Review article: Drug therapy for non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease represents a spectrum of liver diseases, characterized mainly by macrovesicular steatosis in the absence of significant alcohol ingestion. Non-alcoholic fatty liver disease includes both non-alcoholic fatty liver and non-alcoholic steatohepatitis. Non-alcoholic steatohepatitis once considered a benign process is now known to lead to progressive fibrosis and cirrhosis. Histologically indistinguishable from alcoholic liver disease, the exact aetiology of non-alcoholic fatty liver disease remains unknown, but the fundamental pathophysiological process appears to be insulin resistance and oxidative stress related to the metabolic syndrome. Therapy has focused on risk factors, weight reduction and pharmacological intervention. Promising pharmacological treatments have been demonstrated with antioxidants, insulin sensitizers, hepatoprotectants and lipid-lowering agents. However, without larger randomized studies, no pharmacological treatments can be recommended at this time.

Supplemental Conditionally Essential Nutrients in Cardiovascular Disease Therapy

Conditionally essential nutrients (CENs) are organic compounds that are ordinarily produced by the body in amounts sufficient to meet its physiological requirements. However, in disorders, such as cardiovascular disease (CVD), and in other physiologically stressful conditions, their biosynthesis may be inadequate. Under these circumstances, CENs become essential nutrients, comparable to vitamins. The CENs of primary importance in CVD, based on the quantity and quality of human clinical studies, are l-arginine, l-carnitine, propionyl-l-carnitine, and coenzyme Q10. Controlled studies of these CENs are reviewed in depth. Taurine is a CEN of secondary importance caused by a limited human database. Other putative CENs include alpha-lipoic acid, betaine, chondroitin sulfate, glutamine, and d-ribose, each of which is mentioned in passing. Collectively, CENs have demonstrated favorable clinical effects in CVDs, including chronic heart failure, myocardial infarction, angina pectoris, and in CVD risk factors, such as hypertension, hyperlipidemia, and lipoprotein(a). Limited research has pointed to possible benefits in CVD therapy accruing from supplementation with several CENs in combination. Additional controlled clinical studies of CENs in CVD are urgently needed. In view of the efficacy and safety of appropriate supplementation with CENs, it is strongly suggested that healthcare professionals become knowledgeable of these potentially important additions to the CVD therapeutic armamentarium.

Effective use of combination lipid therapy

Despite the benefits of statin therapy, low-density lipoprotein cholesterol (LDL-C) management remains suboptimal and many patients do not achieve their recommended target goals. The aim of combination lipid drug therapy in high-risk patients is to achieve LDL-C and non-high-density lipoprotein cholesterol (HDL-C) goals with a minimum of serious adverse effects. Although statins are the drug of first choice, statin monotherapy may be limited by intolerance of dose escalation or failure to attain non-HDL-C goals in those with mixed hyperlipidemia. Statins plus bile acid resins or ezetimibe can achieve greater than 50% reduction in LDL-C, with little or no increase in adverse effects. Fibrates, niacin, and omega-3 fatty acids, when added to statins, can reduce triglycerides, increase HDL-C, and reduce non-HDL-C to a greater extent than statin monotherapy. The safety profile of combination lipid therapy is acceptable, if the global coronary heart disease risk of the patient is high, thus producing a favorable risk to benefit ratio. Careful surveillance of hepatic transaminases, avoidance of gemfibrozil in statin-fibrate combinations, and awareness of statin-concomitant drug interactions is key to safe and efficacious use of combination lipid drug therapy.

Prenatal and postnatal treatment in cobalamin C defect

OBJECTIVE

To evaluate prenatal treatment with hydroxycobalamin (OH-Cbl) in a pregnancy at risk for a severe form of the cobalamin C defect and postnatal treatment of the affected child.

STUDY DESIGN

Observational study with non-randomized intervention.

RESULTS

In contrast to reported pregnancies with affected fetuses in which maternal methylmalonic aciduria was found in the last trimester of pregnancy, there was no maternal methylmalonic aciduria in our case, given prenatal treatment with intramuscular OH-Cbl. We did not find that the concentration of odd long-chain fatty acids in cord blood erythrocytes reflects fetal methylmalonic academia. After birth, the infant was treated with intramuscular OH-Cbl and oral carnitine. Oral folate and betaine were added as adjunct therapy to decrease plasma total homocysteine. Because of inadequate metabolic control, a diet reduced in natural protein was introduced. The child had normal developmental milestones but had nystagmus, hyperpigmented retinopathy, and discrete truncal muscular hypotonia.

CONCLUSIONS

Despite prenatal and postnatal treatment, adequate metabolic control, absence of metabolic crises, and normal developmental milestones, this patient with the cobalamin C defect had characteristic symptoms of the disease.

Decreasing Oxidative Stress with Choline and Carnitine in Women

OBJECTIVE

Fatty acid oxidation is predominantly a mitochondrial event, which is enhanced by dietary choline and carnitine supplementation resulting in extra reactive oxygen species (ROS) load. The objective was to assess oxidative stress level by thiobarbituric acid reactive substances [TBARS] in choline and carnitine supplemented healthy women before and after mild exercise.

METHODS

Nineteen free-living women completed the placebo control study in which choline and/or L-carnitine was orally taken for 21 days. Anthropometric measurements, dietary recall, exercise routine and blood samples were analyzed to determine body composition, nutrients intake, distance walked and biochemical markers related to oxidative stress.

RESULTS

TBARS were significantly lower in the groups supplemented with choline, carnitine or both and the mild exercise (walking) was not a deterrent in this effect of the supplements. Serum vitamin A and E concentrations were higher in the supplemented groups even though the consumption of these nutrients was not different among the groups.

CONCLUSION

Choline and carnitine supplementation lowers lipid peroxidation, and promotes conservation of retinol and alpha-tocopherol in free-living women.

Effect of homocysteine-lowering nutrients on blood lipids: results from four randomised, placebo-controlled studies in healthy humans

BACKGROUND

Betaine (trimethylglycine) lowers plasma homocysteine, a possible risk factor for cardiovascular disease. However, studies in renal patients and in obese individuals who are on a weight-loss diet suggest that betaine supplementation raises blood cholesterol; data in healthy individuals are lacking. Such an effect on cholesterol would counteract any favourable effect on homocysteine. We therefore investigated the effect of betaine, of its precursor choline in the form of phosphatidylcholine, and of the classical homocysteine-lowering vitamin folic acid on blood lipid concentrations in healthy humans.

METHODS AND FINDINGS

We measured blood lipids in four placebo-controlled, randomised intervention studies that examined the effect of betaine (three studies, n = 151), folic acid (two studies, n = 75), and phosphatidylcholine (one study, n = 26) on plasma homocysteine concentrations. We combined blood lipid data from the individual studies and calculated a weighted mean change in blood lipid concentrations relative to placebo. Betaine supplementation (6 g/d) for 6 wk increased blood LDL cholesterol concentrations by 0.36 mmol/l (95% confidence interval: 0.25-0.46), and triacylglycerol concentrations by 0.14 mmol/l (0.04-0.23) relative to placebo. The ratio of total to HDL cholesterol increased by 0.23 (0.14-0.32). Concentrations of HDL cholesterol were not affected. Doses of betaine lower than 6 g/d also raised LDL cholesterol, but these changes were not statistically significant. Further, the effect of betaine on LDL cholesterol was already evident after 2 wk of intervention. Phosphatidylcholine supplementation (providing approximately 2.6 g/d of choline) for 2 wk increased triacylglycerol concentrations by 0.14 mmol/l (0.06-0.21), but did not affect cholesterol concentrations. Folic acid supplementation (0.8 mg/d) had no effect on lipid concentrations.

CONCLUSIONS

Betaine supplementation increased blood LDL cholesterol and triacylglycerol concentrations in healthy humans, which agrees with the limited previous data. The adverse effects on blood lipids may undo the potential benefits for cardiovascular health of betaine supplementation through homocysteine lowering. In our study phosphatidylcholine supplementation slightly increased triacylglycerol concentrations in healthy humans. Previous studies of phosphatidylcholine and blood lipids showed no clear effect. Thus the effect of phosphatidylcholine supplementation on blood lipids remains inconclusive, but is probably not large. Folic acid supplementation does not seem to affect blood lipids and therefore remains the preferred treatment for lowering of blood homocysteine concentrations.

Mycoplasma gallinarum infection in commercial layers and onset of fatty liver hemorrhagic syndrome

Fatty liver hemorrhagic syndrome (FLHS) was observed in each of three trials in which commercial layers were utilized to determine the effect of Mycoplasma gallinarum (MGn) on egg and eggshell quality parameters and egg production. In each of three trials, FLHS occurred 31-54 days later in MGn-inoculated hens as compared with the Mycoplasma-clean (control) hens. In trials 1 and 2, no therapeutic intervention was initiated to ameliorate FLHS. In trial 3, therapeutic intervention was instituted and consisted of the addition of 1 pound of choline chloride/ton of feed. Total mortality recorded throughout the duration of each trial and attributable to FLHS was not significantly different between the control and the MGn-inoculated treatment. However, FLHS-associated mortality in each of the three trials was numerically greater for the control treatment.

Combination therapy

Adult Treatment Panel III (ATP III) guidelines recommend specific treatment targets for low-density lipoprotein cholesterol (LDL-C) levels according to an individual.s short-term and long-term risk for coronary heart disease (CHD). Therapeutic lifestyle changes are recommended for all patients at any level of risk for CHD. Although most patients will achieve some LDL-C lowering with lifestyle modification, ATP III recognizes that a majority of patients with dyslipidemia will require drug therapy to reach their LDL goal. Surveys of physicians. practices suggest that only a small percentage of patients enrolled in an active treatment program actually achieve their LDL-C target. In addition, other surveys suggest that not all patients who are treatment candidates are receiving assessment. From a medication perspective, either up-titration of statin dose or the use of drug combinations should further enhance the likelihood of achieving target lipid levels. Combination therapies that target both the endogenous and exogenous pathways of cholesterol synthesis are particularly attractive. This paper reviews the pharmacotherapeutic effects of combination therapy, summarizes the strengths and weaknesses of current lipid-lowering drug combinations, and identifies the potential contribution of the novel cholesterol absorption inhibitor, ezetimibe, to the LDL-C treatment algorithm.

Overview of pharmacologic therapy for the treatment of dyslipidemia

Although the National Cholesterol Education Program Adult Treatment Panel III (ATP III) guidelines stress the importance of nonpharmacologic lipid modification interventions such as diet and exercise, the guidelines also recognize that many patients will require drug therapy to achieve low-density lipoprotein cholesterol (LDL-C) target goals. Currently available lipid-modifying drugs include bile acid sequestrants (or resins), fibrates, nicotinic acid, and statins, with each class exerting different effects on the lipid profile. In addition, nonprescription agents such as plant stanols and sterols have been shown to be effective in modifying plasma lipids. Of these agents, the statins are the most effective, most widely prescribed, and best-tolerated form of lipid-lowering drug therapy. New formulations of other drugs, such as niacin and bile acid sequestrants, can also improve treatment regimes and reduce side effects, thereby improving patient compliance with these therapies. In patients who have high levels of LDL-C and triglycerides together with low concentrations of high-density lipoprotein cholesterol (HDL-C), combination therapy may be required. Ezetimibe, a selective cholesterol absorption inhibitor, is the first of a new class of lipid-lowering agents and provides a new agent for the management of patients with dyslipidemia. Data from the ezetimibe clinical development program suggests that this agent can be used alone or in combination with statins to reduce LDL-C, improve compliance, and bring more patients to ATP III target goal.

Nonalcoholic fatty liver disease: relationship to insulin sensitivity and oxidative stress. Treatment approaches using vitamin E, magnesium, and betaine

Nonalcoholic steatotic hepatitis (NASH), the most prevalent form of progressive liver disease in the United States, is considered to be a manifestation of insulin resistance syndrome. There is increasing evidence that steatosis in NASH is a result of the pathology in fat metabolism occurring in obesity and insulin resistance. For steatosis to progress to necroinflammation and fibrosis, however, the theory of mitochondrial oxidative-stress induced cellular damage is receiving wide acceptance. Treatment approaches that address these etiologies are reviewed: betaine, magnesium, and vitamin E.

Drugs affecting homocysteine metabolism: impact on cardiovascular risk

Elevated total plasma homocysteine has been established as an independent risk factor for thrombosis and cardiovascular disease. A strong relationship between plasma homocysteine levels and mortality has been reported in patients with angiographically confirmed coronary artery disease. Homocysteine is a thiol containing amino acid. It can be metabolised by different pathways, requiring various enzymes such as cystathionine beta-synthase and methylenetetrahydrofolate reductase. These reactions also require several co-factors such as vitamin B6 and folate. Medications may interfere with these pathways leading to an alteration of plasma homocysteine levels. Several drugs have been shown to effect homocysteine levels. Some drugs frequently used in patients at risk of cardiovascular disease, such as the fibric acid derivatives used in certain dyslipidaemias and metformin in type 2 (non-insulin-dependent) diabetes mellitus, also raise plasma homocysteine levels. This elevation poses a theoretical risk of negating some of the benefits of these drugs. The mechanisms by which drugs alter plasma homocysteine levels vary. Drugs such as cholestyramine and metformin interfere with vitamin absorption from the gut. Interference with folate and homocysteine metabolism by methotrexate, nicotinic acid (niacin) and fibric acid derivatives, may lead to increased plasma homocysteine levels. Treatment with folate or vitamins B6 and B12 lowers plasma homocysteine levels effectively and is relatively inexpensive. Although it still remains to be demonstrated that lowering plasma homocysteine levels reduces cardiovascular morbidity, surrogate markers for cardiovascular disease have been shown to improve with treatment of hyperhomocystenaemia. Would drugs like metformin, fibric acid derivatives and nicotinic acid be more effective in lowering cardiovascular morbidity and mortality, if the accompanying hyperhomocysteinaemia is treated? The purpose of this review is to highlight the importance of homocysteine as a risk factor, and examine the role and implications of drug induced modulation of homocysteine metabolism.

[Non-alcoholic steatohepatitis]

Non-alcoholic steatohepatitis (NASH) is a chronic liver disease that occurs in patients with no significant alcohol consumption; it is not histologically different from alcoholic hepatitis because it presents macrovesicular steatosis, hepatocellular necrosis, mixed inflammatory infiltrate, and various stages of fibrosis in addition Mallory bodies in some patients. Some authors have even described NASH as a benign disease; however, it is presently considered a potentially serious disease that may evolve into liver cirrhosis and probably, liver cancer. It is more often related to female sex, obesity, and dyslipidemia, although it may be present in other population groups and associated with other factors. Its origin may be multifactorial, including insulin resistance, protein glycation, oxidative stress, and others. The disease may be asymptomatic and found in routine physical exams when the patient shows increased aminotransferases with no other explanation. At present the only specific diagnosis procedure is liver biopsy. The sole available current treatment is body weight control, normalizing glucose and lipid blood levels, as well as the administration of some medication, as illustrated in the subsequent article.

Betaine, a promising new agent for patients with nonalcoholic steatohepatitis: results of a pilot study

OBJECTIVES

No effective therapy currently exists for patients with nonalcoholic steatohepatitis (NASH). Betaine, a naturally occurring metabolite of choline, has been shown to raise S-adenosylmethionine (SAM) levels that may in turn play a role in decreasing hepatic steatosis. Our aim was to determine the safety and effects of betaine on liver biochemistries and histological markers of disease activity in patients with NASH.

METHODS

Ten adult patients with NASH were enrolled. Patients received betaine anhydrous for oral solution (Cystadane) in two divided doses daily for 12 months. Seven out of 10 patients completed 1 yr of treatment with betaine.

RESULTS

A significant improvement in serum levels of aspartate aminotransferase (p = 0.02) and ALAT (p = 0.007) occurred during treatment. Aminotransferases normalized in three of seven patients, decreased by >50% in three of seven patients, and remained unchanged in one patient when compared to baseline values. A marked improvement in serum levels of aminotransferases (ALT -39%; AST -38%) also occurred during treatment in those patients who did not complete 1 yr of treatment. Similarly, a marked improvement in the degree of steatosis, necroinflammatory grade, and stage of fibrosis was noted at 1 yr of treatment with betaine. Transitory GI adverse events that did not require any dose reduction or discontinuation of betaine occurred in four patients.

CONCLUSIONS

Betaine is a safe and well tolerated drug that leads to a significant biochemical and histological improvement in patients with NASH. This novel agent deserves further evaluation in a randomized, placebo-controlled trial.

[Orphan drugs and metabolic disorders]

INTRODUCTION

Over the past twenty years the legal and philosophical concept of orphan diseases has developed to include the diseases with an incidence in the general population of less than 1/5,000. Treatment of these conditions, which is very specific, requires drugs which will be used by a very small number of patients and are therefore not profitable from the financial point of view. This gives rise to the concept of orphan drugs which lack sponsorship, are expensive to investigate and develop, are little used and therefore there is little incentive to market them. All metabolic disorders due to genetic defects may be considered to be orphan diseases , since their incidence in the population is less than 1/5,000 and there may be only a negligible incidence of 1/37,000,000.

DEVELOPMENT

In this study we discuss the treatment of three orphan metabolic diseases, which severely affect the central nervous system by different mechanisms, by three orphan drugs which solve the problems of only a few patients. We describe the treatment of: (1) the deficiency of the synthesis of tetrahydrobiopterin, which causes neurotransmitter deficiency, with tetrahydrobiopterin, (2) N acetylglutamate sythetase deficiency, which causes severe hyperammonaemia and cerebral oedema, with N carbamyl glutamate (3) cystathionine synthetase deficiency which causes hyperhomocyteinaemia and a high risk of thromboembolic accidents, with Betaine.

[State of the hepatobiliary system and intestines in elderly patients with concurrent digestive pathology]

Common aspects have been revealed of structural and functional disorders of the biliary tract and intestine in elderly patients with digestive pathology. We recommend that lipotropic drugs, choleretics, cholekinetics, antioxidants and eubiotics be used in the treatment of the above patients.

Methylenetetrahydrofolate reductase deficiency: importance of early diagnosis

Methylenetetrahydrofolate reductase deficiency is the most common inborn error of folate metabolism and should be suspected when homocystinuria is combined with hypomethioninemia. The main clinical findings are neurologic signs such as severe developmental delay, marked hypotonia, seizures, microcephaly, apnea, and coma. Most patients present in early life. The infantile form is severe, with rapid deterioration leading to death usually within 1 year. Treatment with betaine has been shown to be efficient in lowering homocysteine concentrations and returning methionine to normal, but the clinical response is variable. We report two brothers with methylenetetrahydrofolate reductase deficiency: the first was undiagnosed and died at 8 months of age from neurologic deterioration and apnea, while his brother, who was treated with betaine from the age of 4 months, is now 3 years old and has developmental delay.

Methionine transamination in patients with homocystinuria due to cystathionine beta-synthase deficiency

To assess the ability of patients with homocystinuria due to cystathionine beta-synthase (CBS) deficiency to perform the reactions of the methionine transamination pathway, the concentrations of the products of this pathway were measured in plasma and urine. The results clearly demonstrate that CBS-deficient patients develop elevations of these metabolites once a threshold near 350 micromol/L for the concurrent plasma methionine concentration is exceeded. The absence of elevated methionine transamination products previously reported among 16 CBS-deficient B6-responsive patients may now be attributed to the fact that in those patients the plasma methionine concentrations were below this threshold. The observed elevations of transamination products were similar to those observed among patients with isolated hypermethioninemia. Plasma homocyst(e)ine did not exert a consistent effect on transamination metabolites, and betaine appeared to effect transamination chiefly by its tendency to elevate methionine. Even during betaine administration, the transamination pathway does not appear to be a quantitatively major route for the disposal of methionine.

Efficacy and safety of oral betaine glucuronate in non-alcoholic steatohepatitis. A double-blind, randomized, parallel-group, placebo-controlled prospective clinical study

In a prospective, randomized, double-blind therapeutic trial, 191 patients with non-alcoholic steatohepatitis were treated for 8 weeks daily b.i.d. orally either with betaine glucuronate combined with diethanolamine glucuronate and nicotinamide ascorbate (Ietepar) (96 patients) or with undistinguishable placebo capsules (95 patients). The verum treatment effectively reduced by 25% hepatic steatosis (p < 0.01) and by 6% hepatomegaly (p < 0.05), while placebo did not significantly reduce the disorders. Verum was also more effective than placebo on discomfort in abdominal upper right quadrant. The global efficacy of treatment was rated by the doctor "very good" or "good" in 48% of verum treated patients and only in 17% after placcbo (P of difference = 9 x 10(-6)). 52% of patients self-rated efficacy as "very good" or "good" after verum and only 34% after placebo (P of difference = 0.017). The verum treatment provoked a significant reduction of the increased liver transaminases (ALT, AST and gamma-GT) while placebo was ineffective. Adverse events were recorded in 10% of verum-treated patients and in 7% under placebo (no significant difference). In both groups the adverse events were mild and transient, did not require treatment discontinuation and were undistinguishable from common symptoms of liver disorders. In conclusion, the 8-week treatment with betaine glucuronate combined with diethanolamine glucuronate and nicotinamide ascorbate was found effective in non-alcoholic steatohepatitis, a disorder for which the hitherto pharmacological interventions were poorly and inconsistently effective.

Betaine reduces hepatic lipidosis induced by carbon tetrachloride in Sprague-Dawley rats

Carbon tetrachloride-injected rats were given liquid diets with and without betaine for 7 d. Hepatic lipidosis was induced by 4 daily injections of carbon tetrachloride (CCl4). Animals were killed and their livers and blood taken for analysis of betaine, S-adenosylmethionine (SAM), betaine homocysteine methyltransferase (BHMT), triglyceride, alanine aminotransferase and aspartate aminotransferase. Liver samples were also processed and stained for histological examination. Supplemental betaine reduced triglyceride in the liver and centrilobular hepatic lipidosis induced by the CCl4 injections. In both the control and experimental groups receiving betaine, liver betaine, BHMT and SAM were significantly higher than in their respective groups not receiving betaine. This study provides evidence that betaine protects the liver against CCl4-induced lipidosis and may be a useful therapeutic and prophylactic agent in ameliorating the harmful effects of CCl4.

Homocystinuria presenting with portal vein thrombosis and pancreatic pseudocyst: a case report

Homocystinuria is a rare, inherited metabolic disease frequently associated with severe multisystemic involvement such as dislocated lenses, skeletal deformities, mental retardation, and premature vascular occlusion. Arterial and venous thromboembolic events present frequent and life-threatening complications in homocystinuric patients. It has been suggested that mild homocystinemia would be a risk factor for vascular disease.