Philippe Giral

Liver fibrosis in overweight patients

BACKGROUND & AIMS A common clinical issue is whether overweight patients with abnormal liver function test results should undergo liver biopsy. Although serious liver injury can occur, its prevalence and risk factors are not well known. METHODS Ninety-three consecutive patients with abnormal liver function tests (but without overt liver disease), body mass index (BMI) > 25 kg/m(2), and no alcoholic, viral, autoimmune, drug-induced, or genetic liver disease were retrospectively studied. Clinical, biological, and histological variables were tested for association with septal fibrosis or cirrhosis. RESULTS Septal fibrosis was present in 28 patients (30%) including cirrhosis in 10 (11%). Age >/= 50 years (odds ratio [OR], 14.1), BMI >/= 28 kg/m(2) (OR, 5.7), triglycerides >/= 1.7 mmol/L (OR, 5), and alanine aminotransferase (ALT) >/= 2N (OR, 4.6) were independently associated with septal fibrosis. Among histological features, septal fibrosis was strongly associated with necroinflammatory activity (OR, 44). A score combining age, BMI, triglycerides, and ALT had 100% negative predictive value for septal fibrosis when scoring 0 or 1 (100% sensitivity for a specificity of 47%). CONCLUSIONS Septal fibrosis occurs frequently in overweight patients with abnormal liver function tests. A clinicobiological score combining BMI, age, ALT, and triglycerides could improve selection of patients for liver biopsy.

Long-term efficacy of rosiglitazone in nonalcoholic steatohepatitis: Results of the fatty liver improvement by rosiglitazone therapy (FLIRT 2) extension trial†‡§

Short‐term trials of glitazones in nonalcoholic steatohepatitis (NASH) yielded controversial histological results. Longer treatment might result in additional improvement. After a 1‐year randomized trial, 53 patients underwent a control liver biopsy and were enrolled in an open‐label extension trial of rosiglitazone (RSG), 8 mg/day for 2 additional years. In all, 44 completed the extension phase including 40 with a third liver biopsy. Of these, 22 received placebo (PLB) in the randomized phase (PLB‐RSG), and 18 RSG (RSG‐RSG). During the 2‐year extension phase serum insulin decreased by 26%, homeostasis model assessment (HOMA) by 30%, and alanine aminotransferase (ALT) by 24%. However, there was no significant change in the mean NASH activity score (NAS) (3.8 ± 2.11 versus 3.68 ± 1.8), ballooning score, fibrosis stage (1.76 ± 1.18 versus 1.85 ± 1.19), or area of fibrosis by micromorphometry (4.43% ± 0.68 to 5.54% ± 0.68). In the PLB‐RSG group steatosis significantly decreased after 2 years of RSG (median decrease of 15%); in the RSG‐RSG group, after an initial decline in the first year of 20%, 2 additional years of RSG did not result in further improvement. Likewise, there was no improvement in the NAS score, ballooning, intralobular inflammation, fibrosis stage, or area of fibrosis with 2 additional years of RSG in the RSG‐RSG group. Conclusion: Rosiglitazone has a substantial antisteatogenic effect in the first year of treatment without additional benefit with longer therapy despite a maintained effect on insulin sensitivity and transaminase levels. This suggests that improving insulin sensitivity might not be sufficient in NASH and that additional targets of therapy for liver injury should be explored. (HEPATOLOGY 2009.)

Stimulation of Cholesterol Efflux by LXR Agonists in Cholesterol-Loaded Human Macrophages Is ABCA1-Dependent but ABCG1-Independent

Objective—Maintenance of cholesterol homeostasis in human macrophages is essential to prevent foam cell formation. We evaluated the relative contribution of the ABCA1 and ABCG1 transporters to cholesterol efflux from human macrophages, and of the capacity of LXR agonists to reduce foam cell formation by stimulating export of cellular cholesterol. Methods and Results—ABCG1 mRNA levels were strongly increased in acLDL-loaded THP-1 macrophages and in HMDM on stimulation with LXR agonists. However, silencing of ABCG1 expression using ABCG1-specific siRNA indicated that ABCG1 was not essential for cholesterol efflux to HDL in cholesterol-loaded human macrophages stimulated with LXR agonists. Indeed, ABCA1 was solely responsible for the stimulation of cholesterol efflux to HDL on LXR activation, as this effect was abolished in HMDM from Tangier patients. Furthermore, depletion of cellular ATP indicated that the LXR-induced export of cholesterol was an ATP-dependent transport mechanism in human macrophages. Finally, use of an anti–Cla-1 blocking antibody identified the Cla-1 receptor as a key component in cholesterol efflux to HDL from cholesterol-loaded human macrophages. Conclusion—Our data indicate that stimulation of cholesterol efflux to HDL by LXR agonists in human foam cells involves an ATP-dependent transport mechanism mediated by ABCA1 that it appears to be independent of ABCG1 expression.

Matrix metalloproteinases, inflammation and atherosclerosis: therapeutic perspectives

Abstract Matrix metalloproteinases (MMPs), also called matrixins, are proteinases that participate in extracellular matrix remodelling and degradation. Under normal physiological conditions, the activities of MMPs are precisely regulated at the level of transcription, of activation of the pro-MMP precursor zymogens and of inhibition by endogenous inhibitors (tissue inhibitors of metalloproteinases; TIMPs). Alteration in the regulation of MMP activity is implicated in diseases such as cancer, fibrosis, arthritis and atherosclerosis. The pathological effects of MMPs and TIMPs in cardiovascular diseases involve vascular remodelling, atherosclerotic plaque instability and left ventricular remodelling after myocardial infarction. Since excessive tissue remodelling and increased matrix metalloproteinase activity have been demonstrated during atherosclerotic lesion progression (including plaque disruption), MMPs represent a potential target for therapeutic intervention aimed at modification of vascular pathology by restoring the physiological balance between MMPs and TIMPs. This review describes the members of the MMP and TIMP families and discusses the structure, function and regulation of MMP activity; finally, pharmacological approaches to MMP inhibition are highlighted.

Measurements of carotid intima-media thickness and of interadventitia common carotid diameter improve prediction of cardiovascular events: results of the IMPROVE (Carotid Intima Media Thickness [IMT] and IMT-Progression as Predictors of Vascular Events in a High Risk European Population) study.

OBJECTIVES The goal of this study was to compare the performance of several measures of carotid intima-media thickness (C-IMT) as predictors of cardiovascular events (CVEs), and to investigate whether they add to the predictive accuracy of Framingham risk factors (FRFs). BACKGROUND Various markers of subclinical atherosclerosis have been identified as predictors of CVEs, but the most powerful variable is still under debate. METHODS A cohort study was carried out in 5 European countries. A total of 3,703 subjects (median age 64.4 years; 48% men) were followed-up for a median of 36.2 months, and 215 suffered a first CVE (incidence: 19.9/1,000 person-years). RESULTS All measures of C-IMT and the interadventitia common carotid artery diameter (ICCAD) were associated with the risk of CVEs, after adjustment for FRFs and therapies (all p < 0.005). The average of 8 maximal IMT measurements (IMT(mean-max)), alone or combined with ICCAD, classified events and non-events better than the common carotid mean IMT (net reclassification improvement [NRI]: +11.6% and +19.9%, respectively; both p < 0.01). Compared with classification based on FRFs alone, the NRI resulting from the combination of FRFs+ICCAD+IMT(mean-max) was +12.1% (p < 0.01). The presence of at least 1 plaque (maximum IMT >1.5 mm) performed significantly worse than composite IMTs that incorporated plaques (p < 0.001). Adjusted Kaplan-Meier curves showed that individuals with a FRS = 22.6% (cohort average), and both IMT(mean-max) and ICCAD above the median, had a 6.5% risk to develop a CVE over 3 years versus a 3.4% risk for those with the same FRS, and both IMT(mean-max) and ICCAD below the median. CONCLUSIONS A risk stratification strategy based on C-IMT and ICCAD as an adjunct to FRFs is a rational approach to prevention of cardiovascular disease.

Serum hyaluronan as a marker of liver fibrosis in chronic viral hepatitis C: effect of α-interferon therapy.

BACKGROUND/AIMS It has been suggested that increases in serum hyaluronan levels might be a marker of fibrosis in chronic viral hepatitis C. Patients receiving alpha-interferon therapy are an excellent model to determine the relationship between serum hyaluronan and liver fibrosis, since results suggest that alpha-interferon could reduce liver fibrosis. METHODS We studied the relationship between serum hyaluronan and histopathological indices of liver fibrosis, inflammation and necrosis, before and after alpha-interferon therapy (3 MU, three times weekly for 6 months), and the effect of treatment on serum hyaluronan and on histological liver fibrosis, in 52 patients. Hyaluronan levels were measured using a radiometric assay and the liver histopathological indices were scored according to the Knodell system. RESULTS The serum hyaluronan level correlated with the extent of liver fibrosis both before and after alpha-interferon therapy (p < 0.0001), but not with the histopathological indices of liver inflammation or necrosis. Parallel changes in serum hyaluronan and liver fibrosis occurred: serum hyaluronan levels fell significantly in patients in whom fibrosis improved (p < 0.01, n = 11), increased significantly in patients in whom fibrosis worsened (p < 0.05, n = 10), and did not change significantly in patients in whom fibrosis was unmodified (n = 31). Furthermore, fibrosis improved only when the antiviral effect of alpha-interferon was reflected by persistent normalization of serum alanine aminotransferase, although there was no correlation between serum hyaluronan levels and alanine aminotransferase activities. CONCLUSION Serum hyaluronan thus appears to be a non-invasive index of liver fibrosis.

Relationship between procollagen III aminoterminal propeptide and hyaluronan serum levels and histological fibrosis in primary biliary cirrhosis and chronic viral hepatitis C

The diagnostic values of aminoterminal propeptide of type III procollagen and hyaluronan serum levels were compared as markers of liver fibrosis in two chronic liver diseases of different etiologies and pathophysiologies, namely primary biliary cirrhosis and chronic viral hepatitis C. The results were analysed in terms of the histological extent of fibrosis. Both serum procollagen-III peptide and hyaluronan were elevated in patients with primary biliary cirrhosis and chronic viral hepatitis C (p < 0.0001) relative to control values. A positive correlation was found between serum procollagen-III peptide levels and the histological grade of fibrosis in primary biliary cirrhosis (p < 0.001) but not in chronic viral hepatitis C, while a strong correlation was found between serum hyaluronan levels and histological fibrosis in both primary biliary cirrhosis and chronic viral hepatitis C (p < 0.001), independent of age. These results suggest that, in chronic liver diseases, serum hyaluronan levels could be an important indicator of the extent of fibrosis and should be assayed to monitor the response to treatment in controlled clinical trials.

Apolipoprotein(a) genetic sequence variants associated with systemic atherosclerosis and coronary atherosclerotic burden but not with venous thromboembolism.

OBJECTIVES The purpose of this study is investigate the effects of variants in the apolipoprotein(a) gene (LPA) on vascular diseases with different atherosclerotic and thrombotic components. BACKGROUND It is unclear whether the LPA variants rs10455872 and rs3798220, which correlate with lipoprotein(a) levels and coronary artery disease (CAD), confer susceptibility predominantly via atherosclerosis or thrombosis. METHODS The 2 LPA variants were combined and examined as LPA scores for the association with ischemic stroke (and TOAST [Trial of Org 10172 in Acute Stroke Treatment] subtypes) (effective sample size [n(e)] = 9,396); peripheral arterial disease (n(e) = 5,215); abdominal aortic aneurysm (n(e) = 4,572); venous thromboembolism (n(e) = 4,607); intracranial aneurysm (n(e) = 1,328); CAD (n(e) = 12,716), carotid intima-media thickness (n = 3,714), and angiographic CAD severity (n = 5,588). RESULTS LPA score was associated with ischemic stroke subtype large artery atherosclerosis (odds ratio [OR]: 1.27; p = 6.7 × 10(-4)), peripheral artery disease (OR: 1.47; p = 2.9 × 10(-14)), and abdominal aortic aneurysm (OR: 1.23; p = 6.0 × 10(-5)), but not with the ischemic stroke subtypes cardioembolism (OR: 1.03; p = 0.69) or small vessel disease (OR: 1.06; p = 0.52). Although the LPA variants were not associated with carotid intima-media thickness, they were associated with the number of obstructed coronary vessels (p = 4.8 × 10(-12)). Furthermore, CAD cases carrying LPA risk variants had increased susceptibility to atherosclerotic manifestations outside of the coronary tree (OR: 1.26; p = 0.0010) and had earlier onset of CAD (-1.58 years/allele; p = 8.2 × 10(-8)) than CAD cases not carrying the risk variants. There was no association of LPA score with venous thromboembolism (OR: 0.97; p = 0.63) or intracranial aneurysm (OR: 0.85; p = 0.15). CONCLUSIONS LPA sequence variants were associated with atherosclerotic burden, but not with primarily thrombotic phenotypes.

Homocysteine and lipid lowering agents. A comparison between atorvastatin and fenofibrate in patients with mixed hyperlipidemia.

BACKGROUND Hyperhomocysteinemia is a risk factor for cardiovascular disease. Elevation in homocysteine levels has recently been demonstrated during lipid lowering treatment with fibrates. We compared the effect of a statin and a fibrate (atorvastatin and fenofibrate) on plasma levels of homocysteine and other thiol compounds in hyperlipidemic patients. METHOD AND RESULTS The study was of open randomized, parallel design with a preliminary screening phase, and a 6 week placebo period. After the placebo period, patients were allocated randomly to atorvastatin or fenofibrate for a 6 month period. Plasma thiols were assayed by high pressure liquid chromatography with fluorescence detection. There were 29 patients in the fenofibrate group and 24 in the atorvastatin group. Fenofibrate induced a significant increase in both homocysteine and cysteine plasma levels (+35.8 and +18%, respectively, P<0.0001); by contrast, cysteinylglycine remained stable. There were no significant changes in any thiol compounds in the atorvastatin group. Both treatments induced a significant decrease in uric acid, although fenofibrate was noticeably more effective than atorvastatin (-22.8 and -6.4%, respectively). Fenofibrate induced a non-significant increase in creatinine (12%) while atorvastatin reduced it (4.7%, NS). CONCLUSION Our study confirms that the induction of elevations in plasma homocysteine and cysteine levels are a distinct feature of the pleiotropic effects of fibrates. Further studies are needed not only to investigate the potential deleterious effects of this modification, but also to define the specific mechanism which underlies such fibrate-mediated action.

Perspectives in cholesterol-lowering therapy: The role of ezetimibe, a new selective inhibitor of intestinal cholesterol absorption

Low-density lipoprotein cholesterol (LDL-C) reduction is a key factor in preventing coronary heart disease (CHD), particularly in high-risk patients. The greatest reductions in CHD mortality and morbidity have been achieved with the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, more commonly known as statins.1 Optimal LDL-C levels have been set at 100 mg/dL and 115 mg/dL for high-risk patients by US and European guidelines, respectively.1 To achieve these therapeutic target values for LDL-C, statins have become a mainstay in the treatment of hyperlipidemia.1,2They are recommended as first-line pharmacological therapy in the majority of hyperlipidemic patients at increased risk of initial or recurrent manifestations of CHD.1,2 Nevertheless, in clinical practice, despite major improvement in lipid management, current strategies may have important limitations with regard to the reduction of LDL-C, as illustrated by the following case presentations. ### Case 1 A 51-year-old man showed evidence of an uncomplicated myocardial infarction. His body mass index was 25.5 kg/m2. At baseline, his LDL-C level was 260 mg/dL. Dietary counseling had been strictly applied in combination with simvastatin (40 mg) during the 6 months after the coronary event. The patient had shown poor tolerance to bile acid sequestrants. Despite this strategy, fasting plasma concentrations of relevant metabolic variables (in mg/dL) were as follows: glucose 99, total cholesterol (TC) 220, LDL-C 160, high-density lipoprotein cholesterol (HDL-C) 40, and triglycerides (TG) 100. To achieve therapeutic goals in such a clinical case, there are limited options. Doubling the daily dose of a statin up to 80 mg with either simvastatin or atorvastatin has little chance of decreasing LDL-C to the optimal target,2 and combination therapy with a fibrate may lead to myopathy, and bile acid sequestrants were poorly tolerated. Ten milligrams of ezetimibe was prescribed in combination with 40 mg of simvastatin. Three months later, …