Heart valve calcification in patients with type 2 diabetes and nonalcoholic fatty liver disease.

PURPOSE: Aortic valve sclerosis (AVS) and mitral annulus calcification (MAC) are two powerful predictors of adverse cardiovascular outcomes in patients with type 2 diabetes, but the etiology of valvular calcification is uncertain. Nonalcoholic fatty liver disease (NAFLD) is an emerging cardiovascular risk factor and is very common in type 2 diabetes, but whether NAFLD is associated with valvular calcification in this group of patients is presently unknown. METHODS: We undertook a cross-sectional study of 247 consecutive type 2 diabetic outpatients with no previous history of heart failure, valvular heart diseases (aortic stenosis, mitral stenosis, moderate or severe aortic and mitral regurgitation) or hepatic diseases. Presence of MAC and AVS was detected by echocardiography. NAFLD was diagnosed by ultrasonography. RESULTS: Overall, 139 (56.3%) patients had no heart valve calcification (HVC-0), 65 (26.3%) patients had one valve affected (HVC-1) and 43 (17.4%) patients had both valves affected (HVC-2). 175 (70.8%) patients had NAFLD and the prevalence of this disease markedly increased in patients with HVC-2 compared with either HVC-1 or HVC-0 (86.1% vs. 83.1% vs. 60.4%, respectively; p < 0.001). NAFLD was significantly associated with AVS and/or MAC (unadjusted-odds ratio 3.51, 95% CI 1.89-6.51, p < 0.001). Adjustments for age, sex, waist circumference, smoking, blood pressure, hemoglobin A1c, LDL-cholesterol, kidney function parameters, medication use and echocardiographic variables did not appreciably weaken this association (adjusted-odds ratio 2.70, 95% CI 1.23-7.38, p < 0.01). CONCLUSIONS: Our results show that NAFLD is an independent predictor of cardiac calcification in both the aortic and mitral valves in patients with type 2 diabetes.

Association of nonalcoholic fatty liver disease with QTc interval in patients with type 2 diabetes.

BACKGROUND AND AIMS: The relationship between nonalcoholic fatty liver disease (NAFLD) and prolonged heart rate-corrected QT (QTc) interval, a risk factor for ventricular arrhythmias and sudden cardiac death, is currently unknown. We therefore examined the relationship between NAFLD and QTc interval in patients with type 2 diabetes. METHODS AND RESULTS: We studied a random sample of 400 outpatients with type 2 diabetes. Computerized electrocardiograms were performed for analysis and quantification of QTc interval. NAFLD was diagnosed by ultrasonographic detection of hepatic steatosis in the absence of other liver diseases. Mean QTc interval and the proportion of those with increased QTc interval (defined as either QTc interval above the median, i.e. ≥416 ms, or QTc interval >440 ms) increased steadily with the presence and ultrasonographic severity of NAFLD. NAFLD was associated with increased QTc interval (odds ratio [OR] 2.16, 95% CI 1.4-3.4, p < 0.001). Adjustments for age, sex, smoking, alcohol consumption, BMI, hypertension, electrocardiographic left ventricular hypertrophy, diabetes-related variables and comorbid conditions did not attenuate the association between NAFLD and increased QTc interval (adjusted-OR 2.26, 95% CI 1.4-3.7, p < 0.001). Of note, the exclusion of those with established coronary heart disease or peripheral artery disease from analysis did not appreciably weaken this association. CONCLUSION: This is the first study to demonstrate that the presence and severity of NAFLD on ultrasound is strongly associated with increased QTc interval in patients with type 2 diabetes even after adjusting for multiple established risk factors and potential confounders.

Nonalcoholic fatty liver disease is associated with aortic valve sclerosis in patients with type 2 diabetes mellitus.

BACKGROUND: Recent epidemiological data suggest that non-alcoholic fatty liver disease (NAFLD) is closely associated with aortic valve sclerosis (AVS), an emerging risk factor for adverse cardiovascular outcomes, in nondiabetic and type 2 diabetic individuals. To date, nobody has investigated the association between NAFLD and AVS in people with type 2 diabetes, a group of individuals in which the prevalence of these two diseases is high. METHODS AND RESULTS: We recruited 180 consecutive type 2 diabetic patients without ischemic heart disease, valvular heart disease, hepatic diseases or excessive alcohol consumption. NAFLD was diagnosed by liver ultrasonography whereas AVS was determined by conventional echocardiography in all participants. In the whole sample, 120 (66.7%) patients had NAFLD and 53 (29.4%) had AVS. No patients had aortic stenosis. NAFLD was strongly associated with an increased risk of prevalent AVS (odds ratio [OR] 2.79, 95% CI 1.3-6.1, p<0.01). Adjustments for age, sex, duration of diabetes, diabetes treatment, body mass index, smoking, alcohol consumption, hypertension, dyslipidemia, hemoglobin A1c and estimated glomerular filtration rate did not attenuate the strong association between NAFLD and risk of prevalent AVS (adjusted-OR 3.04, 95% CI 1.3-7.3, p = 0.01). CONCLUSIONS: Our results provide the first demonstration of a positive and independent association between NAFLD and AVS in patients with type 2 diabetes mellitus.

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.

Relationship between abnormal microvolt T-wave alternans and poor glycemic control in type 2 diabetic patients.

BACKGROUND: Abnormal microvolt T-wave alternans (TWA) predicts the risk of ventricular arrhythmias and sudden cardiac death. Although type 2 diabetes is associated with an increased risk of these events, there is a dearth of available data on microvolt TWA measurements in type 2 diabetic populations. METHODS: We studied 59 consecutive type 2 diabetic outpatients without manifest cardiovascular disease (CVD) and 35 non-diabetic controls who were matched for age, sex, and blood pressure values. Microvolt TWA analysis was performed non-invasively using the CH-2000 system during a sub-maximal exercise with the patient sitting on a bicycle ergometer. RESULTS: The frequency of abnormal TWA was significantly higher in diabetic patients than in controls (25.4 vs 5.7%; P < 0.01). Among diabetic patients, those with abnormal TWA (n = 15) had remarkably higher hemoglobin A1c (HbA1c) (8.1 +/- 0.9 vs 7.1 +/- 0.8%, P < 0.001) and slightly smaller time-domain heart rate variability parameters (i.e., RMSSD, root mean square of difference of successive R-R intervals) than those with normal TWA (n = 44). Gender, age, body mass index, lipids, blood pressure values, cigarette smoking, diabetes duration, microvascular complication status, QTc interval, and current use of medications did not significantly differ between the groups. In multivariate regression logistic analysis, HbA1c (OR 13.6, 95% CI 2.0-89.1; P = 0.0076) predicted abnormal TWA independent of RMSSD values and other potential confounders. CONCLUSIONS: Our findings suggest that abnormal TWA is a very common condition (approximately 25%) among people with type 2 diabetes without manifest CVD and is closely correlated to glycemic control.

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.

Associations between serum 25-hydroxyvitamin D3 concentrations and liver histology in patients with non-alcoholic fatty liver disease.

BACKGROUND AND AIM: To explore associations between serum 25-hydroxyvitamin D(3) [25(OH)D] concentrations and liver histology in patients with non-alcoholic fatty liver disease (NAFLD). METHODS AND RESULTS: We studied 60 consecutive patients with biopsy-proven NAFLD, and 60 healthy controls of comparable age, sex and body mass index (BMI). NAFLD patients had a marked decrease in winter serum 25(OH)D concentrations (51.0+/-22 vs. 74.5+/-15 nmol/L, P<0.001) compared with controls. Metabolic syndrome (MetS; as defined by the Adult Treatment Panel III criteria) and its individual components occurred more frequently among NAFLD patients. The marked differences in 25(OH)D concentrations observed between the groups were little affected by adjustment for age, sex, BMI, creatinine, calcium, homeostasis model assessment (HOMA)-insulin resistance, and the presence of the MetS. Interestingly, among NAFLD patients, decreased 25(OH)D concentrations were closely associated with the histological severity of hepatic steatosis, necroinflammation and fibrosis (P<0.001 for all) independent of age, sex, BMI, creatinine, calcium, HOMA-insulin resistance, and presence of the MetS. CONCLUSIONS: Compared with controls, NAFLD patients have a marked decrease in serum 25(OH)D concentrations, which is closely associated with histopathological features of NAFLD. Further investigation into whether vitamin D(3) may play a role in the development and progression of NAFLD appears to be warranted.

Serum 25-hydroxyvitamin D3 concentrations and carotid artery intima-media thickness among type 2 diabetic patients.

OBJECTIVE: To estimate the prevalence of hypovitaminosis D among type 2 diabetic adults and to assess the relationship between hypovitaminosis D and intimal medial thickening (IMT) of the common carotid artery, a marker of preclinical atherosclerosis. DESIGN, PATIENTS AND MEASUREMENTS: We compared winter serum 25-hydroxyvitamin D3 [25(OH)D] concentrations in 390 consecutive type 2 diabetic patients and 390 nondiabetic controls who were comparable for age and sex. Common carotid IMT was measured with ultrasonography only in diabetic patients by a single trained operator blinded to subjects' details. RESULTS: The prevalence of hypovitaminosis D (i.e. 25(OH)D

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.

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 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.

HOMA-estimated insulin resistance is an independent predictor of cardiovascular disease in type 2 diabetic subjects: prospective data from the Verona Diabetes Complications Study.

OBJECTIVE: To evaluate whether homeostasis model assessment-estimated insulin resistance (HOMA-IR) is an independent predictor of cardiovascular disease (CVD) in type 2 diabetes. RESEARCH DESIGN AND METHODS: Conventional CVD risk factors (sex, age, smoking, plasma lipids, blood pressure, and metabolic control) and insulin resistance (estimated by HOMA) were evaluated at baseline in 1,326 patients with type 2 diabetes examined within the Verona Diabetes Complications Study. At baseline and after a mean follow-up of 4.5 years, CVD was assessed by medical history, physical examination, electrocardiography, and echo-Doppler of carotid and lower limb arteries. Death certificates and medical records of subjects who died during the follow-up were carefully scrutinized to identify cardiovascular deaths. In statistical analyses, CVD was an aggregate end point including both fatal and nonfatal coronary, cerebrovascular, and peripheral vascular disease as well as ischemic electrocardiographic abnormalities and vascular lesions identified by echo-Doppler. RESULTS: At baseline, 441 subjects were coded positive for CVD (prevalent cases). Incident cases numbered 126. Multiple logistic regression analyses showed that, along with sex, age, smoking, HDL/total cholesterol ratio, and hypertension, HOMA-IR was an independent predictor of both prevalent and incident CVD. A 1-unit increase in (log)HOMA-IR value was associated with an odds ratio for prevalent CVD at baseline of 1.31 (95% CI 1.10-1.56, P = 0.002) and for incident CVD during follow-up of 1.56 (95% CI 1.14-2.12, P < 0.001). CONCLUSIONS: HOMA-IR is an independent predictor of CVD in type 2 diabetes. The improvement of insulin resistance might have beneficial effects not only on glucose control but also on CVD in patients with type 2 diabetes.