Adipokines: the missing link between insulin resistance and obesity

Steatocholecystitis and fatty gallbladder disease

Obesity has become an epidemic worldwide. It is accompanied by a multitude of medical complications including metabolic syndrome. Obesity may lead to fatty infiltration of multiple internal organs including liver, heart, kidney, and pancreas, causing organ dysfunctions. Fatty infiltration leads to chronic inflammation and tissue damage. Fatty infiltration in the liver results in nonalcoholic fatty liver disease, which is increasingly common nowadays. Recent studies in animals and humans indicate that obesity also is associated with fatty infiltration of gallbladder, resulting in cholecystosteatosis. The increased gallbladder lipids include free fatty acids, phospholipids, and triglycerides. Enhanced inflammation with an increased amount of fat in the gallbladder results in an abnormal wall structure and decreased contractility. In support of this notion, a recent experiment on the effect of Ezetimibe, which is a novel drug that inhibits intestinal fat absorption, on fatty gallbladder disease reveals that Ezetimibe can ameliorate cholecystosteatosis and restore in vivo gallbladder contractility. The proportion of cholecystectomies performed for chronic acalculous cholecystitis has increased significantly over the past two decades. An increase in gallbladder fat, which leads to poor gallbladder emptying and biliary symptoms, may partly explain this phenomenon. Although dietary carbohydrates have been demonstrated to be associated with fatty gallbladder disease, other potential modifiable environmental factors are not clear. The pathogenesis and prognosis of fatty gallbladder disease, including steatocholecystitis, and the relations of fatty gallbladder disease to nonalcoholic fatty liver disease, including steatohepatitis, and other components of metabolic syndrome are largely unknown. More research is needed to answer these questions.

Body fat, insulin resistance, energy expenditure and serum concentrations of leptin, adiponectin and resistin before, during and after pregnancy in healthy Swedish women

Healthy human pregnancy is associated with changes in food intake, body fatness, energy expenditure and insulin resistance. However, available knowledge is limited regarding the physiological basis of these changes. Published evidence suggests that so-called adipokines (i.e. leptin, adiponectin and resistin) have significant roles when such changes are established. We explored, throughout a complete pregnancy, relationships between total body fat (TBF), energy expenditure, insulin resistance (homeostasic model of insulin resistance, HOMA-IR) and serum concentrations of leptin, adiponectin and resistin. Such concentrations were assessed before pregnancy in gestational weeks 8, 14, 20, 32 and 35, and 2 weeks postpartum in twenty-three healthy women. TBF, BMR (n 23) and HOMA-IR (n 17) were assessed before pregnancy in gestational weeks 14 and 32 and 2 weeks postpartum. TBF (%) was correlated with HOMA-IR (r 0.68-0.79, P < 0.01) and with serum leptin (r 0.85-0.88, P < 0.001) before and during pregnancy. Serum leptin was correlated with HOMA-IR (r 0.53-0.70, P < 0.05) before and during pregnancy. Serum adiponectin was inversely correlated with HOMA-IR in gestational week 32 (r - 0.52, P < 0.05). When HOMA-IR was regressed on TBF (%), the slope of the regression line was 0.046 before pregnancy, which was significantly (P < 0.05) different from the corresponding value, 0.111, in gestational week 32. The results indicate that pregnancy has an enhancing effect on the relationship between body fatness and insulin resistance. This effect, possibly mediated by leptin, may represent a mechanism by which offspring size is regulated in response to the nutritional situation of the mother.

Infection, immunity and the neuroendocrine response

The Central Nervous (CNS) and Immune Systems (IS) are the two major adaptive systems which respond rapidly to numerous challenges that are able to compromise health. The defensive response strictly linking innate to acquired immunity, works continuously to limit pathogen invasion and damage. The efficiency of the innate response is crucial for survival and for an optimum priming of acquired immunity. During infection, the immune response is modulated by an integrated neuro-immune network which potentiates innate immunity, controls potential harmful effects and also addresses metabolic and nutritional modifications supporting immune function. In the last decade much knowledge has been gained on the molecular signals that orchestrate this integrated adaptive response, with focus on the systemic mediators which have a crucial role in driving and controlling an efficient protective response. These mediators are also able to signal alterations and control pathway dysfunctions which may be involved in the persistence and/or overexpression of inflammation that may lead to tissue damage and to a negative metabolic impact, causing retarded growth. This review aims to describe some important signalling pathways which drive bidirectional communication between the Immune and Nervous Systems during infection. Particular emphasis is placed on pro-inflammatory cytokines, immunomodulator hormones such as Glucocorticoids (GCs), Growth hormone (GH), Insulin-like Growth Factor-1 (IGF-1), and Leptin, as well as nutritional factors such as Zinc (Zn). Finally, the review includes up-to-date information on this neuroimmune cross-talk in domestic animals. Data in domestic animal species are still limited, but there are several exciting areas of research, like the potential interaction pathways between mediators (i.e. cytokine-HPA regulation, IL-6-GCS-Zn, cytokines-GH/IGF-1, IL-6-GH-Leptin and thymus activity) that are or could be promising topics of future research in veterinary medicine.

Obesity and breast cancer: the roles of peroxisome proliferator-activated receptor-γ and plasminogen activator inhibitor-1

Breast cancer is the most prominent cancer among females in the United States. There are a number of risk factors associated with development of breast cancer, including consumption of a high-fat diet and obesity. Plasminogen activator inhibitor-1 (PAI-1) is a cytokine upregulated in obesity whose expression is correlated with a poor prognosis in breast cancer. As a key mediator of adipogenesis and regulator of adipokine production, peroxisome proliferator-activated receptor-γ (PPAR-γ) is involved in PAI-1 expression from adipose tissue. We summarize the current knowledge linking PPAR-γ and PAI-1 expression to high-fat diet and obesity in the risk of breast cancer.

Use of the metabolic syndrome in pediatrics: a blessing and a curse

The clustering of traditional cardiovascular disease risk factors is known as the metabolic syndrome. The metabolic syndrome was first characterized as a distinct entity by Dr. Gerald Reaven in 1988. The intent was to identify individuals at greatest risk for cardiovascular disease mortality and those in urgent need of lifestyle intervention. Since then the metabolic syndrome has evolved into a diagnosable entity recognized by the National Cholesterol Education Program, Adult Treatment Panel III, World Health Organization, and the International Diabetes Foundation. However, the metabolic syndrome as a diagnosis faces considerable controversy, particularly when applied to the pediatric population. Due to the changes in growth and development, the adult criteria for the metabolic syndrome cannot be applied to children and adolescents. In fact, currently no all-inclusive definition for the metabolic syndrome exists for pediatrics. Despite its controversies, the identification of the metabolic syndrome and its component disorders in childhood and adolescence offers important information about risk for cardiovascular disease. Emerging evidence points to the presence of early functional and morphologic changes to the heart and blood vessels among obese children with the metabolic syndrome phenotype. Yet, the plasticity of the cardiovascular system during childhood and adolescence allows for the reversal of cardiovascular damage, but only if risks are identified early and treated aggressively. Recent national recommendations and screening directives offer pediatricians a comprehensive guide to risk prevention, assessment, and treatment.

Different modulation by dietary restriction of adipokine expression in white adipose tissue sites in the rat

Background

White adipose tissue (WAT) is a disperse organ acting as energy storage depot and endocrine/paracrine controlling factor in the management of energy availability and inflammation. WAT sites response under energy-related stress is not uniform. In the present study we have analyzed how different WAT sites respond to limited food restriction as a way to better understand the role of WAT in the pathogenesis of the metabolic syndrome.

Methods

Overweight male rats had their food intake reduced a 40% compared with free-feeding controls. On day ten, the rats were killed; circulating glucose, insulin, leptin, adiponectin, triacylglycerols and other parameters were measured. The main WAT sites were dissected: mesenteric, retroperitoneal, epididymal and subcutaneous inguinal, which were weighed and frozen. Later all subcutaneous WAT was also dissected and weighed. Samples were used for DNA (cellularity) analysis and mRNA extraction and semiquantitarive RT-PCR analysis of specific cytokine gene expressions.

Results

There was a good correlation between serum leptin and cumulative WAT leptin gene mRNA, but not for adiponectin. Food restriction reduced WAT size, but not its DNA content (except for epididymal WAT). Most cytokines were correlated to WAT site weight, but not to DNA. There was WAT site specialization in the differential expression (and probably secretion) of adipokines: subcutaneous WAT showed the highest concentration for leptin, CD68 and MCP-1, mesenteric WAT for TNFα (and both tissues for the interleukins 1β and 6); resistin was highly expressed in subcutaneous and retroperitoneal WAT.

Conclusion

Food restriction induced different patterns for mesenteric and the other WAT sites, which may be directly related to both the response to intestine-derived energy availability, and an inflammatory-related response. However, retroperitoneal WAT, and to a lower extent, subcutaneous and epididymal, reacted decreasing the expression of inflammatory markers and the signaling of decreased energy availability in their stores. The varying cytokine expression patterns highlight the fact that WAT sites show different inflammatory and signaling responses to energy availability; they are too much different to simply extend to the whole-body WAT the findings of one or even a couple of sites.

Low serum IL-10 concentrations and loss of regulatory association between IL-6 and IL-10 in adults with major depression

Elevated circulating pro-inflammatory cytokines are associated with symptoms of depression, and disorders involving chronic inflammation are often co-morbid with major depression. Since healthy immune regulation is accomplished through counter-balancing effects of pro- and anti-inflammatory cytokines, we hypothesized that depressed subjects (compared to controls) would express lower concentrations of the anti-inflammatory/immunoregulatory cytokine interleukin (IL)-10, and a higher IL-6/IL-10 ratio. We also examined the possibility that depressed subjects may exhibit a deficiency in the regulatory loop involving IL-6 induced secretion of IL-10. Therefore, we hypothesized that circulating IL-6 and IL-10 would be positively correlated in controls, while the correlation would be weaker in depressed subjects. Resting state serum cytokine concentrations were quantified in 12 unmedicated depressed subjects, and 11 age, gender, and ethnicity-matched controls. Depressed subjects showed significantly lower IL-10 (p=0.03, Cohen's d=-0.96), non-significantly higher IL-6, and significantly higher IL-6/IL-10 ratios (p=0.05, Cohen's d=0.50). Across all participants, higher scores on the self-rated Inventory of Depressive Symptoms were associated with lower IL-10 (r(21)=-0.57, p=0.005) and non-significantly higher IL-6/IL-10 ratios (r(21)=0.38, p=0.07), but not related to IL-6 concentrations. As hypothesized, IL-6 and IL-10 concentrations were strongly and positively correlated in controls (r(9)=0.81, p=0.003), but were completely dissociated in depressed subjects (r(10)=0.01, p=0.98). These results suggest that lower IL-10 levels, a higher IL-6/IL-10 ratio, and the apparent absence of a counter-balancing, immunoregulatory increase in IL-10 in response to elevated IL-6 concentrations contribute to the pro-inflammatory physiological milieu that is known to be associated with major depression. Therefore, reduced induction/availability of IL-10, that would normally inhibit pro-inflammatory cytokine actions and resolve inflammation, may contribute to the depressogenic as well as the inflammatory disease-promoting effects of chronic, low-level elevations in pro-inflammatory cytokines.

Transition period-related changes in the abundance of the mRNAs of adiponectin and its receptors, of visfatin, and of fatty acid binding receptors in adipose tissue of high-yielding dairy cows

Adipose tissue expresses adipokines, which are involved in regulation of energy expenditure, lipid metabolism, and insulin sensitivity. To adapt for the transition from pregnancy to lactation, particularly in high-yielding dairy cows, adipokines, their receptors, and particular G-protein coupled receptors (GPRs) are of potential importance. Signaling by GPR 41 stimulates leptin release via activation by short-chain fatty acids; GPR 43/109A inhibits lipolysis, and GPR 109A thereby mediates the lipid-lowering effects of nicotinic acid and beta-hydroxybutyrate. The aim of this study was to compare the mRNA expression of adiponectin and visfatin, adiponectin receptors 1 and 2 (AdipoR1/2), leptin receptor (obRb), insulin receptor as of the aforementioned GPRs during the transition period in high-yielding dairy cows. Biopsies from subcutaneous fat and blood samples were obtained from 10 dairy cows 1 week before and 3 weeks after calving. For AdipoR1 and AdipoR2 mRNA abundance as well as for leptin concentrations in plasma, a reduction (P</=.05) was observed postpartum; for visfatin and putative GPR 109A mRNA abundance in adipose tissue, there was a trend (P<.1) for analogous changes. In contrast, the mRNA content of obRb and GPR 41 in adipose tissue was higher (P</=.05) in samples from early lactation than in those from late gestation. Our results indicate decreasing adiponectin sensitivity in adipose tissue after calving, which might be involved in the reduced insulin sensitivity of adipose tissue during early lactation. In addition, visfatin, GPR 41, and GPR 109A may further modulate insulin sensitivity.

Alternatively activated and immunoregulatory monocytes in human filarial infections

BACKGROUND

Monocytes/macrophages from filaria-infected animals exhibit an alternatively activated phenotype; however, very little is known about the alternative activation phenotype of monocytes in human filarial infection.

METHODS

To elucidate the activation and cytokine profile of monocytes in human filarial infection, we examined the expression patterns of genes encoding arginase, nitric oxide synthase 2, alternative activation markers, and cytokines in monocytes from individuals with asymptomatic filarial infection and individuals without filarial infection, ex vivo and in response to filarial antigen (Brugia malayi antigen [BmA]).

RESULTS

Monocytes from patients with asymptomatic filarial infection exhibited significantly diminished expression of NOS2 and significantly enhanced expression of ARG1. These changes were associated with significantly increased expression of the genes encoding resistin, mannose receptor C type 1 (MRC1), macrophage galactose type C lectin (MGL), and chemokine ligand 18 (CCL18). In response to BmA, purified monocytes from infected individuals also expressed significantly lower levels of interleukin (IL)-12 and IL-18 but, in contrast, expressed significantly higher levels of transforming growth factor beta, IL-10, and suppressor of cytokine signaling 1 mRNA. Inhibition of arginase-1 resulted in significantly diminished expression of the genes encoding resistin, MRC1, MGL, and CCL18, as well as significantly enhanced expression of NOS2 and the genes encoding IL-12 and IL-18.

CONCLUSION

Patent human filarial infection is associated with the presence of monocytes characterized by an alternatively activated immunoregulatory phenotype.

T cells cooperate with palmitic acid in induction of beta cell apoptosis

Background

Diabetes is characterized by progressive failure of insulin producing beta cells. It is well known that both saturated fatty acids and various products of immune cells can contribute to the reduction of beta cell viability and functionality during diabetes pathogenesis. However, their joint action on beta cells has not been investigated, so far. Therefore, we explored the possibility that leukocytes and saturated fatty acids cooperate in beta cell destruction.

Results

Rat pancreatic islets or insulinoma cells (RIN) were co-cultivated with concanavalin A (ConA)-stimulated rat lymph node cells (LNC), or they were treated with cell-free supernatants (Sn) obtained from ConA-stimulated spleen cells or from activated CD3⁺ cells, in the absence or presence of palmitic acid (PA). ConA-stimulated LNC or Sn and PA cooperated in inducing caspase-3-dependent RIN cell apoptosis. The observed effect of PA and Sn on RIN cell viability was mediated by p38 mitogen-activated protein kinase (MAPK)-signaling and was achieved through auto-destructive nitric oxide (NO) production. The cooperative effect of Sn was mimicked with the combination of interleukin-1β, interleukin-2, interleukin-6, interleukin-17, interferon-γ and tumor necrosis factor-α.

Conclusion

These results imply that stimulated T cells produce cytokines that cooperate with saturated free fatty acids in beta cell destruction during diabetes pathogenesis.

Insulin resistance and fuel homeostasis: the role of AMP-activated protein kinase

The worldwide prevalence of type 2 diabetes (T2D) and related disorders of the metabolic syndrome (MS) has reached epidemic proportions. Insulin resistance (IR) is a major perturbation that characterizes these disorders. Extra-adipose accumulation of lipid, particularly within the liver and skeletal muscle, is closely linked with the development of IR. The AMP-activated protein kinase (AMPK) pathway plays an important role in the regulation of both lipid and glucose metabolism. Through its effects to increase fatty acid oxidation and inhibit lipogenesis, AMPK activity in the liver and skeletal muscle could be expected to ameliorate lipid accumulation and associated IR in these tissues. In addition, AMPK promotes glucose uptake into skeletal muscle and suppresses glucose output from the liver via insulin-independent mechanisms. These characteristics make AMPK a highly attractive target for the development of strategies to curb the prevalence and costs of T2D. Recent insights into the regulation of AMPK and mechanisms by which it modulates fuel metabolism in liver and skeletal muscle are discussed here. In addition, we consider the arguments for and against the hypothesis that dysfunctional AMPK contributes to IR. Finally we review studies which assess AMPK as an appropriate target for the prevention and treatment of T2D and MS.

Loss of protein kinase Cbeta function protects mice against diet-induced obesity and development of hepatic steatosis and insulin resistance

Obesity is an energy balance disorder in which intake is greater than expenditure, with most excess calories stored as triglyceride (TG). We previously reported that mice lacking the beta-isoform of protein kinase C (PKCbeta), a diacylglycerol- and phospholipid-dependent kinase, exhibit marked reduction in the whole body TG content, including white adipose tissue (WAT) mass. To investigate the role of this signaling kinase in metabolic adaptations to severe dietary stress, we studied the impact of a high-fat diet (HFD) on PKCbeta expression and the effect of PKCbeta deficiency on profound weight gain. We report herein that HFD selectively increased PKCbeta expression in obesity-prone C57BL/6J mice, specifically in WAT; the expression levels were little or unchanged in the liver, muscle, kidney, and heart. Basal PKCbeta expression was also found to be elevated in WAT of obese ob/ob mice. Remarkably, mice lacking PKCbeta were resistant to HFD-induced obesity, showing significantly reduced WAT and slightly higher core body temperatures. Unlike lean lipodystrophic mouse models, these mice did not have fatty livers, nor did they exhibit insulin resistance. Moreover, PKCbeta(-/-) mice exhibited changes in lipid metabolism gene expression, and such alterations were accompanied by significant changes in serum adipokines. These observations suggest that PKCbeta deficiency induced a unique metabolic state congruous with obesity resistance, thus raising the possibility that dysregulation of PKCbeta expression could contribute to dietary fat-induced obesity and related disorders.

Retinol-binding protein 4 in polycystic ovary syndrome--association with steroid hormones and response to pioglitazone treatment

CONTEXT

Polycystic ovary syndrome (PCOS) is frequently associated with insulin resistance.

OBJECTIVE

The aim of the study was to investigate a putative role of the adipokines retinol-binding protein 4 (RBP4), adiponectin, and visfatin in a cohort of patients with PCOS and their response to treatment with pioglitazone.

DESIGN AND SETTING

We conducted a randomized, controlled, double-blind study at a tertiary referral center.

PATIENTS AND INTERVENTIONS

Forty premenopausal women with PCOS were allocated to receive treatment with either pioglitazone (30 mg/d) or a placebo for a period of 3 months.

MAIN OUTCOME MEASURES

Serum concentrations of RBP4, adiponectin, and visfatin were determined along with metabolic and hormonal parameters before and after treatment.

RESULTS

Serum adiponectin concentrations were higher after treatment with pioglitazone (P = 0.003), whereas RBP4 levels tended to decrease (P = 0.06), and visfatin concentrations remained unchanged. We found RBP4 serum concentrations at baseline to be positively correlated with serum levels of testosterone (R = 0.446; P = 0.005), 17-OH progesterone (R = 0.345, P = 0.037), and dehydroepiandrosterone sulfate (R = 0.347; P = 0.041). However, these correlations were abolished after treatment with pioglitazone. Patients with high RBP4 levels had significantly higher hirsutism scores (P = 0.038 before and P = 0.034 after treatment). In contrast, serum adiponectin concentrations were related to parameters of impaired glucose metabolism, and no significant associations were detected for visfatin.

CONCLUSIONS

Our results suggest that RBP4 may contribute to endocrine changes and to the phenotypic manifestation of patients with PCOS because higher RBP4 concentrations are associated with higher androgen levels and higher clinical hirsutism scores independently of pioglitazone treatment. The molecular involvement of RBP4 in human steroid metabolism requires further clarification.

Molecular mechanisms of insulin resistance in obesity and type 2 diabetes mellitus

A zsírszövetben az inzulinreceptor jelátviteli folyamatait auto-, para- és endokrin hatásokkal szabályozó számos fehérje termelődik és szekretálódik. Ezek közül több, így a tumornekrózis-faktor-α és szolúbilis receptor formái, az sTNFR1 és sTNFR2, a rezisztin, retinolkötő fehérje-4, plazminogénaktivátor-inhibitor, lipokain-1 gátolja az inzulin jelátviteli folyamatait és inzulinrezisztenciát okoz, elsősorban a zsírszövetben, a májban, az izomszövetben, az agyban, az endothelsejtekben, valamint a hasnyálmirigy β-sejtjeiben. Más fehérjék, így az adiponektin, visfatin, vaspin, omentin, apelin és chemerin pedig javítják az inzulinreceptor jelátvitelét. Az összefoglalás áttekinti az inzulinreceptor jelátviteli folyamatainak főbb részleteit és kitér az elhízásban, valamint a 2-es típusú cukorbetegségben észlelhető inzulin- és citokinrezisztenciák patomechanizmusában a közelmúltban megismert molekuláris tényezőkre (például a suppressor of cytokine signaling fehérje család).

Metabolic syndrome pathophysiology: the role of adipose tissue

The metabolic syndrome comprises a set of metabolic and physiological risk factors associated with elevated cardiovascular disease risk. The expression of each one of its major factors (hypertriglyceridemia, low high-density lipoprotein cholesterol levels, hypertension, abdominal obesity, and insulin resistance) has been found to be the result of complex interactions between genetic and environmental factors. Moreover, one of them, obesity, may play a major role in triggering the metabolic syndrome by interacting with genetic variants at candidate genes for dyslipidemia, hypertension, and insulin resistance. In support of this hypothesis, several studies at several candidate genes, mainly adipokines and perilipin, have already demonstrated the significance of these interactions; however, the information and its solidity are still very limited and in many cases, replication studies are still lacking in the literature. Therefore, more studies with better epidemiological design and standardized adiposity measures are needed to estimate the contribution of body weight and fat distribution to the genetic predisposition to the metabolic syndrome, the most common CVD risk factor in industrialized societies.

Beta-conglycinin embeds active peptides that inhibit lipid accumulation in 3T3-L1 adipocytes in vitro

Obesity is a worldwide health concern because it is a well-recognized predictor of premature mortality. The objective was to identify soybean varieties that have improved potential to inhibit fat accumulation in adipocytes by testing the effects of soy hydrolysates having a range of protein subunit compositions on lipid accumulation and adiponectin expression in 3T3-L1 adipocytes. The results showed that differences in the protein distribution of 15 soy genotypes led to different potentials for the reduction of fat accumulation. The inhibition of lipid accumulation of soy alcalase hydrolysates in 3T3-L1 adipocytes ranged from 29 to 46%. Soy hydrolysates made from genotypes with 45.3 +/- 3.3% of total protein as beta-conglycinin, on average, showed significantly higher inhibition of lipid accumulation compared to those with 24.7 +/- 1.5% of extracted total protein as beta-conglycinin. Moreover, after in vitro simulated digestion with pepsin-pancreatin of the soy alcalase hydrolysates, 86% of the original activity remained. Adiponectin expression was induced in 3T3-L1 adipocytes treated with 15 soy hydrolysates up to 2.49- and 2.63-fold for high and low molecular weight adiponectin, respectively. The inhibition of lipid accumulation calculated from a partial least squares (PLS) analysis model correlated well with experimental data (R(2) = 0.91). In conclusion, it was feasible to differentiate soy varieties on the basis of the potential of their proteins to reduce fat accumulation using a statistical model and a cell-based assay in vitro. Furthermore, beta-conglycinin embeds more peptides than glycinin subunits that inhibit lipid accumulation and induce adiponectin in 3T3-L1 adipocytes. Therefore, soy ingredients containing beta-conglycinin may be important food components for the control of lipid accumulation in adipose tissue.

Obesity and vulnerability of the CNS

The incidence of obesity is increasing worldwide, and is especially pronounced in developed western countries. While the consequences of obesity on metabolic and cardiovascular physiology are well established, epidemiological and experimental data are beginning to establish that the central nervous system (CNS) may also be detrimentally affected by obesity and obesity-induced metabolic dysfunction. In particular, data show that obesity in human populations is associated with cognitive decline and enhanced vulnerability to brain injury, while experimental studies in animal models confirm a profile of heightened vulnerability and decreased cognitive function. This review will describe findings from human and animal studies to summarize current understanding of how obesity affects the brain. Furthermore, studies aimed at identifying key elements of body-brain dialog will be discussed to assess how various metabolic and adipose-related signals could adversely affect the CNS. Overall, data suggest that obesity-induced alterations in metabolism may significantly synergize with age to impair brain function and accelerate age-related diseases of the nervous system. Thus, enhanced understanding of the effects of obesity and obesity-related metabolic dysfunction on the brain are especially critical as increasing numbers of obese individuals approach advanced age.

Is there a unique measuring method to assess obesity?

Az elhízás mértékének megállapítására nincs egységesen elfogadott mérőmódszer.Célkitűzésannak megállapítása, hogy milyen összefüggés van a testtömegindex, a testzsírszázalék és a haskörfogat alapján felállított kategóriák és az inzulinrezisztencia, a szérumleptin és -rezisztin koncentrációja között.Módszerek:A vizsgálatot 101 fiú és 115 lány részvételével végezték el. Mérték a testmagasságot, a testtömeget, a haskörfogatot, a testösszetételt pedig InBody3 bioimpedancia-készülékkel határozták meg. A testtömegindexet és a testzsírszázalékot a készülék számította ki. A szérumban a glükózinzulin-, a leptin- és a rezisztintartalom került meghatározásra. Az inzulinrezisztencia mértékét a HOMAIRmodellel becsülték meg.Eredmények:A testzsírszázalék, a szérumleptin és -rezisztin koncentrációja szignifikánsan nagyobb volt a lányok, mint a fiúk esetében. A testtömegindex, a testzsírszázalék és a haskörfogat növekedésével összhangban szignifikánsan nőtt mind a HOMAIR-érték, mind a szérumleptin koncentrációja. A túlsúlyos fiúk – akik, a testzsírszázalék alapján elhízottaknak bizonyultak – szérumleptin-koncentrációja szignifikánsan nagyobb volt, mint nem elhízott társaiké.Következtetés:Mind az epidemiológiai vizsgálatokban, mind a táplálkozási intervenciókban szükséges lenne a testösszetétel meghatározása a szervezetben lezajló biokémiai változások nyomon követése érdekében.

Is adiposopathy (sick fat) an endocrine disease?

OBJECTIVE

To review current consensus and controversy regarding whether obesity is a 'disease', examine the pathogenic potential of adipose tissue to promote metabolic disease and explore the merits of 'adiposopathy' and 'sick fat' as scientifically and clinically useful terms in defining when excessive body fat may represent a 'disease'.

METHODS

A group of clinicians and researchers, all with a background in endocrinology, assembled to evaluate the medical literature, as it pertains to the pathologic and pathogenic potential of adipose tissue, with an emphasis on metabolic diseases that are often promoted by excessive body weight.

RESULTS

The data support pathogenic adipose tissue as a disease. Challenges exist to convince many clinicians, patients, healthcare entities and the public that excessive body fat is often no less a 'disease' than the pathophysiological consequences related to anatomical abnormalities of other body tissues. 'Adiposopathy' has the potential to scientifically define adipose tissue anatomic and physiologic abnormalities, and their adverse consequences to patient health. Adiposopathy acknowledges that when positive caloric balance leads to adipocyte hypertrophy and visceral adiposity, then this may lead to pathogenic adipose tissue metabolic and immune responses that promote metabolic disease. From a patient perspective, explaining how excessive caloric intake might cause fat to become 'sick' also helps provide a rationale for patients to avoid weight gain. Adiposopathy also better justifies recommendations of weight loss as an effective therapeutic modality to improve metabolic disease in overweight and obese patients.

CONCLUSION

Adiposopathy (sick fat) is an endocrine disease.

Association between serum neopterin, obesity and daytime sleepiness in patients with obstructive sleep apnea

OBJECTIVE

Obesity and obstructive sleep apnea (OSA) and systemic inflammation may interact through biochemical pathways. Neopterin (NP) is a monocyte/macrophage activation marker produced by macrophages in response to interferon-gamma secreted by activated T-lymphocytes. This study examines the association between NP, obesity and OSA.

PATIENTS AND METHODS

The study included 22 newly diagnosed OSA (+) patients and 18 OSA (-) patients. Subjects with history of coronary artery disease, transplant patients, history of alcohol and drug abuse, history of HIV and any other significant medical illnesses such as active infections, autoimmune disease, malignancy, liver disease, pulmonary disease (COPD, asthma,...), neuromuscular disease, patients on immunomodulating therapy or HMG-CoA reductase inhibitors were excluded.

RESULTS

There were no significant differences in age, body mass index (BMI), and smoking habits of the OSA (+) patients and OSA (-) patients. Serum NP levels did not show any significant difference between the OSA (+) patients and OSA (-) patients, however, NP levels were positively correlated with BMI (r=0.320, p=0.044). There was no significant correlation between NP and any of the polysomnographic parameters. The result of stepwise regression analyses (r(2)=0.320, p<0.001) showed that high serum NP levels (p=0.004) and apnea-hypopnea index (AHI) were a risk factor for elevated Epworth sleepiness score, independent of BMI.

CONCLUSION

We suggest that serum NP levels correlate with BMI. There was a significant relationship between serum NP levels and excessive daytime sleepiness in OSA patients.