Bone turnover markers, osteoprotegerin and RANKL cytokines in children with cystic fibrosis.

PURPOSE: Some scientific studies show decreased bone mineral density and increased fracture frequency in adult patients with cystic fibrosis (CF). The mechanism for early bone loss in CF patients are multifactorial: chronic pulmonary inflammation, malnutrition, reduced physical activity, delayed pubertal maturation. The aim of this study was to assess bone metabolism markers with special attention paid to osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) balance in CF children. MATERIAL AND METHODS: The study included 35 children with diagnosed CF and 35 healthy controls aged 5-9 years (median 7.0 years). Serum levels of fat soluble vitamins were measured by chemiluminescence (vitamin D) and HPLC (vitamins A, E) methods. Concentrations of bone metabolism markers were determined by immunoenzymatic assay. RESULTS: Mean levels of fat soluble vitamins (A, D, E) were lower in patients with CF compared to controls. In CF children we observed a significant (p<0.01) decrease in concentration of bone formation marker (osteocalcin) and similar bone resorption markers (CTX, TRACP5b) in comparison with healthy children. The serum level of OPG was significantly lower (p<0.05) and RANKL nearly 2-fold higher in patients with CF than in the healthy ones. The ratio of OPG to RANKL was about 2-fold lower in children with CF compared to healthy peers (p<0.01). CONCLUSION: In CF children, an imbalance between bone formation and resorption processes occurs. An increase serum RANKL concentration coexisting with lower levels of OPG may be associated with intensification of bone resorption.

Alterations in markers of bone metabolism and adipokines following a 3-month lifestyle intervention induced weight loss in obese prepubertal children.

BACKGROUND: Adipokines may influence bone metabolism in children, but this phenomenon is not well understood. Therefore, we studied the relationships between bone markers and adipokines during weight loss in obese children. MATERIALS AND METHODS: We determined serum leptin, soluble leptin receptor (sOB-R), adiponectin, BALP (bone alkaline phosphatase), CTX-I (C-terminal telopeptide of type I collagen), body composition and bone mineral density (by dual-energy X-ray absorptiometry) in 100 obese prepubertal children before and after 3 months of lifestyle intervention (low-energy diet, physical activity). The control group consisted of 70 non-obese children. RESULTS: Obese children had higher BALP activity by about 20% (p<0.001) and similar value of CTX-I compared with non-obese children. After weight loss (-0.96 BMI-SDS mean change), the BALP value in obese patients decreased (p<0.001), whereas CTX-I concentration was unchanged. Changes in BALP were positively correlated with changes in BMI (Body Mass Index) (r=0.352, p<0.001), but not associated with adipokine levels. Trend analysis using SDS-BMI subgroups showed that greater reduction of body mass was associated with a greater decrease of BALP (p=0.035) and leptin values (p<0.001), as well as a greater increase of sOB-R (p<0.003). CONCLUSIONS: Obesity during the prepubertal period is associated with an alteration in the adipokines profile and greater whole-body bone mass as a result of increased bone formation rather than reduced bone resorption. Changes in bone metabolism during lifestyle intervention seem to be related to weight loss but not to changes in adipokines. Further studies should elucidate the influence of long-term therapy on bone mass in childhood.

Clinical utility of biochemical bone turnover markers in children and adolescents with osteosarcoma.

PURPOSE: Biochemical markers of bone turnover reflecting the intensity of all bone remodeling processes in skeleton are important for fast and non-invasive assessment of bone formation and resorption processes. They can be used in terms of both physiological and pathological states. The aim of this study was to investigate if bone metabolism markers can be clinically useful for monitoring of treatment in children and adolescents with osteosarcoma. MATERIAL/METHODS: The study consisted of 55 patients (median age 15 years) with osteosarcoma and 60 healthy age matched counterparts. Serum bone turnover markers (bone alkaline phosphatase - BALP, osteocalcin - OC and C-terminal telopeptide of type I collagen - CTX) were analyzed by immunoenzymatic methods in patients at time of diagnosis, during treatment and after therapy. RESULTS: We observed that before treatment the concentration of OC in patients with osteosarcoma was significantly lower (p<0.05) compared to that obtained in healthy children, however, BALP and CTX were at a similar level. During chemotherapy the values of bone formation and resorption markers significantly decreased by about 20-30%. After therapy we observed different concentrations of all bone turnover markers in patients with favorable and unfavorable prognosis. Median values of OC and BALP were over twofold higher in patients with progression as compared to patients with remission of disease (p<0.01 and p<0.001, respectively). Patients with poor prognosis had also higher serum concentration of bone resorption marker in comparison to patients with remission (p<0.01). CONCLUSIONS: Presented results suggest that bone turnover markers identify changes in bone metabolism in patients with osteosarcoma during anticancer therapy. These markers due to the non-invasive methods and their specificity might be useful in monitoring of clinical treatment of osteosarcoma patients.

Serum markers of bone turnover in children and adolescents with classic galactosemia.

PURPOSE: Classic galactosemia is an inherited metabolic disease resulting from galactose-1-phosphate uridyltransferase (GALT) deficiency. Dietary lactose exclusion reverses many clinical manifestations of acute phase of the disease. Unfortunately most of the patients, despite dietary treatment, develop long-term complications among them disturbances of bone mineralization resulting in decrease of bone mineral density (BMD). The aim of our study was to assess bone formation and resorption processes with bone turnover markers in children and adolescents with galactosemia. MATERIALS AND METHODS: We studied 62 galactosemic children (mean age+/-SD 5.9+/-2.7 years) and adolescents (mean age+/-SD 15.6+/-2,4 years). The clinical diagnosis had been confirmed by the absence of GALT activity in erythrocytes. All patients were diagnosed in the neonatal period and had good dietary control. Healthy children (n=70) were the reference group. Serum osteocalcin (OC), bone alkaline phosphatase (BALP), collagen type I crosslinked C-telopeptide (CTX-I), 25(OH)D metabolite of vitamin D were determined by ELISA assays. RESULTS: We observed similar mean values of bone formation markers in children with galactosemia as compared to the age-matched controls. The level of bone resorption marker CTX-I in these patients was lower by about 20% (p<0.001) than in healthy children. On the contrary we obtained slightly higher values of CTX-I in adolescents with galactosemia in comparison to the age-matched controls. In these patients the values of OC and BALP were significantly higher than in healthy adolescents (111.8+/-52.1 microg/L versus 82.3+/-43.0 microg/L, p<0.02; and 95.4+/-45.7 U/L versus 72.6+/-40.6 U/L, p<0.05 respectively). CONCLUSION: Our results suggest that bone turnover in galactosemic patients elevates from childhood to adolescence, whereas in healthy individuals there is a decline during aging. Further studies on adults with galactosemia are necessary to assess bone status in these patients.

Serum concentration of biochemical bone turnover markers in vegetarian children.

PURPOSE: In general, most children on well-planed vegetarian diets can achieve normal growth and development. However, elimination of animal products from the diet decreases the intake of some essential nutrients, such as calcium and vitamin D, and may influence bone metabolism. This is especially important in childhood and adolescence, when growth and bone turnover are most intensive. The aim of this study was to investigate the serum concentrations of biochemical bone turnover markers in prepubertal vegetarian children. MATERIAL AND METHODS: We examined 50 children on vegetarian and 50 on omnivorous diets aged 2-10 years. Dietary constituents were analyzed using a local nutritional program. Serum bone formation (OC, BALP) and resorption (CTX) markers were determined by specific enzyme immunoassays (ELISA) and 25-hydroxyvitamin D by the chemiluminescence method (CLIA). RESULTS: The average daily energetic value and the percentage of energy from protein, fat and carbohydrates in the diets were similar in both groups of children and were within the recommended range. The vegetarian children showed about a two-fold lower daily intake of calcium and vitamin D than their omnivorous counterparts. The level of 25-hydroxyvitamin D in the serum of vegetarian children was also nearly 2-fold lower compared with omnivores. In vegetarians, as compared to non-vegetarians, mean serum concentrations of OC, BALP and CTX were lower by about 20%, 10% and 15%, respectively. CONCLUSION: Our preliminary results suggest that an inadequate dietary intake of calcium and vitamin D may impair bone turnover rate in vegetarian children. The parameters of bone metabolism should be monitored in these children in order to prevent bone abnormalities.

Serum homocysteine, folate, vitamin B12 and total antioxidant status in vegetarian children.

PURPOSE: The results of several studies point to the positive role of vegetarian diets in reducing the risk of diabetes, some cancers and cardiovascular diseases. However, exclusion of animal products in vegetarian diets may affect the cobalamin status and cause an elevation of the plasma homocysteine level. The aim of this study was to assess the effect of vegetarian diets on serum concentrations of homocysteine, folate, vitamin B12 and total antioxidant status (TAS) in children. MATERIAL AND METHODS: The study included 32 vegetarians (including 5 vegans), age 2-10 years. Dietary constituents were analyzed using a local nutritional programme. Serum homocysteine, folate and vitamin B12 were determined with fluorescence and chemiluminescence immunoassays. The concentration of TAS was measured by a colorimetric method. RESULTS: Average daily energy intake and the percentage of energy from protein, fat and carbohydrates in the diets of the studied children were just above or similar to the recommended amounts. It could be shown that vegetarian diets contain high concentrations of folate. In vegan diets it even exceeds the recommended dietary allowance. Mean daily intake of vitamin B12 in the studied diets was adequate but in vegans was below the recommended range. The serum concentrations of homocysteine, folate, vitamin B12 and TAS in vegetarian children remained within the physiological range. CONCLUSIONS: The presented data indicate that vegetarian children, contrary to adults, have enough vitamin B12 in their diet (excluding vegans) and normal serum concentrations of homocysteine, folate and vitamin B12. Therefore, in order to prevent deficiencies in the future, close monitoring of vegetarian children (especially on a vegan diet) is important to make sure that they receive adequate quantities of nutrients needed for healthy growth.

Osteoprotegerin and C-telopeptide of type I collagen in Polish healthy children and adolescents.

PURPOSE: Most metabolic bone diseases are characterized by a disturbances in bone resorption, therefore biochemical markers concerning this process are of special interest. Recently, the novel cytokine osteoprotegerin (OPG), belonging to the tumor necrosis factor receptor family has been established as an endogenous inhibitor of osteoclastogenesis and resorption process. In addition serum C-telopeptide of type I collagen (s-CTX) is one of the resorption markers released into circulation as a result of the osteoclast mediated degradation of type I collagen. However, a clinical application of OPG and s-CTX in children may be difficult by less information of suitable reference data in relation to age, race and sex. The aim of our study was to invastigate serum concentrations of both markers in polish healthy children and adolescents. MATERIAL AND METHODS: We examined 102 healthy children and adolescents in 6-24 years of age, divided on prepubertal, pubertal and postpubertal groups. OPG and s-CTX were determined by ELISA kits from Biomedica (Austria) and Osteometer (Denmark) respectively. RESULTS: The highest mean values of OPG were in prepubertal girls (4.64 +/- 0.57 pmol/L) and boys (4.28 +/- 0.86 pmol/L). Next, in older children and adolescents gradually decreased of OPG concentration was observed. We also obtained the decreased of s-CTX concentration in studied children except these in pubertal period. Generally, we obtained significant positive correlation between OPG and s-CTX in all observed groups (n = 102, r = 0.653; p < 0.0001). CONCLUSIONS: We report the age-related decrease in circulating endogenous OPG during childhood and adolescence. Serum OPG concentration in postpubertal period may be similar to those presented in young adults. Prospective studies are needed to investigate the influence of OPG on bone metabolism in children.

Low serum leptin concentration in vegetarian prepubertal children.

PURPOSE: Vegetarian diet may play a positive role in reducing risk of several chronic diseases such as diabetes, coronary heart disease and some types of cancer. There are different vegetarian dietary patterns, some of which are nutritionally adequate for children, whereas other may lack some essential nutrients. Leptin, a hormone from adipose tissue plays a key role in the control of body fat stores and energy expenditure. Higher leptin levels were observed in obese subjects and lower in anorectic patients. Recent studies support that diet may be a factor which influences leptin levels. The aim of this study was to investigate serum concentrations of leptin, lipids and apolipoproteins in prepubertal children with two different nutritional habits: vegetarian and omnivorous diet. MATERIAL AND METHODS: We examined 22 vegetarians and 13 omnivores in age 2-10 years. Serum leptin concentration was determined by immunoenzyme assay (ELISA) and serum lipids were measured by enzymatic and immunoturbidimetric methods. RESULTS: Average daily dietary energy intake and the percentage of energy from protein, fat and carbohydrates were similar for both groups of children. We observed that in vegetarian diet there is a high rate of fiber nearly twice as high as in omnivorous diet. Vegetarians had lower total cholesterol and HDL- and LDL-cholesterol concentrations than children on traditional mixed diet. There is no significant differences in triglyceride concentration between studied groups. The apolipoproteins levels in vegetarian children were significantly below that of omnivores. The serum concentration of leptin was lower in vegetarians (3.0 +/- 1.1 ng/mL) than in nonvegetarians (5.1 +/- 2.0 ng/mL) (p < 0.01). CONCLUSIONS: Our results suggest that vegetarian diet may be accompanied by lower serum leptin concentration. Further studies on large group of children are needed for understanding this problem better.

[Selected independent risk factors of atherosclerosis in children as the basis of early detection of premature ischemic heart disease]. / Wybrane niezalezne czynniki ryzyka miazdzycy u dzieci jako podstawa wczesnego wykrywania zagrozenia choroba niedokrwienna serca.

This review briefly summarises the scientific evidence for the child's future risk of ischemic heart diseases (IHD). The conventional risk factors such as dyslipidemia, hypertension, diabetes and smoking can not account for all the cases of cardiovascular diseases. Therefore other risk factors such as fibrinogen, homocysteine, paraoxonaze and abnormality in antioxidant defence systems are included. Among the lipids parameters the level of lipoprotein (a) and increased plasma cholesterol, specifically LDL-cholesterol may be used as a marker of family history of IHD and hypercholesterolemia. Additionally, low level of HDL-cholesterol is also related with endothelial dysfunction and increased oxidative stress. It has been hypothesised that free radicals mediate in the development of IHD and that antioxidants play a protective role in prevention of this pathology. Many of the major risk factors can be modified through diet, body mass control, exercise and (if necessary) through pharmacological intervention. Therefore, the efficacious prevention should be related with the early detection of risk factors particularly in children with familial dyslipidemia, hypertension and IHD.

[Homocysteine and some lipid parameters in hypercholesterolemic children]. / Homocysteina i wybrane parametry przemian lipidowych u dzieci z hipercholesterolemia.

High serum homocysteine (tHcy) concentration is increasingly recognised as independent risk factor for atherosclerosis, early coronary heart disease (CHD) and other vascular diseases. It has been proved that adult cardiovascular disease begins in childhood. In the presented studies we determined concentrations of homocysteine, lipids and lipoproteins in plasma of hypercholesterolemic and normocholesterolemic children. In hypercholesterolemic children total cholesterol, LDL cholesterol, apolipoprotein B and triglycerides were significantly higher, whereas HDL cholesterol and apolipoprotein A-I were lower in comparison to the control group. Total serum homocysteine in children with positive family history for cardiovascular disease CHD(+) was significantly higher than in the control groups, and in CHD(-) group. It was respectively 7.3 micromol/1 versus 5.45 micromol/l versus 5.21 micromol/l. The results obtained in our study indicate that in hypercholesterolemic children with positive family history for CHD, the concentration of tHcy can be considered as a separate predictive risk factor for premature cardiovascular disease.

[Level of retinol and beta-carotene in plasma of smoking and non-smoking women]. / Poziom retinolu i beta-karotenu w osoczu krwi palacych i niepalacych kobiet ciezarnych.

Cigarette smoking during pregnancy generates many oxidants and free radicals and it has been implicated in cellular damage. Retinol and its provitamin beta-carotene are natural factors protecting cells from damaging influence of free oxygen species. The aim of our study was the assessment of vitamin A and beta-carotene levels in plasma of smoking and non-smoking pregnant women. Assignment the groups was based on the concentration of serum cotinine. In the presented studies the mean level of serum cotinine in smoking pregnant women was 1326 +/- 790 micrograms/l (range 350-1930 micrograms/l). In the group of tobacco abstinents the level of cotinine was in a range of 0-60 micrograms/l. Plasma concentrations of retinol and beta-carotene were measured by high pressure liquid chromatography (HPLC). Plasma level of vitamin A was lowered by 20% and was 1.64 +/- 0.42 mumol/l and 2.06 +/- 0.58 mumol/l in smoking and abstinent groups respectively. Women who smoke during pregnancy also have significantly lower levels of beta-carotene in plasma (1.9 +/- 0.5 mumol/l) than non-smokers (2.4 +/- 0.6 mumol/l; p < 0.001). We have observed that plasma concentration of beta-carotene has decreased since 21 gestation week in smokers while in abstinent group increased during pregnancy. The increase of plasma level of beta-carotene indicates that their physiological requirement is satisfied by standard vitamins supplementation. The reduced concentrations of plasma retinol and beta-carotene suggest that consumption of these antioxidants for neutralization of free radicals present in cigarette smoking is enhanced. The observed changes indicate that vitamins intake in smoking pregnant women should be carefully controlled.

[Selected parameters of antioxidant capacity in renal allograft recipients]. / Wybrane wskazniki systemu przeciwutleniajacego u biorców allogennej nerki.

UNLABELLED: Various oxidant species, oxygen free radicals (OFR) implicated in patients with chronic renal diseases treated with dialysis and after cadaveric renal transplantation. Oxidative stress occurs when free radical generation exceeds antioxidant defence. We therefore examined markers of lipid peroxidation and antioxidant potential in blood (serum, plasma, RBC) of very carefully (clinically and biochemically) selected 102 subjects (56 female and 46 male, mean age 37.5 +/- 7 years). Included were 51 renal allograft recipients (RARs); 15 patients with glomerulopathies (GL); 36 healthy age- and sex-matched volunteers as a control group (C). All RARs were divided into two subgroups: RARs-A (n = 28) were treated with triple drug therapy including cyclosporin A (CsA) and RARs-Z (n = 23) were on double drug regimen: prednisone, azathioprine. Patients with coronary artery disease (CAD), diabetes, serum creatinine concentration > 2.0 mg/dl, acute rejection and infections were excluded. We used several automated assays to estimate: malondialdehyde (MDA); total radical-trapping antioxidant potential (TRAP), glutathione peroxidase (GPx), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), vit. E and lipid profiles. Patients of RARs-A were found to have significantly elevated triglycerides; cholesterol-LDL; MDA; TRAP and decreased activity of RBC glutathione peroxidase as compared with those of RARs-Z and group C. IN CONCLUSION: our data show that oxidative stress (with prooxidant effect of CsA partly at least), with reduced in antioxidant potential of defences system is associated with kidney transplantation.

Antioxidant status in erythrocytes of cystic fibrosis children.

Activities of superoxide dismutase, catalase and glutathione peroxidase in erythrocytes of cystic fibrosis children were studied in order to estimate the severity of their deficiency. Our results point to increased susceptibility of erythrocytes of cystic fibrosis subjects to oxidative injury and indicate that the antioxidant status of patients should be carefully monitored.

[Homocysteine and hyperhomocysteinemia]. / Homocysteina i hiperhomocysteinemia.

This paper reviews the biochemical and physiological data underlying hyperhomocysteinemia. Elevation of plasma homocysteine arises from disrupted of its metabolism (remethylation to methionine and transsulfuration to cystathionine) and is a function of a complex interaction between multiple genetic and environmental factors. Hyperhomocysteinemia, a conditions that recent epidemiological studies have shown to be associated with an increased risk of vascular diseases, may be a equal importance to hypercholesterolemia, hypertension and smoking in etiology of atherosclerosis. Based on the role of folic acid, vitamin B12 and B6 in homocysteine metabolism supplementation with these vitamins in treatment of hyperhomocysteinemia both in cardiovascular diseases and neural tube defects is reviewed.

Extensive and partial protein hydrolysate preterm formulas: the effect on growth rate, protein metabolism indices, and plasma amino acid concentrations.

BACKGROUND: The use of protein hydrolysate preterm formulas is restricted because data on their nutritional adequacy are scarce. The authors evaluated the rate of growth and indices of protein metabolism in low-birth weight infants fed extensive and partial protein hydrolysate preterm formula followed for 12 weeks. METHODS: A total of 61 low-birth weight infants were assigned randomly to receive extensive protein hydrolysate preterm formula (EH: n = 16), partial protein hydrolysate preterm formula (PH: n = 15), and standard preterm formula (SF; n = 15), or were fed their own mother's fortified breast milk (FBM; n = 15). The infants were investigated at study entry, and at 4, 8, and 12 weeks after study entry. RESULTS: There were no differences with respect to growth rate (weight gain, increments in length and head circumference), urea, albumin, prealbumin, transferrin, and plasma amino acid concentrations (except for tyrosine on a single occasion) according to the degree of hydrolysis. There were also no differences between groups fed hydrolyzed formulas and SF. However, several differences were found when EH and PH were compared with FBM. Weight gain from the entry to 12 weeks, serum urea at 12 weeks, and total plasma essential amino acids at 8 weeks were significantly higher in groups fed EH and PH than in those fed FBM. In addition, valine was significantly higher in groups fed PH (P < 0.05) than in the group fed FBM at 8 and 12 weeks, tyrosine was higher in EH and PH in comparison with FBM at 4 weeks, and in PH versus FBM at 12 weeks after study entry. CONCLUSIONS: This study suggests that experimental EH and PH are at least nutritionally equivalent to SFs.

Serum homocysteine and lipoprotein (a) concentrations in hypercholesterolemic and normocholesterolemic children.

The relationship between lipids, lipoproteins, total homocysteine, and lipoprotein (a) was studied in hypercholesterolemic and normocholesterolemic children. In hypercholesterolemic children, concentrations of total cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein B, and triglycerides were significantly higher compared to levels in controls, whereas concentrations of high-density lipoprotein (HDL) cholesterol and apolipoprotein A-I were lower compared to those in the control group. Total serum homocysteine concentrations in children with a positive family history for cardiovascular disease CHD(+) (7.28 micromol/L) were significantly higher than those in the control group (5.45 micromol/L), and in the group of CHD(-) children (5.25 micromol/L). The median value of lipoprotein (a) in patients was 31.5 mg/dL (range, 11-209 mg/dL) and in the control group, 19 mg/dL (range, 11-95 mg/dL). Concentrations of Lp (a), exceeding 30 mg/dL, were present in 45% of CHD(+) children, in 29% of CHD(-) children, and in only 11% of the control group.

[The role of leptin in human obesity].

The mechanism involved in body mass regulation in humans includes genetic, environmental, and behavioural factors. Human obesity is usually associated with a positive energy balance. Genetic studies in obese mice have revealed the Ob. gene, its products leptin and the leptin receptor to be important factors in the regulation of both appetite and energy expenditure. Leptin is a 16-kilodaltons adipocyte-derived hormone -which circulates in the serum as the free and bound forms. The leptin serum level reflects the amount of energy stored in adipose tissue. Leptin acts through the leptin receptor, -which belongs to the cytokine - receptor family. In rodents as well as in humans, homozygous mutations in genes encoding leptin or the leptin receptor cause early-onset morbid obesity, hyperphagia, and reduced energy expenditure. Recent studies have demonstrated that Ob. gene expression is increased in human obesity. However, mutations of Ob. gene present in the mouse are rare in the human population.

[Levels of lipid peroxides and of some antioxidants in placenta and cord blood of newborns whose mothers smoked during pregnancy].

Cigarette smoking during pregnancy increases the risk of oxidative damage and induces not only intrauterine foetal growth retardation, but also causes disturbances in postnatal growth and development. In the presented studies oxidative damage was estimated through the measurement of lipid peroxides concentration and the level of some antioxidants in placenta and in cord blood of newborns whose mothers smoked during pregnancy. We observed that the concentration of lipid peroxides was higher in cord blood and in placenta tissue (8%) than in the newborns of non-smoking mothers, but the activity of superoxide dismutase and glutathione peroxidase were lower by 20% and 16% respectively. Plasma level of vitamin A (p<0.005), vitamin E (p<0.05), fS-carotene (p< 0.0001) and total plasma antioxidant capacity (p<0.05) were significantly lower in the newborn of smoking than the non-smoking mother group. It is suggested that placental tissue protected the foetus against oxidative stress, but not sufficiently. Antioxidant activities of cord blood may also be insufficient in dismutation of free radicals and their detoxication in order to protect newborns against smoking dependent metabolic disturbances.

[Serum leptin level in prepubertal children with simple obesity. Part one]. / Ocena poziomu leptyny u dzieci w wieku przedpokwitaniowym z otyloscia prosta. Czesc I.

The aim of the study was to determine the serum leptin level and anthropometric indices (body mass index - BMI) in a group of prepubertal children with simple obesity. These parameters were compared with the values characteristic for the group of slim children. The study showed that serum leptin levels were significantly higher in obese children compared with the group of slim children (p<0.0001). There was a positive correlation (r=0.48; p<0.05) between leptin levels and nutritional status indices expressed by BMI. Results of this study suggest that leptin level in the group of children with simple obesity does not have an effect on satiety, on reduction of appetite or on the increment of adipose tissue. The study showed also that hyperleptinemia might be an effect of leptin resistance.

[Serum tyrosine in children with phenylketonuria and mild hyperphenylalaninemia]. / Tyrozyna w surowicy krwi u dzieci z fenyloketonuria i lagodna hiperfenyloalaninemia.

Serum tyrosine concentration, Phe/Tyr scores and psychomotor/mental development scores were analysed in 32 children with phenylketonuria (PKU) and 39 with mild hyperphenylalaninaemia. Observation period included the first 6 years of life. Tendency to tyrosine deficiency was observed; stronger in dietary treated PKU patients than in those with mild hyperphenylalaninaemia. Statistically significant differences between patient groups were found only in 3 and 6 years old children (lower tyrosine values in PKU patients). It was observed that evaluation of Phe/Tyr score value might be usefull in differentiation between PKU and mild hyperphenylalaninaemia. Moreover, the above score may help in the evaluation of hypo- and hyperalimentation state in the course of dietary treatment. The level of tyrosine deficiency in the analysed patient groups did not influence their normal intellectual development.