Biomedical subjects

M Haluzík

Publications and source records attributed to M Haluzík.

At least 37 records · Page 2Linked to original sources

PubMed2004

Adiponectin and its role in the obesity-induced insulin resistance and related complications.

It is now generally accepted that adipose tissue acts as an endocrine organ producing a number of substances with an important role in the regulation of food intake, energy expenditure and a series of metabolic processes. Adiponectin is a recently discovered protein produced exclusively by adipocytes. A number of studies have shown that obesity, insulin resistance and atherosclerosis are accompanied by decreased adiponectin levels and that adiponectin replacement under experimental settings is able to diminish both insulin resistance and atherosclerosis. The aim of this review is to summarize the current knowledge about the physiology and pathophysiology of adiponectin and to discuss its potential in the treatment of insulin resistance and atherosclerosis.

Adiponectin↗

PubMed2004

[Serum leptin levels in patients with heroin addiction, the effect of one year of methadone substitution].

BACKGROUND AND AIM: The aim of the study was to explore the influence of heroin addiction and one year methadone maintenance treatment respectively on serum leptin levels. METHODS AND RESULTS: 14 heroin addicted subjects (9 men and 5 women) with average age 27.1 years (variation 22-38 years) and 17 control healthy subjects were included into the study. Mean duration of heroin addiction was 9 years. The subjects were treated for one year with mean daily dose of 90 mg of methadone. Serum leptin levels were measured by enzymoimmunoassay, the rest of the biochemical parameters was measured by standard laboratory methods. Body Mass Index (BMI) was calculated by conventional method (kg/m2). Statistical analysis was performed using t test and paired t test. Serum leptin levels in heroin addicts (7.08 +/- 2.80 ng/ml) did not significantly differ from those of control group (6.10 +/- 1.23 ng/ml). One year of methadone maintenance treatment significantly increased serum leptin levels to 12.10 +/- 3.17 ng/ml vs control group (< 0.05). The same was true for BMI which increased significantly from basal 21.47 +/- 2.54 to 24.61 +/- 2.82 (< 0.05). CONCLUSIONS: Long term addiction to heroin did not change serum leptin levels as compared with control group. One year of methadone maintenance treatment significantly increased serum leptin levels as well as BMI values. We suggest that the increase in serum leptin levels could be explained by the restoration of hypopituitary-hypothalamo-adrenal and/or hypopituitary-hypothalamo-gonadal axis by methadone maintenance treatment. Alternatively, the improvement of nutritional status with subsequent decrease in the infectious complications may be involved.

Adult↗

PubMed2003

Cutaneous trematode Collyriclum faba in wild birds in the central European Carpathians.

The occurrence of cutaneous trematode Collyriclum faba in wild birds was monitored in the central European Carpathians from 1996 to 2001. A total of 5,414 birds, representing 86 species, was examined. Collyriclum faba was found at 7 sites (5 in Slovakia, 1 in Poland, and 1 in the Czech Republic), and prevalences at the sites varied from 1 to 16%. Ten species of passerine birds were infected: blackcap (Sylvia atricapilla) (16 positive/622 tested, 2% prevalence), black redstart (Phoenicurus ochruros) (2/25, 8%), chaffinch (Fringilla coelebs) (7/113, 6%), common blackbird (Turdus merula) (1/143, 1%), common redstart (Phoenicurus phoenicurus) (1/30, 3%), dipper (Cinclus cinclus) (1/9, 11%), European robin (Erithacus rubecula) (103/838, 12%), goldcrest (Regulus regulus) (1/76, 1%), grey wagtail (Motacilla cinerea) (5/25, 20%), and yellowhammer (Emberiza citrinella) (1/73, 1%). Cutaneous cysts of C. faba were found in the birds from the end of May to mid-September, with the prevalence peaking in July and August. One to 21 cysts per bird were found. In black redstart, chaffinch, common redstart, European robin. and yellowhammer, cysts were most frequently observed on the legs, particularly in the crural region. In blackcap, common blackbird, dipper, and grey wagtail, almost all the cysts were found around the vent and on the abdomen. In goldcrest, the cyst was located above the coccygeal gland. Collyriclum faba is a common parasite in birds during summer in central European Carpathians. Collyriclum faba was observed for the first time in Poland. It appears that C. faba may be fatal for some of the bird hosts.

Animals↗

PubMed2003

Soluble leptin receptor levels in patients with chronic renal failure.

Soluble leptin receptor (SLR) is the extracellular part of the leptin receptor. This protein is released into circulation and constitutes the main circulating leptin-binding protein. The aim of our study was to measure SLR concentrations in patients with chronic renal failure (CRF) and healthy subjects and to explore the relationship of SLR to other hormones and cytokines. The patients with CRF had significantly higher serum leptin, TNF-alpha and insulin levels than healthy subjects (25.1+/-23.5 vs. 9.4+/-7.6 ng.ml(-1) (S.D.); 14.2+/-4.2 vs. 4.55+/-2.5 ng.ml(-1); 39.8+/-36.1 vs. 20.3+/-11.1 mU.l(-1)). Serum soluble leptin receptor levels did not differ between these groups (19.1+/-11.3 vs. 19.6+/-6.1 U.ml(-1)). An inverse relationship between serum SLR and leptin levels was found in both groups. In patients with CRF the inverse relationship between SLR and insulin, body fat content and total protein levels were also found, while in healthy subjects only inverse relationship of SLR with insulin and albumin concentrations were detected. We conclude that soluble leptin receptor levels in patients with chronic renal failure do not differ from those of healthy subjects despite higher serum leptin levels in CRF patients. The physiological consequences of this finding require further investigation.

Blood Proteins↗

PubMed2003

[Leptin levels in female patients with restrictive and purgative types of anorexia nervosa].

BACKGROUND: Anorexia nervosa is an eating disorder with typically chronic course. Two subtypes of anorexia nervosa have been described based on the pattern of eating behavior. Restrictive form of anorexia nervosa is characterized by chronically decreased food intake, while the purgative subtype typically consists of alternating episodes of fasting and overnutrition with factitious vomiting. METHODS AND RESULTS: The aim of this study was to compare anthropometric parameters, serum levels of fat-derived hormone leptin, cholesterol, triacylglycerols and serum leptin/body mass index ratio in patients with restrictive and purgative subtypes of anorexia nervosa respectively. Significantly lower body weight (37.79 +/- 3.93 vs. 49.63 +/- 9.84 kg, p < 0.05), body mass index (13.51 +/- 1.43 vs. 17.75 +/- 2.64 kg/m2, p < 0.05),), body fat percentage (13.28 +/- 2.83 vs. 18.9 +/- 5.65%, p < 0.05), serum leptin (1.117 +/- 0.95 vs. 5.88 +/- 4.7 ng/ml, p < 0.05) and cholesterol levels (4.14 +/- 1.78 vs. 6.31 +/- 1.27 mmol/l, p < 0.05) were found in patient with restrictive relative to purgative subtype of anorexia nervosa. In contrast, no difference in triglyceride levels between both groups was found. Serum leptin levels positively correlated with body mass index and body fat percentage only in patients with purgative subtype of anorexia nervosa (body mass index r = 0.95, p < 0.001, body fat percentage r = 0.64, p < 0.05) but not in those with restrictive subtype. CONCLUSIONS: In conclusion, we demonstrated that serum leptin levels were significantly lower in restrictive relative to purgative subtype of anorexia nervosa. We suggest that this difference is primarily due to distinctions in body fat content.

Adult↗

PubMed2003

The influence of nitric oxide synthase inhibitor L-NAME on bones of male rats with streptozotocin-induced diabetes.

The pathophysiological processes underlying the development of diabetic osteopenia has not hitherto been elucidated. Induction of streptozotocin diabetes leads in our experiments to decrease of bone density, ash, mineral content and to thinner cortical width compared to control male rats. In order to investigate the pathogenetic role of bone resorption by osteoclasts in streptozotocin-induced diabetes, we determined the circulating levels of tartrate-resistant acid phosphatase (TRAP), a biochemical marker for bone resorption. Plasma TRAP values in diabetic rats did not differ from their corresponding controls. Streptozotocin diabetes by itself did not have any effect on the weight of seminal vesicles which are highly testosterone-dependent. Low doses of nitric oxide cause bone resorption, but higher doses of NO inhibit bone resorbing activity. We examined the effect of L-NAME (inhibitor of nitric oxide production) after six weeks of administration to diabetic rats. There was no further significant loss of bone mineral density, ash and mineral content or tibia weight in diabetic rats treated with L-NAME. L-NAME itself did not decrease bone metabolism. In our study no evidence of an increased bone resorption was found. Our results have indicated that a predominance of bone resorption over bone formation is not involved in the pathogenesis of diabetes-associated osteopenia. Inhibition of NO neither increased osteoclastic activity (TRAP) nor induced osteopenia in L-NAME-treated rats. This suggests a possibility that NO is not involved in the pathogenesis of diabetic osteopenia.

Acid Phosphatase↗

PubMed2002

Serum leptin levels in patients with primary hyperaldosteronism before and after treatment: relationships to insulin sensitivity.

BACKGROUND: Leptin is a protein hormone produced predominantly by adipocytes that plays a role in food intake regulation and a series of other physiological processes including blood pressure regulation. OBJECTIVES: The aim of our study was to compare serum leptin levels in patients with primary hyperaldosteronism (PA) with those of healthy subjects and to explore the relationship of serum leptin levels and the parameters of insulin action in these patients before and after surgical or pharmacological treatment. METHODS: Serum potassium, leptin, aldosterone, insulin levels and plasma renin activity were measured and hyperinsulinaemic euglycaemic clamp was performed in 11 patients with PA and 11 healthy age-, gender- and body mass index (BMI)-matched subjects. In eight of 11 patients the same measurements were repeated at least 6 months after surgical or pharmacological treatment. RESULTS: The basal serum leptin levels in PA patients did not significantly differ from those of healthy subjects (mean+/-s.e.m. 8.4+/-1.9 vs 11.2+/-1.8 ng/ml, P=0.30), although their insulin sensitivity was significantly impaired (PA patients vs control subjects: glucose disposal rate in the last 20 min of clamp (M) 18.7+/-1.8 vs 30.6+/-3.3 micromol/kg/min, metabolic clearance rate of glucose (MCR(g)) 3.9+/-0.5 vs 7.2+/-1.1 ml/kg/min, P<0.05). The surgical or pharmacological treatment of PA patients increased significantly their serum leptin levels (10.9+/-3.7 vs 8.4+/-1.9 ng/ml, P<0.05) and simultaneously improved their insulin sensitivity. Basal serum leptin levels in both groups correlated positively with BMI and serum insulin levels. The inverse relationship between serum leptin levels and the insulin sensitivity parameters was found in both PA patients before treatment and healthy subjects. These relationships disappeared after treatment of PA patients except for those between serum leptin levels and MCR(g). CONCLUSION: Basal serum leptin levels in untreated patients with PA do not significantly differ from those of healthy subjects, but increase significantly after surgical or pharmacological treatment. The increase in serum leptin levels is paradoxically accompanied by the improvement of insulin sensitivity in these patients.

Adrenal Glands↗

PubMed2002

[Serum levels of leptin and soluble leptin receptors in women after bilateral ovariectomy].

OBJECTIVE: To determine whether the blood concentrations of leptin and soluble leptin receptor (LEPR) hang in women after bilateral ovariectomy, and whether there is a relationship between the concentrations of leptin, LEPR and LH, FSH and 17 beta-estradiol before and after castration. DESIGN: Prospective clinical study. SETTING: Department of Obstetrics and Gynaecology, First Faculty of Medicine, Charles University and the General Faculty Hospital, Prague. METHODS: 10 women of reproductive age (31-37 years) with a regular menstrual cycle were included in the study. Blood samples were always taken during the follicular phase of the menstrual cycle and 5 days after bilateral ovariectomy. In 9 women, hysterectomy was performed with the bilateral ovariectomy. Evaluated parameters: leptin, soluble leptin receptor, FSH, LH, 17 beta-estradiol and BMI. Serum soluble leptin receptor and leptin concentrations were determined using commercial ELISA kits. Serum concentrations of FSH, LH, and 17 beta-estradiol were determined using commercial RIA kits. RESULTS: We did not find any statistically significant changes in the concentration of leptin (8.9 +/- 5.5 vs 7 +/- 5.6) and LEPR (16.2 +/- 5.6 vs 20.9 +/- 8.9) before and after surgical castration. After surgery, according to expectations, the concentration of LH and FSH significantly increased while the concentration of 17 beta-estradiol decreased (P < 0.05). Five days after surgical castration we found only a tendency toward decrease in the concentration of leptin and an increase in the LEPR concentration. The differences were not statistically significant. Except for the positive correlation between leptin concentration and BMI, we did not find any statistically significant correlation between the concentrations of leptin and LEPR and any of the other evaluated parameters in both groups. CONCLUSION: In our study, there was a significant decrease in 17 beta-estradiol concentration five days after surgery. In contrast, the concentrations of FSH and LH significantly increased after surgery, which is in agreement with the expected endocrinological changes after ovariectomy. There was a tendency toward a decrease in serum concentrations of leptin and increase in serum concentration of LEPR after surgery, but it was not statistically significant, which is in contrast to another study published regarding this topic.

Adult↗

PubMed2002

[The changes in serum ghrelin levels and their relationship to IGF-I, its binding proteins and leptin in women patients with anorexia nervosa].

Ghrelin is recently discovered peptide hormone involved in the regulation of growth hormone secretion as well as in the regulation of food intake and energetic homeostasis. The study was aimed to describe the changes in ghrelin serum levels in patients with anorexia nervosa and its relationship to some other studied parameters. Sixteen women patients with anorexia nervosa and thirteen healthy women of comparable age were examined clinically and blood samples were taken for estimation of serum levels of ghrelin, leptin, soluble leptin receptor, IGF-I, IGFBP-1 and IGFBP-3. Ghrelin serum levels were significantly increased in the group of patients with anorexia nervosa (p < 0,05). In contrary, serum leptin levels were decreased in the group of patients with anorexia nervosa (p < 0,01). Serum ghrelin levels did not correlate with any other of studied parameters with exception of BMI. We can conclude that serum ghrelin levels are increased in patients with anorexia nervosa and their increase fails to significantly stimulate food intake in this group of patients.

Adult↗

PubMed2001

[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.

Adult↗

PubMed2001

The role of dopamine in methylene blue-mediated inhibition of estradiol benzoate-induced anterior pituitary hyperplasia in rats.

Recently, we demonstrated that methylene blue partially inhibited estradiol-benzoate-induced anterior pituitary hyperplasia in rats. Since central dopaminergic systems participate in the regulation of estrogen-induced anterior pituitary growth and tumor transformation, this study examined whether a 3-week treatment with methylene blue could affect anterior pituitary levels of dopamine (DA), dihydroxyphenylalanine (DOPA), and dihydroxyphenylacetic acid and dopamine (D-2) receptors in male rats. Compared to controls, methylene blue significantly decreased anterior pituitary weight, increased basal anterior pituitary DA levels, and inhibited estradiol benzoate-induced decreases in anterior pituitary DA concentrations. Furthermore, we found that methylene blue alone decreased anterior pituitary D-2 receptor number. Methylene blue given in combination with estradiol benzoate partially inhibited estradiol benzoate-induced anterior pituitary growth and estradiol benzoate-induced increases in D-2 receptor number. Estradiol benzoate-treated rats had significantly lower anterior pituitary DOPA accumulation after intraperitoneal administration of 3,4-hydroxybenzyl-hydrazine dihydrochloride (NSD-1015), an irreversible inhibitor of L-aromatic amino acid decarboxylase whereas methylene blue did not affect anterior pituitary DOPA accumulation when compared to controls. Methylene blue decreased anterior pituitary prolactin levels and inhibited increases in anterior pituitary prolactin after estradiol benzoate administration. The present results suggest that anterior pituitary DA may play an important role in estrogen-induced anterior pituitary hyperplasia and tumor formation and that antioxidant drugs such as methylene blue may attenuate estrogen-induced pituitary growth. This may occur via increases in anterior pituitary DA levels associated with down-regulation of anterior pituitary D-2 receptors.

3,4-Dihydroxyphenylacetic Acid↗

PubMed2001

Serum leptin levels in septic men correlate well with C-reactive protein (CRP) and TNF-alpha but not with BMI.

Leptin, an adipocyte-derived signaling factor, is a member of the IL-6 cytokine family. However there is no direct evidence of leptin stimulation of the acute phase protein (APP) synthesis which is typical for all other IL-6-like factors. The purpose of this study was to characterize the dynamics of circulating leptin in relation to ten APPs. We used postoperative septic patients as a model of cytokine network hyperstimulation and intensive APP reaction. The prospective study was performed on 22 patients with proven postoperative intraabdominal sepsis after large abdominal surgery. Plasma levels of leptin, TNF-alpha, IL-1beta, soluble IL-2 receptor (sIL-2R), IL-6 (ELISA analysis) and ten APPs (nephelometric analysis) were estimated. We have demonstrated a statistically significant elevation of plasma leptin concentrations in the septic group compared with healthy subjects (p<0.001). The correlation of plasma leptin and BMI during postoperative sepsis was diminished. The regression coefficient was the highest for leptin and CRP (r=0.48, p<0.05), and for leptin and alpha-1-antitrypsin (r=0.46, p<0.05) in the septic group. There was significant correlation between TNF-alpha and leptin (r=0.47, p<0.05) and between IL-6 and leptin (r=0.45, p<0.05) in septic patients. No significant correlation was found between leptin and "negative" APP and between leptin and IL-1beta. Leptin has thus been shown as an acute phase reactant with a potential hematopoietic, immunomodulatory and hepatocyte stimulating activity during the infectious and non-infectious stress response. The significant correlation between leptin and CRP and leptin and alpha-1-antitrypsin indicates that leptin can participate in APP synthesis regulation during a systemic inflammatory response.

Adult↗

PubMed2000

[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.

Blood Cell Count↗

PubMed2000

[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.

Anorexia Nervosa↗

PubMed2000

[Is leptin physiologically important in the regulation of hematopoiesis?].

Leptin is a protein hormone produced predominantly by adipocytes. Its serum concentrations under stabilised energy balance reflect the total body fat content. Serum leptin levels represent an important peripheral signal informing the hypothalamic satiety center about the body fat stores. Apart from the above mentioned functions the possible physiological significance of leptin in the regulation of angiogenesis, blood pressure, sexual maturation etc. is suggested. The long isoform of leptin receptor belongs to the cytokine receptors group. The leptin receptors were identified in some haematopoietic stem cells. Leptin was found to stimulate the proliferation of haematopoietic stem cells either alone or in combination with some cytokines. Leptin thus seams to represent an additional factor that plays a role in the haematopoiesis regulation as it was demonstrated by some experimental studies. However, this suggestion needs to be further confirmed by clinical studies exploring the changes of serum leptin levels in various phases of haematological diseases and during their treatment.

Animals↗

PubMed2000

Serum leptin levels in patients with hyperlipidemias.

Leptin is a protein hormone produced by adipocytes that reflects the body fat content. The aim of our study was to compare serum leptin levels in randomly selected untreated males and females with hypercholesterolemia and combined hyperlipidemia and in healthy control subjects matched for age and body mass index and to study the relations between leptin and serum lipids and lipoproteins. No statistically significant differences in serum leptin levels were found between the male control group (5.26 +/- 2.81 ng/mL(-1)) and the male group with hypercholesterolemia (8.16 +/- 3.85 ng/mL(-1)) or combined hyperlipidemia (7.51 +/- 4.83 ng/mL(-1)) and between the female control group (13.0 +/- 8.12 ng/mL(-1)) and the female group with hypercholesterolemia (15.36 +/- 8.89 ng/mL(-1)) or combined hyperlipidemia (18.63 +/- 10.15 ng/mL(-1)). Leptin concentration in male group with hypercholesterolemia did not differ significantly from the female control group; in the other male groups, leptin levels were significantly lower than those of the other female groups. Serum leptin levels in all studied groups except for the male group with hypercholesterolemia positively correlated with body mass index. Serum leptin levels correlated negatively with high-density lipoprotein cholesterol in the female group with hypercholesterolemia (r = -0.67, P < 0.01) and the male group with combined hyperlipidemia (r = -0.56, P < 0.01). A positive correlation between serum leptin and high-density lipoprotein cholesterol (r = 0.67, P < 0.01) and between leptin and lipoprotein (a) (r = 0.71, P < 005) was found in female group with combined hyperlipidemia. No other significant relationships between leptin and serum lipids or lipoproteins were found. We conclude that serum leptin levels in patients with hyperlipidemias do not significantly differ from those healthy control subjects matched by age and body mass index.

Adult↗

PubMed2000

Interaction between serum leptin levels and hypothalamo-hypophyseal-thyroid axis in patients with anorexia nervosa.

The main objective of the study was to evaluate the endocrinological picture of anorexia. Serum leptin levels are low in untreated anorexia nervosa (AN), but studies of the exact relationship between leptin, body weight and hormones of hypothalamo-hypophyseal-thyroid axis and the impact of refeeding in anorectics are limited. The sample consistent of 15 patients with anorexia nervosa before and 1 month after partial weight recovery, and 15 age-matched control subjects. The body mass index (BMI), leptin, plasma neuropeptide Y (NPY), serotonin, thyroxine (T4), triiodothyronine (T3) and reverse triiodothyronine (rT3) in serum were evaluated for each subject. The mean serum levels of leptin, T4, and T3 were significantly lower before weight recovery in 15 patients with AN than they were in control subjects. After partial weight recovery, basal T3 levels were unchanged and significantly lower than in controls. Basal T4 was even still more reduced, but we observed significantly elevated ratio of T3/T4 and reduced ratio rT3/T4 of in AN patients after gain recovery, indicating increased conversion of T4 to T3 than to rT3. The levels of serum leptin were low in AN, but after partial weight recovery slightly increased, and correlated with BMI. No differences were observed in serum NPY. Serum levels of IGF-1 and serotonin were lower in AN than in controls before and after partial weight gain. IGF-1 was slightly increased after partial weight gain. We did not find correlation between serum levels of leptin and serum T4. The low serum levels of T3 associated with chronic starvation were thought to be the result of impaired peripheral conversion of T4 to T3. However, decreased levels of T3 were still apparent even after a partial weight gain, and the concentration of T4 was even lower. The diminished serum level of TSH in AN, however, appeared to return to the level of controls. On the basis of these results, we assume that low serum levels of thyroid hormones in AN reflect a dysfunction of the HPT axis in AN patients. It is known that in man serum serotonin levels correlate positively with T3 levels. It is possible that the low serum levels of thyroid hormones in AN subjects result in low serum serotonin and its product, melatonin. While IGF-1 reflects the energy intake of the previous few weeks, the serum leptin concentration reflects the true status of the adipose stores, a fact that has useful clinical implications.

Anorexia Nervosa↗

PubMed2000

[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.

Adipose Tissue↗