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Biomedical subjects

B Koletzko

Publications and source records attributed to B Koletzko.

At least 19 recordsLinked to original sources
PubMed2006

Regulation of ghrelin is related to estimated insulin sensitivity in obese children.

OBJECTIVE: To investigate whether ghrelin concentrations and their changes during weight loss in obese children are associated with parameters of glucose and insulin metabolism. DESIGN: Total plasma ghrelin, insulin and glucose were measured during oral glucose tolerance testing before and after diet-induced weight loss over 6 weeks. SETTING: In-patient rehabilitation program in a pediatric hospital. PARTICIPANTS: Twenty-three obese children (age 10-16 years) and 11 normal weight controls (age 10-15 years). OUTCOME MEASURES: Changes in ghrelin concentrations during weight loss and correlation analysis of changes in ghrelin and changes in parameters of glucose and insulin metabolism. After data collection, subgroup analysis of obese patients with high, medium and low estimated insulin sensitivity whole-body insulin sensitivity index (WBISI) was performed. RESULTS: Weight loss increased the area under the curve (AUC) of ghrelin by 26% (P<0.001). The increase in ghrelin AUC correlated significantly with improved estimated insulin sensitivity (WBISI) (r=0.69, P<0.001). The independent predicting effect of WBISI was confirmed in multivariate analysis. In children with low WBISI, ghrelin reached the level of control values after weight loss. In children with high WBISI, ghrelin increased markedly above control levels. CONCLUSIONS: Changes in ghrelin are independently associated with changes in glucose and insulin metabolism. The increase in plasma ghrelin above control levels was limited to obese children with high WBISI.

Adolescent↗
PubMed2005

An European survey of structure and organisation of nutrition support teams in Germany, Austria and Switzerland.

BACKGROUND & AIMS: Nutritional support teams (NST) have been demonstrated to be an excellent mechanism for identifying patients in need of nutrition support, improving the efficacy of nutrition support in a variety of hospital environments. Focus of this study was the investigation of function, structure and organisation of NST in Germany (D), Austria (A) and Switzerland (CH). METHODS: Prospective investigation of the function, structure and organisation of NST in D, A and CH, using standardised questionnaires. RESULTS: From a total of 3071 hospitals in D, A and CH, NST have been established at 98 hospitals (3.2%). Their main activities were creating nutritional regimes (100%), education (87%) and monitoring nutrition therapy (92%). In general, the NST are not independently operating units but are affiliated to a special discipline. Seventy-one per cent of the physicians, 40% of the nurses and 69% of the dieticians in the NST held a nutrition-specific additional qualification. A total of 12% of the physicians, 37% of the nurses and 46% of the dieticians are exclusively responsible for the NST. A reduction of complications (88%) and cost saving (98%) were indicated since their establishment. The NST received in 32% funding support. CONCLUSION: In D, A, CH neither a uniform nor comprehensive patient care by NST existed in 2004. Standards of practice, development of guidelines in clinical nutrition and better documentation in NSTs are necessary. Special efforts should be aimed at education of NST members and financing of teams.

Austria↗
PubMed2004

n6/n3 hypothesis and allergies: biologically plausible, but not confirmed.

The dietary intake of certain fatty acids might contribute to the development of atopic diseases like allergic rhinitis and asthma. We investigated the association between the ratio of n-6 and n-3 fatty acids in serum phospholipids and hay fever or allergic sensitisation in adults. Data from a population based cross-sectional study on respiratory health including measurement of fatty acids in serum phospholipids of 740 adults between 20 and 64 years of age were analysed. We could not find any significant association between n6/n3-ratio of fatty acids in serum phospholipids and hay fever or allergic sensitisation neither in the total population nor in the sub-population stratified by sex. Since no previous study on fatty acid intake confirmed the n6/n3-ratio hypothesis and this study did not find any association between the n6/n3-ratio in serum-phospholipids and hay fever or allergic sensitization, we conclude that the n6/n3- ratio hypothesis is not confirmed although biological plausible.

Adult↗
PubMed2004

[Current problems in determining children's nutritional needs].

Meeting children's nutritional needs is of fundamental importance for their immediate and later health, well-being, and performance. Age-adapted reference values of nutrient intake form the basis for analysis of the current situation and for policy planning, but for many nutrients they cannot be precisely defined due to inadequate scientific data. Therefore, such values are often extrapolated from adult reference values based on age-adapted mean body weight or body surface data, although such extrapolation does not reflect age-related physiological changes. There are considerable differences between various expert recommendations, in part also due to differences in definitions and underlying concepts for deriving reference values. Improvements and international harmonization are urgently needed. Nutritional needs of many children and adolescents are not adequately met at present. A particularly obvious indication is the epidemic-like increase of pediatric overweight and obesity, which could result in markedly increased prevalences of later metabolic syndrome, diabetes, and cardiovascular diseases. Contributing to increasing childhood obesity are low physical activity, changing eating culture and behavior, frequent consumption of high-fat foods with high energy density, and increasing portion sizes. Changes are urgently needed and might be achievable with close collaboration between scientists, public institutions, and industry.

Adolescent↗
PubMed2004

Reduced antioxidant status in obese children with multimetabolic syndrome.

BACKGROUND: In our previous study, the negative correlation found between plasma insulin levels and plasma alpha-tocopherol concentrations suggested that decreased antioxidant vitamin levels and reduced antioxidant capacity might be a characteristic feature of obese children with multimetabolic syndrome (MMS). OBJECTIVE: To investigate lipid-soluble antioxidant vitamin levels and total antioxidant status (TAS) in obese children with and without MMS and in controls. SUBJECTS: In total, 16 control children (age: 16.2+/-1.1 y, BMI: 20.7+/-1.9 kg/m(2), body fat (BF): 25.6+/-5.7%; mean+/-s.d.), 15 obese children (age: 13.4+/-2.1 y, BMI: 34.2+/-3.1 kg/m(2), BF: 36.9+/-5.8%,) and 17 obese children without MMS (age: 14.4+/-2.3 y, BMI: 30.4+/-6.2 kg/m(2), BF: 36.3+/-5.8%) were included in the study. METHODS: Body composition was determined by anthropometric methods. Vitamin analysis was carried out by high-performance liquid chromatography and TAS of the plasma was measured with commercially available kits. Plasma glucose, lipids and insulin were measured by standard laboratory methods. RESULTS: Plasma alpha-tocopherol and beta-carotene levels corrected for plasma lipids (cholesterol + triglyceride) were significantly (P<0.05) lower in obese children with MMS (2.4 (3.1) micromol/mmol and 12.3 (24.0) pmol/mmol, respectively, median (range from the first to the third quartile)), than in the obese without MMS (3.7 (0.9) micromol/mmol and 48.2 (27.7) pmol/mmol) and in the control group (3.8 (0.7) micromol/mmol and 86.6 (44.5) pmol/mmol). Plasma TAS values of the MMS group (1.2 (0.4) mmol/l) were also significantly (P<0.05) reduced as compared to obese children without MMS (1.62 (0.14) mmol/l) and to controls (1.58 (0.21) mmol/l). CONCLUSION: Obese children with MMS are prone to oxidative stress. Further investigations are necessary to determine if these children may benefit from vitamin E and beta-carotene supplementation.

Adolescent↗
PubMed2004

Breast-feeding and childhood obesity--a systematic review.

OBJECTIVE: To investigate the relationship between breast-feeding and obesity in childhood. DESIGN: Systematic review and meta-analysis of published epidemiological studies (cohort, case-control or cross-sectional studies) comparing early feeding-mode and adjusting for potential confounding factors. Electronic databases were searched and reference lists of relevant articles were checked. Calculations of pooled estimates were conducted in fixed- and random-effects models. Heterogeneity was tested by Q-test. Publication bias was assessed from funnel plots and by a linear regression method. OUTCOME MEASURES: Odds ratio (OR) for obesity in childhood defined as body mass index (BMI) percentiles. RESULTS: Nine studies with more than 69,000 participants met the inclusion criteria. The meta-analysis showed that breast-feeding reduced the risk of obesity in childhood significantly. The adjusted odds ratio was 0.78, 95% CI (0.71, 0.85) in the fixed model. The assumption of homogeneity of results of the included studies could not be refuted (Q-test for heterogeneity, P>0.3), stratified analyses showed no differences regarding different study types, age groups, definition of breast-feeding or obesity and number of confounding factors adjusted for. A dose-dependent effect of breast-feeding duration on the prevalence of obesity was reported in four studies. Funnel plot regression gave no indication of publication bias. CONCLUSION: Breast-feeding seems to have a small but consistent protective effect against obesity in children.

Breast Feeding↗
PubMed2004

Food and fatty acid intake and atopic disease in adults.

The aim of the study was to assess the relationship between dietary intake of selected foods and fatty acids with atopic disease prevalence in adults. Data from the European Community Respiratory Health Survey in Erfurt, combined with a 3-day weighed records dietary survey, was used. Complete data was available from 469 males and 333 females aged 20-64 yrs. Multiple logistic regression was applied comparing the highest with the lowest quartile of dietary exposures and linear trends were tested stratified by sex. In males, margarine intake and a high ratio of omega-6 to omega-3 fatty acids were positively associated with hay fever. In females, a high intake of total fat, palmitoleic and oleic acids were positively associated with sensitisation. A high total fat, high monounsaturated fatty acid and high oleic acid consumption were positively associated with hay fever. Whilst an excessive intake of fat or imbalance in fat intake, particular of monounsaturated fatty acids, increased the risk for hay fever and allergic sensitisation in females, mostly no significant associations were found for males. Dietary factors were mostly not related with prevalence rates of bronchial hyperresponsiveness and atopic eczema either in males or in females.

Adult↗
PubMed2003

Analysis of FA contents in individual lipid fractions from human placental tissue.

Data on FA contents in the human placenta are limited. Different methods have been used for the FA analysis, and only percentage results have been presented. We developed and evaluated a method for the determination of FA concentrations in placental tissue. Lipids were extracted from placental tissue with a chloroform/methanol mixture; and phospholipids (PL), nonesterified FA (NEFA), TG, and cholesterol esters (CE) were isolated by TLC. Individual lipid fractions were derivatized with methanolic hydrochloric acid, and the FAME were quantified by GC with FID. The CV of intra-assay (n = 8) of absolute concentrations were evaluated for FA showing a tissue content > 0.01 mg/g. CV ranges were 4.6-11.0% for PL, 6.4-9.3% for NEFA, 6.1-8.9% for TG, and 11.4-16.3% for CE. The relative FA composition across a term placenta indicated no differences between samples of central and peripheral locations of maternal and fetal site (CV 0.5-9.9%), whereas the absolute FA concentrations were only reproducible in the PL fraction (CV 7.0-12.8%). The method shows a reasonably high precision that is well suited for physiological and nutritional studies.

Butylated Hydroxytoluene↗
PubMed2002

Losses of vitamin A and E in parenteral nutrition suitable for premature infants.

OBJECTIVE: To assess the bioavailability of vitamins A and E administered parenterally with either water-soluble or lipid-soluble preparations. STUDY DESIGN: A water soluble preparation (MVI Pediatric) administered with a glucose-amino acid solution and a lipid soluble preparation (Vitalipid N Infant) infused with a lipid emulsion were subjected to phototherapy light, different flow rates, light protection, different tubing materials and tubing sizes, and concentrations in the effluents were determined. RESULTS: Recovery of retinol in glucose-amino acid solution was poor under all conditions (16-30% without; 21-42% with light protection tubing) and increased to 61% with polyethylene and to 44% with polyurethane tubings. Polyurethane tubings with reduced volume improved retinol delivery to 56%. Retinylpalmitate (Vitalipid) losses were low, with recovery of 86 and 77% with and without light protection, respectively. Recoveries of alpha-tocopherylacetate in GLUC-AA were 103-107% without and 94-102% with light protection and of alpha-tocopherol in LIPID 89% without and 85% with light protection. CONCLUSIONS: Parenteral vitamin A delivery is improved by the infusion of retinylpalmitate with lipids. Light protecting tubings provide only a marginal benefit with artificial light and none with phototherapy light. Polyethylene and polyvinylchloride tubings adsorb less retinol than polyurethane tubings. Small tubing diameters resulting in higher flow rates enhance retinol delivery.

Diterpenes↗
PubMed2002

Reduced risk for overweight and obesity in 5- and 6-y-old children by duration of sleep--a cross-sectional study.

OBJECTIVE: To assess the relationship between sleep duration and adiposity in 5- and 6-y-old Bavarian children. DESIGN: Cross-sectional study. SUBJECTS: A total of 6862 German children aged 5-6 y participating in the obligatory health examination in Bavaria, southern Germany. MEASUREMENTS: Routine data were collected on the height and weight of children at the time of school entry in six public health offices in 1999 and in another two in 2000. Body fat mass was estimated by BIA performed in three of those offices. An extensive questionnaire was given to all children's parents in order to assess risk factors for overweight and obesity. The main outcome measures were overweight, defined by a body mass index (BMI) above the 90th centile and obesity, defined by a BMI above the 97th centile for the German children in Bavaria. Excessive body fat was defined as fat mass above the 90th centile for all German children seen in this survey. The main exposure was usual sleeping hours on week days. RESULTS: The prevalence of obesity decreased by duration of sleep: < or =10 h, 5.4% (95% CI 4.1-7.0), 10.5-11.0 h, 2.8% (95% CI 2.3-3.3), and > or =11.5 h, 2.1% (95% CI 1.5-2.9). Similar relations were found with the prevalence of overweight and excessive body fat. These effects could not be explained by confounding due to a wide range of constitutional, sociodemographic and lifestyle factors. The adjusted odds ratio for obesity were: for sleeping 10.5-11.0 h, 0.52 (95% CI 0.34-0.78) and 0.46 (95% CI 0.28-0.75) for sleeping 11.5 h. CONCLUSION: The effect of sleep duration on obesity in children reflects a higher body fat composition and appears to be independent of other risk factors for childhood obesity.

Adipose Tissue↗
PubMed2002

Different quantities and quality of fat in milk products given to young children: effects on long chain polyunsaturated fatty acids and trans fatty acids in plasma.

UNLABELLED: In this study we compared plasma contents of long-chain polyunsaturated fatty acids (LC-PUFAs) and trans fatty acids in triglycerides (TG), phospholipids (PL) and cholesterolesters (CE) in young children fed milk diets containing different amounts of linoleic (LA) and alpha-linolenic acid (ALA). Because the diets differed in vitamin A and E content, plasma concentrations of vitamin A and E were also studied. Thirty-seven 1-y-old children were randomly assigned to one of four feeding groups: (1) low-fat milk (LF) (1.0 g cow's milk fat/dL); (2) standard-fat milk (SF) (3.5 g cow's milk fat/dL); (3) partially vegetable fat milk (PVF) (3.5 g fat/dL; 50% vegetable fat from rapeseed oil, 50% milk fat); and (4) full vegetable fat milk (FVF) (3.5 g fat/dL; 100% vegetable fat from palm-, coconut- and soybean oil). We found higher amounts of plasma LA in the FVF group than in the LF and SF groups (p < 0.001) and higher amounts of ALA in the PVF group than in the SF (p < 0.001 in TGs, p < 0.05 in CEs) and LF (p < 0.01 in PLs and CEs, p < 0.05 in TGs) groups. However, amounts of plasma arachidonic acid (AA) were similar between groups as well as the amounts of docosahexaenoic acid (DHA) in CEs and PLs. Total trans FAs were lower in CEs in the PVF and FVF groups than in the SF group (p < 0.05 SF vs PVF; p < 0.01 SF vs FVF). Plasma concentrations of alpha-tocopherol were higher in the FVF group than in the other groups (p < 0.05 FVF vs SF, p < 0.01 FVF vs SF and PVF). CONCLUSION: Children consuming milk diets containing high amounts of vegetable fat present with higher plasma LA and ALA without any effects on amounts of plasma LC-PUFA. The plasma LC-PUFA status is not adversely affected by a low-fat milk diet. AHA and DHA in plasma are not affected by the diets studied, presumably because 15-mo-old children may be able to compensate for dietary influences through endogenous LC-PUFA metabolism.

Animals↗
PubMed2001

Fish oil supplementation improves visual evoked potentials in children with phenylketonuria.

Visual evoked potentials (VEP) were measured in 36 patients with early-treated phenylketonuria (PKU; aged 1 to 11 years) and good metabolic control before and after supplementation with omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) from fish oil. Patients with PKU had significantly longer P100 latencies than 22 age-matched control subjects. After 3 months of LC-PUFA supplementation, VEP latencies improved significantly in PKU patients but did not change in 12 untreated healthy children. The authors conclude that omega-3 LC-PUFA are essential substrates for nervous system function even beyond infancy.

Child↗
PubMed2001

Investigation of long-chain polyunsaturated fatty acid metabolism in lactating women by means of stable isotope techniques.

Long-chain polyunsaturated fatty acids are important components of human milk that seem to influence infant development. After oral administration of U-13C-labeled linoleic acid to a lactating woman the recovery of tracer in milk linoleic acid was 6.4%, whereas tracer recovery in dihomo-gamma-linolenic acid (DGLA) was 0.3% and in arachidonic acid (AA), <0.01%. Some 14.9% of linoleic acid intake was converted to breath-CO2. In combination with data on dietary intake and quantitative milk output, we estimate that 23% of milk linoleic acid, 7% of milk dihomo-gamma-linolenic acids and 0.5% of milk arachidonic acid were contributed by direct endogenous conversion and transfer from dietary linoleic acid. These findings lead us to conclude that long-chain polyunsaturated fatty acids for human milk synthesis are produced in the body, but either a relatively low percentage is contributed under these dietary conditions, or there are large body pools for intermediate storage of these fatty acids that are utilized for secretion into milk.

8,11,14-Eicosatrienoic Acid↗
PubMed2001

Fat content and fatty acid composition of fresh, pasteurized, or sterilized human milk.

In hospitals, human milk is subjected to heat treatment to reduce risk of transmission of infectious agents such as human immunodeficiency virus (HIV), hepatitis B, cytomegalovirus, and bacterial contamination, especially during feeding of banked milk to preterm infants. Fat losses due to heat treatment have been extensively studied in cow milk but have received little attention in human milk. We studied the effect of human milk pasteurization and sterilization on total fat content available to the infant as well as on fatty acid composition. Milk samples from 12 mothers (days 5-35 of lactation) were divided into three equal parts: one remained fresh, one was pasteurized (62.5 degrees C for 30min), and one was sterilized (120 degrees C for 30min). Fat content was determined gravimetrically, and the contribution of 30 fatty acids was determined by gas chromatography. For investigation of loss of available fat in sterilized milk, milk was collected from two additional mothers and analyzed with a modified extraction method. Total fat content was the same in fresh, pasteurized, and sterilized milk. The available fat content was 3.1+/-0.4g/dL (mean +/- SE) in fresh human milk, 3.1+/-0.4g/dL in pasteurized human milk, and 2.7+/-0.3g/dL (P < 0.001 vs. fresh) in sterilized human milk because of formation of a surface skin and fat adherence to the vial wall after sterilization. The fatty acid composition of 10 saturated, 10 monounsaturated, and 10 polyunsaturated fatty acids of both the n6 and n3 series was not affected by pasteurization. In sterilized milk there was a slight decrease of linoleic acid (C18:2n6; -0.7% vs. fresh; P = 0.006) and arachidonic acid (C20:4n6; -2.5%; P = 0.045). Pasteurization and sterilization do not affect total fat content of human milk, but sterilization may reduce available fat content by >10%. Fatty acid composition of human milk is not changed by pasteurization, but is slightly changed by sterilization.

Arachidonic Acid↗
PubMed2001

Consumption of lipophilic contaminants in human milk by infants: quantities are usually incorrect.

We evaluated several reports on the detection of nitromusks (artificial perfumes) in human milk. The nitromusks found were separated by gas-liquid chromatography and identified by mass spectrometry. However, the quantities reported as being consumed by infants were often questionable (Jensen, 1995). The investigators did not always a) obtain a representative samples of milk, b) extract and quantify the fat by a recognized, accurate method, or c) determine the amount of milk, hence fat, consumed by the infant. Some investigators gave almost no data on the milk, except to say that a sample was obtained. Reports on some other contaminants in human milk were similarly deficient. We have published a description of recommended extraction procedures in a paper presenting a detailed protocol for the processing of milk so as to determine the actual amounts of lipophilic contaminants ingested by the nursing infant (Jensen et al. 1997).

Breast Feeding↗
PubMed2001

Homocysteine concentrations in a German cohort of 500 individuals: reference ranges and determinants of plasma levels in healthy children and their parents.

Elevated plasma homocysteine is a risk factor for cardiovascular disease and a sensitive marker of inadequate vitamin B12 and folate status. We studied 257 pupils (120 boys, 137 girls, aged 6-17 years) and their parents (88 males, 172 females, aged 26-50 years). Our measurements were part of a national Bavarian health and nutrition examination survey evaluating cardiovascular risk factors. A mild hyperhomocysteinemia (Hcys >15 micromol/l) occurred in 7% of the adults, but in none of the children. Men had significantly higher Hcys levels than women (p<0.0001), boys and girls had comparable concentrations. For adults and children, Hcys correlated inversely with vitamin B12 and folate and positively with the lean body mass and creatinine in serum, but not with cystatin C. Genetic and nutritional factors are determinants of Hcys metabolism. The correlation of Hcys and serum creatinine is dependent on the metabolic link between Hcys production and creatine synthesis.

Adolescent↗