Enzyme replacement therapy with velmanase alfa (human recombinant alpha-mannosidase): Novel global treatment response model and outcomes in patients with alpha-mannosidosis.

Alpha-mannosidosis is an ultra-rare monogenic disorder resulting from a deficiency in the lysosomal enzyme alpha-mannosidase, with a prevalence estimated to be as low as 1:1,000,000 live births. The resulting accumulation of mannose-rich oligosaccharides in all tissues leads to a very heterogeneous disorder with a continuum of clinical manifestations with no distinctive phenotypes. Long-term enzyme replacement therapy (ERT) with velmanase alfa is approved in Europe for the treatment of non-neurological manifestations in patients with mild to moderate alpha-mannosidosis. The clinical heterogeneity and rarity of the disease limit the sensitivity of single parameters to detect clinically relevant treatment effects. Thus, we propose a novel multiple variable responder analysis to evaluate the efficacy of ERT for alpha-mannosidosis and present efficacy analyses for velmanase alfa using this method. Global treatment response to velmanase alfa (defined by response to ≥2 domains comprising pharmacodynamic, functional, and quality of life outcomes) was applied post hoc to data from the pivotal placebo-controlled rhLAMAN-05 study and to the longer-term integrated data from all patients in the clinical development program (rhLAMAN-10). After 12 months of treatment, a global treatment response was achieved by 87% of patients receiving velmanase alfa (n = 15) compared with 30% of patients receiving placebo (n = 10). Longer-term data from all patients in the clinical program (n = 33) showed 88% of patients were global responders, including all (100%) pediatric patients (n = 19) and the majority (71%) of adult patients (n = 14). The responder analysis model demonstrates a clinically meaningful treatment effect with velmanase alfa and supports the early initiation and continued benefit of longer-term treatment of all patients with alpha-mannosidosis with this ERT.

Efficacy and safety of Velmanase alfa in the treatment of patients with alpha-mannosidosis: results from the core and extension phase analysis of a phase III multicentre, double-blind, randomised, placebo-controlled trial.

INTRODUCTION: This phase III, double-blind, randomised, placebo-controlled trial (and extension phase) was designed to assess the efficacy and safety of velmanase alfa (VA) in alpha-mannosidosis (AM) patients. METHODS: Twenty-five patients were randomised to weekly 1 mg/kg VA or placebo for 52 weeks. At study conclusion, placebo patients switched to VA; 23 patients continued receiving VA in compassionate-use/follow-on studies and were evaluated in the extension phase [last observation (LO)]. Co-primary endpoints were changes in serum oligosaccharide (S-oligo) and in the 3-min stair-climb test (3MSCT). RESULTS: Mean relative change in S-oligo in the VA arm was -77.6% [95% confidence interval (CI) -81.6 to -72.8] at week 52 and -62.9% (95% CI -85.8 to -40.0) at LO; mean relative change in the placebo arm was -24.1% (95% CI -40.3 to -3.6) at week 52 and -55.7% (95% CI -76.4 to -34.9) at LO after switch to active treatment. Mean relative change in 3MSCT at week 52 was -1.1% (95% CI -9.0 to 7.6) and - % (95% CI -13.4 to 6.5) for VA and placebo, respectively. At LO, the mean relative change was 3.9% (95% CI -5.5 to 13.2) in the VA arm and 9.0% (95% CI -10.3 to 28.3) in placebo patients after switch to active treatment. Similar improvement pattern was observed in secondary parameters. A post hoc analysis investigated whether some factors at baseline could account for treatment outcome; none of those factors were predictive of the response to VA, besides age. CONCLUSIONS: These findings support the utility of VA for the treatment of AM, with more evident benefit over time and when treatment is started in the paediatric age.

Comprehensive long-term efficacy and safety of recombinant human alpha-mannosidase (velmanase alfa) treatment in patients with alpha-mannosidosis.

INTRODUCTION: Long-term outcome data provide important insights into the clinical utility of enzyme replacement therapies. Such data are presented for velmanase alfa in the treatment of alpha-mannosidosis (AM). METHODS: Patient data (n = 33; 14 adults, 19 paediatric) from the clinical development programme for velmanase alfa were integrated in this prospectively-designed analysis of long-term efficacy and safety. Patients who participated in the phase I/II or phase III trials and were continuing to receive treatment after completion of the trials were invited to participate in a comprehensive evaluation visit to assess long-term outcomes. Primary endpoints were changes in serum oligosaccharide and the 3-minute stair climb test (3MSCT). RESULTS: Mean (SD) treatment exposure was 29.3 (15.2) months. Serum oligosaccharide levels were significantly reduced in the overall population at 12 months (mean change: -72.7%, P < 0.001) and remained statistically significant at last observation (-62.8%, P < 0.001). A mean improvement of +9.3% in 3MSCT was observed at 12 months (P = 0.013), which also remained statistically significant at last observation (+13.8%, P = 0.004), with a more pronounced improvement detected in the paediatric subgroup. No treatment-emergent adverse events were reported leading to permanent treatment discontinuation. CONCLUSIONS: Patients treated with velmanase alfa experienced improvements in biochemical and functional measures that were maintained for up to 4 years. Long term follow-up is important and further supports the use of velmanase alfa as an effective and well-tolerated treatment for AM. Based on the currently available data set, no baseline characteristic can be predictive of treatment outcome. Early treatment during paediatric age showed better outcome in functional endpoints.

Challenges and opportunities in neurometabolic disease treatment with enzyme delivery.

INTRODUCTION: Neurometabolic disorders remain challenging to treat, largely due to the limited availability of drugs that can cross the blood-brain barrier (BBB) and effectively target brain impairment. Key reasons for inadequate treatment include a lack of coordinated knowledge, few studies on BBB status in these diseases, and poorly designed therapies. AREAS COVERED: This paper provides an overview of current research on neurometabolic disorders and therapeutic options, focusing on the treatment of neurological involvement. It highlights the limitations of existing therapies, describes innovative protocols recently developed, and explores new opportunities for therapy design and testing, some of which are already under investigation. The goal is to guide researchers toward innovative and potentially more effective treatments. EXPERT OPINION: Advancing research on neurometabolic diseases is crucial for designing effective treatment strategies. The field suffers from a lack of collaboration, and a strong collective effort is needed to enhance synergy, increase knowledge, and develop a new therapeutic paradigm for neurometabolic disorders.

In vivo functional and transcriptional profiling of bone marrow stem cells after transplantation into ischemic myocardium.

OBJECTIVE: Clinical trials of bone marrow-derived stem cell therapy for the heart have yielded variable results. The basic mechanism(s) that underlies their potential efficacy remains unknown. In the present study, we evaluated the survival kinetics, transcriptional response, and functional outcome of intramyocardial bone marrow mononuclear cell (BMMC) transplantation for cardiac repair in a murine myocardial infarction model. METHODS AND RESULTS: We used bioluminescence imaging and high-throughput transcriptional profiling to evaluate the in vivo survival kinetics and gene expression changes of transplanted BMMCs after their engraftment into ischemic myocardium. Our results demonstrate short-lived survival of cells following transplant, with less than 1% of cells surviving by 6 weeks posttransplantation. Moreover, transcriptomic analysis of BMMCs revealed nonspecific upregulation of various cell regulatory genes, with a marked downregulation of cell differentiation and maturation pathways. BMMC therapy caused limited improvement of heart function as assessed by echocardiography, invasive hemodynamics, and positron emission tomography. Histological evaluation of cell fate further confirmed findings of the in vivo cell tracking and transcriptomic analysis. CONCLUSIONS: Collectively, these data suggest that BMMC therapy, in its present iteration, may be less efficacious than once thought. Additional refinement of existing cell delivery protocols should be considered to induce better therapeutic efficacy.

How to START? Four pillars to optimally begin your orphan drug development.

Drug development is a complex, resource intensive and long process in any disease area, and developing medicines to treat rare diseases presents even more challenges due to the small patient populations, often limited disease knowledge, heterogeneous clinical manifestations, and disease progression. However, common to all drug development programs is the need to gather as much information as possible on both the disease and the patients' needs ahead of the development path definition. Here, we propose a checklist named START, a tool that provides an overview of the key pillars to be considered when starting an orphan drug development: STakeholder mapping, Available information on the disease, Resources, and Target patient value profile. This tool helps to build solid foundations of a successful patient-centered medicines development program and guides different types of developers through a set of questions to ask for guidance through the starting phase of a rare disease therapeutic pathway.

Enabling heterogeneous data integration and biomedical event prediction through ICT: the test case of cancer reoccurrence.

Early prediction of cancer reoccurrence constitutes a challenge for oncologists and surgeons. This chapter describes one ongoing experience, the EU-Project NeoMark, where scientists from different medical and biology research fields joined efforts with Information Technology experts to identify methods and algorithms that are able to early predict the reoccurrence risk for one of the most devastating tumors, the oral cavity squamous cell carcinoma (OSCC). The challenge of NeoMark is to develop algorithms able to identify a "signature" or bio-profile of the disease, by integrating multiscale and multivariate data from medical images, genomic profile from tissue and circulating cells RNA, and other medical parameters collected from patients before and after treatment. A limited number of relevant biomarkers will be identified and used in a real-time PCR device for early detection of disease reoccurrence.

Use of the Bruininks-Oseretsky test of motor proficiency (BOT-2) to assess efficacy of velmanase alfa as enzyme therapy for alpha-mannosidosis.

OBJECTIVES: Alpha-mannosidosis is a rare autosomal recessive lysosomal storage disorder resulting from deficient lysosomal alpha-mannosidase activity. Clinical manifestations include progressive balance disorders, immune deficiency, skeletal abnormalities and cognitive deficits beginning in early childhood. Enzyme replacement therapy with recombinant human alpha-mannosidase (velmanase alfa) is scheduled for clinical development in the US beginning in 2020 and has been approved in the EU for treatment of non-neurological manifestations in cases of mild to moderate disease. This study assessed effects of velmanase alfa on fine and gross motor proficiency in children and adults. METHODS: Integrated Bruininks-Oseretsky (BOT-2) test of Motor Proficiency data from velmanase alfa clinical trials was stratified by age for 14 adults and 19 children treated for up to 4 years. RESULTS: Patients showed global developmental delays at baseline. For the combined adult and pediatric group there was a statistically significant increase (improvement) in BOT-2 total point score of 13% (p = .035, 95% CI 1.0, 25.0) from baseline to last observation. When stratified by pediatric versus adult patients, there was improvement in BOT-2 total point score in patients <18 years (mean percent increase from baseline to last observation 23%) compared to adults (mean decrease of -0.7%). Subtest analysis of individual BOT-2 items captured some improvement following velmanase alfa treatment in pediatric patients. CONCLUSIONS: There was limited ability to assess the BOT-2 change responses in adults. Pediatric patients showed stability or improvement in scaled scores relative to healthy peers, indicating continued skill acquisition, which may increase independence and contribute to improved patient quality of life.

Clinically driven semi-supervised class discovery in gene expression data.

MOTIVATION: Unsupervised class discovery in gene expression data relies on the statistical signals in the data to exclusively drive the results. It is often the case, however, that one is interested in constraining the search space to respect certain biological prior knowledge while still allowing a flexible search within these boundaries. RESULTS: We develop an approach to semi-supervised class discovery. One component of our approach uses clinical sample information to constrain the search space and guide the class discovery process to yield biologically relevant partitions. A second component consists of using known biological annotation of genes to drive the search, seeking partitions that manifest strong differential expression in specific sets of genes. We develop efficient algorithmics for these tasks, implementing both approaches and combinations thereof. We show that our method is robust enough to detect known clinical parameters in accordance with expected clinical values. We also use our method to elucidate cardiovascular disease (CVD) putative risk factors. AVAILABILITY: MonoClaD (Monotone Class Discovery). See http:// bioinfo.cs.technion.ac.il/people/zohar/MonoClad/. SUPPLEMENTARY INFORMATION: Supplementary data is available at http://bioinfo.cs.technion.ac.il/people/zohar/MonoClad/software. html

The use or generation of biomedical data and existing medicines to discover and establish new treatments for patients with rare diseases - recommendations of the IRDiRC Data Mining and Repurposing Task Force.

The number of available therapies for rare diseases remains low, as fewer than 6% of rare diseases have an approved treatment option. The International Rare Diseases Research Consortium (IRDiRC) set up the multi-stakeholder Data Mining and Repurposing (DMR) Task Force to examine the potential of applying biomedical data mining strategies to identify new opportunities to use existing pharmaceutical compounds in new ways and to accelerate the pace of drug development for rare disease patients. In reviewing past successes of data mining for drug repurposing, and planning for future biomedical research capacity, the DMR Task Force identified four strategic infrastructure investment areas to focus on in order to accelerate rare disease research productivity and drug development: (1) improving the capture and sharing of self-reported patient data, (2) better integration of existing research data, (3) increasing experimental testing capacity, and (4) sharing of rare disease research and development expertise. Additionally, the DMR Task Force also recommended a number of strategies to increase data mining and repurposing opportunities for rare diseases research as well as the development of individualized and precision medicine strategies.

Correction: Identification of an early transcriptomic signature of insulin resistance and related diseases in lymphomonocytes of healthy subjects.

[This corrects the article DOI: 10.1371/journal.pone.0182559.].

Addressing challenges in the diagnosis and treatment of rare genetic diseases.

The past 5 years have seen an unprecedented rate of discovery of genes that cause rare diseases and with it a commensurate increase in the number of diagnosable but nevertheless untreatable disorders. Here, we discuss the increasing opportunity for diagnosis and therapy of rare diseases and how to tackle the associated challenges.

Navigating Market Authorization: The Path Holoclar Took to Become the First Stem Cell Product Approved in the European Union.

Gene therapy, cell therapy, and tissue engineering have the potential to revolutionize the treatment of disease and injury. Attaining marketing authorization for such advanced therapy medicinal products (ATMPs) requires a rigorous scientific evaluation by the European Medicines Agency-authorization is only granted if the product can fulfil stringent requirements for quality, safety, and efficacy. However, many ATMPs are being provided to patients under alternative means, such as "hospital exemption" schemes. Holoclar (ex vivo expanded autologous human corneal epithelial cells containing stem cells), a novel treatment for eye burns, is one of the few ATMPs to have been granted marketing authorization and is the first containing stem cells. This review highlights the differences in standards between an authorized and unauthorized medicinal product, and specifically discusses how the manufacture of Holoclar had to be updated to achieve authorization. The result is that patients will have access to a therapy that is manufactured to high commercial standards, and is supported by robust clinical safety and efficacy data. Stem Cells Translational Medicine 2018;7:146-154.

Circulating chemokines accurately identify individuals with clinically significant atherosclerotic heart disease.

Serum inflammatory markers correlate with outcome and response to therapy in subjects with cardiovascular disease. However, current individual markers lack specificity for the diagnosis of coronary artery disease (CAD). We hypothesize that a multimarker proteomic approach measuring serum levels of vascular derived inflammatory biomarkers could reveal a "signature of disease" that can serve as a highly accurate method to assess for the presence of coronary atherosclerosis. We simultaneously measured serum levels of seven chemokines [CXCL10 (IP-10), CCL11 (eotaxin), CCL3 (MIP1 alpha), CCL2 (MCP1), CCL8 (MCP2), CCL7 (MCP3), and CCL13 (MCP4)] in 48 subjects with clinically significant CAD ("cases") and 44 controls from the ADVANCE Study. We applied three classification algorithms to identify the combination of variables that would best predict case-control status and assessed the diagnostic performance of these models with receiver operating characteristic (ROC) curves. The serum levels of six chemokines were significantly higher in cases compared with controls (P < 0.05). All three classification algorithms entered three chemokines in their final model, and only logistic regression selected clinical variables. Logistic regression produced the highest ROC of the three algorithms (AUC = 0.95; SE = 0.03), which was markedly better than the AUC for the logistic regression model of traditional risk factors of CAD without (AUC = 0.67; SE = 0.06) or with CRP (AUC = 0.68; SE = 0.06). A combination of serum levels of multiple chemokines identifies subjects with clinically significant atherosclerotic heart disease with a very high degree of accuracy. These results need to be replicated in larger cross-sectional studies and their prognostic value explored.

Identification of an early transcriptomic signature of insulin resistance and related diseases in lymphomonocytes of healthy subjects.

Insulin resistance is considered to be a pathogenetic mechanism in several and diverse diseases (e.g. type 2 diabetes, atherosclerosis) often antedating them in apparently healthy subjects. The aim of this study is to investigate with a microarray based approach whether IR per se is characterized by a specific pattern of gene expression. For this purpose we analyzed the transcriptomic profile of peripheral blood mononuclear cells in two groups (10 subjects each) of healthy individuals, with extreme insulin resistance or sensitivity, matched for BMI, age and gender, selected within the MultiKnowledge Study cohort (n = 148). Data were analyzed with an ad-hoc rank-based classification method. 321 genes composed the gene set distinguishing the insulin resistant and sensitive groups, within which the "Adrenergic signaling in cardiomyocytes" KEGG pathway was significantly represented, suggesting a pattern of increased intracellular cAMP and Ca2+, and apoptosis in the IR group. The same pathway allowed to discriminate between insulin resistance and insulin sensitive subjects with BMI >25, supporting his role as a biomarker of IR. Moreover, ASCM pathway harbored biomarkers able to distinguish healthy and diseased subjects (from publicly available data sets) in IR-related diseases involving excitable cells: type 2 diabetes, chronic heart failure, and Alzheimer's disease. The altered gene expression profile of the ASCM pathway is an early molecular signature of IR and could provide a common molecular pathogenetic platform for IR-related disorders, possibly representing an important aid in the efforts aiming at preventing, early detecting and optimally treating IR-related diseases.

Dietary glycemic index and liver steatosis.

BACKGROUND: Insulin resistance (IR) and liver steatosis (LS) are interlinked metabolic derangements whose prevalence is rapidly increasing, but the effect of dietary carbohydrate quality on LS is unknown. OBJECTIVE: The objective was to describe the relation of IR and LS to total carbohydrate, total dietary fiber, and the glycemic index (GI) and glycemic load of the diet. DESIGN: The study was a cross-sectional evaluation of 247 apparently healthy subjects who had no evidence of viral, toxic, or autoimmune hepatitis and who were unselected for alcohol intake. The homeostasis model assessment index was used as a surrogate measure of IR, and a liver echography was used as a proxy for LS grading. Dietary data were collected by using 3-d food records. Total carbohydrate intake, total dietary fiber, GI, and glycemic load were calculated by using a semiquantitative food-frequency questionnaire concerning the dietary sources of carbohydrates. RESULTS: The prevalence of high-grade LS (HG-LS) increased significantly across quartiles of dietary GI (P for trend < 0.034): HG-LS in the 4th quartile (high GI) was twice that in the first 3 quartiles (low to medium GIs), whereas no relation was observed with total carbohydrates, total dietary fiber, or glycemic load. In insulin-sensitive subjects (first 3 quartiles of homeostasis model assessment index of IR), the prevalence of HG-LS did not differ significantly between GI groups, but, in insulin-resistant subjects (4th quartile of homeostasis model assessment index of IR), it was twice as high in those with high GI as in those with low to medium GIs (P = 0.005). CONCLUSIONS: High-GI dietary habits are associated with HG-LS, particularly in insulin-resistant subjects. Dietary advice on the quality of carbohydrate sources therefore may be a complementary tool for preventing or treating LS of metabolic origin.

Relation of plasma insulin levels to forearm flow-mediated dilatation in healthy volunteers.

Although several observations suggest that insulin resistance/compensatory hyperinsulinemia (IR/CH) has a direct effect on endothelial function, independently of the metabolic abnormalities associated with the defect in insulin action, this relation has not been evaluated in apparently healthy individuals. To address this issue, we measured endothelial-dependent vasodilation in response to forearm ischemia (flow-mediated dilation [FMD]) in 47 nonsmoking, healthy volunteers without known risk factors for atherosclerosis. Measurements were also made of multiple anthropometric, metabolic, and hemodynamic variables related to IR/CH. Decreases in FMD were significantly correlated (analysis of variance for linear trend) with (1) male gender (p = 0.003), (2) waist circumference (p = 0.038), (3) higher fasting plasma insulin (p = 0.015) and triglyceride concentrations (p = 0.023), and (4) lower concentrations of high-density lipoprotein cholesterol (p = 0.001). Multivariate linear regression analysis indicated that only plasma insulin (beta -0.424) was independently associated (p <0.001) with changes in FMD, and individual differences in insulin concentrations, along with gender and brachial artery diameter at baseline, accounted for approximately 39% of the variability in FMD. In conclusion, IR/CH is an independent predictor of decreases in endothelial-dependent vasodilation in apparently healthy individuals, in the absence of traditional risk factors for atherosclerosis.

Long-Term Retrospective Analysis of Gene Therapy with Alipogene Tiparvovec and Its Effect on Lipoprotein Lipase Deficiency-Induced Pancreatitis.

Alipogene tiparvovec (Glybera) is a gene therapy product approved in Europe under the "exceptional circumstances" pathway as a treatment for lipoprotein lipase deficiency (LPLD), a rare genetic disease resulting in chylomicronemia and a concomitantly increased risk of acute and recurrent pancreatitis, with potentially lethal outcome. This retrospective study analyzed the frequency and severity of pancreatitis in 19 patients with LPLD up to 6 years after a single treatment with alipogene tiparvovec. An independent adjudication board of three pancreas experts, blinded to patient identification and to pre- or post-gene therapy period, performed a retrospective review of data extracted from the patients' medical records and categorized LPLD-related acute abdominal pain events requiring hospital visits and/or hospitalizations based on the adapted 2012 Atlanta diagnostic criteria for pancreatitis. Both entire disease time period data and data from an equal time period before and after gene therapy were analyzed. Events with available medical record information meeting the Atlanta diagnostic criteria were categorized as definite pancreatitis; events treated as pancreatitis but with variable levels of laboratory and imaging data were categorized as probable pancreatitis or acute abdominal pain events. A reduction of approximately 50% was observed in all three categories of the adjudicated post-gene therapy events. Notably, no severe pancreatitis and only one intensive care unit admission was observed in the post-alipogene tiparvovec period. However, important inter- and intraindividual variations in the pre- and post-gene therapy incidence of events were observed. There was no relationship between the posttreatment incidence of events and the number of LPL gene copies injected, the administration of immunosuppressive regimen or the percent triglyceride decrease achieved at 12 weeks (primary end point in the prospective clinical studies). Although a causal relationship cannot be established and despite the limited number of individuals evaluated, results from this long-term analysis suggest that alipogene tiparvovec was associated with a lower frequency and severity of pancreatitis events, and a consequent overall reduction in health care resource use up to 6 years posttreatment.

Relationship between leptin, insulin, body composition and liver steatosis in non-diabetic moderate drinkers with normal transaminase levels.

OBJECTIVE: Obesity and insulin resistance play a major role in the development of liver steatosis (LS), but also relative leptin resistance has been reported to correlate with LS in humans. Our objective was to investigate the relationship between serum leptin, insulin, obesity and LS in non-diabetic males (n = 74) and postmenopausal females (n = 50) with normal transaminase levels and low-to-moderate alcohol intake. METHODS: A medical history to retrieve information about health status, current medications, alcohol consumption and history of viral or toxic hepatitis; a physical examination including height, weight, waist circumference and blood pressure; a fasting blood draw for the determination of glucose, insulin, leptin, lipid profile, transaminases and uric acid; an oral glucose tolerance test to exclude type 2 diabetes; a dual-energy X-ray absorptiometry scan to assess fat mass (FM) and lean body mass (LBM), and an echography of the liver to assess LS. RESULTS: Fasting leptin and insulin were highly correlated with FM in men (R = 0.767 and R = 0.495 respectively, P < 0.001) and women (R = 0.713 and R = 0.526 respectively, P < 0.001). After correction for FM, leptin showed a significant negative correlation with LBM in men (R = -0.240, P = 0.039), but not in women (R = -0.214, P = 0.132). The positive relationship observed between leptin, insulin and LS persisted after adjustment of leptin and insulin for body composition only in men (R = 0.415, P < 0.001 and R = 0.339, P = 0.003 respectively for leptin and insulin vs LS). Adjusted means (95% confidence intervals) of leptin increased significantly across categories of LS in men even when insulin was considered in the model (absent = 7.1 ng/ml (5.6-8.5), mild = 8.2 ng/ml (7.2-9.2), moderate/severe = 12.1 ng/ml (10.3-14.0); P < 0.001), whereas no significant relationship was observed between insulin and LS after leptin was accounted for. CONCLUSION: Serum concentrations of leptin and insulin are positively correlated in men independently of body composition, but not in postmenopausal women. In men, the steatogenic effect of hyperinsulinemia/insulin resistance in the context of low-to-moderate alcohol consumption appears to be mediated by high concentrations of serum leptin, whereas body fat alone could identify postmenopausal women at high risk for LS.

Hyperinsulinemia predicts hepatic fat content in healthy individuals with normal transaminase concentrations.

Although the prevalence of insulin resistance (IR) and compensatory hyperinsulinemia (CH) is increased in patients with nonalcoholic fatty liver disease, the role of IR/CH in regulation of hepatic fat content in healthy volunteers with normal concentrations of alanine transaminase (ALT) has not been defined. To address this issue, hepatic fat content was quantified by ultrasound in 69 (30 men, 39 women) healthy individuals, without known risk factors for liver disease and with plasma ALT concentrations of less than 30 U/L. Experimental variables quantified included body mass index, waist circumference, systolic and diastolic blood pressures, and fasting plasma glucose, fasting plasma insulin (FPI), and lipid concentrations. Subjects were classified as having no (55%), mild (27%), or moderate to severe (18%) hepatic steatosis on the basis of the ultrasound results. Statistically significant (P < .05-.001) correlations (Spearman rho values) existed between liver fat content and ALT (0.26), body mass index (0.52), waist circumference (0.50), systolic blood pressure (0.28), diastolic blood pressure (0.27), fasting plasma glucose (0.47), FPI (0.56), triglycerides (0.30), and high-density lipoprotein cholesterol (-0.35). Multivariate general discriminant analysis and multiple linear regression analysis indicated that FPI was the only independent predictor (P < .001) of both liver fat content and ALT concentrations. Fasting plasma insulin (a surrogate estimate of IR/CH) predicts hepatic fat content and ALT in healthy volunteers with normal transaminase concentrations, independently of the other anthropometric and metabolic variables measured.