 and 11.2/33.2, respectively. In conclusion, the cutoff value of FLI for prediction of NAFLD in Japanese individuals was lower than that in the original study, and there is a significant sex difference. The simple and useful cutoff values in Japanese men and women are FLI ≥35 (non-obese/obese: 23/53) and FLI ≥16 (non-obese/obese: 11/33), respectively.

Circulating level of fatty acid-binding protein 4 is an independent predictor of metabolic dysfunction-associated fatty liver disease in middle-aged and elderly individuals

Aims/Introduction

Metabolic dysfunction‐associated fatty liver disease (MAFLD), defined as hepatosteatosis with type 2 diabetes mellitus, overweight/obesity or metabolic dysregulation, has been proposed as a new feature of chronic liver disease. Fatty acid‐binding protein 4 (FABP4) is expressed in adipose tissue, and secreted FABP4 is associated with the development of insulin resistance and atherosclerosis. However, the relationship between MAFLD and FABP4 has not been fully addressed.

Materials and Methods

Associations of MAFLD with metabolic markers, including FABP4, fibroblast growth factor 21 and adiponectin, were investigated in 627 individuals (men/women 292/335) in the Tanno‐Sobetsu Study, a population‐based cohort.

Results

The mean age was 65 years (range 19–98 years, median [interquartile range] 68 [56–76] years). Hepatosteatosis was determined by the fatty liver index (FLI), and FLI ≥35 for men and FLI ≥16 for women were used for detection of fatty liver, as previously reported using 14,471 Japanese individuals. FLI was positively correlated with systolic blood pressure and levels of FABP4 (r = 0.331, P < 0.001), fibroblast growth factor 21, homeostasis model assessment of insulin resistance as an insulin resistance index and uric acid, and was negatively correlated with levels of high‐density lipoprotein cholesterol and adiponectin. FABP4 concentration was independently associated with FLI after adjustment of age, sex, systolic blood pressure and levels of uric acid, high‐density lipoprotein cholesterol, homeostasis model assessment of insulin resistance, adiponectin and fibroblast growth factor 21 in multivariable regression analysis. Logistic regression analysis showed that FABP4 was an independent predictor of MAFLD after adjustment of age, sex, presence of diabetes mellitus, hypertension and dyslipidemia, and levels of uric acid, homeostasis model assessment of insulin resistance, adiponectin and fibroblast growth factor 21.

Conclusions

FABP4 concentration is independently associated with FLI and is an independent predictor of MAFLD in middle‐aged and elderly individuals.

Independent Association of Fatty Liver Index With Left Ventricular Diastolic Dysfunction in Subjects Without Medication

Nonalcoholic fatty liver disease has been reported to be potentially linked to cardiovascular disease. Fatty liver index (FLI) is a noninvasive and simple predictor of nonalcoholic fatty liver disease. However, little is known about the relationship between FLI and cardiac function, especially in a general population. We investigated the relationships of FLI with echocardiographic parameters in 185 subjects (men/women: 79/106) of the Tanno-Sobetsu Study, a population-based cohort, who were not being treated with any medication and who underwent echocardiography. FLI was negatively correlated with high-density lipoprotein cholesterol and peak myocardial velocity during early diastole (e'; r = -0.342, p <0.001), an index of left ventricular (LV) diastolic function, and ratio of peak mitral velocities during early and late diastole (E/A) and was positively correlated with age, systolic and diastolic blood pressures, creatinine, uric acid, homeostasis model assessment of insulin resistance, high-sensitivity C-reactive protein, ratio of mitral to myocardial early diastolic peak velocity (E/e'), left atrial volume index and LV mass index. No significant correlation was found between FLI and LV ejection fraction. Stepwise multivariable regression analysis showed that FLI was independently and negatively associated with e' after adjustment of age, gender, high-density lipoprotein cholesterol, homeostasis model assessment of insulin resistance, and high-sensitivity C-reactive protein. Conversely, e' was independently and negatively associated with FLI after adjustment of age, gender, systolic blood pressure, and LV ejection fraction. In conclusion, elevated FLI is independently associated with LV diastolic dysfunction in a general population without medication. FLI would be a novel marker of LV diastolic dysfunction as an early sign of myocardial injury.

Circulating PCSK7 Level is Independently Associated with Obesity, Triglycerides Level and Fatty Liver Index in a General Population without Medication

AIM

Dyslipidemia and altered iron metabolism are typical features of non-alcoholic fatty liver disease (NAFLD). Proprotein convertase subtilisin/kexin type 7 (PCSK7), a transmembrane-anchored endonuclease, is associated with triglycerides level and processing of transferrin receptor 1. However, the significance of circulating PCSK7 has not been fully addressed, though prosegment PCSK7 is secreted from cells. We investigated the associations of plasma PCSK7 level with several parameters.

METHODS

Plasma PCSK7 concentration was measured in 282 subjects (male/female: 126/156) without medication of the Tanno-Sobetsu Study, a population-based cohort study.

RESULTS

There was no significant sex difference in PCSK7 level. Current smoking habit, but not alcohol drinking habit, was associated with increased PCSK7 level. PCSK7 concentration was negatively correlated with age and blood urea nitrogen and was positively correlated with body mass index (BMI) and levels of γ-glutamyl transpeptidase (γGTP), triglycerides and fatty liver index (FLI), which is calculated by BMI, waist circumference and levels of γGTP and triglycerides, as a noninvasive and simple predictor of NAFLD. There were no significant correlations of PCSK7 level with levels of iron and plasma PCSK9, a secreted PCSK family member and a regulator of low-density lipoprotein cholesterol level. Multivariable regression analyses after adjustment of age, sex and current smoking habit showed that PCSK7 concentration was independently associated with BMI (β=0.130, P=0.035), triglycerides (β=0.141, P=0.027) or FLI (β=0.139, P=0.030).

CONCLUSIONS

Plasma PCSK7 concentration is independently associated with chronic liver disease including obesity and elevated triglycerides level in a general population of individuals who had not regularly taken any medications.