Non-alcoholic fatty liver disease is associated with an increased incidence of atrial fibrillation in patients with type 2 diabetes.

BACKGROUND: The relationship between non-alcoholic fatty liver disease (NAFLD) and atrial fibrillation (AF) in type 2 diabetes is currently unknown. We examined the relationship between NAFLD and risk of incident AF in people with type 2 diabetes. METHODS AND RESULTS: We prospectively followed for 10 years a random sample of 400 patients with type 2 diabetes, who were free from AF at baseline. A standard 12-lead electrocardiogram was undertaken annually and a diagnosis of incident AF was confirmed in affected participants by a single cardiologist. At baseline, NAFLD was defined by ultrasonographic detection of hepatic steatosis in the absence of other liver diseases. During the 10 years of follow-up, there were 42 (10.5%) incident AF cases. NAFLD was associated with an increased risk of incident AF (odds ratio [OR] 4.49, 95% CI 1.6-12.9, p<0.005). Adjustments for age, sex, hypertension and electrocardiographic features (left ventricular hypertrophy and PR interval) did not attenuate the association between NAFLD and incident AF (adjusted-OR 6.38, 95% CI 1.7-24.2, p = 0.005). Further adjustment for variables that were included in the 10-year Framingham Heart Study-derived AF risk score did not appreciably weaken this association. Other independent predictors of AF were older age, longer PR interval and left ventricular hypertrophy. CONCLUSIONS: Our results indicate that ultrasound-diagnosed NAFLD is strongly associated with an increased incidence of AF in patients with type 2 diabetes even after adjustment for important clinical risk factors for AF.

Relationship between kidney function and liver histology in subjects with nonalcoholic steatohepatitis.

BACKGROUND AND OBJECTIVES: We assessed whether nonalcoholic steatohepatitis (NASH) diagnosed by liver biopsy is associated with decreased kidney function and whether such association is independent of insulin resistance and features of the metabolic syndrome. DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS: We enrolled 80 consecutive overweight patients with biopsy-proven NASH and 80 nonsteatotic control subjects who were matched for age, gender, and body mass index. Chronic kidney disease (CKD) was defined as the presence of estimated GFR (eGFR) of ≤60 ml/min per 1.73 m(2) and/or abnormal albuminuria (i.e., urinary albumin/creatinine ratio ≥30 mg/g). RESULTS: NASH patients had significantly (P < 0.001) lower eGFR (75.3 ± 12 versus 87.5 ± 6 ml/min per 1.73 m(2)) and a greater frequency of abnormal albuminuria (14 versus 2.5%) and CKD (25 versus 3.7%) than control subjects. The significant differences in eGFR, albuminuria, and CKD that were observed between the two groups were only slightly weakened after adjustment for age, gender, body mass index, smoking status, insulin resistance (by homeostasis model assessment), and components of the metabolic syndrome. Notably, histologic severity of NASH (i.e., fibrosis stage) was strongly associated with either decreasing eGFR or increasing albuminuria (P < 0.01 or less), independently of potential confounding factors. CONCLUSIONS: Our findings suggest that patients with biopsy-proven NASH have moderately decreased eGFR and a higher frequency of abnormal albuminuria and CKD than matched control subjects and that the severity of NASH histology is associated with decreased kidney function, independently of traditional risk factors, insulin resistance, and components of the metabolic syndrome.

Prevalence of non-alcoholic fatty liver disease and its association with cardiovascular disease in patients with type 1 diabetes.

BACKGROUND & AIMS: To estimate the prevalence of non-alcoholic fatty liver disease (NAFLD) in type 1 diabetic individuals, and to evaluate whether NAFLD is associated with increased prevalence of cardiovascular disease (CVD). METHODS: All patients with diagnosed type 1 diabetes with available liver ultrasound data (n=250), who regularly attended our diabetes clinic, were enrolled. Main study measures were detection of NAFLD (by patient history and liver ultrasound) and asymptomatic/symptomatic CVD (by patient history, chart review, electrocardiogram, and echo-Doppler scanning of carotid and lower limb arteries). RESULTS: The prevalence of NAFLD was 44.4%, and NAFLD was the most common cause (69.8%) of hepatic steatosis on ultrasound examination. Patients with NAFLD had a remarkably higher (p<0.001) age- and sex-adjusted prevalence of coronary (10.8% vs. 1.1%), cerebrovascular (37.3% vs. 5.5%) and peripheral (24.5% vs. 2.5%) vascular disease than their counterparts without NAFLD. In logistic regression analysis, NAFLD was associated with prevalent CVD (as composite endpoint), independently of age, sex, diabetes duration, hemoglobin A(1c), smoking history, systolic blood pressure, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and medication use (adjusted odds ratio 7.36, 95% confidence intervals 1.60-34.3, p<0.01). CONCLUSIONS: Our findings suggest that NAFLD is very common in type 1 diabetic subjects and is associated, independently of several confounding factors, with a higher prevalence of CVD. Future prospective studies are needed to evaluate whether NAFLD predicts incident CVD events in type 1 diabetes.

Increased risk of CKD among type 2 diabetics with nonalcoholic fatty liver disease.

It is unknown whether chronic kidney disease (CKD) is associated with nonalcoholic fatty liver disease among patients with type 2 diabetes. We followed 1760 outpatients with type 2 diabetes and normal or near-normal kidney function and without overt proteinuria for 6.5 yr for the occurrence of CKD (defined as overt proteinuria and/or estimated GFR <60 ml/min per 1.73 m(2)). During follow-up, 547 participants developed incident CKD. Nonalcoholic fatty liver disease, diagnosed by liver ultrasound and exclusion of other common causes of chronic liver disease, was associated with a moderately increased risk for CKD (hazard ratio 1.69; 95% confidence interval 1.3 to 2.6; P < 0.001). Adjustments for gender, age, body mass index, waist circumference, BP, smoking, diabetes duration, glycosylated hemoglobin, lipids, baseline estimated GFR, microalbuminuria, and medications (hypoglycemic, lipid-lowering, antihypertensive, or antiplatelet drugs) did not appreciably attenuate this association (hazard ratio 1.49; 95% confidence interval 1.1 to 2.2; P < 0.01). In conclusion, our findings suggest that nonalcoholic fatty liver disease is associated with an increased incidence of CKD in individuals with type 2 diabetes, independent of numerous baseline confounding factors.

NASH predicts plasma inflammatory biomarkers independently of visceral fat in men.

We assessed the differential contribution of nonalcoholic steatohepatitis (NASH) and visceral adiposity to nontraditional cardiovascular risk biomarkers in adult men. We enrolled 45 consecutive, overweight, male patients with biopsy-proven NASH, 45 overweight male patients without ultrasound-diagnosed hepatic steatosis, and 45 healthy male volunteers. All participants were matched for age; NASH and overweight patients were also matched for BMI and visceral adiposity (as estimated by abdominal ultrasonography). Nontraditional cardiovascular risk biomarkers were measured in all participants. Plasma concentrations of high-sensitivity C-reactive protein (hs-CRP), fibrinogen, plasminogen activator inhibitor-1 (PAI-1) activity, and adiponectin were markedly different among the groups; the lowest values (the highest for adiponectin) were in nonobese healthy subjects, intermediate in overweight nonsteatotic patients, and the highest (the lowest for adiponectin) in those with biopsy-proven NASH. The marked differences in these cardiovascular risk biomarkers that were observed between overweight and NASH patients were only slightly weakened after adjustment for age, BMI, smoking, plasma triglycerides, and insulin resistance (IR) as assessed by homeostasis model assessment (HOMA). In multivariate regression analysis, NASH and visceral adiposity predicted cardiovascular risk biomarkers independently of potential confounders. In conclusion, our results suggest that NASH can predict a more atherogenic risk profile in a manner that is partly independent from the contribution of visceral adiposity in adult men.

Differences and similarities in early atherosclerosis between patients with non-alcoholic steatohepatitis and chronic hepatitis B and C.

BACKGROUND/AIMS: To compare carotid intima-media thickness (IMT) - an index of early atherosclerosis - among patients with non-alcoholic steatohepatitis (NASH), patients with chronic hepatitis B (HBV) or C (HCV) and control subjects. METHODS: We studied 60 consecutive patients with biopsy-proven NASH, 60 patients with HCV, 35 patients with HBV, and 60 healthy controls who were comparable for age and sex. Common carotid IMT was measured with ultrasonography in all participants by a single operator blinded to subjects' characteristics. RESULTS: Carotid IMT measurements were markedly different among the groups; the lowest values were in controls, intermediate in patients with HBV or HCV, and highest in those with NASH (0.84+/-0.1 vs. 0.97+/-0.1 vs. 1.09+/-0.2 vs. 1.23+/-0.2mm, respectively; p<0.001). The marked differences in carotid IMT that were observed among the groups were little affected by adjustment for age, sex, body mass index, smoking, LDL cholesterol, insulin resistance (by homeostasis model assessment) and components of the Adult Treatment Panel III-defined metabolic syndrome. Concordantly, in logistic regression analysis, NASH, HBV and HCV predicted carotid IMT independent of potential confounders. CONCLUSIONS: These data suggest that NASH, HCV and HBV are strongly associated with early atherosclerosis independent of classical risk factors, insulin resistance and metabolic syndrome components.

Prevalence of nonalcoholic fatty liver disease and its association with cardiovascular disease among type 2 diabetic patients.

OBJECTIVE: To determine the prevalence of nonalcoholic fatty liver disease (NAFLD) in type 2 diabetic population and to compare the prevalence of cardiovascular disease (CVD) and its risk factors between people with and without NAFLD. RESEARCH DESIGN AND METHODS: The entire sample of type 2 diabetic outpatients (n = 2,839) who regularly attended our clinic was screened. Main outcome measures were NAFLD (by patient history and liver ultrasound) and manifest CVD (by patient history, review of patient records, electrocardiogram, and echo-Doppler scanning of carotid and lower limb arteries). RESULTS: The unadjusted prevalence of NAFLD was 69.5% among participants, and NAFLD was the most common cause (81.5%) of hepatic steatosis on ultrasound examination. The prevalence of NAFLD increased with age (65.4% among participants aged 40-59 years and 74.6% among those aged > or = 60 years; P < 0.001) and the age-adjusted prevalence of NAFLD was 71.1% in men and 68% in women. NAFLD patients had remarkably (P < 0.001) higher age and sex-adjusted prevalences of coronary (26.6 vs. 18.3%), cerebrovascular (20.0 vs. 13.3%), and peripheral (15.4 vs. 10.0%) vascular disease than their counterparts without NAFLD. In logistic regression analysis, NAFLD was associated with prevalent CVD independent of classical risk factors, glycemic control, medications, and metabolic syndrome features. CONCLUSIONS: NAFLD is extremely common in people with type 2 diabetes and is associated with a higher prevalence of CVD. Follow-up studies are needed to determine whether NAFLD predicts the development and progression of CVD.

Relations between carotid artery wall thickness and liver histology in subjects with nonalcoholic fatty liver disease.

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) is closely associated with several metabolic syndrome features. We assessed whether NAFLD is associated with carotid artery intima-media thickness (IMT) as a marker of subclinical atherosclerosis and whether such an association is independent of classical risk factors, insulin resistance, and metabolic syndrome features. RESEARCH DESIGN AND METHODS: We compared carotid IMT, as assessed by ultrasonography, in 85 consecutive patients with biopsy-proven NAFLD and 160 age-, sex-, and BMI-matched healthy control subjects. RESULTS: NAFLD patients had a markedly greater carotid IMT (1.14 +/- 0.20 vs. 0.82 +/- 0.12 mm; P < 0.001) than control subjects. The metabolic syndrome (according to Adult Treatment Panel III criteria) and its individual components were more frequent in those with NAFLD (P < 0.001). The marked differences in carotid IMT observed between the groups were only slightly weakened after adjustment for age, sex, BMI, smoking history, LDL cholesterol, insulin resistance (by homeostasis model assessment), and metabolic syndrome components. Notably, carotid IMT was strongly associated with degree of hepatic steatosis, necroinflammation, and fibrosis among NAFLD patients (P < 0.001 for all). Similarly, by logistic regression analysis, the severity of histological features of NAFLD independently predicted carotid IMT (P < 0.001) after adjustment for all potential confounders. CONCLUSIONS: These results suggest that the severity of liver histopathology among NAFLD patients is strongly associated with early carotid atherosclerosis, independent of classical risk factors, insulin resistance, and the presence of metabolic syndrome.

Associations between plasma adiponectin concentrations and liver histology in patients with nonalcoholic fatty liver disease.

OBJECTIVES: To explore associations between plasma adiponectin concentrations and liver histology in patients with nonalcoholic fatty liver disease (NAFLD). DESIGN AND PATIENTS: In a cross-sectional study, we enrolled 60 consecutive NAFLD patients and 60 age-, sex- and body mass index (BMI)-matched healthy controls. MEASUREMENTS: NAFLD (by liver biopsy), plasma adiponectin concentrations, insulin resistance (by homeostasis model assessment, HOMA-IR) and metabolic syndrome (MetS) features. RESULTS: NAFLD patients had a marked decrease in plasma adiponectin concentration (6.1 +/- 2.8 vs. 13.6 +/- 3.8 microg/ml, P < 0.001) compared with matched controls. MetS, as defined by the Adult Treatment Panel III (ATP III) criteria, and its individual components were more frequent among NAFLD patients. The marked differences in adiponectin concentrations that were observed between the groups were little affected by adjustment for age, sex, BMI, HOMA-IR score and MetS components. Notably, decreased adiponectin levels were closely associated with the degree of hepatic steatosis, necroinflammation and fibrosis (P < 0.001 for all) among NAFLD patients. By logistic regression analysis, low adiponectin levels independently predicted hepatic steatosis [odds ratio (OR) 2.3, 95% confidence interval (CI) 1.5-5.8, P < 0.001] and necroinflammation (OR 3.1, 95% CI 1.9-7, P < 0.001), but not fibrosis (P = 0.07), after adjustment for age, sex, BMI, HOMA-IR and MetS components. CONCLUSIONS: NAFLD patients have markedly lower plasma adiponectin concentrations than control subjects. Low adiponectin levels are strongly associated with the severity of liver histology, thus further supporting the hypothesis that adiponectin might be involved in the development of NAFLD.

Associations between liver histology and cortisol secretion in subjects with nonalcoholic fatty liver disease.

OBJECTIVES: To assess associations between the activity of hypothalamo-pituitary-adrenal (HPA) axis and liver histology in patients with nonalcoholic fatty liver disease (NAFLD). DESIGN AND PATIENTS: In a cross-sectional study, we enrolled 50 consecutive, overweight, NAFLD patients and 40 control subjects who were comparable for age, sex and body mass index (BMI). MEASUREMENTS: NAFLD (by liver biopsy), HPA axis activity (by 24-hour urinary free cortisol [UFC] excretion and serum cortisol levels after 1 mg dexamethasone), insulin resistance (by homeostasis model assessment: HOMA-IR), and metabolic syndrome (MetS) features. RESULTS: NAFLD patients had markedly higher (P < 0.001) 24-h UFC (149 +/- 24 vs. 90 +/- 16 nmol/day) and postdex suppression cortisol concentrations (32 +/- 10 vs. 16 +/- 7 nmol/l) than controls. The MetS and its individual components were more frequent among NAFLD patients. The marked differences in urinary/serum cortisol concentrations that were observed between the groups were little affected by adjustment for age, sex, BMI, waist circumference, systolic blood pressure, triglycerides, homeostasis model assessment for insulin resistance score and presence of diabetes. Importantly, 24-h UFC and postdex cortisol concentrations strongly correlated to hepatic necroinflammatory grade (P < 0.01) and fibrosis stage (P < 0.001) among NAFLD patients. By logistic regression analysis, 24-h UFC (odds ratio (OR) 1.80, 95%CI 1.3-2.8) or postdex cortisol concentrations (OR 1.95, 95%CI 1.4-3.1) independently predicted the severity of hepatic fibrosis, but not necroinflammation, after adjustment for potential confounders. CONCLUSIONS: These results suggest that NAFLD patients have a subtle, chronic overactivity in the HPA axis (that is closely associated with the severity of liver histopathology) leading to subclinical hypercortisolism that might be implicated in the development of NAFLD.

Nonalcoholic fatty liver disease and risk of future cardiovascular events among type 2 diabetic patients.

Nonalcoholic fatty liver disease (NAFLD) is closely correlated to several metabolic syndrome features. We assessed prospectively whether NAFLD predicts future cardiovascular disease (CVD) events among type 2 diabetic individuals, independent of metabolic syndrome features and other classical risk factors. We carried out a prospective nested case-control study in 2,103 type 2 diabetic patients who were free of diagnosed CVD at baseline. During 5 years of follow-up, 248 participants (case subjects) subsequently developed nonfatal coronary heart disease (myocardial infarction and coronary revascularization procedures), ischemic stroke, or cardiovascular death. Using risk-set sampling, 496 patients (control subjects) among those who remained free of diagnosed CVD during follow-up were randomly selected in a 2:1 ratio, matched for age and sex to the case subjects. After adjustment for age, sex, smoking history, diabetes duration, HbA1c, LDL cholesterol, liver enzymes, and use of medications, the presence of NAFLD was significantly associated with an increased CVD risk (odds ratio 1.84, 95% CI 1.4-2.1, P < 0.001). Additional adjustment for the metabolic syndrome (as defined by National Cholesterol Education Program Adult Treatment Panel III criteria) appreciably attenuated, but did not abolish, this association (1.53, 1.1-1.7, P = 0.02). In conclusion, NAFLD is significantly associated with a moderately increased CVD risk among type 2 diabetic individuals. This relationship is independent of classical risk factors and is only partly explained by occurrence of metabolic syndrome.