MAFLD: How is it different from NAFLD?

"Metabolic dysfunction-associated fatty liver disease (MAFLD)" is the term suggested in 2020 to refer to fatty liver disease related to systemic metabolic dysregulation. The name change from nonalcoholic fatty liver disease (NAFLD) to MAFLD comes with a simple set of criteria to enable easy diagnosis at the bedside for the general medical community, including primary care physicians. Since the introduction of the term, there have been key areas in which the superiority of MAFLD over the traditional NAFLD terminology has been demonstrated, including for the risk of liver and extrahepatic mortality, disease associations, and for identifying high-risk individuals. Additionally, MAFLD has been adopted by a number of leading pan-national and national societies due to its concise diagnostic criterion, removal of the requirement to exclude concomitant liver diseases, and reduction in the stigma associated with this condition. The current article explores the differences between MAFLD and NAFLD diagnosis, areas of benefit, some potential limitations, and how the MAFLD terminology has opened up new fields of research.

To help aging populations, classify organismal senescence

Comprehensive disease classification and staging is required to address unmet needs of aging populations

The Adipokine Profile and the Cardiometabolic Risk in Non-Obese Young Adults

Background

Young, non-obese adults are considered at low risk for cardiometabolic diseases, although markers of an unhealthy metabolic state are not uncommon findings in this population. Adipose tissue dysfunction, evaluated by the adipokine profile, significantly influences lipid and glucose metabolism and low-grade systemic inflammation.

Aims

To determine the relation between adipose tissue dysfunction and the already confirmed cardiometabolic risk indicators, including the atherogenic index of plasma, lipid accumulation product, homeostatic model assessment of insulin resistance, and the low-grade inflammation markers, namely, interleukin 6 and high-sensitivity C-reactive protein.

Study Design

Cross-sectional study.

Methods

We recruited 93 non-obese, healthy young adults. Anthropometric, lipid profile, inflammatory markers, and adipokines were measured. An abnormal adipokine profile (high leptin-to-adiponectin ratio) was considered as a marker of a dysfunctional adipose tissue. The correlation between the leptin-to-adiponectin ratio and the anthropometric measurements, atherogenic index of plasma, lipid accumulation product, homeostatic model assessment of insulin resistance, interleukin 6, and high-sensitivity C-reactive protein was determined.

Results

We found a direct correlation between the abnormal adipokine profile and the cardiometabolic risk indicators mentioned above, except for the low-grade inflammatory markers. In the regression model derived from our data, the leptin-to-adiponectin ratio was best correlated with the unfavorable plasma lipid profile, as estimated by the atherogenic index of plasma (r=0.097, confidence interval=0.015-0.180, p=0.021). A significantly higher leptin-to-adiponectin ratio was found in the insulin-resistant group (p=0.012) and in the highest lipid accumulation product quartile (p=0.032).

Conclusion

In a non-obese young population, the high rate of leptin-adiponectin may be a good predictor of cardiovascular and metabolic risk assessment.

Safety profile of anakinra in the management of rheumatologic, metabolic and autoinflammatory disorders

Anakinra is a biologic response modifier that competitively antagonises the biologic effects of interleukin-1, the ancestor pleiotropic proinflammatory cytokine produced by numerous cell types, found in excess in the serum, synovial fluid and any involved tissues of patients with many inflammatory diseases. The magnitude of the risk of different infections, including Mycobacterium tuberculosis (Mtb) infection, associated with the large use of anakinra in many rheumatologic, metabolic or autoinflammatory disorders is still unknown. In addition, it is unclear whether this effect is modified by the concomitant use of antirheumatic drugs and corticosteroids. The rates of development of Mtb disease in patients treated with anakinra due to rheumatoid arthritis, systemic autoinflammatory diseases, Schnitzler's syndrome, Behçet's disease, adult-onset Still disease, systemic juvenile idiopathic arthritis, gout and diabetes mellitus have been usually very low. However, clinicians must carefully weigh the benefits of biological drugs against their risks, particularly in patients prone to infections. Additional data are needed to understand whether this risk of Mtb infection and reactivation are representative of a class effect related to biologics or whether anakinra bears specifically an intrinsic lower risk in comparison with other biologic drugs.

Disorders of phospholipids, sphingolipids and fatty acids biosynthesis: toward a new category of inherited metabolic diseases

We wish to delineate a novel, and rapidly expanding, group of inborn errors of metabolism with neurological/muscular presentations: the defects in phospholipids, sphingolipids and long chain fatty acids biosynthesis. At least 14 disorders have been described so far. Clinical presentations are diverse but can be divided into (1) diseases of the central nervous system; (2) peripheral neuropathies; and (3) muscular/cardiac presentations. (1) Leukodystrophy and/or iron deposits in basal ganglia is a common feature of phospholipase A2 deficiency, fatty acid hydroxylase deficiency, and pantothenate kinase-associated neurodegeneration. Infantile epilepsy has been reported in GM3 synthetase deficiency. Spastic quadriplegia with ichthyosis and intellectual disability are the presenting signs of the elongase 4 deficiency and the Sjogren-Larsson syndrome caused by fatty aldehyde dehydrogenase deficiency. Spastic paraplegia and muscle wasting are also seen in patients with mutations in the neuropathy target esterase gene. (2) Peripheral neuropathy is a prominent feature in PHARC syndrome due to α/β-hydrolase 12 deficiency, and in hereditary sensory autonomic neuropathy type I due to serine palmitoyl-CoA transferase deficiency. (3) Muscular/cardiac presentations include recurrent myoglobinuria in phosphatidate phosphatase 1 (Lipin1) deficiency; cardiomyopathy and multivisceral involvement in Barth syndrome secondary to tafazzin mutations; congenital muscular dystrophy due to choline kinase deficiency, Sengers syndrome due to acylglycerol kinase deficiency and Chanarin Dorfman syndrome due to α/β- hydrolase 5 deficiency. These synthesis defects of complex lipid molecules stand at the frontier between classical inborn errors of metabolism and other genetic diseases involving the metabolism of structural proteins.

Application of the WHOQOL-100 for the assessment of quality of life of adult patients with inherited metabolic diseases

BACKGROUND

As advances in neonatal and pediatric care for patients affected by inherited metabolic diseases (IMD) improve their outcome and allow for better survival rates, there is a growing interest in the quality of life (QoL) of patients reaching adulthood. In order to address this subject we designed a study to evaluate the QoL of a group of adult IMD patients who are receiving various treatments, in a comprehensive manner.

METHODS

A mixed-method study was conducted to assess the QoL in adult IMD patients. The multidimensional World Health Organization Quality of Life questionnaire (WHOQOL-100) was applied for quantitative evaluations, and an additional semi-standardized interview, was conducted for qualitative measurement of patients' perceptions of the impact of illness on their daily life, and the perceived adherence to their treatment recommendations. A total of 82 patients affected by IMD were enrolled. The inherited metabolic disorders included principally amino acids disorders, urea cycle defects, organic acidurias, carbohydrates disorders, and lysosomal disorders. The WHOQOL-100 and the semi-standardized interview were administered in a clinical setting to adult patients with IMD.

RESULTS

The mean for the whole group indicates that adult patients with IMD can have a normal value of General QoL. Despite this value, the results of each domain show lower scores in the domains of perception of independence and quality of social relationships. We made a further analysis to compare the patients with dietary treatment with the patients with pharmacological treatment, and we observed a statistically significant difference in General QoL, in the Physical, Independence, Spiritual domains and in the facet of Medication. These results suggest that Global QoL measures might not be sufficient to assess the QoL for adult patients with IMD. Furthermore, the implementation of a qualitative semi-standardized interview, especially suitable for adult patients, added important features on illness perception and on perceived adherence to the treatment by adult IMD patients.

CONCLUSION

In this study we underlined the importance of applying multidimensional instruments, like WHOQOL-100, to evaluate the quality of life of adult patients with IMD. The WHOQOL-100 has been demonstrated to be a valid instrument to measure the QoL of IMD patients. Moreover, the administration of a tailored psychometric instrument in combination with a qualitative interview may help us to better characterize special issues related to IMD. Indeed, other factors beyond the physical manifestations of the disease, such as psychological wellbeing, social behavior, illness perception and adherence to the treatment, strongly influence QoL and may serve as valid targets for intervention to improve patients' care. We believe this kind of approach is especially useful for adult patients with inherited metabolic diseases.

From glycosylation disorders to dolichol biosynthesis defects: a new class of metabolic diseases

Polyisoprenoid alcohols are membrane lipids that are present in every cell, conserved from archaea to higher eukaryotes. The most common form, alpha-saturated polyprenol or dolichol is present in all tissues and most organelle membranes of eukaryotic cells. Dolichol has a well defined role as a lipid carrier for the glycan precursor in the early stages of N-linked protein glycosylation, which is assembled in the endoplasmic reticulum of all eukaryotic cells. Other glycosylation processes including C- and O-mannosylation, GPI-anchor biosynthesis and O-glucosylation also depend on dolichol biosynthesis via the availability of dolichol-P-mannose and dolichol-P-glucose in the ER. The ubiquity of dolichol in cellular compartments that are not involved in glycosylation raises the possibility of additional functions independent of these protein post-translational modifications. The molecular basis of several steps involved in the synthesis and the recycling of dolichol and its derivatives is still unknown, which hampers further research into this direction. In this review, we summarize the current knowledge on structural and functional aspects of dolichol metabolites. We will describe the metabolic disorders with a defect in known steps of dolichol biosynthesis and recycling in human and discuss their pathogenic mechanisms. Exploration of the developmental, cellular and biochemical defects associated with these disorders will provide a better understanding of the functions of this lipid class in human.

On the nomenclature of congenital disorders of glycosylation (CDG)

A new nomenclature of CDG is proposed because the current one is too complex for clinicians and provides no added value.

Hepatic cirrhosis, dystonia, polycythaemia and hypermanganesaemia--a new metabolic disorder

We report a new constellation of clinical features consisting of hypermanganesaemia, liver cirrhosis, an extrapyramidal motor disorder and polycythaemia in a 12 year-old girl born to consanguineous parents. Blood manganese levels were >3000 nmol/L (normal range <320 nmol/L) and MRI revealed signal abnormalities of the basal ganglia consistent with manganese deposition. An older brother with the same phenotype died at 18 years, suggesting a potentially lethal, autosomal recessive disease. This disorder is probably caused by a defect of manganese metabolism with the accumulation of manganese in the liver and the basal ganglia similar to the copper accumulation in Wilson disease. In order to assess the genetic basis of this syndrome we investigated two candidate genes: ATP2C2 and ATP2A3 encoding the manganese-transporting calcium-ATPases, SPCA2 and SERCA3, respectively. Genotyping of the patient and the family for microsatellite markers surrounding ATP2C2 and ATP2A3 excluded these genes. The patient was found to be heterozygous for both gene loci. Despite the unknown pathophysiology, we were able to develop a successful treatment regime. Chelation therapy with disodium calcium edetate combined with iron supplementation is the treatment of choice, lowering blood manganese levels significantly and improving clinical symptoms.

Definition of the metabolic syndrome: current proposals and controversies

Metabolic syndrome includes a clustering of metabolic derangements that cause affected subjects to have an increased risk for developing diabetes, cardiovascular disease, and, according to recent epidemiologic studies, chronic kidney disease. The present review discusses four definitions of metabolic syndrome published by different national and international committees. In an effort to bridge the differences existent in those classifications, a unified definition that recognizes the increased biologic activity of the upper visceral fatty tissue and the strong association of abdominal obesity as a leading part of metabolic syndrome is proposed herein. The diagnosis of metabolic syndrome is reserved for pre-diabetic patients who share the risk of becoming diabetic or developing cardiovascular or chronic kidney disease.

Clinicians' recognition of the metabolic adverse effects of antipsychotic medications

There is a growing concern regarding the propensity of second generation antipsychotics (SGAs) to induce weight gain and metabolic adverse effects. Recent consensus guidelines have recommended assessment and monitoring procedures to appropriately detect and manage these adverse effects. This study addresses the appreciation and readiness of clinicians to implement management guidelines for these adverse effects. Respondents indicated awareness of the risks of treatment with SGAs. The extent of monitoring for metabolic adverse effects was low and inconsistent across measures and in frequency of evaluation. Ongoing efforts are needed to support and encourage change in clinician practice.

Second-generation (atypical) antipsychotics and metabolic effects: a comprehensive literature review

Increasing numbers of reports concerning diabetes, ketoacidosis, hyperglycaemia and lipid dysregulation in patients treated with second-generation (or atypical) antipsychotics have raised concerns about a possible association between these metabolic effects and treatment with these medications. This comprehensive literature review considers the evidence for and against an association between glucose or lipid dysregulation and eight separate second-generation antipsychotics currently available in the US and/or Europe, specifically clozapine, olanzapine, risperidone, quetiapine, zotepine, amisulpride, ziprasidone and aripiprazole. This review also includes an assessment of the potential contributory role of treatment-induced weight gain in conferring risk for hyperglycaemia and dyslipidaemia during treatment with different antipsychotic medications. Substantial evidence from a variety of human populations, including some recent confirmatory evidence in treated psychiatric patients, indicates that increased adiposity is associated with a variety of adverse physiological effects, including decreases in insulin sensitivity and changes in plasma glucose and lipid levels. Comparison of mean weight changes and relative percentages of patients experiencing specific levels of weight increase from controlled, randomised clinical trials indicates that weight gain liability varies significantly across the different second generation antipsychotic agents. Clozapine and olanzapine treatment are associated with the greatest risk of clinically significant weight gain, with other agents producing relatively lower levels of risk. Risperidone, quetiapine, amisulpride and zotepine generally show low to moderate levels of mean weight gain and a modest risk of clinically significant increases in weight. Ziprasidone and aripiprazole treatment are generally associated with minimal mean weight gain and the lowest risk of more significant increases. Published studies including uncontrolled observations, large retrospective database analyses and controlled experimental studies, including randomised clinical trials, indicate that the different second-generation antipsychotics are associated with differing effects on glucose and lipid metabolism. These studies offer generally consistent evidence that clozapine and olanzapine treatment are associated with an increased risk of diabetes mellitus and dyslipidaemia. Inconsistent results, and a generally smaller effect in studies where an effect is reported, suggest limited if any increased risk for treatment-induced diabetes mellitus and dyslipidaemia during risperidone treatment, despite a comparable volume of published data. A similarly smaller and inconsistent signal suggests limited if any increased risk of diabetes or dyslipidaemia during quetiapine treatment, but this is based on less published data than is available for risperidone. The absence of retrospective database studies, and little or no relevant published data from clinical trials, makes it difficult to draw conclusions concerning risk for zotepine or amisulpride, although amisulpride appears to have less risk of treatment-emergent dyslipidaemia in comparison to olanzapine. With increasing data from clinical trials but little or no currently published data from large retrospective database analyses, there is no evidence at this time to suggest that ziprasidone and aripiprazole treatment are associated with an increase in risk for diabetes, dyslipidaemia or other adverse effects on glucose or lipid metabolism. In general, the rank order of risk observed for the second-generation antipsychotic medications suggests that the differing weight gain liability of atypical agents contributes to the differing relative risk of insulin resistance, dyslipidaemia and hyperglycaemia. This would be consistent with effects observed in nonpsychiatric samples, where risk for adverse metabolic changes tends to increase with increasing adiposity. From this perspective, a possible increase in risk would be predicted to occur in association with any treatment that produces increases in weight and adiposity. However, case reports tentatively suggest that substantial weight gain or obesity may not be a factor in up to one-quarter of cases of new-onset diabetes that occur during treatment. Pending further testing from preclinical and clinical studies, limited controlled studies support the hypothesis that clozapine and olanzapine may have a direct effect on glucose regulation independent of adiposity. The results of studies in this area are relevant to primary and secondary prevention efforts that aim to address the multiple factors that contribute to increased prevalence of type 2 diabetes mellitus and cardiovascular disease in populations that are often treated with second-generation antipsychotic medications.

Maladies héréditaires du métabolisme et apports de la métabolomique

Both hope and illusion, the recent progress in biology has raised our expectations that one day it will be possible to introduce a biological sample into an apparatus which will then deliver in a few minutes thousands of qualitative and quantitative data concerning the genome, transcriptome, proteome and metabolome, thereby contributing to diagnosis and follow-up of diseases which are now difficult to identify. Such machines do not exist yet and, in any case, should be associated with the appropriate and adequate clinical work on the disease and with the patient. This << total >> approach is of course being pushed by the recent decoding of the genomes of several species (genomics), the development of high throughput analysis of mRNAs (transcriptomics), and the efforts to identify the protein products on a large scale (proteomics). Wide sectors of medicine are waiting for the results of these new medium and high throughput technological approaches, for example, in order to identify early markers of diseases. The object of this article is to present a biochemist's point of view on hereditary metabolic diseases (also referred to as inborn errors of metabolism), a field of medicine and research covering very diverse clinical and biochemical aspects. Significant advances will be made possible by improving the present methods of analysis of the metabolome which establishes a link between genotypes and phenotypes, an area now called metabolomics. The contribution of proteomics will be important as well but will still require some time.

Prevalence of the Metabolic Syndrome using the Modified ATP III Definitions for Workers in Japan, Korea and Mongolia

A clustering of insulin resistance, hypertension and dyslipidemia has been labeled as the metabolic syndrome. Asians have a lower frequency of obesity than do Caucasians, but have an increasing tendency toward metabolic syndrome. Most data on metabolic syndrome are based on studies from Western countries with only limited information derived from Asian populations. We conducted a cross-sectional study of individuals aged 30-60 yr in workplace settings. We examined and analyzed the health data of 1,384 Japanese, Koreans and Mongolians for metabolic syndrome based on the modified definitions of the working definition proposed by the Third Report of the National Cholesterol Educational Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III definition). The prevalence of metabolic syndrome using the ATP III-BMI30 and ATP III-BMI25 definitions was 7% and 12% for Japanese, 7% and 13% for Koreans, and 12% and 16% for Mongolians, respectively. With the exception of obesity, the prevalences of individual metabolic abnormalities within each of the three Asian groups were similar to each other and to reported rates of prevalence in the U.S.A. Nevertheless, the values of sensitivity and specificity by the metabolic syndrome definitions are remarkably different relative to ethnicity. A universal metabolic syndrome definition is inappropriate for comparisons of metabolic syndrome among Asian ethnic groups. We believe that the ATP III-BMI25 definition is suitable for the determination of metabolic syndrome among Japanese and Koreans, and that the ATP III-BMI30 is more appropriate for Mongolians.

Concept-based annotation of enzyme classes

MOTIVATION

Given the explosive growth of biomedical data as well as the literature describing results and findings, it is getting increasingly difficult to keep up to date with new information. Keeping databases synchronized with current knowledge is a time-consuming and expensive task-one which can be alleviated by automatically gathering findings from the literature using linguistic approaches. We describe a method to automatically annotate enzyme classes with disease-related information extracted from the biomedical literature for inclusion in such a database.

RESULTS

Enzyme names for the 3901 enzyme classes in the BRENDA database, a repository for quantitative and qualitative enzyme information, were identified in more than 100,000 abstracts retrieved from the PubMed literature database. Phrases in the abstracts were assigned to concepts from the Unified Medical Language System (UMLS) utilizing the MetaMap program, allowing for the identification of disease-related concepts by their semantic fields in the UMLS ontology. Assignments between enzyme classes and diseases were created based on their co-occurrence within a single sentence. False positives could be removed by a variety of filters including minimum number of co-occurrences, removal of sentences containing a negation and the classification of sentences based on their semantic fields by a Support Vector Machine. Verification of the assignments with a manually annotated set of 1500 sentences yielded favorable results of 92% precision at 50% recall, sufficient for inclusion in a high-quality database.

AVAILABILITY

Source code is available from the author upon request.

SUPPLEMENTARY INFORMATION

ftp.uni-koeln.de/institute/biochemie/pub/brenda/info/diseaseSupp.pdf.

Evidence for substantial effect modification by gender in a large-scale genetic association study of the metabolic syndrome among coronary heart disease patients

Major genetic determinants of the metabolic syndrome - a clustering of abdominal obesity, high triglycerides, low HDL cholesterol, high blood pressure and high fasting glucose - remain elusive. We surveyed 207 single-nucleotide polymorphisms in 110 candidate genes among coronary artery disease patients, a population enriched for metabolic abnormalities. The number of abnormalities (0-5) was determined in the 214 male and 91 female patients, and the association with each polymorphism evaluated by means of ordinal regression analysis. Polymorphisms in eight genes, including LDLR, GBE1, IL1R1, TGFB1, IL6, COL5A2, SELE and LIPC, were associated with metabolic syndrome in the whole population ( P values ranged from 0.047 to 0.008). Variants in seven additional genes showed significant gene by gender interaction. Among these, separate analyses in men and women revealed a strong association with a silent polymorphism in the low-density lipoprotein receptor-related protein gene, LRPAP1, among females ( P=0.0003), but not males ( P=0.292). Other genes associated only in females included THBS1, ACAT2, ITGB3, F2 and SELP ( P values ranging from 0.032 to 0.002). Only one gene ( PRCP) was significantly associated in men alone ( P=0.039). Our results propose several new candidate genes for the metabolic syndrome and suggest that the genetic basis of this syndrome may be strongly modified by gender.

[Hemopyrrollactamuria (HPU); from spots to pseudo-disease]

In recent years, patients in the Netherlands confront their doctors with the diagnosis 'haemopyrollactamuria' (HPU), based on the presence of the haemopyrrollactam complex in their urine. The diagnosis is made by a commercial laboratory in the Netherlands (www.keac.nl). We have not been able to find peer-reviewed scientific literature on this metabolic disease. The haemopyrrollactam complex represents the so-called mauve spot, which was the subject of much controversy in schizophrenia research in the previous century. Reviewing all of the available data, we feel that HPU should be classified as a pseudo-disease.

Hypermetabolism in clinically stable patients with liver cirrhosis

BACKGROUND

Hypermetabolism has a negative effect on prognosis in patients with liver cirrhosis. Its exact prevalence and associations with clinical data, the nutritional state, and beta-adrenergic activity are unclear.

OBJECTIVE

We investigated resting energy expenditure (REE) in 473 patients with biopsy-proven liver cirrhosis.

DESIGN

This was a cross-sectional study with a controlled intervention (beta-blockade) in a subgroup of patients.

RESULTS

Mean REE was 7.12 +/- 1.34 MJ/d and correlated closely with predicted values (r = 0.70, P < 0.0001). Hypermetabolism was seen in 160 patients with cirrhosis (33.8% of the study population). REE was > 30% above the predicted value in 41% of the hypermetabolic patients with cirrhosis. Hypermetabolism had no association with clinical or biochemical data on liver function. REE correlated with total body potassium content (TBP; r = 0.49, P < 0.0001). Hypermetabolic patients had lower than normal body weight and TBP (P < 0.05). About 47% of the variance in REE could be explained by body composition whereas clinical state could maximally explain 3%. Plasma epinephrine and norepinephrine concentrations were elevated in hypermetabolic cirrhotic patients (by 56% and 41%, respectively; P < 0.001 and 0.01). Differences in REE from predicted values were positively correlated with epinephrine concentration (r = 0.462, P < 0.001). Propranolol infusion resulted in a decrease in energy expenditure (by 5 +/- 3%; P < 0.05), heart rate (by 13 +/- 4%; P < 0.01), and plasma lactate concentrations (by 32 +/- 12%; P < 0.01); these effects were more pronounced in hypermetabolic patients (by 50%, 33%, and 68%, respectively; each P < 0.05).

CONCLUSIONS

Hypermetabolism has no association with clinical data and thus is an extrahepatic manifestation of liver disease. Increased beta-adrenergic activity may explain approximately 25% of hypermetabolism.

Syndrome X and mortality: a population-based study. Risk Factor and Life Expectancy Research Group

The present report analyzes the prevalence of the cluster of metabolic abnormalities defined as syndrome X (high blood glucose, high blood pressure, low high density lipoprotein (HDL) cholesterol, and high triglycerides) and its impact on cardiovascular disease mortality in a large cohort of men and women (22,561 men and 18,495 women). These individuals were participants in a series of epidemiologic investigations of cardiovascular disease conducted in Italy between 1978 and 1987. They were followed for an average of 7 years, during which time a total of 1,218 deaths occurred (1,003 in men and 215 in women). Deaths were coded according to the International Classification of Diseases, 9th Revision (ICD-9). The prevalence of the full cluster of metabolic abnormalities (syndrome X) was low in the population as a whole, with only 3.0 percent of men and 3.4 percent of women exhibiting the full cluster of abnormalities that comprise syndrome X. The risk of death from all causes and cardiovascular disease increased with increased numbers of metabolic abnormalities in both men and women. Mortality from cancer was significantly increased in women (but not in men) with syndrome X, compared with women with no metabolic abnormalities. Population attributable risks for all cause mortality and cardiovascular disease mortality were 0.06 and 0.09 in men and 0.04 and 0.48 in women when assessed by population cutpoints. These data from a large population-based epidemiologic investigation indicate that the presence of a full cluster of metabolic abnormalities from syndrome X is an important risk factor for cardiovascular disease and all-cause mortality in both men and women, but that the low prevalence of such a cluster in the population reduces the public health impact of syndrome X. The majority of individuals who die from cardiovascular disease present elevations in any one, two, or three of the metabolic abnormalities. The notion of the cluster of metabolic abnormalities (syndrome X) should not distract our attention from established individual risk factors that have been proven to be major causes of cardiovascular disease death and disability in our society.

Clinical manifestation of myeloperoxidase deficiency

Myeloperoxidase (MPO), an iron-containing heme protein localized in the azurophilic granules of neutrophil granulocytes and in the lysosomes of monocytes, is involved in the killing of several micro-organisms and foreign cells, including bacteria, fungi, viruses, red cells, and malignant and nonmalignant nucleated cells. Despite the primary role of the oxygen-dependent MPO system in the destruction of certain phagocytosed microbes, subjects with total or partial MPO deficiency generally do not have an increased frequency of infections, probably because other MPO-independent mechanism(s) for microbicidal activity compensate for the lack of MPO. Infectious diseases, especially with species of Candida, have been observed predominantly in MPO-deficient patients who also have diabetes mellitus, but the frequency of such cases is very low, less than 5% of reported MPO-deficient subjects. Evidence from a number of investigators indicates that individuals with total MPO deficiency show a high incidence of malignant tumors. Since MPO-deficient PMNs exhibit in vitro a depressed lytic action against malignant human cells, it can be speculated that the neutrophil MPO system plays a central role in the tumor surveillance of the host. However, any definitive conclusion on the association between MPO deficiency and the occurrence of cancers needs to be confirmed in further clinical studies. Clinical manifestations of this disorder depend on the nature of the defect; an acquired abnormality associated with other hematological or nonhematological diseases has been occasionally described, but the primary deficiency is the form more commonly reported. Another area of interest pertinent to MPO expression is related to the use of anti-MPO monoclonal antibodies for the lineage assignment of acute leukemic cells, the definition of FAB MO acute myeloid leukemia, the identification of biphenotypic acute leukemias, and their distinction from acute leukemia with minimal phenotypic deviation. The advantage of MPO monoclonal antibodies over the MPO cytochemical assay relies in the ability of the former method to recognize the enzymatically inactive precursor forms of MPO.

Observations on increased CPK levels in "asymptomatic" cocaine abusers

In order to assess increased creatinine phosphokinase (CPK) among medically asymptomatic active crack cocaine abusers, retrospective analysis of daily supervised urine data collected in a 20 day daily visit plus 12 week followup weekly visit study of heavy crack cocaine abusers was performed. The subjects were 36 black male chronic crack cocaine users unmotivated in drug abuse treatment, willing to be studied for daily payment, who were recruited by word of mouth on the street. Of the 464 CPK results obtained, the mean CPK value was 397 (SD = 784) IU/L. Two-thirds of the results were greater than 200; 19% were greater than 500 IU/L. CPK test results were systematically eliminated if related to medical causes or concurrent other drug use. The relative contribution of recent alcohol use versus recent cocaine use in raising CPK was assessed by dividing the remaining 435 observations into sequential use groups. With alcohol use instances excluded, a statistically significant relationship between urine cocaine metabolite and elevated CPK was found. When all other possible causes of elevated CPK levels were controlled, crack cocaine use was associated with a significant quantitative effect on CPK level.

White matter disorders

Magnetic resonance imaging (MRI) has a leading role in the diagnosis of white matter disorders because of its superior sensitivity. It also allows a detailed analysis of white matter disorders, improving the specificity of the diagnoses. There is an increasing knowledge about MRI patterns, in particular in hereditary metabolic disorders. Although these patterns are not always pathognomonic, they often serve as a guide for further diagnostic steps. In the non-hereditary white matter disorders, MRI has an increasing role in the diagnoses, follow-up, and monitoring of clinical trials. In inflammatory disorders, gadolinium-diethylenetriamine-penta-acetic acid (Gd-DTPA) appears to be helpful in analyzing the 'natural' course of the disease. Magnetic resonance spectroscopy (MRS) is gradually also finding a niche in the diagnosis of white matter disorders, both as a marker of neuronal loss and as an indicator of the age and activity of a lesion. New magnetic resonance techniques, such as diffusion and magnetic transfer imaging, will probably provide more information about the involvement of myelin sheaths.

Human lymphocyte messenger RNA activity profiles in type I and type II diabetes: a tool for classification of metabolic disease

We have previously used rat hepatic messenger ribonucleic acid (mRNA) activity profiles to categorize various pathophysiologic states. To test the hypothesis that similar techniques can be used to categorize disease states in humans, we examined the mRNA activity profiles by using in vitro translational assays of Ficoll-Hypaque-separated mononuclear cells obtained from six normal volunteers, six patients with type I diabetes, and five patients with type II diabetes as example of different disease states. Translated proteins were labeled with sulfur 35-labeled methionine, separated by two-dimensional gel electrophoresis, and quantitated by videodensitometry of autoradiographs derived from the two-dimensional gels. Of approximately 160 quantitated mRNAs, the levels of 12 were found to be altered in one of the diabetic states. The values of nine were changed in patients with type I diabetes and the values of 11 were altered in patients with type II diabetes. Although the values of most mRNAs increased, significant decreases were also observed. Moreover, four spots showed significant differences in response between the two diabetic states. Discriminant analysis allowed the separation of all three states. Finally, several mRNAs also displayed an age-related correlation. We have demonstrated that unstimulated mononuclear cell mRNAs can be used to study the effects of pathophysiologic states on gene expression in humans. Furthermore, our results support the potential use of this issue to study the effect of a wide variety of disease states on gene expression.

The biochemical basis of mitochondrial diseases

Dysfunctioning of human mitochondria is found in a rapidly increasing number of patients. The mitochondrial system for energy transduction is very vulnerable to damage by genetic and environmental factors. A primary mitochondrial disease is caused by a genetic defect in a mitochondrial enzyme or translocator. More than 60 mitochondrial enzyme deficiencies have been reported. Secondary mitochondrial defects are caused by lack of compounds to enable a proper mitochondrial function or by inhibition of that function. This may result from malnutrition, circulatory or hormonal disturbances, viral infection, poisoning, or an extramitochondrial error of metabolism. Once mitochondrial ATP synthesis decreases, secondary mitochondrial lesions may be generated further, due to changes in synthesis and degradation of mitochondrial phospholipids and proteins, to mitochondrial antibody formation following massive degradation, to accumulation of toxic products as excess acyl-CoA, to the depletion of Krebs cycle intermediates, and to the increase of free radical formation and lipid peroxidation.