Different Effects of Cyclical Ketogenic vs. Nutritionally Balanced Reduction Diet on Serum Concentrations of Myokines in Healthy Young Males Undergoing Combined Resistance/Aerobic Training

Myokines represent important regulators of muscle metabolism. Our study aimed to explore the effects of a cyclical ketogenic reduction diet (CKD) vs. a nutritionally balanced reduction diet (RD) combined with regular resistance/aerobic training in healthy young males on serum concentrations of myokines and their potential role in changes in physical fitness. Twenty-five subjects undergoing regular resistance/aerobic training were randomized to the CKD (n = 13) or RD (n = 12) groups. Anthropometric and spiroergometric parameters, muscle strength, biochemical parameters, and serum concentrations of myokines and cytokines were assessed at baseline and after 8 weeks of intervention. Both diets reduced body weight, body fat, and BMI. Muscle strength and endurance performance were improved only by RD. Increased musclin (32.9 pg/mL vs. 74.5 pg/mL, p = 0.028) and decreased osteonectin levels (562 pg/mL vs. 511 pg/mL, p = 0.023) were observed in RD but not in the CKD group. In contrast, decreased levels of FGF21 (181 pg/mL vs. 86.4 pg/mL, p = 0.003) were found in the CKD group only. Other tested myokines and cytokines were not significantly affected by the intervention. Our data suggest that changes in systemic osteonectin and musclin levels could contribute to improved muscle strength and endurance performance and partially explain the differential effects of CKD and RD on physical fitness.

Gene Profile of Adipose Tissue of Patients with Pheochromocytoma/Paraganglioma

Background: Brown adipose tissue (BAT) is a therapeutic target to combat obesity and related disorders. Pheochromocytoma and functional paraganglioma (PPGL) are associated with activated BAT due to catecholamine excess. Our aim was to evaluate BAT activity by gene profile and assess its relation to clinical characteristics and overproduced catecholamine. Methods: mRNA expression of 15 genes in subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) was measured via RT-PCR in 25 patients with PPGL and 14 controls undergoing cholecystectomy. Results: We found in VAT of PPGL higher expression of UCP1 (p < 0.001), CEBPB, PPARGC1A (both p < 0.001), PRDM16 (p = 0.069) and DIO2 (p = 0.005). UCP1 expression correlated only with norepinephrine levels and its metabolite. UCP1 expression, among others, correlated negatively with BMI, age and positively with HDLc levels. Dominance of BAT or BeAT markers was not assessed in PPGL. In SAT of PPGL, we found higher expression of ADRB3, CIDEA (both p < 0.05), and PPARGC1A (p = 0.001), but not UCP1. Conclusion: We demonstrate signs of UCP1-dependent norepinephrine-induced thermogenesis connected with higher expression of DIO2, PPARGC1A, CEBPB and PRDM16 in retroperitoneal VAT of PPGL and its relations to circulating HDLc and triglycerides levels. However, no direct relationship with increased basal energy metabolism measured by calorimetry was found.

The Influence of Cyclical Ketogenic Reduction Diet vs. Nutritionally Balanced Reduction Diet on Body Composition, Strength, and Endurance Performance in Healthy Young Males: A Randomized Controlled Trial

(1) Background: The influence of ketogenic diet on physical fitness remains controversial. We performed a randomized controlled trial to compare the effect of cyclical ketogenic reduction diet (CKD) vs. nutritionally balanced reduction diet (RD) on body composition, muscle strength, and endurance performance. (2) Methods: 25 healthy young males undergoing regular resistance training combined with aerobic training were randomized to CKD (n = 13) or RD (n = 12). Body composition, muscle strength and spiroergometric parameters were measured at baseline and after eight weeks of intervention. (3) Results: Both CKD and RD decreased body weight, body fat, and BMI. Lean body mass and body water decreased in CKD and did not significantly change in RD group. Muscle strength parameters were not affected in CKD while in RD group lat pull-down and leg press values increased. Similarly, endurance performance was not changed in CKD group while in RD group peak workload and peak oxygen uptake increased. (4) Conclusions: Our data show that in healthy young males undergoing resistance and aerobic training comparable weight reduction were achieved by CKD and RD. In RD group; improved muscle strength and endurance performance was noted relative to neutral effect of CKD that also slightly reduced lean body mass.

Pheochromocytoma With Adrenergic Biochemical Phenotype Shows Decreased GLP-1 Secretion and Impaired Glucose Tolerance

CONTEXT

Impaired glucose homeostasis is a common finding in pheochromocytoma (PHEO), especially with adrenergic phenotype. The possible contribution of incretin dysfunction to dysglycemia in PHEO patients has not been studied.

OBJECTIVE

To compare changes in pancreatic endocrine function and gut hormones' production during a liquid meal test before and 1 year after adrenalectomy.

METHODS

In a prospective study, we included 18 patients with PHEO (13 females) with adrenergic biochemical phenotype. A liquid meal test with predefined isocaloric enteral nutrition was performed to evaluate dynamic changes in pancreatic hormones and incretins.

RESULTS

During the meal test, insulin levels were significantly lower before adrenalectomy only in the early phase of insulin secretion, but changes in area under the curve (AUC) did not reach statistical significance (AUC = 0.07). Plasma glucagon (AUC < 0.01) and pancreatic polypeptide levels (AUC < 0.01) were suppressed in comparison with the postoperative state. Impaired response to the meal was found preoperatively for glucagon-like peptide-1 (GLP-1; AUC P < 0.05), but not glucose-dependent insulinotropic polypepide (GIP; AUC P = 0.21). No significant changes in insulin resistance indices were found, except for the homeostatic model assessment-beta index, an indicator of the function of islet β cells, which negatively correlated with plasma metanephrine (R = -0.66, P < 0.01).

CONCLUSIONS

Our study shows suppression of pancreatic α and β cell function and impaired GLP-1 secretion during a dynamic meal test in patients with PHEO, which is improved after its surgical treatment. These data demonstrate a novel and potentially significant interconnection between excessive catecholamine production and the secretion of glucoregulatory hormones.

Changes in omentin levels and its mRNA expression in epicardial adipose tissue in patients undergoing elective cardiac surgery: the influence of type 2 diabetes and coronary heart disease

Omentin is a protein produced by numerous tissues including adipose tissue. Its concentrations are decreased in patients with obesity, type 2 diabetes mellitus (DM) and coronary artery disease (CAD). Experimental studies suggest that omentin may have anti-inflammatory and insulin-sensitizing properties. In the present study, we measured circulating omentin levels and its mRNA expression in epicardial and subcutaneous fat, intercostal and heart muscle before and after elective cardiac surgery in patients with CAD (CAD+, DM-, n=18), combination of CAD and DM (CAD+, DM+, n=9) or with none of these conditions (CAD-, DM-, n=11). The groups did not differ in baseline anthropometric and biochemical characteristics with the exception of higher blood glucose and HBA(1c) in CAD+, DM+ group. Baseline circulating omentin levels tended to be lower in CAD+, DM- and CAD+, DM+ groups as compared to CAD-, DM- group and cardiac surgery increased its concentration only in CAD-, DM- group. The change in serum omentin levels during surgery inversely correlated with epicardial fat thickness. While baseline omentin mRNA expression did not differ among the groups in any of the studied tissues, its increase after surgery was present only in subcutaneous fat in CAD-, DM- and CAD+, DM- groups, but not in CAD+, DM+ group. Intercostal muscle omentin mRNA expression increased after surgery only in CAD-, DM- group. In conclusion, cardiac surgery differentially affects omentin levels and subcutaneous fat and skeletal muscle mRNA expression in patients without coronary artery disease and diabetes as compared to patients with these conditions.

Gut as an emerging organ for the treatment of diabetes: focus on mechanism of action of bariatric and endoscopic interventions

Increasing worldwide prevalence of type 2 diabetes mellitus and its accompanying pathologies such as obesity, arterial hypertension and dyslipidemia represents one of the most important challenges of current medicine. Despite intensive efforts, high percentage of patients with type 2 diabetes does not achieve treatment goals and struggle with increasing body weight and poor glucose control. While novel classes of antidiabetic medications such as incretin-based therapies and gliflozins have some favorable characteristics compared to older antidiabetics, the only therapeutic option shown to substantially modify the progression of diabetes or to achieve its remission is bariatric surgery. Its efficacy in the treatment of diabetes is well established, but the exact underlying modes of action are still only partially described. They include restriction of food amount, enhanced passage of chymus into distal part of small intestine with subsequent modification of gastrointestinal hormones and bile acids secretion, neural mechanisms, changes in gut microbiota and many other possible mechanisms underscoring the importance of the gut in the regulation of glucose metabolism. In addition to bariatric surgery, less-invasive endoscopic methods based on the principles of bariatric surgery were introduced and showed promising results. This review highlights the role of the intestine in the regulation of glucose homeostasis focusing on the mechanisms of action of bariatric and especially endoscopic methods of the treatment of diabetes. A better understanding of these mechanisms may lead to less invasive endoscopic treatments of diabetes and obesity that may complement and widen current therapeutic options.

The effect of very-low-calorie diet on mitochondrial dysfunction in subcutaneous adipose tissue and peripheral monocytes of obese subjects with type 2 diabetes mellitus

Mitochondrial dysfunction is a potentially important player in the development of insulin resistance and type 2 diabetes mellitus (T2DM). We investigated the changes of mRNA expression of genes encoding main enzymatic complexes of mitochondrial respiratory chain in subcutaneous adipose tissue (SCAT) and peripheral monocytes (PM) of 11 subjects with simple obesity (OB), 16 obese patients with T2DM and 17 healthy lean subjects (C) before and after very low-calorie diet (VLCD) using quantitative real time PCR. At baseline in SCAT, both T2DM and OB group had decreased mRNA expression of all investigated mitochondrial genes with the exception of 2 complex I (NDUFA 12) and complex IV (COX 4/1) enzymes in OB subjects. In contrast, in PM only the expression of complex I enzymes NDUFA 12 and MT-ND5 was reduced in both T2DM and OB subjects along with decreased expression of citrate synthase (CS) in T2DM group. Additionally, T2DM subjects showed reduced activity of pyruvate dehydrogenase and complex IV in peripheral blood elements. VLCD further decreased mRNA expression of CS and complex I (NT-ND5) and II (SDHA) enzymes in SCAT and complex IV (COX4/1) and ATP synthase in PM of T2DM group, while increasing the activity of complex IV in their peripheral blood elements. We conclude that impaired mitochondrial biogenesis and decreased activity of respiratory chain enzymatic complexes was present in SCAT and PM of obese and diabetic patients. VLCD improved metabolic parameters and ameliorated mitochondrial oxidative function in peripheral blood elements of T2DM subjects but had only minor and inconsistent effect on mitochondrial gene mRNA expression in SCAT and PM.

Endocrine effects of duodenal-jejunal exclusion in obese patients with type 2 diabetes mellitus

Duodenal-jejunal bypass liner (DJBL) is an endoscopically implantable device designed to noninvasively mimic the effects of gastrointestinal bypass operations by excluding the duodenum and proximal jejunum from the contact with ingested food. The aim of our study was to assess the influence of DJBL on anthropometric parameters, glucose regulation, metabolic and hormonal profile in obese patients with type 2 diabetes mellitus (T2DM) and to characterize both the magnitude and the possible mechanisms of its effect. Thirty obese patients with poorly controlled T2DM underwent the implantation of DJBL and were assessed before and 1, 6 and 10months after the implantation, and 3months after the removal of DJBL. The implantation decreased body weight, and improved lipid levels and glucose regulation along with reduced glycemic variability. Serum concentrations of fibroblast growth factor 19 (FGF19) and bile acids markedly increased together with a tendency to restoration of postprandial peak of GLP1. White blood cell count slightly increased and red blood cell count decreased throughout the DJBL implantation period along with decreased ferritin, iron and vitamin B12 concentrations. Blood count returned to baseline values 3months after DJBL removal. Decreased body weight and improved glucose control persisted with only slight deterioration 3months after DJBL removal while the effect on lipids was lost. We conclude that the implantation of DJBL induced a sustained reduction in body weight and improvement in regulation of lipid and glucose. The increase in FGF19 and bile acids levels could be at least partially responsible for these effects.

Plasma concentrations and subcutaneous adipose tissue mRNA expression of clusterin in obesity and type 2 diabetes mellitus: the effect of short-term hyperinsulinemia, very-low-calorie diet and bariatric surgery

Clusterin is a heterodimeric glycoprotein with wide range of functions. To further explore its possible regulatory role in energy homeostasis and in adipose tissue, we measured plasma clusterin and its mRNA expression in subcutaneous adipose tissue (SCAT) of 15 healthy lean women, 15 obese women (OB) and 15 obese women with type 2 diabetes mellitus (T2DM) who underwent a 2-week very low-calorie diet (VLCD), 10 obese women without T2DM who underwent laparoscopic sleeve gastrectomy (LSG) and 8 patients with T2DM, 8 patients with impaired glucose tolerance (IGT) and 8 normoglycemic patients who underwent hyperinsulinemic euglycemic clamp (HEC). VLCD decreased plasma clusterin in OB but not in T2DM patients while LSG and HEC had no effect. Clusterin mRNA expression in SCAT at baseline was increased in OB and T2DM patients compared with controls. Clusterin mRNA expression decreased 6 months after LSG and remained decreased 12 months after LSG. mRNA expression of clusterin was elevated at the end of HEC compared with baseline only in normoglycemic but not in IGT or T2DM patients. In summary, our data suggest a possible local regulatory role for clusterin in the adipose tissue rather than its systemic involvement in the regulation of energy homeostasis.

Laparoscopic sleeve gastrectomy ameliorates mRNA expression of inflammation-related genes in subcutaneous adipose tissue but not in peripheral monocytes of obese patients

Low-grade inflammation links obesity, insulin resistance, and cardiovascular diseases. We investigated the effects of laparoscopic sleeve gastrectomy (LSG) on expression profile of genes involved in inflammatory pathways in subcutaneous adipose tissue (SCAT) and peripheral monocytes (PM). At baseline, obese group had significantly increased mRNA expression of proinflammatory chemokines (CCL-3, -17, -22), chemokine receptor CCR1 and cytokines (IL-10, IL-18) in SCAT and chemokine and other proinflammatory receptors (CCR-1, -2, -3, TLR-2, -4) in PM relative to control group. LSG decreased body weight, improved metabolic profile and reduced mRNA expression of up-regulated chemokine receptors, chemokines and cytokines in SCAT. In contrast, expression profiles in PM were largely unaffected by LSG. We conclude that LSG improved proinflammatory profile in subcutaneous fat but not in peripheral monocytes. The sustained proinflammatory and chemotactic profile in PM even 2 years after LSG may contribute to partial persistence of metabolic complications in obese patients after metabolic surgery.

Serum concentrations and subcutaneous adipose tissue mRNA expression of omentin in morbid obesity and type 2 diabetes mellitus: the effect of very-low-calorie diet, physical activity and laparoscopic sleeve gastrectomy

Omentin is a novel adipokine with insulin-sensitizing effects expressed predominantly in visceral fat. We investigated serum omentin levels and its mRNA expression in subcutaneous adipose tissue (SCAT) of 11 women with type 2 diabetes mellitus (T2DM), 37 obese non-diabetic women (OB) and 26 healthy lean women (C) before and after various weight loss interventions: 2-week very-low-calorie diet (VLCD), 3-month regular exercise and laparoscopic sleeve gastrectomy (LSG). At baseline, both T2DM and OB groups had decreased serum omentin concentrations compared with C group while omentin mRNA expression in SCAT did not significantly differ among the groups. Neither VLCD nor exercise significantly affected serum omentin concentrations and its mRNA expression in SCAT of OB or T2DM group. LSG significantly increased serum omentin levels in OB group. In contrast, omentin mRNA expression in SCAT was significantly reduced after LSG. Baseline fasting serum omentin levels in a combined group of the studied subjects (C, OB, T2DM) negatively correlated with BMI, CRP, insulin, LDL-cholesterol, triglycerides and leptin and were positively related to HDL-cholesterol. Reduced circulating omentin levels could play a role in the etiopathogenesis of obesity and T2DM. The increase in circulating omentin levels and the decrease in omentin mRNA expression in SCAT of obese women after LSG might contribute to surgery-induced metabolic improvements and sustained reduction of body weight.

Laparoscopic sleeve gastrectomy differentially affects serum concentrations of FGF-19 and FGF-21 in morbidly obese subjects

OBJECTIVE

Fibroblast growth factor (FGF)-19 and FGF-21 are novel metabolic regulators that improve insulin resistance and obesity in rodents. The aim of the study was to assess the effects of laparoscopic sleeve gastrectomy (LSG) on serum concentrations of FGF-19 and FGF-21 along with circulating bile acids and other relevant hormonal and biochemical parameters.

DESIGN AND METHODS

Seventeen females with obesity undergoing LSG and 15 lean healthy females were included into the study. Anthropometric and biochemical parameters, serum concentrations of FGF-19 and -21, insulin, adiponectin, leptin, C-reactive protein, resistin, amylin (total), ghrelin (active), glucagon-like peptide 1 (GLP-1, active), glucose-dependent insulinotropic peptide (GIP, total), peptide YY (PYY, total), pancreatic polypeptide (PP), and bile acids, and mRNA expression of selected adipokines and inflammatory markers in bioptic samples of subcutaneous fat were assessed at baseline and 6, 12, and 24 months after LSG.

RESULTS

LSG markedly decreased body weight, BMI, waist circumference, and insulin levels and improved systemic inflammation and lipid levels. FGF-19 concentrations increased and FGF-21 concentrations decreased after LSG along with increased adiponectin and decreased leptin, amylin, and ghrelin levels. GLP-1, GIP, PP, and circulating bile acids were not affected by LSG. PYY decreased significantly 24 months after surgery only. mRNA expression analysis in subcutaneous fat showed markedly reduced proinflammatory state.

CONCLUSIONS

Our results indicate that increased FGF-19 and decreased ghrelin concentrations could have partially contributed to the improvement of systemic inflammation and some metabolic parameters after LSG, while changes of FGF-21 are rather secondary because of weight loss.

Changes in energy metabolism in pheochromocytoma

CONTEXT

Catecholamine overproduction in pheochromocytoma affects basal metabolism, resulting in weight loss despite normal food intake.

OBJECTIVE

The objective of the study was to evaluate changes in energy metabolism expressed as resting energy expenditure (REE) in patients with pheochromocytoma before and after adrenalectomy and the possible relationship with circulating inflammatory markers.

DESIGN

We measured REE in 17 patients (8 women) with pheochromocytoma by indirect calorimetry (Vmax-Encore 29N system) before and 1 year after adrenalectomy. Body fat percentage was measured with a Bodystat device. Inflammatory markers (leukocytes count and C-reactive protein) and cytokines (TNF-α, IL-6, and IL-8) were analyzed with a Luminex 200.

RESULTS

REE measured in the pheochromocytoma group was 10.4% higher than the predicted value (1731 ± 314 vs 1581 ± 271 kcal/d; P = .004). Adrenalectomy significantly increased body mass index (P =0.004) and the percentage of body fat (P = .01), with a proportional increase in fat distribution (waist circumference, P = .045; hip circumference, P = .001). REE significantly decreased after adrenalectomy (1731 ± 314 vs 1539 ± 215 kcal/d; P = .002), even after adjustments in body surface and body weight (P < .001). After adrenalectomy, we found a significant decrease in leukocyte counts (P = .014) and in the levels of TNF-α (P < .001), IL-6 (P = .048), and IL-8 (P = .007) but not C-reactive protein (P = .09). No significant correlations among calorimetry parameters, hormones, and proinflammatory markers were detected.

CONCLUSIONS

Chronic catecholamine overproduction in pheochromocytoma may lead to a proinflammatory and hypermetabolic state characterized by increased REE. Adrenalectomy leads to the normalization of energy metabolism followed by an increase in body mass index and body fat content and decreases in inflammatory markers and cytokines.

[Pathophysiological background for incretin therapy: is it capable of more than we think?]

Incretin-based therapy functions through the increase of endogenous glucagon-like peptide-1 (GLP-1) levels due to inhibition of dipeptidyl peptidase-4--an enzyme degrading GLP-1 (gliptins) or through the administration of drugs activating GLP-1 receptor (GLP-1 agonists). Both approaches increase insulin and decrease glucagon secretion leading to improved diabetes compensation. The advantages of gliptins include little side effects, body weight neutrality and potential protective effects on pancreatic beta cells. GLP-1 agonists on the top of that consistently decrease body weight and blood pressure and their effects on diabetes compensation and likelihood of protective effects on beta cells is somewhat higher than those of gliptins. Another advantage of both approaches includes their safety with respect to induction of hypoglycemia. In addition to well-known metabolic effects, other potentially benefitial consequences of incretin based therapy in both type 2 diabetic and non-diabetic patients are anticipated. Direct positive effects of incretin-based therapy on myocardial metabolism and function as well as its positive influence on endothelial dysfunction and neuroprotective effects are intensively studied. The possible indications for GLP-1 agonists could be in future further widened to obese patients with type 1 diabetes and obese patients without diabetes. The aim of this review is to summarize both metabolic and extrapancreatic effects of incretin-based therapies and to outline perspectives of potential wider use of this treatment approach.

[Adipose tissue hormones]

Adipose tissue had been traditionally considered a passive energy storage site without direct influence on energy homeostasis regulation. This view has been principally changed during early nineties by the discovery of hormonal production of adipose tissue. At present, the list of hormonally active substances of adipose tissue includes more than one hundred factors with paracrine or endocrine activity that play an important role in metabolic, food intake a inflammatory regulations and many other processes. Only minority of adipose tissue-derived hormones is produced exclusively in fat. Most of these factors is primarily put out by other tissues and organs. Adipose tissue-derived hormones are produced not only by adipocytes but also by preadipocytes, immunocompetent and endothelial cells and other cell types residing in fat. This paper summarizes current knowledge about endocrine function of adipose tissue with special respect to its changes in obesity. It also describes its possible role in the ethiopathogenesis of insulin resistance, atherosclerosis and other obesity-related pathologies.

Plasma concentrations of adipocyte fatty acid binding protein in patients with Cushing's syndrome

Serum adipocyte fatty acid-binding protein (FABP-4) concentrations are linked to human obesity and other features of metabolic syndrome. Patients with Cushing´s syndrome (CS) develop numerous features of metabolic syndrome due to chronic cortisol excess. Here we tested the hypothesis that chronically increased cortisol levels in CS patients may alter circulating levels of FABP-4. Fourteen patients with CS, 19 patients with simple obesity (OB) and 36 healthy control subjects (C) were included in the study. Serum FABP-4 concentrations were significantly higher in both CS and OB patients relative to C group, but they did not differ between CS and OB groups. In a combined population of all groups, serum FABP-4 levels correlated positively with BMI, body fat content, serum glucose, triglycerides, HbA1c and HOMA index and were inversely related to HDL-cholesterol, resting energy expenditure and freeT3 levels. We conclude that FABP-4 levels are significantly increased in both patients with simple obesity and obese patients with Cushing´s syndrome. We suggest that increased FABP-4 concentrations in CS patients are rather due to their excessive fat accumulation and related metabolic abnormalities than due to a direct effect of cortisol on FABP-4 production.

[The influence of 6-months treatment with exenatide on type 2 diabetes mellitus compensation, anthropometric and biochemical parameters]

OBJECTIVES

Exenatide, a synthetic GLP-1 analogue, is a new antidiabetic agent from the group ofincretine mimetics coming into the daily clinical practice. In our study we evaluated the effect of 6-months treatment with exenatide on diabetes compensation, anthropometric and biochemical parameters in the patients with poorly controlled type 2 diabetes mellitus and obesity.

METHOD

We included 18 patients with poorly controlled diabetes (mean HbA1c 8.5 +/- 0.3%) treated with diet and peroral antidiabetic agents (4 patients were treated with insulin in the past). Exenatide was administered via subcutaneous injection twice daily for 6 months. Patients were examined after 1 month, when the dose ofexenatide was increased from 5 microg twice daily to 10 microg twice daily and after 3 and 6 months. We evaluated the diabetes compensation, biochemical parameters, body weight changes and side effects ofexenatide.

RESULTS

6-months exenatide treatment significant decreased body weight (baseline vs 6 month treatment 107.3 +/- 4.4 kg vs 103.7 +/- 4.6 kg, p = 0.02), BMI (36.7 +/- 1.2 kg/m2 vs 35.3 +/- 1.3 kg/m2, p = 0.01) a HbA1c (8.5 +/- 0.3% vs 7.4 +/- 0.4%, p = 0.04) and increased HDL-cholesterol (0.92 +/- 0.1 mmol/l vs 0.98 +/- 0.1 mmol/l, p = 0.02). Fasting glycemia tended to decline at the end of the study, but the difference did not reach the statistical significance. The area under the curve of glycemia levels after the standardized breakfast in the subgroup of 8 patients after the 6-months exenatide treatment was significantly lower when compared to baseline values (2,908 +/- 148 vs 2,093 +/- 194, p = 0.03). Concentrations of total and LDL-cholesterol and triglycerides did not change significantly. The most frequent side effects of exenatide treatments were transient anorexia and nausea (38.5%), dyspepsia and functional gastrointestinal discomfort (38.5%) and various neuropsychical symptoms (nervosity and insomnia - 30.8%). Most of the side effects disappeared during the treatment, none of these side effects was a reason for discontinuation of a treatment. 3 minor hypoglycemic episodes occured in patients simultaneously treated with derivates of sulfonylurea, but no serious hypoglycemia occured during the entire study.

CONCLUSION

Exenatide treatment in obese patients with poor diabetes control was accompanied by statistically significant decrease of body weight, improvement of diabetes control and increase in HDL-cholesterol.

Increased serum concentrations of macrophage inhibitory cytokine-1 in patients with obesity and type 2 diabetes mellitus: the influence of very low calorie diet

OBJECTIVE

Macrophage inhibitory cytokine-1 (MIC-1) is a novel regulator of energy homeostasis. We explored whether alterations in MIC-1 levels contribute to metabolic disturbances in patients with obesity and/or obesity and type 2 diabetes mellitus (T2DM).

DESIGN

We measured serum MIC-1 levels and its mRNA expression in subcutaneous and visceral adipose tissue of 17 obese nondiabetic women, 14 obese women with T2DM and 23 healthy lean women. We also explored the relationship of MIC-1 with anthropometric and biochemical parameters and studied the influence of 2-week very low calorie diet (VLCD) on serum MIC-1 levels.

METHODS

Serum MIC-1 levels were measured by ELISA and its mRNA expression was determined by RT-PCR.

RESULTS

Both obese and T2DM group had significantly elevated serum MIC-1 levels relative to controls. T2DM group had significantly higher serum MIC-1 levels relative to obese group. Serum MIC-1 positively correlated with body weight, body fat, and serum levels of triglycerides, glucose, HbAlc, and C-reactive protein and it was inversely related to serum high-density lipoprotein cholesterol. Fat mRNA MIC-1 expression did not significantly differ between lean and obese women but it was significantly higher in subcutaneous than in visceral fat in both groups. VLCD significantly increased serum MIC-1 levels in obese but not T2DM group.

CONCLUSION

Elevated MIC-1 levels in patients with obesity are further increased by the presence of T2DM. We suggest that in contrast to patients with cancer cachexia, increased MIC-1 levels in obese patients and diabetic patients do not induce weight loss.

Plasma concentrations of fibroblast growth factors 21 and 19 in patients with Cushing's syndrome

The objective of this study was to measure plasma fibroblast growth factor 21 and 19 (FGF21 and FGF19) levels in patients with Cushing's syndrome (CS) and to compare it with those of lean control subjects (C) and patients with obesity (OB). Fourteen untreated patients with CS, 19 patients with OB and 36 controls were included in the study. Plasma FGF21 and FGF19 levels were measured by ELISA kits, other hormonal and biochemical parameters were measured by standard laboratory methods. Plasma FGF19 did not significantly differ among the studied groups. Plasma FGF21 levels were significantly higher in both CS and OB groups relative to C group but they did not differ between CS and OB groups. In a combined population of all three groups FGF21 levels positively correlated with BMI, waist circumference and percentage of total and truncal fat mass. Less prominent inverse relationship with these parameters was found for FGF19. Neither FGF21 nor FGF19 were significantly related to cortisol concentrations. Increased FGF21 concentrations in both patients with CS and OB relative to lean subjects suggest that excessive body fat and/or related metabolic abnormalities rather than direct effects of cortisol are responsible. In contrast neither obesity nor hypercortisolism significantly affected FGF19 concentrations.

Fibroblast growth factor 21: a novel metabolic regulator with potential therapeutic properties in obesity/type 2 diabetes mellitus

Fibroblast growth factor 21 (FGF21) is a novel metabolic regulator produced primarily by the liver that exerts potent antidiabetic and lipid-lowering effects in animal models of obesity and type 2 diabetes mellitus. This hormone contributes to body weight regulation and is strongly involved in the response to nutritional deprivation and ketogenic state in mice. The principal sites of metabolic actions of FGF21 are adipose tissue, liver and pancreas. Experimental studies have shown marked improvements in diabetes compensation and dyslipidemia after FGF21 administration in diabetic mice and primates. Positive metabolic actions of FGF21 without the presence of apparent side effects make this factor a hot candidate to treat type 2 diabetes and accompanying metabolic diseases. The aim of this review is to summarize the current knowledge about the metabolic effects of FGF21 including some preliminary data on changes of its levels in humans with a special emphasis on its therapeutic potential in type 2 diabetes mellitus.

[Comparison of various methods of body fat analysis in overweight and obese women]

INTRODUCTION

Body composition assessment and determination of the amount and distribution of body fat, respectively, form an essential part of the basic clinical assessment of an obese patient. However, there are no recommended methods to determine the amount of fat in obese population. The aim of our study was to compare the methods most frequently used to determine the amount of body fat in overweight and obese women in clinical practice (multi-frequency bio-electrical impedance analysis--BIA using the Bodystat, Omron and Tanita machines and the skinfold test using a calliper) with a reference method (DEXA). The study further aimed to compile prediction formulae enabling clinicians to calculate the percentage of body fat when using the available body fat measurement techniques.

METHODS

The study included 61 overweight and obese women (mean age 48.6 years +/- 13.9 years). Four practice-based body fat assessment methods were used - bioimpedance technique with tetra-polar electrode arrangement (Bodystat machine), bioimpedance technique with bi-pedal electrode arrangement (Tanita machine), hand-held bioimpedance technique (Omron machine) and the anthropometry assessment--the skinfold calliper technique. These methods were compared to the method considered as the reference--the whole body densinometry (DEXA).

RESULTS

The results obtained using the listed body fat assessment methods suggest that the resulting body fat measurements differ importantly depending on the method used. The highest correlation with DEXA was found for the Bodystat BIA (r = 0.9096, p < 0.001). Prediction formulae were constructed for a more accurate calculation of body fat content when using the techniques evaluated in the present study.

CONCLUSION

When the newly compiled formulae are employed, the body fat assessment obtained with any of the methods applied in the present study will approximate DEXA. The BIA techniques were found to be particularly precise. Therefore, further evaluation of these techniques is recommendable to support their use as methods for monitoring the efficacy of weight reduction programmes in overweight and obese patients.

The influence of obesity and different fat depots on adipose tissue gene expression and protein levels of cell adhesion molecules

Increased circulating adhesion molecules in patients with obesity play an important role in the development of endothelial dysfunction/atherosclerosis. The aim of this study was to assess the contribution of various fat depots to the production of adhesion molecules in obesity. 12 women with first and second degree of obesity, 13 women with third degree of obesity and 14 lean age-matched women were included into study. Circulating levels of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin were measured by Luminex kits. mRNA expression of ICAM-1, VCAM-1, E-selectin, monocyte chemoattractant protein-1 (MCP-1), and CD68 in subcutaneous (SAT) and visceral adipose tissue (VAT) was measured by RT-PCR; ICAM-1 and VCAM-1 protein levels by Luminex kits, normalized to protein content. Obesity increased ICAM-1 and VCAM-1 mRNA expression and protein levels and CD68 mRNA expression in VAT. Expression of E-selectin and MCP-1 did not significantly differ between groups. Expression of ICAM-1 and VCAM-1 positively correlated with expression of CD68 in both adipose depots. In VAT, ICAM-1 and VCAM-1 expression and protein levels positively correlated with BMI. Obesity was associated with increased adhesion molecules mRNA expression and protein levels in VAT, but not in SAT. Increased adhesion molecules production in visceral fat may provide a novel direct link between visceral adiposity and increased risk of cardiovascular complications.

The endocrine profile of subcutaneous and visceral adipose tissue of obese patients

The aim of the present study was to evaluate the expression profile of genes potentially related to metabolic complications of obesity in the whole adipose tissue and isolated adipocytes from subcutaneous (SAT) and visceral adipose tissue (VAT) from 12 non-diabetic obese women and 12 lean women. Real-time polymerase chain reaction was used for expression analysis of 41 genes of interest and two housekeeping genes. We found increased expression of specific proinflammatory and adipogenic genes and reduced expression of specific lipogenic and insulin signaling pathway genes in obese relative to lean women with no preferable localization in SAT or VAT depot. The gene expression significantly differed between adipocytes and adipose tissue but both contributed to the proinflammatory profile in obesity. We conclude that both SAT and VAT exhibit alterations in the expression of specific genes possibly contributing to proinflammatory and insulin resistance state and consequently to metabolic complications of obesity.

Plasma concentrations of fibroblast growth factors 19 and 21 in patients with anorexia nervosa

CONTEXT

Fibroblast growth factor 19 (FGF19) and FGF21 are novel metabolic regulators that improve insulin sensitivity and decrease adiposity in mice. However, little is known about the nutritional regulation of these factors in humans.

OBJECTIVE

The objective of this study was to measure plasma FGF19 and FGF21 levels in patients with anorexia nervosa (AN) and to explore its relationship with anthropometric and endocrine parameters.

DESIGN

This was a single-center cross-sectional study.

SETTING

The study was performed in a university hospital.

PATIENTS

Seventeen untreated women with a restrictive type of AN and 17 healthy women (control group) were included.

MAIN OUTCOME MEASURES

Fasting plasma FGF19 and FGF21, serum insulin, leptin, soluble leptin receptor, adiponectin, resistin, and C-reactive protein were the main outcome measures.

RESULTS

Plasma FGF19 levels did not significantly differ between the groups studied, whereas plasma FGF21 levels were significantly reduced in AN relative to the control group. Plasma FGF21 positively correlated with body mass index and serum leptin and insulin and was inversely related to serum adiponectin in both groups. In contrast, plasma FGF19 was not related to any of parameters studied. Partial realimentation significantly reduced plasma FGF21 levels in AN.

CONCLUSION

Circulating levels of FGF21 but not FGF19 are strongly related to body weight and serum levels of leptin, adiponectin, and insulin in both anorectic and normal-weight women. We suggest that reduced plasma FGF21 levels could be involved in the pathophysiology of AN or in a complex adaptive response to this disease.

Serum concentrations of adipocyte fatty acid binding protein in patients with anorexia nervosa

Serum adipocyte fatty acid-binding protein (FABP) concentrations are linked to human obesity and other features of metabolic syndrome. Whether FABP associates with metabolic alterations in chronic malnutrition is unknown. In the present study, we measured fasting serum levels of FABP, leptin, soluble leptin receptor, adiponectin, resistin, C-reactive protein (CRP), insulin, glucose, cholesterol and triglycerides in 19 patients with a restrictive type of anorexia nervosa (AN) and in 16 healthy age-matched control women (C). Body mass index, serum leptin, and CRP concentrations were significantly lower, while serum adiponectin and soluble leptin receptor levels were significantly higher in AN relative to C group. Serum insulin, glucose, cholesterol and triglyceride levels did not differ between the groups studied. Serum FABP levels were unchanged in patients with AN and were not related to any of parameters studied. We conclude that, in contrast to patients with obesity where FAPB is a prominent marker of metabolic alterations, chronic malnutrition in AN does not significantly affect its serum levels.

Serum adipocyte fatty acid binding protein levels in patients with type 2 diabetes mellitus and obesity: the influence of fenofibrate treatment

Recent studies have demonstrated that adipocyte fatty acid binding proteins (FABP) may play a role in the etiopathogenesis of insulin resistance. The aim of our study was to assess serum FABP levels in obese patients with type 2 diabetes mellitus (T2DM) before and after 3 months of treatment with PPAR-alpha agonist fenofibrate (F) and to explore the relationship of FABP to biochemical parameters and measures of insulin sensitivity assessed by hyperinsulinemic-isoglycemic clamp. We measured biochemical parameters by standard laboratory methods, insulin sensitivity by hyperinsulinemic-isoglycemic clamp and serum concentrations of FABP by commercial ELISA kit in 11 obese females with T2DM before and after three months of treatment with PPAR-alpha agonist fenofibrate and in 10 lean healthy control women (C). Serum FABP levels were 2.5-fold higher in T2DM group relative to C and were not affected by fenofibrate treatment (C: 20.6+/-2.1 microg/l, T2DM before F: 55.6+/-5.7 microg/l, T2DM after F: 54.2+/-5.4 microg/l, p 0.0001 for C vs. T2DM before F). Hyperinsulinemia during the clamp significantly suppressed FABP levels in both C and T2DM group. FABP levels positively correlated with BMI, triglyceride levels, blood glucose, glycated hemoglobin, atherogenic index and insulin levels. An inverse relationship was found between FABP and HDL levels, metabolic clearance rate of glucose, M/I and MCR(glc)/I sensitivity indexes. We conclude that FABP levels are closely related to BMI, parameters of insulin sensitivity, HDL levels and measures of diabetes compensation. This combination makes FABP a valuable marker of metabolic disturbances in patients with type 2 diabetes mellitus.

[The influence of very-low-calorie diet on soluble adhesion molecules and their gene expression in adipose tissue of obese women]

BACKGROUND

Adhesion molecules (AM) are proteins expressed on the endothelial surface that play an important role in development of endothelial dysfunction. Higher concentrations of AM were found in patients with atherosclerosis, obesity or type 2 diabetes mellitus. The aim of our study was to measure serum concentrations and gene expression of ICAM-1 (intercellular adhesion molecule 1), VCAM-1 (vascular adhesion molecule 1) and E-selectin in subcutaneous adipose tissue samples obtained by needle biopsy from obese women and healthy controls and to evaluate the effect of 3-weeks very-low-calorie diet (VLCD) on these parameters.

METHODS AND RESULTS

20 obese women (BMI 46.2 +/- 9.7 kg/m2) and 13 lean control women (BMI 23.8 +/- 2.3 kg/m2) were included into the study. Gene expression of AM in subcutaneous adipose tissue was measured using RT-PCR, serum AM levels were measured by multiplex immunoanalysis. At the baseline, serum E-selectin concentrations were higher in obese women compared to controls (24.4 +/- 2.3 vs. 15 +/- 1,5 ng/ml, p < 0,05). 3 weeks of VLCD significantly decreased BMI and serum E-selectin levels. Baseline mRNA expression of E-selectin, ICAM-1 and VCAM-1 in subcutaneous adipose tissue was lower in obese relative to lean women (p < 0.05). Weight reduction increased ICAM-1 and VCAM-1 gene expression (p < 0.05).

CONCLUSIONS

Our results suggest that the subcutaneous adipose tissue is not the major source of the studied soluble adhesion molecules in obese women and that the regulation of AM local gene expression in subcutaneous adipose tissue probably differs from its circulating levels.

Increased angiotensinogen production in epicardial adipose tissue during cardiac surgery: possible role in a postoperative insulin resistance

Critical illness induces among other events production of proinflammatory cytokines that in turn interfere with insulin signaling cascade and induce insulin resistance on a postreceptor level. Recently, local renin-angiotensin system of adipose tissue has been suggested as a possible contributor to the development of insulin resistance in patients with obesity. The aim of our study was to determine local changes of the renin-angiotensin system of subcutaneous and epicardial adipose tissue during a major cardiac surgery, which may serve as a model of an acute stress potentially affecting endocrine function of adipose tissue. Ten patients undergoing elective cardiac surgery were included into the study. Blood samples and samples of subcutaneous and epicardial adipose tissue were collected at the beginning and at the end of the surgery. Blood glucose, serum insulin and adiponectin levels were measured and mRNA for angiotensinogen, angiotensin-converting enzyme and angiotensin II type 1 receptor were determined in adipose tissue samples using RT PCR. Cardiac surgery significantly increased both insulin and blood glucose levels suggesting the development of insulin resistance, while serum adiponectin levels did not change. Expression of angiotensinogen mRNA significantly increased in epicardial adipose tissue at the end of surgery relative to baseline but remained unchanged in subcutaneous adipose tissue. Fat expression of angiotensin-converting enzyme and type 1 receptor for angiotensin II were not affected by surgery. Our study suggests that increased angiotensinogen production in epicardial adipose tissue may contribute to the development of postoperative insulin resistance.

[The influence of obesity on the gene expression of adiponectin and its receptor in subcutaneous adipose tissue]

The objective of the study was to measure the concentration of adiponectin in plasma, its mRNA expression and the expression of the adiponectin receptors AdipoR1 and AdipoR2 in subcutaneous adpipose tissue (ST) of women with various levels of fat in their organism. A further objective of the study was to determine to what extent the stated parameters correlate with obesity as defined by BMI (body mass index) and how it can be affected by a very low calorie diet (VLCD).

PATIENT SAMPLE

The sample of 70 women was divided into groups by BMI: patients with class 3 obesity (BMI > 40 kg.m(-2), n = 25), patients with class 1 and 2 obesity (BMI 30-40 kg.m(-2), n = 15), overweight patients (BMI 25-30 kg.m(-2), n = 10) and a normal healthy control group (BMI 20-25 kg.m(-2), n = 20). In the case of 14 women with class 3 obesity, the parameters were measured before and after a three-week diet with an energy content of 2200 kJ (550 kcal)/day (VLCD).

METHOD

Plasma concentrations of adiponectin were measured using an ELISA kit (LINCO Research, USA). Subcutaneous adipose tissue was taken using biopsy. RNA was isolated using a MagNA Pure Compact RNA Isolation Kit (Tissue) (Roche, SRN). The gene expression of adiponectin, AdipoR1 and AdipoR2 was determined using the real-time PCR (RT-PCR) method on a ABI Real-Time PCR 7500 instrument (Applied Biosystems, USA) with TaqMan Gene Expression Assays hydrolisation probes. beta-2-mikroglobulin (beta2M) was used as an endogenous control, to which the data was normalised.

RESULTS

The circulatory concentration of adiponectin, its mRNA expression and the mRNA expression of AdipoR1 in ST correlate negatively with BMI (r = -0.524, p < 0.001; r = -0.460, p < 0 001; p = -0.354, p = 0.004). The expression of AdipoR2 in ST did not correlate with BMI. The VLCD reduced weight by 9% but did not affect the plasma concentration of adiponectin or the rate of its expression, or the expression of AdipoR1 and AdipoR2.

CONCLUSION

Our results show that not only the circulatory concentration of adiponectin but also its mRNA expression and the expression of AdipoR1 in ST are significantly lower in obese women compared to a control group and may contribute to the development of metabolic complications in obesity.

Adiponectin and resistin gene polymorphisms in patients with anorexia nervosa and obesity and its influence on metabolic phenotype

Genes for adiponectin and resistin are candidate genes of insulin resistance and type 2 diabetes mellitus. The aim of our study was to determine the frequency of single nucleotide polymorphisms (SNP) 45T>G and 276G>T of the adiponectin gene and 62G>A and -180C>G of the resistin gene in patients with obesity (OB), anorexia nervosa (AN) and in control healthy normal-weight women (NW) and to study the influence of particular genotypes on serum concentrations of these hormones and on insulin sensitivity. Serum adiponectin, resistin, tumor necrosis factor alpha (TNF-alpha), insulin, cholesterol, glycated hemoglobin (HbA1c) and blood glucose levels were measured in 77 patients with OB, 28 with AN and 38 NW. DNA analysis was carried out by polymerase chain reaction with restriction analysis of PCR product. The presence of SNP ADP+276 G>T allele was accompanied by higher cholesterol levels in AN patients, higher adiponectin concentrations in OB patients and lower HbA1c levels in NW. SNP of the resistin gene 62G>A was associated with lower HbA1c in NW and higher cholesterol concentrations in OB group. The carriers of the minor G allele in the position -180 of the resistin gene within AN group had significantly higher BMI relative to non-carriers. We conclude that polymorphisms in adiponectin and resistin genes can contribute to metabolic phenotype of patients with obesity and anorexia nervosa.

[Adiponectin and atherosclerosis]

Obesity combined with other components of the insulin resistance syndrome is an important risk factor for atherosclerosis and its complications. The exact mechanisms through which the above diseases are linked have not yet been fully elucidated. One of the possible links may be a disturbance of the endocrine function of the adipose tissue of obese persons which produces an increased amount of proinflammatory and proatherogenic hormones and a lower amount of factors protecting against such pathologies. Adiponectin is the only hormone produced by the adipose tissue with a proven antiinflammatory and antiatherosclerotic effect. This hormone is predominantly produced by adipocytes and its concentrations are decreased in patients with obesity, insulin resistance and atherosclerosis. The objective of the article is to summarize current experimental and clinical knowledge of the links between adiponectin and atherosclerosis and to discuss possible utilization of adiponectin as a marker for atherosclerosis, and the potential for its exploitation in the prevention and/or treatment of atherosclerosis.

Influence of PPAR-alpha agonist fenofibrate on insulin sensitivity and selected adipose tissue-derived hormones in obese women with type 2 diabetes

PPAR-alpha agonists improve insulin sensitivity in rodent models of obesity/insulin resistance, but their effects on insulin sensitivity in humans are less clear. We measured insulin sensitivity by hyperinsulinemic-isoglycemic clamp in 10 obese females with type 2 diabetes before and after three months of treatment with PPAR-alpha agonist fenofibrate and studied the possible role of the changes in endocrine function of adipose tissue in the metabolic effects of fenofibrate. At baseline, body mass index, serum glucose, triglycerides, glycated hemoglobin and atherogenic index were significantly elevated in obese women with type 2 diabetes, while serum HDL cholesterol and adiponectin concentrations were significantly lower than in the control group (n=10). No differences were found in serum resistin levels between obese and control group. Fenofibrate treatment decreased serum triglyceride concentrations, while both blood glucose and glycated hemoglobin increased after three months of fenofibrate administration. Serum adiponectin or resistin concentrations were not significantly affected by fenofibrate treatment. All parameters of insulin sensitivity as measured by hyperinsulinemic-isoglycemic clamp were significantly lower in an obese diabetic group compared to the control group before treatment and were not affected by fenofibrate administration. We conclude that administration of PPAR-alpha agonist fenofibrate for three months did not significantly affect insulin sensitivity or resistin and adiponectin concentrations in obese subjects with type 2 diabetes mellitus. The lack of insulin-sensitizing effects of fenofibrate in humans relative to rodents could be due to a generally lower PPAR-alpha expression in human liver and muscle.

The influence of very-low-calorie diet on serum leptin, soluble leptin receptor, adiponectin and resistin levels in obese women

The aim of our study was to determine whether adipocyte-derived hormones leptin, adiponectin and resistin contribute to the improvement of insulin sensitivity after very-low calorie diet (VLCD). Therefore, serum levels of these hormones were measured in fourteen obese females before and after three weeks VLCD and in seventeen age- and sex-matched healthy controls. Body mass index, HOMA index, serum insulin and leptin levels in obese women before VLCD were significantly higher than in control group (BMI 48.01+/-2.02 vs. 21.38+/-0.42 kg/m(2), HOMA 10.72+/-2.03 vs. 4.69+/-0.42, insulin 38.63+/-5.10 vs. 18.76+/-1.90 microIU/ml, leptin 77.87+/-8.98 vs. 8.82+/-1.52 ng/ml). In contrast, serum adiponectin and soluble leptin receptors levels were significantly lower in obese women before VLCD than in the control group. No differences were found in serum glucose and resistin levels between the obese group before VLCD and the control group. VLCD significantly decreased BMI, HOMA index, serum glucose, insulin and leptin levels and increased soluble leptin receptor levels. The changes in serum adiponectin and resistin levels in obese women after VLCD did not reach statistical significance. We conclude that leptin and soluble leptin receptor levels were affected by VLCD while adiponectin and resistin concentrations were not. Therefore, other mechanisms rather than changes in the endocrine function of the adipose tissue are probably involved in the VLCD-induced improvement of insulin sensitivity.

[Effect of sideropenic anemia and its therapy on serum levels of leptin]

BACKGROUND

Leptin is a protein hormone produced predominantly by adipocytes. Its major role in human body is probably to regulate the food intake through the hypothalamic satiety center. One of the peripheral effects of leptin, which was studied mainly in vitro so far, is its stimulating effect on the haematopoietic stem cells. The information concerning the changes of serum leptin levels in various haematological diseases is very limited. The aim of our study was to explore changes of serum leptin levels in patients with sideropenic anaemia at the time of diagnosis and in the various phases of their treatment.

METHODS AND RESULTS

18 patients with untreated sideropenic anaemia (SA) and 20 healthy age, gender and weight-matched control subjects were included into the study. The blood testing in SA patients was performed before anaemia treatment, at the time of maximal increase of reticulocytes and after haemoglobin levels normalisation. Blood count, serum leptin, erythropoietin (EPO) and transpherine receptor (TfR) levels were estimated in all samples. Basal serum leptin levels in SA patients did not differ significantly from those of control subjects (13.9 +/- 14.6 SD vs 10.4 +/- 8.8 SD ng.ml-1). Treatment anaemia of did not significantly affect the serum leptin levels in SA patients (13.9 +/- 14.6 SD vs 12.9 +/- 12.6 SD vs 12.8 +/- 15.1 SD ng-ml-1). Serum EPO and TfR levels in SA patients were higher before the start of treatment and decreased significantly after the anaemia recovery. In both groups serum leptin levels correlated positively with body mass index. No unambiguous statistically significant relationships between serum leptin levels and blood count parameters or serum EPO and TfR levels were found in any of the groups studied.

CONCLUSION

Neither the changes of red blood cell count during the sideropenic anemia treatment nor the increased erythropoiesis affect significantly serum leptin levels.

[Effect of physical activity on serum leptin levels]

Leptin is a protein hormone produced predominantly by adipocytes. Its serum concentrations usually reflect the total body fat content i.e. they are higher in obese than in lean subjects. The aim of our study was to follow the influence of the regular hard physical training on the serum leptin levels. Therefore, the serum leptin levels in top rugby players, top race walkers and age and gender-matched control group were compared. The relationship between serum leptin concentrations and body mass index and body fat content was also studied. It was found that serum leptin levels in rugby players were significantly higher than in race walkers group, but lower than in control one. Serum leptin levels in race walkers were lower than those of rugby players and of control group. The body fat content in race walkers was lower than in resting two groups. There was no significant difference in body fat content between control and rugby players group. Serum leptin levels correlated positively with body mass index and body fat content both in control and in rugby players group. No statistically significant relationship was found between leptin and body mass index or body fat content respectively in race walkers group. We conclude that serum leptin levels in top sportsmen are lower than in non-sporting healthy age and gender-matched controls. The lower leptin levels in top sportsmen are probably in part the result of lower body fat content and in part the result of complex neurohormonal adaptation on the long term physical training.

[Relation between serum leptin levels, blood parameters and erythropoietin levels in hemodialyzed patients]

BACKGROUND

Serum leptin levels are significantly increased in hemodialysed patients compared to healthy subjects. There are some data suggesting the possible relationship of leptin and the regulation of haematopoiesis. The aim of our study was to compare serum leptin levels in two groups of hemodialysed patients: the group treated by recombinant human erythropoietin (n = 40) (HD + EPO), the group without erythropoietin treatment (HD) and the control group of healthy subjects (n = 20) to explore the influence of erythropoietin treatment on serum leptin levels.

METHODS AND RESULTS

The tendency towards lower body fat content and higher serum leptin levels was found in both groups of HD patients compared to control group, but the differences did not reach statistical significance due to high variability of those parameters (leptinu levels: HD 19.5 +/- 18.5, HD + EPO 24.9 +/- 23.3, K 10.4 +/- 8.8 ng.ml-1). The erythrocyte count and haemoglobin levels in both groups of HD patients were significantly lower than in control group. The erythrocyte count and haemoglobin levels were significantly lower in HD patients treated by erythropoietin compared to untreated HD group. The leptin/body fat content ratio was significantly higher in HD patients compared to healthy subjects (HD 0.86 +/- 0.72, HD + EPO 0.92 +/- 0.78, K 0.35 +/- 0.21, p < 0.05). Serum leptin levels in all studied groups correlated positively with body fat content and negatively with erythrocyte count. No significant relationships of serum leptin levels to erythropoietin levels or other parameters studied were found in any of groups.

CONCLUSIONS

Our study further supported the fact that serum leptin levels in HD patients are relatively higher than in healthy subjects. Serum leptin levels in HD patients treated by recombinant human erythropoietin did not significantly differ from HD patients without this treatment. Except of the negative correlation between serum leptin levels and the erythrocyte count no statistically significant relationships of serum leptin levels and the blood count parameters were found.

[Serum leptin levels and soluble leptin receptors in female patients with anorexia nervosa]

BACKGROUND

Leptin action in peripheral tissues is enabled by an interaction with specific transmembrane receptors. Several of leptin receptor isoforms were identified, including soluble leptin receptor isoform structurally identical to extracellular domain of the the long leptin receptor isoform. The soluble receptor isoform is released to the circulation and acts probably as leptin-binding factor. The aim of our study was to measure serum concentrations of the soluble leptin receptor in patients with anorexia nervosa and in the control group of healthy women. Relationships of soluble leptin receptor levels to body mass index (BMI), body fat content, serum leptin, TNF-alpha and insulin levels were also studied.

METHOD AND RESULTS

16 patients with anorexia nervosa and 16 age-matched lean healthy women were included into the study. All of the subjects were measured and weighed, the body fat content was estimated from the skinfold thickness measurement. The blood for the determination of leptin, soluble leptin receptor and other hormonal parameters was obtained from all subjects after the overnight fasting. BMI, body fat content, serum leptin and insulin levels in patients with anorexia nervosa were significantly lower than in the control group (BMI: 14.98 +/- 2.32 vs. 22.21 +/- 2.48, p < 0.01, % fat content: 16.43 +/- 4.56 vs. 27.19 +/- 4.59, p < 0.01, leptin: 1.37 +/- 1.85 ng.ml-1 vs. 7.19 +/- 3.49 ng.ml-1, p < 0.01, insulin: 12.97 +/- 2.89 mU.l-1 vs. 17.09 +/- 5.57 mU.l-1, p < 0.05). Serum soluble leptin receptor levels in patients with anorexia nervosa were significantly higher compared the to control group (24.67 +/- 8.3 U.ml-1 vs. 15.71 +/- 2.79 U.ml-1, p < 0.01). No significant differences in serum TNF-alpha levels between the groups studied were found. Serum leptin levels in both groups correlated positively with BMI and body fat content. Serum soluble leptin receptor levels in both groups correlated negatively with BMI only. No statistically significant relationships between serum soluble leptin receptor levels and the rest of parameters studied were found in any of the groups studied.

CONCLUSIONS

Serum soluble leptin receptors levels in patients with anorexia nervosa were significantly higher in comparison with the healthy subjects. Except of the negative correlation between serum soluble leptin receptor levels and BMI no statistically significant relationships between serum soluble leptin receptor and the rest of parameters studied were found.

[Effect of aerobic training in top athletes on serum leptin: comparison with healthy non-athletes]

Leptin is a protein hormone produced by adipocytes. Its serum concentration in the most of cases precisely reflect the total body fat content. The aim of our study was to follow up the influence of regular aerobic training on serum leptin levels. Therefore the serum leptin levels, basic anthropometric parameters and serum lipids were compared in 11 intensively trained race walkers and 10 age-matched non sporting control subjects. We have found, that serum levels, body weight, body mass index, body fat content, total and LDL-cholesterol were significantly decreased in walkers group in comparison with control subjects. Serum leptin levels positively correlated with body fat content and body mass index only in control group, in the walkers group the correlation was non-significant. The results of our study demonstrate, that regular aerobic training accompanied with the decrease of body fat content leads to the significant drop of serum leptin levels.

Lower serum leptin concentrations in rugby players in comparison with healthy non-sporting subjects--relationships to anthropometric and biochemical parameters

Leptin is a protein hormone synthesized by adipocytes. Its serum concentrations reflect the total body fat content. Serum leptin concentrations are significantly higher in obese than in lean people and in women than in men. However little information about the influence of physical activity on serum leptin concentrations is available. We have compared the body weight, the body mass index (BMI), the body fat content (measured by caliper as skinfold thickness) and the serum concentrations of leptin, triglycerides, total, high density and low density lipoprotein (LDL) cholesterol in 14 top rugby players and 10 healthy controls. We found that serum leptin, total and LDL cholesterol concentrations were significantly lower in the rugby players group than in the control subjects. The body weight and BMI were significantly higher in the rugby players, while the body fat content was only slightly (non-significantly) higher in the control group. The serum leptin concentrations in both groups positively correlated with the BMI and body fat content and also with LDL concentrations in the control group. The serum leptin concentrations in the rugby players were lower than in the non-sporting subjects despite a similar body fat content in both groups. We would therefore suggest the possibility that regular hard physical training decreases serum leptin concentrations not only by the decrease of total body fat content, but also by a separate mechanism, which is not directly dependent on the changes in the amount of body adipose tissue.