Diseases caused by mitochondrial dysfunction / Mitochondrialis diszfunkció okozta betegségek

The morphological description of mitochondria has been known for nearly two hundred years. Mitochondria are found in all human cells, and a thorough understanding of their function in healthy and pathological conditions was a slow progress. In recent decades, the understanding of this extensive network has accelerated, both in the theoretical field and in clinical practice. Our aim was to review the biogenesis of mitochondria and the diseases caused by their dysfunction, based on the current state of the art. We review the literature to describe the major areas of mitochondrial function, such as ATP production, which is crucial for the energy supply of the body, and the importance of the pyruvate and citric acid cycles, the electron transport chain, oxidative phosphorylation and ROS formation. The function of mitohormesis, which contributes to the body's defences, is described. After a description of mitochondrial dysfunction, we turn to the characterisation of the different mitochondrial pathologies. Having discussed the congenital mitochondrial pathologies, we highlight the fibrosis that severely impairs the function of certain parenchymal organs, heart, liver, kidneys, lungs. We emphasize the importance of cardiac fibrosis, in particular cardiac arrhythmias associated with mitochondrial dysfunction, briefly mentioning the latest therapeutic recommendations. In this context, results are expected from the use of SGLT2 or combined SGLT1/2 inhibitor. The role of this system in type 1 diabetes mellitus and in the development of insulin resistance and type 2 diabetes is mentioned as well. We outline the role of mitochondrial dysfunction in the development of nerodegenerative diseases. The importance of exercise, antioxidant therapy, cardiolipin protection, enhancement of mitochondrial biogenesis, use of sodium-glucose co-transporter inhibitors, and - underlined - the recently introduced hopeful mitochondrial transplantation in the management of these pathologies are highlighted. The mitochondrial system is not only an energy centre but also regulates the function of all our vital organs. We have shown that in the case of mitochondrial dysfunction, the function of our vital organs becomes critical due to the fibrosis that develops. However, we do not address the oncological aspects of mitochondria and mitochondrial dysfunction, as this is beyond the scope of this article. The aim of this work is primarily to explore the multiple interrelationships of this system, to deepen our knowledge and to use it for the better care of our patients. Some believe that mitochondria will determine the future of medicine.

Role of endocrinological factors and metabolic processes in regulating life-span / Endokrinológiai tényezok és metabolikus folyamatok szerepe az élettartam szabályozásában.

Összefoglaló. Az emberek a leheto leghosszabb ideig akarnak élni, jó egészségben. Ha kiküszöbölnénk a kedvezotlen külso körülményeket, a várható élettartam meghaladhatná a 100 évet. A 20. és 21. században a jóléti társadalmakban a várható élettartam jelentosen megnott, így Magyarországon is. Az áttekintett irodalom alapján megvizsgáltuk, hogy a genetika és az öröklodés mellett milyen endokrinológiai és metabolikus tényezok játszanak szerepet az élet meghosszabbításában. Megvizsgáltunk minden endogén tényezot, amely pozitívan vagy negatívan befolyásolhatja az életkorral összefüggo betegségeket (Alzheimer-kór, szív- és érrendszeri betegségek, rák) és az élettartamot. Kiemeltük a hyperinsulinaemia, az inzulinrezisztencia, a metabolikus szindróma öregedést gyorsító hatását, az inzulinszeru növekedési hormon-1 ellentmondásos szerepét, valamint az élet meghosszabbításában részt vevo, újabban felfedezett peptideket, mint a klotho és a humanin. Ismertettük a mitochondriumok szerepét az élettartam meghatározásában, bemutattuk a mitohormesis folyamatát és annak stresszvédo funkcióját. Bemutattuk a rapamicin célszervét, az mTOR-t, amelynek gátlása meghosszabbítja az élettartamot, valamint a szirtuinokat. Kitértünk az autophagia folyamatára, és ismertettük a szenolitikumok szerepét az öregedésben. Az idoskori autoimmunitás csökkenése hozzájárul az élettartam rövidüléséhez, utaltunk a thymus koordináló szerepére. Kiemeltük a bélmikrobiom fontos szerepét az élettartam szabályozásában. Hivatkoztunk a "centenáriusok" megfigyelésébol nyert humánadatokra. Megvizsgáltuk, milyen beavatkozási lehetoségek állnak rendelkezésre az egészségben töltheto élettartam meghosszabbításához. Az életmódbeli lehetoségek közül kiemeltük a kalóriabevitel-csökkentés és a testmozgás jótékony szerepét. Megvizsgáltuk egyes gyógyszerek feltételezett hatásait. Ezek közé tartozik a metformin, az akarbóz, a rezveratrol. E gyógyszerek mindegyikének hatása hasonló a kalóriamegszorításéhoz. Nincs olyan "csodaszer", amely igazoltan meghosszabbítja az élettartamot emberben. Egyes géneknek és génmutációknak jótékony hatásuk van, de ezt környezeti tényezok, betegségek, balesetek és más külso ártalmak módosíthatják. Kiemeljük az elhízás, az alacsony fokozatú gyulladás és az inzulinrezisztencia öregedésre gyakorolt gyorsító hatását. A metabolikus szindróma elterjedtsége miatt ez jelentos népegészségügyi kockázatot jelent. Az inzulin, a növekedési hormon és az inzulinszeru növekedési faktorok hatásainak értékelése továbbra is ellentmondásos. Az egészséges, szellemileg és fizikailag aktív életmód, a kalóriacsökkentés mindenképpen elonyös. Az életet meghosszabbító szerek értékelése még vitatott. Orv Hetil. 2021; 162(33): 1318-1327. Summary. People want to live as long as possible in good health. If we eliminate the unfavorable external conditions, the life expectancy could exceed 100 years. In the 20th and 21th centuries, life expectancy in welfare societies increased significantly, including in Hungary. Based on the reviewed literature, we examined what endocrinological and metabolic factors play a role in prolonging life in addition to genetics and inheritance. We examined all endogenous factors that can positively or negatively affect age-related diseases (Alzheimer's disease, cardiovascular disease, cancer) and longevity. We highlighted the aging effects of hyperinsulinemia, insulin resistance, metabolic syndrome, the controversial role of insulin-like growth factor-1, and more recently discovered peptides involved in prolonging lifespan, such as klotho and humanin. We described the role of mitochondria in determining longevity, we demonstrated the process of mitohormesis and its stress-protective function. We presented the target organ of rapamycin, mTOR, the inhibition of which prolongs lifespan, as well as sirtuins. We covered the process of autophagy and described the role of senolytics in aging. The decrease in autoimmunity in old age contributes to the shortening of life expectancy, we referred to the coordinating role of the thymus. We highlighted the important role of intestinal microbiome in the regulation of longevity. We referred to human data obtained from observations on "centenarians". We examined what intervention options are available to prolong healthy life expectancy. Among the lifestyle options, we highlighted the beneficial role of calorie reduction and exercise. We examined the putative beneficial effects of some drugs. These include metformin, acarbose, resveratrol. The effect of each of these drugs is similar to calorie restriction. There is no "miracle cure" that has been shown to prolong life-span in humans. Some genes and gene mutations have beneficial effects, but this can be modified by environmental factors, diseases, accidents, and other external harms. We highlight the accelerating effects of obesity, low-grade inflammation, and insulin resistance on aging. Due to the prevalence of metabolic syndrome, this poses a significant risk to public health. The assessment of the effects of insulin, growth hormone, and insulin-like growth factors remains controversial. A healthy, mentally and physically active lifestyle, calorie reduction is definitely beneficial. The evaluation of life-prolonging agents is still controversial. Orv Hetil. 2021; 162(33): 1318-1327.

[The physiological role of growth hormone and insulin-like growth factors]. / A növekedési hormon és az inzulinszeru növekedési faktorok élettani szerepe.

The existence of insulin-like growth factors (IGFs) was recognized in connection with the stimulation of sulfate incorporation into cartilage. IGFs take part in the embryonal development and postnatal growth, in interaction with the growth hormone (GH). The physiological effects of IGF1 are promotion of tissue growth and development, stimulation of cell proliferation, effects on lipid and carbohydrate metabolism, anti-aging, anti-inflammatory, anabolic, anti-oxidant, neuro- and hepatoprotective properties. Our knowledge about the GH/IGF axis is diverse, partly contradictory, their research is continued intensively nowadays. We considered it worthwhile to review and interpret this information. Study on GH/IGF medical reports, with particular reference to the less known metabolic control. 75% of the growth factors are produced in the liver by GH and insulin stimulation; their effects are expressed on specific receptors, and modified by specific binding proteins. IGF1 directly increases the muscle mass, bone density, and the structure of the bones. Intestinal microbiota induces secretion of IGF1, which promotes the development and remodeling of the bones. Short-chain fatty acids, produced in microbial fermented fibers, induce secretion of IGF1, suggesting that microbial activity also affects bone health via IGF1. IGF1 also has a direct and indirect glucose-lowering effect, enhances free fatty acid oxidation in the muscle, reducing the flow of free fatty acid into the liver, improving insulin signaling, resulting in the reduction of hepatic glucose output, and improves insulin sensitivity. IGF1 directly influences the expression of circadian BMAL1 in hypothalamic cells: this refers to the newly recognized 'zeitgeber' role of IGF1. The bioactivity of insulin-like peptides in the brain is characterized by neuronal survival, excitatory and inhibitory neurotransmission, maintenance of normal free fatty acid levels, improvement of cognitive function, protection against cell damage, neurogenesis and angiogenesis. The effects of IGF2 are less outlined, however, it has a relevant role in the development of the fetus, and acts protectively on the brain. Lack or over-expression of IGF1 can be detected or may causally associated in many pathological conditions. According to these collected data, insulin sensitivity may be improved by different pathways. The role of IGFs in these processes should be a task of future research. Orv Hetil. 2019; 160(45): 1774-1783.

[Non-alcoholic fatty liver disease, as a component of the metabolic syndrome, and its causal correlations with other extrahepatic diseases]. / A nem alkoholos zsírmáj mint a metabolikus szindróma komponense és kauzális kapcsolatai egyéb kórképekkel.

Non-alcoholic fatty liver disease is the most common non-infectious chronic liver-disease in our age, and is a spectrum of all the diseases associated with increased fat accumulation in the hepatocytes. Its development is promoted by sedentary life-style, over-feeding, and certain genetic predisposition. Prevalence in the adult population, even in Hungary is ~30%. In a part of cases, this disease may pass into non-alcoholic steatohepatitis, later into fibrosis, rarely into primary hepatocellular cancer. Fatty liver is closely and bidirectionally related to the metabolic syndrome and type 2 diabetes, and nowadays there is a general consensus that fatty liver is the hepatic manifestation of the metabolic sycndrome. The importance of the fatty liver has been highly emphasized recently. In addition to the progression into steatohepatitis, its causal relationship with numerous extrahepatic disorders has been discovered. In our overview, we deal with the epidemiology, pathomechanism of the disease, discuss the possibilities of diagnosis, its relationship with the intestinal microbiota, its recently recognized correlations with bile acids and their receptors, and its supposed correlations with the circadian CLOCK system. Hereinafter, we overview those extrahepatic disorders, which have been shown to be causal link with the non-alcoholic fatty liver disease. Among these, we emphasize the metabolic syndrome/type 2 diabetes, cardiovascular disorders, chronic kidney disease, sleep apnea/hypoventilation syndrome, inflammatory bowel disease, Alzheimer's disease, osteoporosis, and psoriasis, as well. Based on the above, it can be stated, that high risk individuals with non-alcoholic fatty liver disease need systemic care, and require the detection of other components of this systemic pathological condition. While currently specific therapy for the disease is not yet known, life-style changes, adequate use of available medicines can prevent disease progression. Promising research is under way, including drugs, manipulation of the intestinal flora or the possibility of therapeutic use of bile acid receptors, and also bariatric surgery. Orv Hetil. 2017; 158(52): 2051-2061.

[Alzheimer's disease and diabetes - the common pathogenesis]. / Alzheimer-kór és diabétesz mellitusz - a közös patomechanizmus.

Epidemiological studies presented evidence that Alzheimer's disease and type 2 diabetes share common features in their pathophysiology and clinical patterns. Insulin resistance is a characteristic feature of both diseases. According to the pathomechanism, inflammatory, metabolic, and an atypical form based on the deficiency of zinc ions can be distinguished. Glucose metabolic disorders, related to Alzheimer's disease, are type 2 diabetes, and prediabetes/metabolic syndrome. Based on the common pathophysiological patterns of these two diseases, Alzheimer's disease is customary called type 3 diabetes. In the research on dementias, insulin resistance stands in the highlight for its documented harmful effects on cognitive function and causes dementia. Insulin-like growth factor also influences cognitive functions. Reduced input of this hormone into the brain may also cause dementia, however literary data are controversial. In Alzheimer's disease, deposition of amyloid ß in the brain, hyperphosphorylation of tau proteins and dysruption of neurofibrilles are characteristic. Amyloid ß is co-secreted in the ß-cells of the pancreas with insulin. Amyloid ß and hyperphosphorylated tau protein were detected in the Langerhans islets by autopsy. Amyloid deposits, found in the pancreas and brain presented similarities. As a consequence of hyperglycemia, glycation endproducts cause the development of amyloid plaques, dysruption of neurofibrilles, and activated microglia, all are typical to Alzheimer's disease. Continuous hyperglycemia leads to oxidative stress, which used to play significant role in the development of both diseases. Low-grade inflammation is also a significant pathophysiological factor in both disorders. The sources of inflammation are proinflammatorical adipocytokines, dysbacteriosis, metabolic endotoxaemia, caused by lipopolysaccharides, and high fat diet which also lead to insulin resistance. Based on recent data, microbial amyloid, the main product of bacteria, is also contributing to the pathophysiology of the human central nervous system. Alzheimer's disease is a heterogeneous disorder, and as yet there is no effective therapy. Encouraging results have emerged by using intranasal insulin spray. Insulin sensitizers like metformin, thiazolidines have also resulted in improvements in cognitive functions, mainly in animal experiments. Glucagon-like peptide-1, beyond its insulin-stimulating effect, also has central pleiotropic influences. Research results with the application of these molecules seem to be enouraging. More recently, glucagon-like peptide-1, and glucose-dependent insulinotropic peptide were administered together, with promising early results. The real breakthrough has not yet arrived. For the time being we have to endeavour to the prevention of both chronic diseases via a more healthy life-style.

[Physiological patterns of intestinal microbiota. The role of dysbacteriosis in obesity, insulin resistance, diabetes and metabolic syndrome]. / A bélbakterióta élettani jellemzoi és a dysbacteriosis szerepe az elhízásban, inzulinrezisztenciában, diabetesben és metabolikus szindrómában.

The intestinal microbiota is well-known for a long time, but due to newly recognized functions, clinician's attention has turned to it again in the last decade. About 100 000 billion bacteria are present in the human intestines. The composition of bacteriota living in diverse parts of the intestinal tract is variable according to age, body weight, geological site, and diet as well. Normal bacteriota defend the organism against the penetration of harmful microorganisms, and has many other functions in the gut wall integrity, innate immunity, insulin sensitivity, metabolism, and it is in cross-talk with the brain functions as well. It's a recent recognition, that intestinal microbiota has a direct effect on the brain, and the brain also influences the microbiota. This two-way gut-brain axis consists of microbiota, immune and neuroendocrine system, as well as of the autonomic and central nervous system. Emerging from fermentation of carbohydrates, short-chain fatty acids develop into the intestines, which produce butyrates, acetates and propionates, having favorable effects on different metabolic processes. Composition of the intestinal microbiota is affected by the circadian rhythm, such as in shift workers. Dysruption of circadian rhythm may influence intestinal microbiota. The imbalance between the microbiota and host organism leads to dysbacteriosis. From the membrane of Gram-negative bacteria lipopolysacharides penetrate into the blood stream, via impaired permeability of the intestinal mucosa. These processes induce metabolic endotoxaemia, inflammation, impaired glucose metabolism, insulin resistance, obesity, and contribute to the development of metabolic syndrome, type 2 diabetes, inflammarory bowel diseases, autoimmunity and carcinogenesis. Encouraging therapeutic possibility is to restore the normal microbiota either using pro- or prebiotics, fecal transplantation or bariatric surgery. Human investigations seem to prove that fecal transplant from lean healthy individuals into obese diabetic patients improved all the pathological parameters. Wide spread use of bariatric surgery altered gut microbiota and improved metabolic parameters apart from surgery itself. Pathomechanism is not yet completely clarified. Clinicians hope, that deeper understanding of complex functions of intestinal microbiota will contribute to develop more effective therapeutic proceedings against diabetes, metabolic syndrome, and obesity.

[The secretory function of skeletal muscles and its role in energy metabolism and utilization]. / A vázizomzat szekretoros muködésének szerepe az anyagcserében és az energiaforgalomban.

It is well-known for a long-time, that intensive exercise is favourable for many metabolic parameters. Up-till now the exact mechanism has not been clarified. Recently it has turned out, that the muscular system is an extended endocrine organ, which, during contraction, secretes many hundred peptides, so called adipomyokines into the blood stream. Many of them improve glucose-utilization of the muscular system, and insulin-sensitivity, via endocrine, paracrine, or autocrine pathways. Worldwide intensive research takes place to clear up the exact pathomechanism of these processes. It came to light: 1. The newly discovered adipomyokine, irisin induces "browning" of beige precursor fat-cells, which are present in white adipose tissue. The developed beige adipose tissue by this way disposes with the advantegous properties of the brown adipose tissue. Taking together these facts, irisin might be a therapeutic choice in treating certain diseases, caused by inactive life-style. 2. Therapeutic application of brown adipose tissue in obesity, metabolic syndrome, and type 2 diabetes seems to be successful. This mechanism is based on removal of unnecessary calories via thermogenesis. 3. The role of myostatin, which is also produced by muscle contraction, is contradictory. It is not clear, why does the muscle system produce damaging product for the metabolism. On the other hand, inhibition of myostatin might be a therapeutic option. It is still questionable, whether the other hundreds of myokines could possess practicable roles on glucose, lipid, insulin secretion/effects. At present one can establish, that regular exercise is essential for the everyday practise, in order to optimise quality of life.

[Physiological and pathophysiological role of the circadian clock system]. / A cirkadián CLOCK-rendszer élettani és patológiai szerepe.

It has been well known for ages that in living organisms the rhythmicity of biological processes is linked to the ~ 24-hour light-dark cycle. However, the exact function of the circadian clock system has been explored only in the past decades. It came to light that the photosensitive primary "master clock" is situated in the suprachiasmatic photosensitive nuclei of the special hypothalamic region, and that it is working according to ~24-hour changes of light and darkness. The master clock sends its messages to the peripheral "slave clocks". In many organs, like pancreatic ß-cells, the slave clocks have autonomic functions as well. Two essential components of the clock system are proteins encoded by the CLOCK and BMAL1 genes. CLOCK genes are in interaction with endonuclear receptors such as peroxisoma-proliferator activated receptors and Rev-erb-α, as well as with the hypothalamic-pituitary-adrenal axis, regulating the adaptation to stressors, energy supply, metabolic processes and cardiovascular system. Melatonin, the product of corpus pineale has a significant role in the functions of the clock system. The detailed discovery of the clock system has changed our previous knowledge about the development of many diseases. The most explored fields are hypertension, cardiovascular diseases, metabolic processes, mental disorders, cancers, sleep apnoe and joint disorders. CLOCK genes influence ageing as well. The recognition of the periodicity of biological processes makes the optimal dosing of certain drugs feasible. The more detailed discovery of the interaction of the clock system might further improve treatment and prevention of many disorders.

[Role of the brain in the regulation of metabolism and energy expenditure: the central role of insulin, and insulin resistance of the brain]. / Az agy szerepe az anyagcsere és energiaforgalom szabályozásában: az inzulin központi idegrendszeri hatásai, az agy inzulinrezisztenciája.

Regulatory role of the brain in energy expenditure, appetite, glucose metabolism, and central effects of insulin has been prominently studied. Certain neurons in the hypothalamus increase or decrease appetite via orexigenes and anorexigenes, regulating energy balance and food intake. Hypothalamus is the site of afferent and efferent stimuli between special nuclei and beta- and alpha cells, and it regulates induction/inhibition of glucose output from the liver. Incretines, produced in intestine and in certain brain cells (brain-gut hormones), link to special receptors in the hypothalamus. Central role of insulin has been proved both in animals and in humans. Insulin gets across the blood-brain barrier, links to special hypothalamic receptors, regulating peripheral glucose metabolism. Central glucose sensing, via "glucose-excited" and "glucose-inhibited" cells have outstanding role. Former are active in hyperglycaemia, latter in hypoglycaemia, via influencing beta- and alpha cells, independently of traditional metabolic pathways. Evidence of brain insulin resistance needs centrally acting drugs, paradigm changes in therapy and prevention of metabolic syndrome, diabetes, cardiovascular and oncological diseases.

[The metabolic syndrome and type-2 diabetes mellitus as conditions predisposing for malignant tumors]. / A metabolikus szindróma és a 2-es típusú diabetes mellitus mint rosszindulatú daganatra hajlamosító állapotok.

Recently more and more evidences have emerged about the oncogenic effect of type 2 diabetes and metabolic syndrome. Among these evidences epidemiological data are in first line. There is a causal relationship according to gender, ethnicity and geographic situation between different tumors and type 2 diabetes/metabolic syndrome as well. Supposed pathomechanisms are obesity, cytokines, secreted excessively in adipose tissue, permanent and postprandial hyperglycemia, hyperinsulinism and insulin resistance, other growth factors, like proinsulin, insulin like growth factor-1, reactive oxygen species, angiogenesis, inflammation, and the multiple effects of inflammatory cytokines. It proved to be evident that both peroxisome-proliferator-activated receptors and the regulatory ubiquitin proteasome system have significant role in insulin sensitivity and in co-ordinating cell proliferation and angiogenesis. These mechanisms in metabolic syndrome are risk factors towards atherosclerosis and cancer diseases as well. This newly emerged knowledge may open new pathways in treating and preventing the above-mentioned pathologic processes.

Tesaglitazar, a dual peroxisome proliferator-activated receptor alpha/gamma agonist, improves apolipoprotein levels in non-diabetic subjects with insulin resistance.

AIM: To determine the effects of the peroxisome proliferator-activated receptor (PPAR) alpha/gamma agonist tesaglitazar on serum levels of apolipoprotein (apo) A-I, apoB, and apoCIII in non-diabetic insulin-resistant subjects. METHODS: This randomized, double-blind, multicentre, placebo-controlled trial examined the effect of tesaglitazar (0.1, 0.25, 0.5, and 1mg) once daily for 12 weeks on apolipoprotein levels in 390 abdominally obese subjects with hypertriglyceridaemia. RESULTS: Tesaglitazar dose-dependently increased serum concentrations of apoA-I (p<0.009) and decreased concentrations of apoB (p<0.0001), the apoB/apoA-I ratio (p<0.0001), and apoCIII (p<0.0001). Similar improvements were observed in all subgroups of subjects, where individuals were grouped according to age, gender, baseline body mass index, serum triglycerides and high-density lipoprotein cholesterol levels. Low-density lipoprotein particle concentrations were also dose-dependently reduced by tesaglitazar (p<0.0001). CONCLUSION: Although tesaglitazar is no longer in clinical development, these data indicate that dual PPARalpha/gamma agonism may be a useful pharmacological approach to improve the atherogenic dyslipidaemia associated with insulin resistance.

[Current issues in the therapy of diabetes mellitus]. / A diabetes mellitus kezelésének aktuális kérdései.

Up-to-date therapy and patient care in diabetes started with reliable measuring of endogenous insulin in blood. In the past decades, extensive epidemiologic studies proved, that long lasting normoglycemia inhibits the development of chronic diabetic complications. It became also clear, that continuous normotension, and normal lipid values have equal protective effect. These new findings were in strong correlation with the adoption of the concept of the Metabolic Syndrome. Holistic patient care and therapy must include all pathologic alterations of the Syndrome. This concept also fertilised the therapeutic possibilities of the prevention. Cleaning of up-to-date insulin preparations, with their better timing effect, contributed a lot to achieve and maintain normoglycemia. Besides rapid acting insulin analogues, long acting analogues are available on the market, with a significantly smoother effect. These new preparations provide a near ideal insulin effect. Modern oral antidiabetics try to restore physiologic circumstances. Their combined application in type 2 diabetes--in the majority of these patients--is able to maintain normoglycemia. In case when oral drugs seem to be ineffective in obtaining physiologic conditions, insulin therapy should introduced as early, as possible. Data gained from up-to-date clinical investigations, offer evidence about inflammatory origin of atherosclerosis, type 2 diabetes, and the Metabolic Syndrome as well. This new concept changes very likely therapeutic implications in the (very) next future. It seems, that widespread and radical transformation about our notion according to the diabetes syndrome, has priority in everyday practice. New insulin and oral preparations--together with frequent home checking of blood pressure and blood sugar--just comply with our new concept.

[New diagnostic and classification system in diabetic syndrome]. / A diabetes szindróma új diagnosztikai és klasszifikációs rendszere.

Diabetes mellitus is a heterogeneous disorder. Evidence for heterogeneity is based on measuring endogenous insulin level since some forty years ago. Insulin is lacking at the time of diagnosis in most patients, whose disease started rapidly, with classical symptoms, and who are mainly children, adolescents or young adults. In the majority of middle-aged, obese diabetics, insulin levels are frequently high at diagnosis. Since insulin measuring from sera became a routine laboratory test these two main types were nominated as insulin-dependent, and insulin non-dependent types (IDDM and NIDDM). The aim of the recent classification was, that different diabetic subgroups should be based on etiologic evidence. (Previous classification was based mainly due to the current therapy!). To avoid confusing nominations, the recent classification recommended to abandon the acronyms, IDDM and NIDDM, and only type-1 and type-2 should be used In the third subgroup-other diabetic groups--there are selected many disorders, whose etiology is mostly clear. As fourth subgroup gestational diabetes preserved its previous place. There are some differential-diagnostic problems in between type-1 and type-2 subgroups, especially between lean body weight type-2 and-the newly discovered latent-onset diabetes in adults (LADA). Diagnostic criteria of diabetes and prediabetic states are being changed according to epidemiological data, because type-2 patients die frequently from cardio-cerebrovascular fatal disorders, and elevated blood sugar values-especially postprandially-contribute to it. Thresholds of blood sugar values for diagnosing diabetes are therefore decreasing, and a new category: impaired fasting glucose (IFG, blood sugar: 6, 1-7.0 mmol/l) was introduced. Impaired glucose tolerance (IGT) remained as prediabetic state. IGT + IFG are nominated as impaired glucoregulation. These two categories cover different populations. Oral glucose loading test in most problematic cases should be carried out. The clinical importance of postprandial hyperglycaemia (postprandial state) is discussed. As a new clinical concept, the Metabolic Syndrome seems to replace type-2 diabetes in the majority of these patients, even in the impaired glucose tolerance (IGT) state. Diabetics, carrying the features of this syndrome need holistic care.