Adipose tissue is at a point of high interest in medical research, not only as an energy depot, but also because it secretes nearly more than 600 cytokines. These are termed‚ adipokines’. Human adipokines are involved in numerous metabolic processes, including the regulation of appetite, energy expenditure, insulin sensitivity, inflammation and cardiovascular activity. Thus, these could be clinically important as a markers of adipose tissue function and increased metabolic risk. The search for novel adipokines linking obesity to related co-morbidities has become a major topic in obesity research. In such work, there is an increasing need to define their function, their molecular targets and their potential clinical relevance as biomarkers or in the treatment of obesity and other metabolic diseases. Omentin (34 kDa) is a recently identified fat deposition-specific adipokine with multiple interactions. Concentrations of omentin have been shown to be decreased in patients with obesity and impaired glucose regulation, in patients afflicted with diabetes type 1 and 2, and in patients with polycystic ovary syndrome. These are all diseases commonly associated with insulin resistance and obesity. The aim of this study was to show and compare the latest information about omentin and its relationships with obesity, diabetes mellitus (DM), metabolic syndrome (MetS), inflammation, cardiac problems, sex hormone imbalances and cancer. The association of omentin with particular metabolic indexes may suggest that an elevation in omentin level may be seen as being a marker for leanness, while a decreased level will underline possible situations of overweight and obesity along with their comorbidities (diabetes, cardiovascular disease, metabolic syndrome, inflammation and even cancer). However, a challenge for the future is to fully understand the multiple role played by omentin. Thus, more studies in these matter are required.

Abstract:Disturbances in the metabolism of lipoprotein profiles and oxidative stress in hemodialyzed (HD) and post-renal transplant (Tx) patients are proatherogenic, but elevated concentrations of plasma high-density lipoprotein (HDL) reduce the risk of cardiovascular disease. We investigated the concentrations of lipid, lipoprotein, HDL particle, oxidized low-density lipoprotein (ox-LDL) and anti-ox-LDL, and paraoxonase-1 (PON-1) activity in HD (n=33) and Tx (n=71) patients who were non-smokers without active inflammatory disease, liver disease, diabetes, or malignancy. HD patients had moderate hypertriglyceridemia, normocholesterolemia, low HDL-C, apolipoprotein A-I (apoA-I) and HDL particle concentrations as well as PON-1 activity, and increased ox-LDL and anti-ox-LDL levels. Tx patients had hypertriglyceridemia, hypercholesterolemia, moderately decreased HDL-C and HDL particle concentrations and PON-1 activity, and moderately increased ox-LDL and anti-ox-LDL levels as compared to the reference, but ox-LDL and anti-ox-LDL levels and PON-1 activity were more disturbed in HD patients. However, in both patient groups, lipid and lipoprotein ratios (total cholesterol (TC)/HDL-C, LDL-C/HDL-C, triglyceride (TG)/HDL-C, HDL-C/non-HDL-C, apoA-I/apoB, HDL-C/apoA-I, TG/HDL) were atherogenic. The Spearman's rank coefficient test showed that the concentration of ox-LDL correlated positively with HDL particle level (R=0.363, P=0.004), and negatively with TC (R=−0.306, P=0.012), LDL-C (R=−0.283, P=0.020), and non-HDL-C (R=−0.263, P=0.030) levels in Tx patients. Multiple stepwise forward regression analysis in Tx patients demonstrated that ox-LDL concentration, as an independent variable, was associated significantly positively with HDL particle level. The results indicated that ox-LDL and decreased PON-1 activity in Tx patients may give rise to more mildly-oxidized HDLs, which are less stable, easily undergo metabolic remodeling, generate a greater number of smaller pre-β-HDL particles, and thus accelerate reverse cholesterol transport, which may be beneficial for Tx patients. Further studies are necessary to confirm this.

High-density lipoprotein (HDL) remodeling within the plasma compartment and the association between lecithin-cholesterol acyltransferase (LCAT) and cholesterol ester transfer protein (CETP) activity, and lipid, lipoprotein concentrations and composition were investigated. The aim was to examine the high sensitivity of C-reactive protein (hsCRP), lipid, apolipoprotein B (apoB), apoAI, total apoAII, apoAIInonB, apoB-containing apoAII (apoB:AII), total apoCIII, apoCIIInonB, apoB-containing apoCIII (apoB:CIII) concentration and LCAT and CETP activity to gain an insight into the association between them and LCAT and CETP, 57 post-renal transplant (Tx) patients with and without statin therapy and in 15 healthy subjects. Tx patients had moderate hypertriglyceridemia, hypercholesterolemia, and dyslipoproteinemia, disturbed triglyceride-rich lipoproteins (TRLs) and HDL composition, decreased LCAT, and slightly increased hsCRP but no CETP activity. Spearman’s correlation test showed the association between lipids and lipoproteins and LCAT or CETP, and multiple ridge stepwise forward regression showed that immunosuppressive therapy in Tx patients can disturb HDL and TRLs composition. The results suggest that inhibition or activation of LCAT is due, in part, to HDL-associated lipoprotein. Lipoprotein composition of apoAI, apoAIInonB, and apoCIIInonB in HDL particle and apoB:AII TRLs can contribute to decrease LCAT mass in Tx patients. Tx patients without statin and with lower triglycerides but higher HDL cholesterol concentration and disturbed lipoprotein composition of ApoAI and apoAII in HDL particle can decrease LCAT, increase LDL cholesterol, aggravate renal graft, and accelerate atherosclerosis and chronic heart diseases.

Abstract:Objective: Disturbances in lipid and lipoprotein profiles in patients after kidney transplantation (Tx) are still not understood. Methods: Serum levels of lipids, lipoprotein, triglyceride-rich lipoproteins (TRLs), and high-density lipoprotein (HDL) particles were determined, lipid and lipoprotein ratios were calculated, and their relationships in Tx patients with hypertriglyceridemia (HTG) and lower apolipoprotein AI (apoAI) concentration were examined. Serum lipid and lipoprotein levels were measured in 109 Tx patients and 89 healthy subjects. HDL particle levels were determined by enzyme-linked immunosorbent assay (ELISA). Results: Tx patients had disturbed concentration, composition, and metabolism of TRLs and HDL particles. Multivariance analysis showed significant and positive correlation between HDL cholesterol/apoAI (HDL-C/apoAI) and HDL-C/HDL ratios, which indicates that both ratios could sensitively reflect changes in the HDL subclasses and their distribution into smaller size particles. In Tx patients, the decreased HDL-C/apoAI ratio indicates that, along with the decreased apoAI concentration, the HDL-C level is decreased. However, a low HDL-C/HDL ratio indicates that HDL particles in Tx patients transport lesser content of HDL-C but more triglyceride (TG) (high TG/HDL ratio), and thus are hypercatabolized and removed; therefore, concentration of HDL particles in serum was decreased. Conclusion: The decrease of HDL-C/apoAI ratio seems to be a good marker of HDL subclass distribution into smaller size particles.

Anti-Müllerian hormone (AMH) is a glycoprotein produced by the granulosa cells of preantral and small antral follicles. AMH concentrations reflect ovarian physiology with high precision, thus serving as a more sensitive marker of the ovarian reserve than the chronological age. This hormone plays a role in the pathogenesis of menstrual disorders and fertility in obesity and polycystic ovary syndrome. The evaluation of AMH may also be useful in the diagnosis or the monitoring therapy of granulosa cells ovarian tumors.

Fibroblast growth factor 21 (FGF21) is a newly discovered adipokine, synthesized by several organs, mostly by the liver, which was introduced as a potent metabolic regulator and insulin-sensitizing factor. Numerous animal studies have demonstrated that FGF21 improves glucose and lipids metabolism and exerts anti-inflammatory effects. However, data obtained from human studies have shown contradictory results, in which circulating FGF21 levels were often elevated in obesity, dyslipidemia, type 2 diabetes (DM2) and other conditions connected with insulin resistance. This increase in basal FGF21 concentrations observed in patients with obesity and other conditions related to insulin resistance was being explained as a compensatory response to the underlying metabolic disturbances or tissue resistance to FGF21 action. Furthermore, the results of clinical trials have shown that increased FGF21 concentrations were associated with increased cardiovascular (CV) risk and had a prognostic value in CV outcomes. In recent years, it has been reported that FGF21 may exert cardioprotective effects. This mini-review aims to summarize the current state of knowledge about the role of FGF21 in CV disorders, and discuss the molecular mechanism underlying the anti-atherogenic properties of this compound.

Dyslipidemia and oxidative stress are considered one of the major causes which lead to many diseases, especially atherosclerosis development, cardiovascular disorders and aggravate risk for cancers, aging and others. Lipid hydroperoxides are the initial products when lipids are damaged by free radicals and in plasma HDL is their major carrier. F2-IsoP are stable compounds and specific products of lipid peroxidation only in phospholipids in vivo through nonenzymatic free-radical mechanisms. Also, they are found in detectable quantities esterified in all biological tissues and in free form in all normal biological fluids. Quantifying of them is considered as accurate way to measure oxidative stress in vivo and could be used as an indicator of lipid peroxidation which process is a risk factor for atherosclerosis and other systemic diseases. Our study was performed in the group of young people (n=10, age 19-30) with moderate dyslipidemia and the reference group. In both groups we have investigated serum lipids (TG, TC, LDL-C, HDL-C, nonHDL-C), lipoproteins (apoAI, apoB) and lipid (TC/HDL-C, TG/HDL-C, LDL-C/HDL-C) and lipoprotein (apoA, apoB, HDL-C/apoAI) ratios and oxidative status by measuring free and total (free and esterified) F2-isoprostanes (F2-IsoP). According to the available data reports and taking into account results obtained in our study we concluded that even mild lipid and lipoprotein abnormalities which are often present in population might by connected with elevated oxidative status which is sensitively reflected by F2-IsoP concentration. Thus measurement of F2-IsoP seems to be very helpful in recognition of early stage of oxidative stress however further studies are required.

Anti-Müllerian hormone (AMH) is a glycoprotein produced by the granulosa cells of preantral and small antral follicles. AMH concentrations reflect ovarian physiology with high precision, thus serving as a more sensitive marker of the ovarian reserve than chronological age. This hormone plays a role in the pathogenesis of menstrual disorders and fertility in both obesity and polycystic ovary syndrome. The evaluation of AMH may also be useful in diagnosing or monitoring therapy of granulosa cell ovarian tumors.