Ghrelin levels before and after reduction of overweight due to a low-fat high-carbohydrate diet in obese children and adolescents

BACKGROUND: There are conflicting results for ghrelin changes in reduction of overweight. Increasing ghrelin levels in weight reduction are considered to be responsible for compensatory mechanisms that make the reduction of overweight unlikely to be sustained. METHODS: We have analyzed fasting serum ghrelin levels, weighed dietary record and, as biochemical markers of clinically relevant reduction of overweight, leptin, adiponectin and insulin levels and insulin resistance measured by homeostasis model assessment (HOMA) at baseline and after a 1-y outpatient weight reduction program based on a high-carbohydrate and low-fat diet in 37 obese children (median age 10 y). We divided these children into two subgroups according to their degree of weight loss (substantial reduction of overweight: decrease in SDS-BMI > or = 0.5). Furthermore, we analyzed ghrelin levels in 16 normal-weight children. RESULTS: Obese children demonstrated significant (P<0.001) lower ghrelin levels compared to normal-weight children. Daily caloric intake (P = 0.004) and percentage fat content decreased significantly (P<0.001), while percentage carbohydrate content increased significantly (P = 0.003) between baseline and 1-y follow-up in the obese children. The substantial reduction of overweight in 16 children (median SDS-BMI = -0.7) was associated with significant changes in insulin resistance (median decrease of HOMA 27%; P = 0.013), insulin (median decrease 25%, P = 0.036), adiponectin (median increase 15%; P = 0.003), and leptin levels (median decrease 19%; P = 0.023), while there were no significant changes in ghrelin levels (median increase 4%; P = 0.326). In the 21 children without substantial reduction of overweight (median SDS-BMI = -0.3), there were no significant changes in insulin resistance and in insulin, adiponectin, leptin and ghrelin levels. CONCLUSIONS: We conclude that in obese children, low-fat high-carbohydrate diet-induced weight loss does not change ghrelin secretion, but significantly decreases leptin levels, increases adiponectin levels and improves insulin resistance determined by significantly decreased insulin resistance indices as well as lowered serum insulin levels.     

Nutrient Intake and Status of German Children and Adolescents Consuming Vegetarian,Vegan or Omnivore Diets: Results of the VeChi Youth Study

There is a lack of data on associations between modern vegetarian and vegan diets and health among children and adolescents. The aim of the Vechi Youth Study was to cross-sectionally examine anthropometry, dietary intakes and nutritional status in a sample of 149 vegetarian, 115 vegan and 137 omnivore children and adolescents (6–18 years old, mean age: 12.7 ± 3.9 years). Group differences of dietary intake (calculated from three-day dietary records), nutrient biomarker and blood lipid concentrations were assessed using an analysis of covariance, adjusted for sex, age and other covariates. The total energy intake did not differ significantly between groups, but intake of carbohydrates was higher among vegetarians and vegans than among omnivores (p = 0.0002, respectively). The median protein intake exceeded 0.9 g/kg body weight/day in all diet groups and was lowest among vegetarians (p < 0.02). There was no significant difference of haemoglobin, vitamin B2, 25-OH vitamin D3, HDL-C and triglycerides blood concentrations between diet groups. Vegan participants had higher folate concentrations than vegetarian participants (p = 0.0053). Ferritin concentration was significantly higher in omnivores than in vegetarians (p = 0.0134) and vegans (p = 0.0404). Vegetarians had lower concentrations of holotranscobalamin (p = 0.0042) and higher concentrations of methylmalonic acid (p = 0.0253) than omnivores. Vegans had the lowest non-HDL-C and LDL-C concentrations in comparison to vegetarians (p = 0.0053 and p = 0.0041) and omnivores (p = 0.0010 and p = 0.0010). A high prevalence (>30%) of 25-OH vitamin D3 and vitamin B2 concentrations below reference values were found irrespective of the diet group. In conclusion, the Vechi Youth Study did not indicate specific nutritional risks among vegetarian and vegan children and adolescents compared to omnivores.     

Inhibition of ADP-evoked platelet aggregation by selected poly(ADP-ribose) polymerase inhibitors

Pathologic platelet activation has been implicated in the pathogenesis of ischemic heart disease. Since cardiomyocytes can be protected from ischemia-reoxygenation injury by poly(ADP-ribose) polymerase (PARP) inhibitors mimicking the adenine/ADP part of NAD, their structural resemblance to ADP may also enable the blockade of platelet aggregation via binding to ADP receptors.Blood samples drawn from healthy volunteers were pre-incubated with different concentrations of PARP inhibitors: 4-hydroxyquinazoline, 2-mercapto-4(3 H)-quinazolinone, or HO-3089. ADP-, collagen- and epinephrine-induced platelet aggregation was evaluated according to the method described by Born. The effect of PARP inhibitors on thrombocyte aggregation was also examined when platelets were sensitized by heparin and in the presence of incremental concentrations of ADP.All examined PARP inhibitors reduced the ADP-induced platelet aggregation in a dose-dependent manner (significant inhibition at 20 microM for HO-3089 and at 500 microM for the other agents; P < 0.05), even if platelets were sensitized with heparin. However, their hindrance on platelet aggregation waned as the concentration of ADP rose (no effect at 40 microM ADP). PARP inhibitors had minimal effect on both collagen- and epinephrine-induced platelet aggregation.Our study first demonstrates the feasibility of a design for PARP inhibitors that does not only protect against ischemia-reperfusion-induced cardiac damage but may also prevent thrombotic events.     

Scavenger effect of experimental and clinically used cardiovascular drugs

Oxygen free radicals play an important role in several physiologic and pathophysiologic processes. In pathophysiologic circumstances they can modify and damage biologic systems. Their functional properties (exposed to high oxygen tension) place red blood cells among the most susceptible cells to the harmful effect of free radicals. Because oxygen free radicals are involved in a wide range of diseases, scavenging these radicals should be an important therapeutic approach. In this study the antioxidant capacities of experimental and clinically used cardiovascular drugs were investigated. Phenazine methosulfate was used to generate free radicals and thus harden red blood cells. Filtration technique and potassium leaking were used to detect the scavenging effect of the examined drugs. The experimental drug H-2545 provided 43% protection against phenazine methosulfate-induced changes in red blood cell filterability (p < 0.001). Although some of the examined, clinically used cardiovascular drugs (carvedilol, metoprolol, verapamil, trimetazidine) also showed significant (p < 0.05) antioxidant effect, they were less efficient than H-2545. The scavenger effect of this novel drug exceeded the antioxidant properties of vitamin E. Modification of mexiletine with a pyrroline ring significantly improved its antioxidant capacity, suggesting that this molecular segment is responsible for the antioxidant effect.     

Time trends in the consumption of dairy foods in German children and adolescents

OBJECTIVE: Examination of time trends in the consumption of dairy food and their impact on fat and calcium intakes in German children and adolescents. DESIGN: Dietary records from the DONALD Study (DOrtmund Nutritional and Anthropometric Longitudinally Designed Study). METHODS: A total of 5068 3-day weighed dietary records from 914 1 to 13-y-old children and adolescents collected between 1986 and 2001 were analysed using a mixed linear model, in which the means of the data and the covariance structure specific to the DONALD Study were modelled. RESULTS: During the study period, the consumption of 'milk products' in children and adolescents >/=4 y remained stable, since the reduced consumption of 'fluid milk' (between -2.8 and -7.4 g/day/study year) was compensated for by an increased consumption of 'yoghurt' (between +2.4 and +3.3 g/day/study year). The consumption of 'cheese' increased in subjects >/=4 y (between +0.2 and +0.7 g/day/study year). In 1 to 3-y-old children, the decreased intake of 'fluid milk' (-6.5 g/day/study year) was not compensated for by the increased intake of 'formula' (+3.5 g/day/study year). The percentage of 'low-fat milk products' significantly increased (although not significant in 9-13-y-old boys) to nearly 25% of milk products. The impact of dairy food on fat intake (as percentage of energy intake) remained stable with the exception of a slight reduction in 4-8 y olds, the impact of dairy on calcium (as percentage of US adequate intake) decreased only in 1-3 y olds. CONCLUSIONS: The consumption of dairy food remained widely stable over time in >/=4-y-old children and adolescents, but decreased in 1-3 y olds. A further decline in this age group would be undesirable as is the shift from common milk to formula. The intake of 'low-fat milk products' increased and should be continuously promoted.     

Trends in dietary intake of vitamins A, C, and E in German children and adolescents--results of the DONALD Study

Intake of vitamins A, C, and E was evaluated and age and time trends were assessed on the basis of 3-day weighed dietary records (n = 5121) of 2- to 18-year old boys (n = 417) and girls (n = 425) enrolled in the DONALD Study (Dortmund Nutritional and Anthropometric Longitudinally Designed Study) 1986-2001. Intake of vitamin A remains stable over time, intake of vitamin C increases linearly, and intake of vitamin E follows a nonlinear trend. Age trends of vitamins A and C (per MJ) were nonlinear with a minimum at the beginning adolescence, while intake of vitamin E (per MJ) increased linearly. Girls had higher nutrient densities but lower intakes expressed as percent of reference values. Fortified food in total had a higher impact on time trends of nutrient intake than other single food groups defined here. Our results point to the impact of the food industry on long-term nutrient intake, but also underline the necessity of nutrition education even in young age groups to improve vitamin intake.     

Long-term follow-up of overweight children: after training,after a single consultation session,and without treatment

BACKGROUND: A satisfactory treatment of childhood obesity has not yet been found. An individual consultation session is the usual practice while experts recommend an outpatient training program consisting of a combination of physical exercise, nutrition education, and behavior therapy. METHODS: We analyzed degree of overweight (SDS-BMI) after one and two years in overweight children (aged 6-15 years) who had had a single consultation session (n = 66) and who had finished a one-year, structured outpatient training program consisting of physical exercise, nutrition education, and behavior therapy (n = 81). Furthermore we collected data on changes in weight for a control group of overweight children not receiving any treatment (n = 100) over the same period of time. RESULTS: There was no significant change in the degree of overweight over the period of two years either for the control group or for those having received single consultation. The participants of the training were in mean significantly less overweight than at the beginning of the training (P < 0.001), both after one year (mean change in SDS-BMI -0.38) and after the second year (mean change in SDS-BMI -0.30). CONCLUSIONS: Overweight children not receiving treatment do not reduce in weight. A single consultation session is not sufficient to achieve weight reduction in children. Weight reduction over at least two years can be achieved in part of the participants of a long-term, specialized treatment.     

Investigation of von Willebrand-factor as a marker of endothelial dysfunction in atherosclerotic patients

OBJECTIVE: To determine von Willebrand-factor activity as the marker of endothelium dysfunction in vascular diseases and to compare it to healthy controls. METHODS: von Willebrand-factor activity was determined by enzyme-linked immunosorbant assay (ELISA) in patients with acute coronary syndromes (29 patients, 67 +/- 13 years), acute stroke (15 pts, 67 +/- 12 years) on admission, 2nd and 6th day; and chronic vascular diseases (56 pts, 67 +/- 10 years) and was compared to the values of healthy controls (23 persons, 36 +/- 12 years). RESULTS: von Willebrand-factor activity was significantly (p < 0.001) higher in all the measured vascular patients than in the control group. The values of acute patients were significantly (p < 0.05-0.001) higher than those of patients with chronic vascular diseases. In the hospital phase von Willebrand-factor activity in acute patients increased continuously and on day 6 was significantly (p < 0.05-0.01) higher than on admission. von Willebrand-factor activity was significantly (p < 0.05) higher in troponin positive patients with acute coronary syndromes compared to the troponin negative subjects. CONCLUSIONS: von Willebrand-factor was found to be a suitable marker of endothelial dysfunction. The higher von Willebrand-factor activity in patients with vascular diseases compared to the control group can be caused by the endothelial dysfunction and extensive atherosclerosis. The significantly higher von Willebrand-factor activity in acute disorders suggests the more severe endothelium dysfunction and could be related to the development of acute event through increased platelet adhesion and aggregation.