Circulating Levels of Nesfatin-1 and Spexin in Children with Prader-Willi Syndrome during Growth Hormone Treatment and Dietary Intervention.

BACKGROUND: Despite observable improvement in the treatment outcomes of patients with Prader-Willi syndrome (PWS), adequate weight control is still a clinical problem. Therefore, the aim of this study was to analyze the profiles of neuroendocrine peptides regulating appetite-mainly nesfatin-1 and spexin-in children with PWS undergoing growth hormone treatment and reduced energy intake. METHODS: Twenty-five non-obese children (aged 2-12 years) with PWS and 30 healthy children of the same age following an unrestricted age-appropriate diet were examined. Serum concentrations of nesfatin-1, spexin, leptin, leptin receptor, total adiponectin, high molecular weight adiponectin, proinsulin, insulin-like growth factor-I, and total and functional IGF-binding protein-3 concentrations were determined using immunoenzymatic methods. RESULTS: The daily energy intake in children with PWS was lower by about 30% (p < 0.001) compared with the controls. Daily protein intake was similar in both groups, but carbohydrate and fat intakes were significantly lower in the patient group than the controls (p < 0.001). Similar values for nesfatin-1 in the PWS subgroup with BMI Z-score < -0.5 and the control group, while higher values in the PWS subgroup with BMI Z-score ≥ -0.5 (p < 0.001) were found. Spexin concentrations were significantly lower in both subgroups with PWS than the controls (p < 0.001; p = 0.005). Significant differences in the lipid profile between the PWS subgroups and the controls were also observed. Nesfatin-1 and leptin were positively related with BMI (p = 0.018; p = 0.001, respectively) and BMI Z-score (p = 0.031; p = 0.027, respectively) in the whole group with PWS. Both neuropeptides also correlated positively in these patients (p = 0.042). CONCLUSIONS: Altered profiles of anorexigenic peptides-especially nesfatin-1 and spexin-in non-obese children with Prader-Willi syndrome during growth hormone treatment and reduced energy intake were found. These differences may play a role in the etiology of metabolic disorders in Prader-Willi syndrome despite the applied therapy.

Assessment of Oxidant and Antioxidant Status in Prepubertal Children following Vegetarian and Omnivorous Diets.

Oxidant-antioxidant balance is crucial for maintaining one's health, and the diet is possibly one of the most important factors affecting this balance. Therefore, the aim of this study was to determine the oxidant-antioxidant balance in children on a lacto-ovo-vegetarian diet. The study was conducted between January 2020 and December 2021. The concentrations of total oxidant capacity (TOC), total antioxidant capacity (TAC), reduced (GSH), and oxidized (GSSG) glutathione, as well as C-reactive protein (CRP) and calprotectin were measured in serum samples of 72 healthy prepubertal children (32 vegetarians and 40 omnivores). The oxidative stress index (OSI) and the GSH/GSSG ratio (R-index) were calculated. Children on a vegetarian diet had significantly lower median values of TOC, GSH, and GSSG, and higher TAC compared with the omnivores. OSI was significantly lower in vegetarians, while R-index, as well as median values of CRP and calprotectin did not differ between both groups of children. Significant negative correlations were observed between TOC and TAC levels in the whole group of children and in vegetarians. GSH and GSSG levels correlated positively in the groups of vegetarians, omnivores, and in all the children. There were significant positive correlations between TOC and GSH, as well as GSSG levels in all the studied groups of children. Our study results suggest that the vegetarian model of nutrition allows to maintain the oxidant-antioxidant balance in the serum of prepubertal children.

Associations Between Antioxidant Vitamin Status, Dietary Intake, and Retinol-binding Protein 4 Levels in Prepubertal Obese Children After 3-month Weight Loss Therapy

Objective: Adiposity is associated with increased oxidative stress, leading to changed fat-soluble vitamin concentrations. The aim of this study was to determine whether weight loss alters fat-soluble vitamin status and whether these alterations are associated with dietary intake, anthropometric parameters and adipokines in obese children. Methods: Vitamin A and E concentrations were measured using high-pressure liquid chromatography in 60 obese children before and after weight loss therapy. Retinol-binding protein 4 (RBP4), leptin, soluble leptin receptor (sOB-R), and high molecular weight adiponectin concentrations were determined by immunoenzymatic assays. Results: The intake of vitamin E was lower in obese children with weight loss after therapy (p=0.038). In this group, an increase was found in the vitamin A/lipids (p=0.022) and the vitamin E/lipids (p=0.008) ratios but due to the reduction in triglyceride levels. In the obese group, changes in vitamin E level were positively correlated with changes in dietary vitamin E (p=0.017) and the leptin/sOB-R ratio (p=0.046). Changes in vitamin A level were positively correlated with changes in dietary vitamin A (p=0.001) and RBP4 concentration (p=0.023). Associations between changes in RBP4 level with the changes in body mass index (BMI) (p=0.011) and total cholesterol concentration (p=0.023) but not with changes in vitamin A concentration were found in the obese after therapy. Conclusion: An increased risk of vitamin E deficiency may occur in children losing weight during lifestyle intervention. Changes in BMI value may influence changes in RBP4 concentrations and consequently the vitamin A status in obese children after therapy.

Ferroportin-Hepcidin Axis in Prepubertal Obese Children with Sufficient Daily Iron Intake.

Iron metabolism may be disrupted in obesity, therefore, the present study assessed the iron status, especially ferroportin and hepcidin concentrations, as well as associations between the ferroportin-hepcidin axis and other iron markers in prepubertal obese children. The following were determined: serum ferroportin, hepcidin, ferritin, soluble transferrin receptor (sTfR), iron concentrations and values of hematological parameters as well as the daily dietary intake in 40 obese and 40 normal-weight children. The ferroportin/hepcidin and ferritin/hepcidin ratios were almost two-fold lower in obese children (p = 0.001; p = 0.026, respectively). Similar iron concentrations (13.2 vs. 15.2 µmol/L, p = 0.324), the sTfR/ferritin index (0.033 vs. 0.041, p = 0.384) and values of hematological parameters were found in obese and control groups, respectively. Iron daily intake in the obese children examined was consistent with recommendations. In this group, the ferroportin/hepcidin ratio positively correlated with energy intake (p = 0.012), dietary iron (p = 0.003) and vitamin B12 (p = 0.024). In the multivariate regression model an association between the ferroportin/hepcidin ratio and the sTfR/ferritin index in obese children (ß = 0.399, p = 0.017) was found. These associations did not exist in the controls. The results obtained suggest that in obese children with sufficient iron intake, the altered ferroportin-hepcidin axis may occur without signs of iron deficiency or iron deficiency anemia. The role of other micronutrients, besides dietary iron, may also be considered in the iron status of these children.

Comparison of body composition and adipokine levels between thin and normal-weight prepubertal children / Comparação da composição corporal e dos níveis de adipocina entre crianças pré-púberes magras e com peso normal

Abstract Objective: Thinness can have substantial consequences for child development and health. Adipokines, including leptin and adiponectin, play a significant role in the regulation of important metabolic functions. The aim of this study was to investigate associations between body composition and serum leptin and adiponectin levels in thin and normal-weight children. Methods: The authors examined 100 healthy prepubertal children, who were divided into two subgroups: thin (n = 50) and normal-weight children (n = 50). Body composition was assessed by dual-energy X-ray absorptiometry. Serum concentrations of adipokines were determined by immunoenzymatic assays. Results: Thin children had a similar body height but significantly lower (p < 0.0001) body weight, body mass index, fat mass, lean mass, and bone mineral content compared with normal-weight children. Serum concentrations of leptin were about 2-fold lower (p < 0.0001) in thin vs. normal-weight subjects. Serum levels of total adiponectin, adiponectin multimers, and soluble leptin receptor (sOB-R) were similar in both groups. The leptin/soluble leptin receptor ratio and leptin/adiponectin ratios were lower (p < 0.0001) in thin vs. normal-weight children. In both groups of children, it was found that body composition parameters were positively related with leptin but not with adiponectin levels. Additionally, bone mineral content was positively related with body mass index, fat mass, lean mass, and leptin level in thin and normal-weight children. Conclusions: Prepubertal thin children have disturbances in body composition and adipokine profile. Early recognition of thinness and determination of body composition parameters and adipokine levels can be useful in medical and nutritional care of thin children for the optimization of bone mineral accrual.

Resumo Objetivo: A magreza pode ter consequências substanciais para o desenvolvimento e a saúde das crianças. As adipocinas, inclusive a leptina e a adiponectina, desempenham um papel significativo na regulação de importantes funções metabólicas. O objetivo do estudo foi investigar as associações entre a composição corporal e os níveis séricos de leptina e adiponectina em crianças magras e com peso normal. Métodos: Examinamos 100 crianças pré-púberes saudáveis, divididas em dois subgrupos: crianças magras (n = 50) e com peso normal (n = 50). A composição corporal foi avaliada pelo método de absorciometria de dupla energia de raios X. As concentrações séricas das adipocinas foram determinadas por ensaios imunoenzimáticos. Resultados: As crianças magras apresentaram altura semelhante, porém peso corporal (p < 0,0001), índice de massa corporal (IMC), massa gorda, massa magra e conteúdo mineral ósseo (CMO) significativamente menores em comparação com crianças com peso normal. As concentrações séricas de leptina foram aproximadamente duas vezes mais baixas (p < 0,0001) em indivíduos magros do que em crianças com peso normal. Os níveis séricos de adiponectina total, multímeros de adiponectina e receptor de leptina solúvel (sOB-R) foram semelhantes em ambos os grupos. Os índices de leptina/sOB-R e leptina/adiponectina foram inferiores (p < 0,0001) em crianças magras do que crianças com peso normal. Em ambos os grupos de crianças descobrimos que os parâmetros de composição corporal estavam positivamente relacionados à leptina, porém não aos níveis de adiponectina. Além disso, observamos que o CMO estava positivamente relacionado ao IMC, à massa gorda, à massa magra e ao nível de leptina em crianças magras e com peso normal. Conclusões: As crianças pré-púberes magras têm alterações na composição corporal e no perfil de adipocinas. O reconhecimento precoce da magreza e a determinação dos parâmetros de composição corporal e dos níveis de adipocina podem ser úteis no cuidado médico e nutricional de crianças magras para aprimoramento do acúmulo mineral ósseo.

Serum Hepcidin and Soluble Transferrin Receptor in the Assessment of Iron Metabolism in Children on a Vegetarian Diet.

The aim of this study was to assess the effect of vegetarian diet on iron metabolism parameters paying special attention to serum hepcidin and soluble transferrin receptor (sTfR) concentrations in 43 prepubertal children (age range 4.5-9.0 years) on vegetarian and in 46 children on omnivorous diets. There were no significant differences according to age, weight, height, and body mass index (BMI) between vegetarian and omnivorous children. Vegetarians had similar intake of iron and vitamin B12 and a significantly higher intake of vitamin C (p < 0.05) compared with non-vegetarians. Hematologic parameters and serum iron concentrations were within the reference range in both groups of children. Serum transferrin levels were similar in all subjects; however, ferritin concentrations were significantly (p < 0.01) lower in vegetarians than in omnivores. In children on a vegetarian diet, median hepcidin levels were lower (p < 0.05) but sTfR concentrations significantly higher (p < 0.001) compared with omnivorous children. In the multivariate regression model, we observed associations between hepcidin level and ferritin concentration (ß = 0.241, p = 0.05) in the whole group of children as well as between hepcidin concentration and CRP level (ß = 0.419, p = 0.047) in vegetarians. We did not find significant associations with concentration of sTfR and selected biochemical, anthropometric, and dietary parameters in any of the studied groups of children. As hematologic parameters and iron concentrations in vegetarians and omnivores were comparable and ferritin level was lower in vegetarians, we suggest that inclusion of novel markers, in particular sTfR (not cofounded by inflammation) and hepcidin, can better detect subclinical iron deficiency in children following vegetarian diets.

[Influence of vegetarian diet on serum values of homocysteine and total antioxidant status in children]. / Wplyw stosowania diety wegetarianskiej na stezenie homocysteiny oraz calkowita aktywnosc przeciwutleniajaca w surowicy u dzieci.

UNLABELLED: The vegetarian diet may play a preventive role in the development of chronic diseases such as coronary heart and cardiovascular disease. However increase of homocysteine (Hcy) concentration in peoples avoiding animal products may contribute to an increased atherosclerotic risk in these subjects. Recent evidence has suggested that role of hyperhomocysteinemia in atherogenesis is associated with process of autooxidation, which can promote the production of hydroxyl radicals, resulting in oxidative modification of low density lipoprotein and endothelium injury. The oxidant-antioxidant imbalance depends not only on the amount of enhanced free oxygen species but also insufficiency of antioxidant defence system. Total antioxidant status (TAS) expresses capacity for scavenging of free radicals minimizes oxidative damage. The aim of this study was to asses concentrations of homocysteine and total antioxidant status in serum of children on vegetarian and omnivorous diet. We also studied levels of vitamin A (retinol) and vitamin E (alpha-tocopherol) particular components of TAS. MATERIAL AND METHODS: The study included 35 children, aged 5-16 who had been referred to Institute of Mother and Child for dietary consultation. From those, 17 were lacto-ovo-vegetarians and 18 omnivores. Dietary constituents were analyzed using the nutritional programme Dietetyk2 and completed with supplementation data. Concentration of homocysteine was estimated in serum with fluorescence polarization immunoassay and TAS by colorimetric method. Levels of vitamin A and E were determined using high-pressure liquid chromatography (HPLC). RESULTS: The mean concentration of homocysteine was similar in both studied groups (vegetarians: 6.13 +/- 1.01 micromol/l vs. omnivores: 5.45 +/- 0.98 micromol/l). In vegetarian children serum level of TAS was significantly lower (1.21 +/- 0.06 mmol/I) as compared to those in non-vegetarian ones (1.30 +/- 0.05 mmol/l, p < 0.0001), but remained within the physiological range (1.16-1.40 mmol/l). The mean concentrations of vitamins A and E in serum of vegetarians were lower than observed in omnivores group, but only in case of alpha-tocopherol the difference was statistically significant (vegetarians: 15.58 +/- 4.12 vs. omnivores: 18.41 +/- 3.10; p < 0.05). CONCLUSION: In studied group of children on lacto-ovo-vegetarian diet, serum concentrations of homocysteine are normal and daily food intake of antioxidants and their level in blood are sufficient for preserving adequate total antioxidant status.

Low levels of osteocalcin and leptin in serum of vegetarian prepubertal children.

BACKGROUND: Scientific literature points to the positive association between vegetarian diet and reduced risk for cardiovascular diseases, some types of cancer and diabetes. On the other hand elimination of animal products from the diet decreases the intake of some essential nutrients which may influence bone metabolism. This is a very important problem especially in childhood and adolescence, when growth and bone turnover are the most intensive. Bone metabolism is regulated by variety factors, which are involved in the bone formation and bone resorption processes. Osteocalcin is one of the markers of bone formation (produced by osteoblast) which plays an important role in the regulation of bone growth. Recent data support the concept that other modulators such as leptin (hormone from adipose tissue) may influence bone formation process. AIM: Our study is designed to investigate serum concentration of osteocalcin and leptin in prepubertal children with two different nutritional habits: vegetarian and omnivorous diet. MATERIAL AND METHODS: We examined 49 healthy children in age 2-10 years, who were divided into vegetarian and omnivores groups. RESULTS: The serum osteocalcin levels in prepubertal children on vegetarian diet was significantly lower than in nonvegetarians (86.7+/-27.4 microg/L versus 100.1+/-16.4 microg/L; p<0.05). Lower level of osteocalcin is accompanied by lower leptin concentration. In children on vegetarian diet mean leptin level was 3.0+/-1.0 microg/L, whereas in omnivorous children it was 5.5+/-2.0 microg/L, (p<0.0001). CONCLUSIONS: Our observation indicates that deficiencies in some of the nutrient components together with reduced serum concentration of leptin may retard relevant bone growth and development in childhood.

[Lipids and vitamin A and E status in vegetarian children]. / Status witaminy A i E oraz profil lipidowy u dzieci na diecie wegeterianskiej.

BACKGROUND: The vegetarian diet may play a preventive role in the development of chronic diseases such as coronary heart disease, cancer and diabetes. In the literature only a few papers concerning benefits to health from vegetarian diet have been reported in children. AIM: The aim of this study was to investigate serum concentration of vitamin A (retinol) and E (alpha-tocopherol) in children on vegetarian and omnivorous diet. Material and methods. Vitamins A and E were measured by high-pressure liquid chromatography (HPLC) in blood of 17 vegetarians and 16 nonvegetarian children. RESULTS: In the group of vegetarian mean plasma concentration of vitamin A and E was statistically lower as compared to those in nonvegetarian children (1.56 micromol/l vs 1.93 micromol/l, p < 0.05; 13.6 micromol/l vs 18.4 micromol/l, p < 0.001). In children on vegetarian diet total cholesterol and LDL-cholesterol were significantly lower, whereas HDL cholesterol and triglycerides were in the range observed in control group. In vegetarian ratio of tocopherol-to-total cholesterol and tocopherol-to-lipids was statistically lower than those in children on omnivorous diet. CONCLUSION: Since vitamins A and E are important parts in antioxidant defence systems, their low levels may be insufficient for scavenging of free radicals in the cells. In order to recommend dietary guidelines the further studies are needed on large groups of children on different types of vegetarian diet.