Associations between nonalcoholic fatty liver disease and subclinical atherosclerosis in middle-aged adults: the Coronary Artery Risk Development in Young Adults Study

Association of Non-alcoholic Fatty Liver Disease with Metabolic Syndrome Independently of Central Obesity and Insulin Resistance

Non-alcoholic fatty liver disease (NAFLD) is an emerging chronic liver disease that may lead to liver cirrhosis and hepatocellular carcinoma. We aimed to determine the association between the prevalence of metabolic syndrome (MetS) and NAFLD severity using semi-quantitative ultrasonography (US). A total of 614 participants were recruited from the community. NAFLD was evaluated according to the ultrasonographic Fatty Liver Indicator (US-FLI), which is a semi-quantitative liver ultrasound score. Insulin resistance was estimated with the homeostasis model assessment index for insulin resistance (HOMA-IR). NAFLD and MetS were found in 53.7 and 17.3% of the participants, respectively. Linear relationships were found between the severity of NAFLD and waist circumference, fasting glucose, HOMA-IR, triglycerides, HDL-C and blood pressure. After adjusting for confounding factors, i.e., body mass index and HOMA-IR, the odds ratios for MetS were 3.64 (95% confidence interval (CI): 1.5-8.83) for those with mild NAFLD and 9.4 (95% CI: 3.54-24.98) for those with moderate-to-severe NAFLD compared to those without NAFLD. The combination of the HOMA-IR and US-FLI scores better differentiated MetS than the HOMA-IR alone. In addition to obesity, the severity of NAFLD and the HOMA-IR both play important roles in MetS. Whether NAFLD is a component of MetS warrants further research.

Comparison of the Phenotype and Approach to Pediatric vs Adult Patients With Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the main chronic noncommunicable diseases in Westernized societies; its worldwide prevalence has doubled during the last 20 years. NAFLD has serious health implications not only for adults, but also for children. However, pediatric NAFLD is not only an important global problem in itself, but it is likely to be associated with increases in comorbidities, such as metabolic syndrome and cardiovascular diseases. There are several differences between NAFLD in children and adults, and it is not clear whether the disease observed in children is the initial phase of a process that progresses with age. The increasing prevalence of pediatric NAFLD has serious implications for the future adult population requiring appropriate action. Studies of NAFLD progression, pathogenesis, and management should evaluate disease phenotypes in children and follow these over the patient's lifetime. We review the similarities and differences of NAFLD between children and adults.

Nonalcoholic Fatty Liver Disease is Associated with Increased Carotid Intima-Media Thickness in Type 1 Diabetic Patients

A growing body of evidence suggests that NAFLD is associated with an increased risk of incident CVD events both in patients without diabetes and in those with type 2 diabetes (T2DM). However, no published data are available regarding the association between NAFLD and C-IMT in T1DM. A total of 722 patients (371 men) with T1DM were included in this cross-sectional study. The main outcome measures were detection of NAFLD, C-IMT and classical risk factors. The mean age of the subjects was 46.2 years, and 51.1% were male. The prevalence of NAFLD was 15.9%. NAFLD patients had a markedly greater C-IMT (0.81 ± 0.25 vs. 0.69 ± 0.18 mm; p < 0.001) and frequency of carotid plaque (28.9% vs. 16.9%; p < 0.05) than those without fatty liver. Moreover, the differences in C-IMT remained after adjusting for potential confounders. A stepwise linear regression analysis revealed that age (standardized β, 0.326; p < 0.001), NAFLD (standardized β, 0.151, p < 0.001), and hsCRP (standardized β, 0.115, p = 0.008) were independently associated with C-IMT in all subjects. Our data show NAFLD is associated with elevated C-IMT in T1DM independent of conventional cardiovascular disease risk factors.

Extrahepatic Complications of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is an important cause of liver disease that is often associated with the metabolic syndrome. There is a growing awareness that extrahepatic complications occur in individuals with NAFLD, especially an increased risk of cardiovascular disease. Development of diabetes mellitus, chronic kidney disease, colorectal cancer, and endocrinopathies has been linked to NAFLD. This article reviews the extrahepatic complications affecting individuals with NAFLD and the pathogenesis underlying their development.

Gestational Diabetes Mellitus Is Strongly Associated With Non-Alcoholic Fatty Liver Disease

OBJECTIVES

Insulin resistance is central to the development of non-alcoholic fatty liver disease (NAFLD), and gestational diabetes mellitus (GDM) is an early marker of insulin resistance. We hypothesized that a history of GDM would identify women at higher risk of NAFLD in middle age.

METHODS

Women from the multicenter Coronary Artery Risk Development in Young Adults (CARDIA) cohort study who delivered ≥1 birth, were free of diabetes prior to pregnancy(ies), and underwent CT quantification of hepatic steatosis 25 years following cohort entry (Y25: 2010-2011) were included (n=1,115). History of GDM by self-report, validated in a subsample by review of antenatal glucose testing, and metabolic risk factors were assessed prospectively. NAFLD was defined by liver attenuation (LA)≤40 Hounsfield Units on CT scan after exclusion of other causes of hepatic steatosis.

RESULTS

Of 1,115 women meeting selection criteria (57% black, 43% white, median age 25 years at baseline), 124 (11%) reported a history of GDM and 75 (7%) met the CT definition for NAFLD at year 25. The crude risk of NAFLD at the 25-year visit was significantly higher in women with GDM compared to those without (14 vs. 5.8%, OR: 2.56, 95% CI: 1.44-4.55, P<0.01). History of GDM remained associated with NAFLD (OR: 2.29, 95% CI: 1.23-4.27, P=0.01) after adjustment for covariates in multivariable logistic regression. Addition of incident diabetes mellitus (DM) into the final model attenuated the association between GDM and NAFLD (OR: 1.48, 95% CI: 0.73-3.02, P=0.28).

CONCLUSION

GDM is a risk marker for NAFLD and represents an opportunity to identify women at risk for NAFLD at a young age and may be mediated by the development of incident DM.

Nonalcoholic fatty liver disease as a multi-systemic disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. NAFLD includes a wide spectrum of liver conditions ranging from simple steatosis to nonalcoholic steatohepatitis and advanced hepatic fibrosis. NAFLD has been recognized as a hepatic manifestation of metabolic syndrome linked with insulin resistance. NAFLD should be considered not only a liver specific disease but also an early mediator of systemic diseases. Therefore, NAFLD is usually associated with cardiovascular disease, chronic kidney disease, type 2 diabetes, obesity, and dyslipidemia. NAFLD is highly prevalent in the general population and is associated with increased cardiovascular morbidity and mortality. The underlying mechanisms and pathogenesis of NAFLD with regard to other medical disorders are not yet fully understood. This review focuses on pathogenesis of NAFLD and its relation with other systemic diseases.

Extrahepatic Manifestations of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide with an increased prevalence of metabolic, macro- and microvascular complications. The primary causes of mortality in NAFLD are cardiovascular disease (CVD), malignancy and liver disease. NAFLD is a multisystem disease that affects a variety of extra-hepatic organ systems. The main focus of this review is to summarize the reported extra-hepatic associations, which include CVD, chronic kidney disease, obstructive sleep apnea, osteoporosis, psoriasis, colorectal cancer, iron overload and various endocrinopathies (e.g. type 2 diabetes mellitus, thyroid dysfunction, and polycystic ovarian syndrome). Due to the systemic manifestations of NAFLD patients require a multidisciplinary assessment and may benefit from more rigorous surveillance and early treatment interventions to decrease mortality related to malignancy or cardiometabolic diseases.

Aortic flow propagation velocity, epicardial fat thickness, and osteoprotegerin level to predict subclinical atherosclerosis in patients with nonalcoholic fatty liver disease

Objective:

Nonalcoholic fatty liver disease is the most common cause of liver dysfunction in Western countries and an independent risk factor for atherosclerotic heart disease. Appropriate noninvasive parameters are lacking for optimal risk stratification of cardiovascular disease in these patients. We evaluated several recently discovered noninvasive parameters for atherosclerosis in patients with nonalcoholic fatty liver disease: epicardial fat thickness, aortic flow propagation velocity, and osteoprotegerin level.

Methods:

Forty-one patients (27 men and 14 women; mean age, 37.9±8.9 years) with nonalcoholic fatty liver disease and 37 control subjects (17 men and 20 women; mean age, 34.5±8.6 years) were enrolled in this observational case-control study. Patients with nonalcoholic fatty liver disease diagnosed at a gastroenterology outpatient clinic were included. Patients with cardiac pathology other than hypertension were excluded. Epicardial fat thickness and aortic flow propagation velocity were measured by echocardiography. The serum concentration of osteoprotegerin was measured using a commercial enzyme-linked immunosorbent assay kit.

Results:

Nonalcoholic fatty liver disease patients exhibited a significantly lower aortic flow propagation velocity (155.17±30.00 vs. 179.00±18.14 cm/s, p=0.000) and significantly higher epicardial fat thickness (0.51±0.25 vs. 0.29±0.09 cm, p=0.000) than control subjects. Osteoprotegerin levels were higher, but not significant, in patients with nonalcoholic fatty liver disease (28.0±13.0 vs. 25.2±10.8 pg/mL, p=0.244). Binary logistic regression analysis showed that aortic flow propagation velocity (OR, –0.973; 95% CI, 0.947–0.999) and waist circumference (OR, –1.191; 95% CI, 1.088–1.303) were independent predictors of nonalcoholic fatty liver disease.

Conclusion:

In this study, epicardial fat thickness and osteoprotegerin level were higher and aortic flow propagation velocity was lower in patients with nonalcoholic fatty liver disease. Early detection of abnormal epicardial fat thickness and aortic flow propagation velocity may warrant a search for undetected cardiovascular disease in patients with nonalcoholic fatty liver disease. (Anatol J Cardiol 2016; 16: 974-9)

Cardiovascular risk assessment in the treatment of nonalcoholic steatohepatitis: a secondary analysis of the MOZART trial

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is associated with increased cardiovascular risk and mortality. No US Food and Drug Administration (FDA) approved therapies for NASH are available; clinical trials to date have not yet systematically assessed for changes in cardiovascular risk. This study examines the prospective utility of cardiovascular risk assessments, the Framingham risk score (FRS) and coronary artery calcium (CAC) score, as endpoints in a NASH randomized clinical trial, and assesses whether histologic improvements lead to lower cardiovascular risk.

METHODS

Secondary analysis of a 24-week randomized, double-blind, placebo-controlled trial (MOZART) in which 50 biopsy-proven NASH patients received oral ezetimibe 10 mg daily (n = 25) versus placebo (n = 25). Biochemical profiling, FRS, CAC scores, liver biopsies were obtained at baseline and endpoint.

RESULTS

Ezetimibe improved FRS whereas placebo did not (4.4 ± 6.2 to 2.9 ± 4.8, p = 0.038; 3.0 ± 4.4 to 2.9 ± 4.2, p = 0.794). CAC scores did not change with ezetimibe or placebo (180.4 ± 577.2 to 194.1 ± 623.9, p = 0.293; 151.4 ± 448.9 to 183.3 ± 555.7, p = 0.256). Ezetimibe improved FRS and CAC scores in more patients than placebo (48% versus 23%, p = 0.079, and 21% versus 0%, p = 0.090, respectively), though not significantly. No differences were noted in cardiovascular risk scores among histologic responders versus nonresponders.

CONCLUSIONS

Ezetimibe improved FRS whereas placebo did not. FRS and CAC scores improved in a greater proportion of patients with ezetimibe; this trend did not reach significance. These findings indicate the utility and feasibility of monitoring cardiovascular risk in a NASH trial. The utility of CAC scores may be higher in trials of longer duration (⩾52 weeks) and with older patients (age ⩾45). ClinicalTrials.gov registration: NCT01766713.

Relationship of epicardial fat thickness and nonalcoholic fatty liver disease to coronary artery calcification: From the CAESAR study

BACKGROUND

Epicardial fat and nonalcoholic fatty liver disease (NAFLD) are associated with subclinical atherosclerosis; however, the combined effect of both EAT and NAFLD on coronary artery calcium (CAC) is unclear.

OBJECTIVE

The present study was performed to evaluate the association of both epicardial fat thickness (EFT) and NAFLD with CAC.

METHODS

Among 2277 individuals enrolled in the CArdiometabolic risk, Epicardial fat, and Subclinical Atherosclerosis Registry (CAESAR) Study, 1473 individuals (1242 men, mean age, 44 ± 9 years) were included for analysis. Echocardiographic EFT and ultrasonographic fatty liver were measured. Individuals were divided into 4 groups according to EFT and NAFLD (group I: low EFT and without NAFLD; group II: low EFT and with NAFLD; group III: high EFT and without NAFLD; and group IV: high EFT and with NAFLD).

RESULTS

The median EFT value (interquartiles) was 3.17 mm (2.58 mm, 3.85 mm), and the prevalence of NAFLD and CACS >0 was 46.0% and 16.8%, respectively. The prevalence of CACS >0 was 7.9%, 16.8%, 18.0%, and 26.0% in group I, II, III, and IV, respectively (P < .001). On multivariate regression after adjusting for variables with a univariate relationship (P < .20), group IV had a significantly higher OR for CACS >0, and the OR in group III was marginally significant, compared to group I (1.458 [0.795, 2.672], 1.744 [0.999, 3.046], and 1.864 [1.041, 3.337] for groups II, III, and IV, respectively).

CONCLUSION

This study shows that both increased EFT and presence of NAFLD are associated with coronary artery calcification, and that increased EFT is more strongly related to CAC than NAFLD, in spite of NAFLD having greater cardiometabolic risk than EFT.

Subclinical atherosclerosis is associated with Epicardial Fat Thickness and hepatic steatosis in the general population

BACKGROUND AND AIMS

Abdominal obesity and hepatic steatosis are ectopic fat depots associated with Metabolic Syndrome (MetS). Epicardial Fat Thickness (EFT) is a newly discovered one, increasing with obesity, insulin resistance and MetS. Therefore we studied whether different ectopic fat markers, and EFT in particular, are associated with MetS and markers of subclinical cardiovascular disease.

METHODS AND RESULTS

868 subjects from the PLIC Study were included, EFT, aortic calcifications, carotid Intima-Media Thickness (c-IMT) and echocardiographic parameters were determined by ultrasound; extra-cardiac atherosclerotic lesions were defined in presence of plaques at both carotid and aortic levels. Hepatic steatosis degrees were defined according to a scoring system. Abdominal adiposity was determined using Dual X-ray Absorbimetry (DEXA). Independently from age, women showed higher EFT versus men (4.5 (0.20-9.00) mm vs 4.00 (0.10-8.00) mm, p = 0.013); EFT was thicker in post-menopausal women (independently from hormone-replacement therapy). EFT, liver steatosis and abdominal adiposity increased with MetS (p < 0.001). EFT was the only ectopic fat marker associated with cardiac dysfunction (OR = 1.340 [1.088-1.651 95% C.I., p = 0.006); liver steatosis and EFT were associated with extra-cardiac plaques (OR = 2.529 [1.328-4.819] 95% C.I., p < 0.001 and OR = 1.195 [1.008-1.299] 95% C.I., p = 0.042; respectively). On top of cardiovascular risk factors, only EFT improved the discrimination of subjects with cardiac dysfunction and atherosclerotic plaques.

CONCLUSIONS

EFT is associated with left ventricular dysfunction and subclinical atherosclerosis. Our data suggest that EFT may represent an additional tool for the stratification of cardiovascular risk.

Pathobiological Determinants of Atherosclerosis in Youth (PDAY) Risk Score in Young Adults Predicts Coronary Artery and Abdominal Aorta Calcium in Middle Age: The CARDIA Study

BACKGROUND

We explored whether, the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) coronary and abdominal risk scores measured at 18 to 30 years of age and changes in these scores would more strongly predict coronary artery calcium (CAC) and abdominal aortic calcium (AAC) assessed 25 years later, than scores measured 25 years later.

METHODS AND RESULTS

In the Coronary Artery Risk Development in Young Adults (CARDIA) study, 3008 participants had measurements of risk score components at 5-year intervals beginning at 18 to 30 years of age. CAC and AAC were assessed at 43 to 55 years of age. Odds ratios (ORs) for the presence and extent of CAC/AAC per/point higher score and c-statistics for predicting CAC/AAC were calculated. The prevalence of CAC was 28% and AAC was 53%. For each 1 point higher PDAY score, the odds of CAC were higher using baseline scores than year 25 scores (OR, 1.29; 95% confidence interval [CI], 1.25-1.33 versus OR, 1.12; 95% CI, 1.11-1.14). For AAC, ORs at years 0 and 25 were similar (OR, 1.29; 95% CI, 1.24-1.34 versus OR, 1.22; 95% CI, 1.19-1.26). C-statistic for CAC prediction was higher at year 0 than year 25 (0.731 versus 0.705) but similar at years 0 and 25 for AAC (0.665 versus 0.670). ORs for CAC were highest at baseline, and, for AAC, ORs were highest at year 10. Including change in PDAY scores with baseline scores improved prediction.

CONCLUSIONS

Atherosclerosis risk and change in risk assessed in young adulthood years before subclinical atherosclerosis imaging provide strong prediction of future subclinical atherosclerosis. CAC and AAC reflect chronic risk exposure in addition to risk measured at the time of study.

Progression of carotid vascular damage and cardiovascular events in non-alcoholic fatty liver disease patients compared to the general population during 10 years of follow-up

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) is associated not only with liver related morbidity and mortality but also with an increased risk of cardiovascular disease.

AIM

to evaluate in patients with NAFLD and in matched Controls after 10 years of follow-up 1 the incidence of major cardiovascular and cerebral events 2 the progression of vascular damage.

METHODS

Clinical and cardio-metabolic data were collected in 125 NAFLD patients and 250 age and gender matched Controls at baseline and 10 years later. Incidence of cardiovascular and cerebral events was recorded. By ultrasonography, carotid intima-media thickness (cIMT), presence of plaques and presence of fatty liver were evaluated.

RESULTS

25% of the overall series was lost to follow-up. Sixty-eight (37%) Controls developed steatosis. Major cardiovascular events were observed in thirty-five subjects (17/91 (19%) NAFLD and 18/182 (10%) Controls), with an estimated cumulative risk significantly higher in NAFLD than in Controls, log-rank test for equality of failure functions p = 0.007. At multivariate analysis, presence of plaques (hazard ratio 5.08 (95% C.I. 2.56-10.96) and of steatosis (hazard ratio 1.99 (1.01-3.94)) were the strongest predictors for cardiovascular events. Grade of steatosis, ALT and GGT levels were higher in NAFLD patients who developed cardiovascular events. cIMT value after 10 years was significantly higher in NAFLD than in Controls, but the mean progression rate was higher in Controls (0.015 and 0.006 mm/year, p = 0.001). In conclusion our results suggest that NAFLD has to be included among risk factors for cardiovascular damage and underline the utility to evaluate, once NAFLD is diagnosed, the presence of atherosclerotic lesions.

Impact of renal impairment on cardiovascular disease mortality after liver transplantation for nonalcoholic steatohepatitis cirrhosis

BACKGROUND & AIMS

Non-alcoholic steatohepatitis (NASH) is an independent risk factor for cardiovascular disease (CVD) morbidity after liver transplantation, but its impact on CVD mortality is unknown. We sought to assess the impact of NASH on CVD mortality after liver transplantation and to predict which NASH recipients are at highest risk of a CVD-related death following a liver transplant.

METHODS

Using the Organ Procurement and Transplantation Network database, we examined associations between NASH and post-liver transplant CVD mortality, defined as primary cause of death from thromboembolism, arrhythmia, heart failure, myocardial infarction or stroke. A physician panel reviewed cause of death.

RESULTS

Of 48 360 liver transplants (2/2002-12/2011), 5057 (10.5%) were performed for NASH cirrhosis. NASH recipients were more likely to be older, female, obese, diabetic and have history of renal failure or prior CVD vs. non-NASH (P < 0.001 for all). Although there was no difference in overall all-cause mortality (log-rank P = 0.96), both early (30-day) and long-term CVD-specific mortality was increased among NASH recipients (Odds ratio = 1.30, 95% Confidence interval (CI): 1.02-1.66; Hazard ratio = 1.42, 95% CI: 1.07-1.41 respectively). These associations were no longer significant after adjustment for pre-transplant diabetes, renal impairment or CVD. A risk score comprising age ≥55, male sex, diabetes and renal impairment was developed for prediction of post-liver transplant CVD mortality (c-statistic 0.60).

CONCLUSION

NASH recipients have an increased risk of CVD mortality after liver transplantation explained by a high prevalence of comorbid cardiometabolic risk factors that in aggregate identify those at highest risk of post-transplant CVD mortality.

Endocrine causes of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the industrialized world. The prevalence of NAFLD is increasing, becoming a substantial public health burden. NAFLD includes a broad spectrum of disorders, from simple conditions such as steatosis to severe manifestations such as fibrosis and cirrhosis. The relationship of NAFLD with metabolic alterations such as type 2 diabetes is well described and related to insulin resistance, with NAFLD being recognized as the hepatic manifestation of metabolic syndrome. However, NAFLD may also coincide with endocrine diseases such as polycystic ovary syndrome, hypothyroidism, growth hormone deficiency or hypercortisolism. It is therefore essential to remember, when discovering altered liver enzymes or hepatic steatosis on radiological exams, that endocrine diseases can cause NAFLD. Indeed, the overall prognosis of NAFLD may be modified by treatment of the underlying endocrine pathology. In this review, we will discuss endocrine diseases that can cause NALFD. Underlying pathophysiological mechanisms will be presented and specific treatments will be reviewed.

Hepatic fibrosis assessed using transient elastography independently associated with coronary artery calcification

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) has a close relationship with coronary atherosclerosis. We investigated the association between coronary atherosclerosis and liver fibrosis, represented as coronary artery calcification (CAC) score, and live stiffness (LS) value assessed using transient elastography (TE), respectively, in patients with NAFLD.

METHODS

Between January 2013 and March 2014, a total of 285 asymptomatic subjects without chronic liver and ischemic heart diseases who underwent comprehensive medical health check-up were recruited. NAFLD was defined as controlled attenuation parameter (CAP) ≥ 250 dB/m on TE.

RESULTS

The median age of the study population (men 161 and women 124) was 56 (interquartile [IQR], 50-63) years. Of these, 142 (49.8%) subjects had NAFLD. Among subjects with NAFLD, CAC score was independently correlated with the male gender (β = 0.230; P = 0.010), elevated erythrocyte sedimentation rate (β = 0.220; P = 0.019), reduced estimated glomerular filtration rate (β=-0.220; P = 0.004), increased left ventricular mass index (β = 0.226; P = 0.027), and higher LS values (β = 0.274; P < 0.001). In addition, alanine aminotransferase level (β = 0.214, P = 0.012) and CAC score (β = 0.311; P = 0.001) are the only independent factors associated with LS values in subjects with NAFLD.

CONCLUSIONS

Higher CAC score was independently correlated with LS values in subjects with NAFLD. However, it should be further investigated whether TE can be incorporated into a screening tool to identify the high-risk population for coronary artery disease.

Association of nonalcoholic fatty liver disease with subclinical myocardial remodeling and dysfunction: A population-based study

Nonalcoholic fatty liver disease (NAFLD) and heart failure (HF) are obesity-related conditions with high cardiovascular mortality. Whether NAFLD is independently associated with subclinical myocardial remodeling or dysfunction among the general population is unknown. We performed a cross-sectional analysis of 2,713 participants from the multicenter, community-based Coronary Artery Risk Development in Young Adults (CARDIA) study who underwent concurrent computed tomography (CT) quantification of liver fat and comprehensive echocardiography with myocardial strain measured by speckle tracking during the Year-25 examination (age, 43-55 years; 58.8% female and 48.0% black). NAFLD was defined as liver attenuation ≤40 Hounsfield units after excluding other causes of liver fat. Subclinical left ventricular (LV) systolic dysfunction was defined using values of absolute peak global longitudinal strain (GLS). Diastolic dysfunction was defined using Doppler and tissue Doppler imaging markers. Prevalence of NAFLD was 10.0%. Participants with NAFLD had lower early diastolic relaxation (e') velocity (10.8 ± 2.6 vs. 11.9 ± 2.8 cm/s), higher LV filling pressure (E/e' ratio: 7.7 ± 2.6 vs. 7.0 ± 2.3), and worse absolute GLS (14.2 ± 2.4% vs. 15.2 ± 2.4%) than non-NAFLD (P < 0.0001 for all). When adjusted for HF risk factors or body mass index, NAFLD remained associated with subclinical myocardial remodeling and dysfunction (P < 0.01). The association of NAFLD with e' velocity (β = -0.36 [standard error = 0.15] cm/s; P = 0.02), E/e' ratio (β = 0.35 [0.16]; P = 0.03), and GLS (β = -0.42 [0.18]%; P = 0.02) was attenuated after controlling for visceral adipose tissue. Effect modification by race and sex was not observed.

CONCLUSIONS

NAFLD is independently associated with subclinical myocardial remodeling and dysfunction and provides further insight into a possible link between NAFLD and HF.

Imaging methods for analyzing body composition in human obesity and cardiometabolic disease

Advances in the technological qualities of imaging modalities for assessing human body composition have been stimulated by accumulating evidence that individual components of body composition have significant influences on chronic disease onset, disease progression, treatment response, and health outcomes. Importantly, imaging modalities have provided a systematic method for differentiating phenotypes of body composition that diverge from what is considered normal, that is, having low bone mass (osteopenia/osteoporosis), low muscle mass (sarcopenia), high fat mass (obesity), or high fat with low muscle mass (sarcopenic obesity). Moreover, advances over the past three decades in the sensitivity and quality of imaging not just to discern the amount and distribution of adipose and lean tissue but also to differentiate layers or depots within tissues and cells is enhancing our understanding of distinct mechanistic, metabolic, and functional roles of body composition within human phenotypes. In this review, we focus on advances in imaging technologies that show great promise for future investigation of human body composition and how they are being used to address the pandemic of obesity, metabolic syndrome, and diabetes.

Association Between Quantity of Liver Fat and Cardiovascular Risk in Patients With Nonalcoholic Fatty Liver Disease Independent of Nonalcoholic Steatohepatitis

BACKGROUND & AIMS

The association between quantity of liver fat and the presence of metabolic syndrome needs to be assessed systematically. We aimed to determine the association between the quantity of liver fat and the presence of the metabolic syndrome in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD), independent of nonalcoholic steatohepatitis (NASH).

METHODS

We recruited 146 patients with well-characterized biopsy-proven NAFLD and 50 individuals without NAFLD (controls) to participate in a case-control study at the NAFLD Translational Research Unit at the University of California San Diego. Liver fat was quantified in patients with NAFLD and controls using an advanced magnetic resonance imaging-based biomarker, the proton-density-fat-fraction (MRI-PDFF). Patients with NAFLD were divided into groups based on whether they were above or below the median MRI-PDFF value (15.4% in patients with NAFLD); the MRI-PDFF value for controls was less than 5%. The primary outcome was the presence of the metabolic syndrome using Adult Treatment Panel III criteria without and with adjustment for the presence of NASH.

RESULTS

Compared with NAFLD patients with MRI-PDFF values below the median, and compared with controls, NAFLD patients with MRI-PDFF values above the median were more likely to have abdominal obesity (P < .0001), lower levels of high-density cholesterol (P < .0001), higher levels of triglycerides (P < .0001), and higher fasting glucose levels (P < .001). Compared with NAFLD patients with MRI-PDFF values below the median, NAFLD patients with MRI-PDFF above the median were more likely to have the metabolic syndrome (60.3% vs. 44.4%; P < .04), independent of biopsy-detected NASH.

CONCLUSIONS

Increased liver fat content in patients with NAFLD is associated with increased rates of the metabolic syndrome, independent of NASH. There appears to be an association between the quantity of liver fat and the risk for cardiovascular disease in patients with NAFLD.

Higher association of coronary artery calcification with non-alcoholic fatty liver disease than with abdominal obesity in middle-aged Korean men: the Kangbuk Samsung Health Study

BACKGROUND

It is uncertain whether non-alcoholic fatty liver disease (NAFLD) or abdominal obesity is more associated with atherosclerosis. The aim of this study was to determine whether NAFLD or abdominal obesity is more strongly associated with subclinical atherosclerosis represented by coronary artery calcification (CAC).

METHODS

A total of 21,335 male participants in a health screening program (mean age 41 years) were enrolled. Ultrasonographic measurements of fatty liver and multi-detector computed tomography were performed to determine the coronary artery calcium score (CACS). The presence of CAC was defined as CACS > 0. Subjects were divided into four groups according to the presence or absence of NAFLD and/or abdominal obesity as assessed by waist-hip ratio (WHR) > 0.9.

RESULTS

The presence of CAC was detected in 2,385 subjects (11.2%). The proportion of subjects with CAC was highest in the abdominal obesity only group (23.2%). After adjustment for age, diabetes history, hypertension, cigarette smoking, and physical inactivity, the odds ratio (OR) for CAC was the highest in the group with both abnormalities [1.465 (1.324-1.623)]. The NAFLD only group showed significantly increased OR for CAC compared to that in the abdominal obesity only group [1.286 (1.151-1.436) vs. 1.076 (0.939-1.233)].

CONCLUSION

Non-alcoholic fatty liver disease is more closely associated with CAC than abdominal obesity as assessed by the WHR. NAFLD could be considered an independent determinant of subclinical atherosclerosis as assessed by CAC.

Advanced fibrosis associates with atherosclerosis in subjects with nonalcoholic fatty liver disease

OBJECTIVE

Nonalcoholic fatty liver (NAFLD) with advanced fibrosis usually has a deteriorated prognosis, which was mainly attributed to cardiovascular cause. We investigated whether advanced fibrosis assessed by noninvasive fibrosis markers was associated with subclinical atherosclerosis in NAFLD patients.

METHODS

A total of 2550 participants with ultrasound confirmed NAFLD from a community based population study were included in the present analysis. NAFLD fibrosis score (NFS) derived from available parameters was calculated to assess severity of fibrosis of the NAFLD patients. The NAFLD patients with a NFS > 0.676 indicated of presence of advanced fibrosis. The carotid intima-media thickness (CIMT), carotid plaques and brachial-ankle pulse wave velocity (ba-PWV) were used as the indicators of early atherosclerosis.

RESULTS

NAFLD patients with advanced fibrosis had higher CIMT and ba-PWV, compared with those without fibrosis (CIMT: 0.65 versus 0.57 mm; ba-PWV: 1884 versus 1535 cm/s, both p < 0.0001). Participants with advanced fibrosis were more likely to have higher homeostasis model assessment of insulin resistance index (HOMA_IR, 3.28 versus 2.45, p < 0.0001). After adjusting the confounders, participants with advanced fibrosis associated with 1.98-folds increased risk for elevated CIMT, 2.28-folds increased risk for present carotid plaque and 2.68-folds increased risk for arterial stiffness, respectively, as compared to participants without fibrosis. After further adjustment for HOMA_IR, the positive associations did not appreciably change.

CONCLUSION

Advanced fibrosis indicated by NFS was positively associated with CIMT, presence of carotid plaque and arterial stiffness in the NAFLD patients, independent of conventional cardiometabolic risk factors and insulin resistance.

Nonalcoholic fatty liver disease as a risk factor of arterial stiffness measured by the cardioankle vascular index

Nonalcoholic fatty liver disease (NAFLD) is associated with risk factors for cardiovascular disease. The cardioankle vascular index (CAVI), a new measure of arterial stiffness, was recently developed and is independent of blood pressure. We investigated whether NAFLD is associated with arterial stiffness as measured using the CAVI in an apparently healthy population.A total of 2954 subjects without any known liver diseases were enrolled. NAFLD was diagnosed via typical ultrasonography. The clinical characteristics examined included age, sex, body mass index (BMI), waist circumference (WC), and the levels of aspartate aminotransferase, alanine aminotransferase, total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol triglycerides, and glucose. Arterial stiffness was defined using an age- and sex-specific threshold of the upper quartile of the CAVI.NAFLD was found in 1249 (42.3%) of the analyzed subjects. Using an age-, sex-, and BMI-adjusted model, NAFLD was associated with a 42% increase in the risk for arterial stiffness (highest quartile of the CAVI). The risk for arterial stiffness increased according to the severity of NAFLD (adjusted odds ratio [95% confidence interval], 1.27 [1.02 - 1.57] vs 1.78 [1.37 - 2.31], mild vs moderate-to-severe, respectively). When adjusted for other risk factors, including BMI, WC, smoking status, diabetes, and hypertension, these relationships remained statistically significant.Patients with NAFLD are at a high risk for arterial stiffness regardless of classical risk factors. The presence of cardiometabolic risk factors may attenuate the prediction of arterial stiffness by means of NAFLD presence. Thus, physicians should carefully assess subjects with NAFLD for atherosclerosis and associated comorbidities.

The association of nonalcoholic fatty liver disease, obesity, and metabolic syndrome, with systemic inflammation and subclinical atherosclerosis: the Multi-Ethnic Study of Atherosclerosis (MESA)

INTRODUCTION

We characterized the association of 3 metabolic conditions - obesity, metabolic syndrome, and nonalcoholic fatty liver disease (NAFLD) - with increased inflammation and subclinical atherosclerosis.

METHODS

We conducted cross-sectional analysis of 3976 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) with adequate CT imaging to diagnose NAFLD. Obesity was defined as BMI ≥ 30 kg/m(2), metabolic syndrome by AHA/NHLBI criteria, and NAFLD using non-contrast cardiac CT and a liver/spleen attenuation ratio (L/S) < 1. Increased inflammation was defined as high sensitivity C-reactive protein (hsCRP) ≥2 mg/L and subclinical atherosclerosis as coronary artery calcium (CAC) > 0. We studied the association of a stepwise increase in number of these metabolic conditions (0-3) with increased inflammation and CAC, stratifying results by gender and ethnicity.

RESULTS

Mean age of participants was 63 (±10) years, 45% were male, 37% white, 10% Chinese, 30% African American, and 23% were Hispanic. Adjusting for obesity, metabolic syndrome and traditional risk factors, NAFLD was associated with a prevalence odds ratio for hsCRP ≥2 mg/L and CAC >0 of 1.47 (1.20-1.79) and 1.37 (1.11-1.68) respectively. There was a positive interaction between female gender and NAFLD in the association with hsCRP ≥2 mg/L (p = 0.006), with no interaction by race. With increasing number of metabolic conditions, there was a graded increase in prevalence odds ratios of hsCRP ≥2 mg/L and CAC >0.

CONCLUSION

NAFLD is associated with increased inflammation and CAC independent of traditional risk factors, obesity and metabolic syndrome. There is a graded association between obesity, metabolic syndrome, and NAFLD with inflammation and CAC.

The association between physical activity and liver fat after five years of follow-up in a primary prevention multi-ethnic cohort

OBJECTIVE

Excess liver fat (LF) is associated with dyslipidemia, insulin resistance and cardiovascular disease. Evidence suggests that there is an independent relationship between physical activity (PA) and LF although little is known of the role of PA intensity in reducing LF. The purpose was to evaluate whether meeting PA guidelines, the amount of PA and the intensity of PA at baseline were associated with LF after five-years.

METHODS

Men and women (n=478) living in Vancouver, Canada of Aboriginal, Chinese, European or South Asian background completed baseline measurements in 2004-2005. Liver fat was assessed using CT scans at 5-year follow-up, and PA using a PA questionnaire at baseline as well as demographics and anthropometry.

RESULTS

In separate unadjusted models, meeting moderate-vigorous PA (MVPA) guidelines (p=0.009), vigorous PA (p=0.002) and MVPA (p=0.017) but not moderate PA (p=0.068) was predictive of LF at five years (p=0.009). In multiple linear regression models, when adjusted for covariates, meeting MVPA guidelines and MVPA with LF at five years was no longer significant (p>0.05) while vigorous PA remained significant (p=0.021).

CONCLUSION

Meeting PA guidelines through MVPA may not be adequate to prevent the accumulation of LF and PA guidelines may require revision. Vigorous PA should be encouraged to prevent LF accumulation.