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Biomedical subjects

B Koletzko

Publications and source records attributed to B Koletzko.

At least 55 records · Page 3Linked to original sources
PubMed2000

Effects of protein-energy malnutrition and human immunodeficiency virus-1 infection on essential fatty acid metabolism in children.

This report summarizes data on the availability of essential fatty acids (EFAs) and their long-chain polyunsaturated fatty acid (LCPUFA) metabolites in protein-energy malnutrition (PEM), in human immunodeficiency virus-1 (HIV-1) infection for which less information is available, and the combination of both PEM and HIV-1. The contribution of different EFAs and LCPUFAs to the fatty-acid composition of plasma and erythrocyte membrane lipids was found to be reduced in children with PEM in comparison with well-nourished children. In addition to limited dietary EFA supply, reduced bioconversion of EFAs to their respective LCPUFA metabolites and/or peroxidative degradation of LCPUFAs may contribute to the reduction of LCPUFA status in malnourished children. Restoration of normal energy, protein, and EFA intakes does not appear to readily correct abnormalities of plasma and erythrocyte membrane LCPUFA values. Enhanced dietary supply of LCPUFAs and/or improved supply of antioxidant vitamins may represent novel therapeutic modalities in severe PEM. With and without PEM, HIV infection was related to altered availability of various EFAs and LCPUFAs in HIV-seropositive children. The plasma total lipid fatty-acid profiles seen in well-nourished children with HIV infection were compatible with an HIV infection-related enhancement of the metabolic activity of the conversion of EFAs to their respective LCPUFA metabolites. However, the plasma phospholipid EFA and LCPUFA profiles seen in severely malnourished children with HIV infection more closely resembled those seen in children with PEM but without HIV infection than in those in children with HIV infection but no PEM. Metabolic studies using stable isotope-labeled fatty acids may contribute to better understanding of the HIV-related changes in EFA metabolism and clearly are needed before therapeutic conclusions can be drawn.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Dietary fat intakes in infants and primary school children in Germany.

We report dietary fat intake data in groups of infants and children in Germany. A group of 148 healthy infants was followed prospectively from birth through the first year of life. After birth, 78.9% of infants were breast-fed; 50% were breast-fed at 3 mo and 9. 8% were breast-fed at 12 mo. Infant formula was given to 22% of infants after birth, 53% at 3 mo, and 58% at 12 mo. Complementary foods were consumed by 16% of infants at 3 mo, 97% at 6 mo, and 98-100% at 7-12 mo. In non-breast-fed infants, mean dietary fat intakes were 44.8%, 42.9%, 37.4%, and 35.7% of energy intake at the ages of 1, 4, 6, and 12 mo, respectively. Calculated energy and nutrient intakes were within recommended ranges and weight gain was normal. Therefore, we see no compelling reason to actively modify total fat intakes at this age. In 158 primary school children aged 6-11 y, 7-d checklist protocols showed 41% of energy intake as fat with approximately 50% as saturated fat. Because German children of this age are experiencing increasing rates of obesity and high serum cholesterol concentrations, a stepwise reduction of total fat and saturated fat intakes in primary school children appears desirable to improve long-term health.

Adult↗
PubMed2000

Influence of age on 13C-urea breath test results in children.

BACKGROUND: The 13C-urea breath test for diagnosis of Helicobacter pylori infection has not been validated in infants and young children. The influence of age on the test results was studied by conventional validation against invasive methods and by mathematical estimation in a large pediatric population. METHODS: The breath test was performed in 1499 children aged 2 months to 18 years. After a fasting period of 4 hours or more, 75 mg 13C-urea was ingested with cold apple juice, breath samples were taken at baseline and at 15 and 30 minutes. The distribution of the natural logarithms of the delta-over baseline (DOB) values were calculated, and the optimal cutoff values between positive and negative test results and gray zones with a risk of misclassification more than 10% were determined for both time points. In a subgroup of 149 children results of the breath test were compared with concordant results of histology and rapid urease test; 53 of them were less than 6 years of age. RESULTS: Logarithmic results of 1499 breath tests revealed two normally distributed subgroups with minimal overlap. The calculated optimal cutoff values were 4.7/1000 at 15 minutes and 5.0/1000 at 30 minutes. At 30 minutes, only 2.6% of all results were in the calculated gray zone (2.6-6.5/1000). Age was negatively correlated to DOB values of both negative (r = -0.223) and positive results (r = -0.291; P < 0.001). Breath test-negative and -positive children 6 or less years of age had significantly higher mean DOB values (P < 0.02) and a larger proportion of results within the gray zone than older children. Compared with biopsy-based results, the least discrepancies occurred at a cutoff of 5.0/1000: 0 of 61 infected (sensitivity 100%) and 6 of 88 noninfected children. Because five of the false-positive results were obtained in children less than 6 years of age, specificity and positive predictive values were lower in this age group than in older patients (88.1% vs. 97.8% and 68.8% vs. 98.0%, respectively). CONCLUSIONS: Under the applied conditions, the 13C-urea breath test shows an excellent separation between positive and negative results. Because of some overlap and a strong age effect, definition of a gray zone appears more meaningful than a threshold value. Because infants and young children have a high risk for false-positive breath test results, the values for cutoff and gray zones may have to be adapted. Further validation studies against invasive methods are warranted in this age group.

Adolescent↗
PubMed2000

Fatty acid content of plasma lipid fractions, blood lipids, and apolipoproteins in children fed milk products containing different quantity and quality of fat.

BACKGROUND: Differences in fatty acid content of plasma lipid fractions and serum lipid concentrations were investigated among young children fed different milk diets composed to achieve a recommended saturated fat intake. METHODS: Thirty-eight healthy children were randomly assigned to one of four feeding groups at 12 months: 1) low-fat milk (1.0 g/dL cow's milk fat); 2) standard-fat milk (3.5 g/dL cow's milk fat); 3) partially vegetable fat milk (3.5 gtat/dL fat; 50% vegetable fat: rapeseed oil); and 4) full vegetable-fat milk (3.5 gtat/dL fat; 100% vegetable fat: palm, coconut, and soy oil). Plasma fatty acids, blood lipids, and apolipoproteins were analyzed at 15 months, and dietary intakes at 12, 15, and 18 months. RESULTS: There were significantly lower percentage contributions of saturated fatty acids in plasma triglycerides in children fed low-fat milk or milk with 50% or 100% vegetable fat than in children fed standard-fat milk. Plasma polyunsaturated fatty acid levels were significantly higher in children fed milks with vegetable fat than in children fed standard-fat milk. Plasma saturated and polyunsaturated fatty acids in triglycerides most closely reflected dietary intake. Blood lipid concentrations were lower in children fed milk with 50% vegetable fat. CONCLUSIONS: Children fed milk with 50% or 100% vegetable fat, together with high vegetable-fat and low milk-fat dairy products have lower percentages of plasma saturated fatty acids and higher percentages of polyunsaturated fatty acids than children fed standard- or low-fat milk and dairy products.

Animals↗
PubMed2000

Energy supplements rich in linoleic acid improve body weight and essential fatty acid status of cystic fibrosis patients.

BACKGROUND: Patients with cystic fibrosis who have steatorrhea frequently are underweight and have essential fatty acid (EFA) depletion, which is associated with a poor clinical course. It has been stated that poor EFA status is difficult to correct in patients with cystic fibrosis, and an impaired EFA metabolism with reduced synthesis of long-chain polyunsaturated fatty acids has been proposed. In this study, the effects of an oral energy supplement rich in linoleic acid were investigated in patients with cystic fibrosis who had a body weight below 95% of normal for height. METHODS: Thirty-six patients (16 girls) more than 4 years of age were randomized either to a control group (n = 20, age 13.3 +/- 3.8 years, mean +/- SD) receiving intensive dietary counseling only, or an intervention group (n = 16, age, 10.4 +/- 4.3 years) treated for 3 months with dietary counseling plus 628 +/- 254 mL (= kcal) per day of an energy supplement rich in fat (31% of energy) and linoleic acid (16% of energy). RESULTS: In contrast to the control group, the patients with supplemented diets achieved significant increases of energy intake (2189 +/- 731 kcal/day vs. 2733 +/- 762 kcal/day), weight for height (82.8% +/- 8.6% vs. 84.8% +/- 9.6% of normal), and body fat (5.1 +/- 1.7 kg vs. 5.8 +/- 2.2 kg) as well as the initially low values of plasma phospholipid linoleic acid (11.8% +/- 1.1% vs. 17.6% +/- 1.6% of total phospholipid fatty acids) and its main metabolite arachidonic acid (4.4% +/- 0.4% vs. 5.9% +/- 0.3%). CONCLUSIONS: Patients with cystic fibrosis with low body weight and poor EFA status benefit from EFA-rich energy supplements and can synthesize arachidonic acid from the precursor linoleic acid.

Adolescent↗
PubMed2000

Determination of protein synthesis in human ileum in situ by continuous [1-(13)C]leucine infusion.

Efficient protein synthesis plays an important role in the physiology and pathophysiology of the human gastrointestinal tract. Because of methodological restrictions, no studies on ileal protein synthesis in situ are available in humans. We used advanced mass spectrometry techniques (capillary gas chromatography/combustion isotope ratio mass spectrometry) to determine directly the incorporation rate of [1-(13)C]leucine into ileal mucosal protein in control subjects and postoperative patients. All subjects had an ileostomy, which allowed easy access to the ileal mucosa. To examine changes in ileal protein synthesis during prolonged isotope infusion (0.16 micromol. kg(-1). min(-1), 9.6 micromol/kg prime), studies were performed over a 10-h period. Mucosal biopsies were performed after 3, 6, and 10 h of infusion. Protein synthesis was calculated separately between hour 3 and hour 6 (period 1) and hour 6 and hour 10 (period 2). Control subjects demonstrated an ileal protein fractional synthetic rate of 0.62 +/- 0.06%/h in period 1 and of 0. 52 +/- 0.08%/h in period 2 (not significant). In postsurgical subjects, ileal protein synthesis was significantly higher (1.11 +/- 0.14%/h in period 1, P < 0.01 vs. controls in period 1) but declined markedly in period 2 (0.39 +/- 0.13, P < 0.01 vs. period 1 after surgery). The rate of protein synthesis in the small bowel of control subjects is, thus far, among the lowest measured in mammals and reflects the comparably slow turnover of human ileal mucosa. Postoperative disturbances of gut integrity lead to an accelerated anabolic response. During prolonged isotope infusion, stimulated protein synthesis declines because of diurnal variations or is erroneously reduced by tracer loss due to an accelerated cell turnover.

Aged↗
PubMed2000

Essential fatty acids and their long-chain polyunsaturated metabolites in maternal and cord plasma triglycerides during late gestation.

The fatty acid composition of plasma lipids was determined in 41 pairs of mothers and their term infants at time of birth (38-42 postmenstrual weeks) by high-resolution capillary gas-liquid chromatography. Linoleic and alpha-linolenic acids were found at smaller concentrations in cord than in maternal triglycerides, in contrast to strikingly higher proportions of their long-chain polyunsaturated metabolites (LC-PUFA), which indicates a preferential maternofetal transport for certain physiologically important LC-PUFA. While no significant gestational age-dependent changes occurred in maternal plasma triglycerides, the values for most of the fetal long-chain n-3 metabolites increased with the duration of gestation, possibly reflecting an increased transplacental fatty acid passage during late pregnancy or a maturation of desaturation in the fetal liver.

Adult↗
PubMed2000

Docosahexaenoic acid transfer into human milk after dietary supplementation: a randomized clinical trial.

Docosahexaenoic acid (DHA) is important for infant development. The DHA transfer from maternal diet into human milk has not been investigated in detail. We studied the effects of DHA supplementation on the fatty acid composition of human milk and the secretion of dietary (13)C-labeled fatty acids, including DHA, into human milk. Ten lactating women were randomized to consume, from 4 to 6 weeks postpartum, an oil rich in DHA (DHASCO, 200 mg of DHA/day) (n = 5) or a placebo oil (n = 5). Dietary intakes were followed by 7-day protocols. On study day 14 a single dose of [U-(13)C]DHASCO was given orally, milk samples were collected over 48 h, and milk production was recorded. Milk fatty acid composition was determined by gas-liquid chromatography and isotopic enrichment was determined by gas chromatography- combustion-isotope ratio mass spectrometry (GC-C-IRMS). Milk DHA content did not differ between the supplemented and placebo group at study entry (0.29 vs. 0.28 wt%, median). After 2 weeks of supplementation the milk DHA content was almost 2-fold higher in the supplemented versus placebo group (0.37 vs. 0.21 wt%, P = 0.003). Cumulative recovery of [(13)C]palmitic, [(13)C]oleic, and [(13)C]docosahexaenoic acids in human milk at 48 h was similar between supplemented and placebo groups (palmitic acid 7.40 vs. 8. 14%, oleic acid 9.14 vs. 9.97%, and docosahexaenoic acid 9.09 vs. 8. 03% of dose, respectively). Notable lower recovery was observed for [(13)C]myristic acid in both the supplemented and placebo groups, 0. 62 versus 0.77% of dose. Dietary DHA supplementation increases the DHA content in human milk. DHA transfer from the diet into human milk is comparable to palmitic and oleic acid transfer.

Adult↗
PubMed2000

Polyunsaturated fatty acid supply with human milk. Physiological aspects and in vivo studies of metabolism.

The origin of polyunsaturated fatty acids (PUFA) in human milk has not been studied in detail. Diet, liberation from maternal stores and endogenous synthesis from precursors may contribute to PUFA present in human milk. Other factors influencing lipid content and fatty acid composition such as gestational age, stage of lactation, nutritional status and genetical background are known. In a series of in vivo studies using stable isotope methodologies we investigated the metabolism of PUFA during lactation. With this techniques the transfer of single dietary fatty acids into human milk, the oxidation and the deposition in tissues were estimated. Our studies demonstrate that the major part of PUFA in human milk seems not to be derived directly from the maternal diet but from body stores. Nevertheless diet is important, because long term intakes affect composition of body stores.

Body Composition↗
PubMed1999

Breast feeding and obesity: cross sectional study.

OBJECTIVE: To assess the impact of breast feeding on the risk of obesity and risk of being overweight in children at the time of entry to school. DESIGN: Cross sectional survey SETTING: Bavaria, southern Germany. METHODS: Routine data were collected on the height and weight of 134 577 children participating in the obligatory health examination at the time of school entry in Bavaria. In a subsample of 13 345 children, early feeding, diet, and lifestyle factors were assessed using responses to a questionnaire completed by parents. SUBJECTS: 9357 children aged 5 and 6 who had German nationality. MAIN OUTCOME MEASURES: Being overweight was defined as having a body mass index above the 90th centile and obesity was defined as body mass index above the 97th centile of all enrolled German children. Exclusive breast feeding was defined as the child being fed no food other than breast milk. RESULTS: The prevalence of obesity in children who had never been breast fed was 4.5% as compared with 2.8% in breastfed children. A clear dose-response effect was identified for the duration of breast feeding on the prevalence of obesity: the prevalence was 3.8% for 2 months of exclusive breast feeding, 2.3% for 3-5 months, 1.7% for 6-12 months, and 0.8% for more than 12 months. Similar relations were found with the prevalence of being overweight. The protective effect of breast feeding was not attributable to differences in social class or lifestyle. After adjusting for potential confounding factors, breast feeding remained a significant protective factor against the development of obesity (odds ratio 0.75, 95% CI 0.57 to 0.98) and being overweight (0.79, 0.68 to 0.93). CONCLUSIONS: In industrialised countries promoting prolonged breast feeding may help decrease the prevalence of obesity in childhood. Since obese children have a high risk of becoming obese adults, such preventive measures may eventually result in a reduction in the prevalence of cardiovascular diseases and other diseases related to obesity.

Adult↗
PubMed1999

Long-chain polyunsaturated fatty acids and eicosanoids in infants--physiological and pathophysiological aspects and open questions.

Eicosanoids are highly active lipid mediators in physiologic and pathologic processes, with their effects ranging from cytoprotection and vasoactivity to modulation of inflammatory and proliferative reactions. Generation of eicosanoids can be affected by changes in the pools of their precursors, the long-chain polyunsaturated fatty acids (LCPUFA). Thus, dietary interventions such as supplementation of infant formula with specific n-3 and n-6 LCPUFA will alter formation as well as activity of the eicosanoids produced. This report summarizes the results and discussion of the workshop on "Eicosanoids and Polyunsaturated Fatty Acids in Infants." The intention of the workshop organizers was to give an overview of the role of eicosanoids in physiological and pathophysiological processes in infants, to discuss the implications that an increased n-3 and n-6 LCPUFA intake may have on eicosanoid generation, and to point out open questions and controversies for future research.

Central Nervous System↗
PubMed1999

Long-chain polyunsaturated fatty acids in diets for infants: choices for recommending and regulating bodies and for manufacturers of dietary products.

While the scientific evaluation of the physiologic effects, potential benefits, and risks of dietary preformed long-chain polyunsaturated fatty acids (LCPUFA) for infants have been discussed elsewhere, this manuscript addresses some of the resulting consequences and challenges of interpreting the available knowledge from the perspective of recommending and regulating bodies, and of manufacturers of dietary products and their ingredient materials. Traditionally human milk composition has served as a reference point for infant formula design. With respect to the use of LCPUFA in infant formula, much more emphasis than ever before invested for any other group of micronutrients has been put on clinical studies investigating the potential advantages and disadvantages of LCPUFA in infant foods, including growth, safety aspects, and a variety of other outcome measures.

Evaluation Studies as Topic↗
PubMed1999

Polyunsaturated fatty acids in human milk and their role in early infant development.

The lipid fraction of human milk represents the main source of energy for the newborn infant and supplies essential nutrients such as fat-soluble vitamins and polyunsaturated fatty acids (PUFA). The essential fatty acids linoleic and alpha-linolenic acids are precursors of long-chain polyunsaturated fatty acids (LC-PUFA), such as arachidonic (C20:4 n-6) and docosahexaenoic (C22:6 n-3) acids, present in human milk in considerable amounts. LC-PUFA are indispensable structural components of all cellular membranes, and they are incorporated in relatively large amounts during early growth of the brain and the retina. Moreover, some LC-PUFA are precursors of eicosanoids, molecules with potent biological activity that modulates various cellular and tissue processes. The supply of long-chain fatty acids has been associated with functional outcomes of the recipient infants such as visual acuity and development of cognitive functions during the first year of life. Here we discuss the PUFA composition of human milk, factors which determine and modulate milk PUFA content, and possible effects of milk LC-PUFA on infant growth and development.

Breast Feeding↗
PubMed1999

Response to and range of acceptable fat intakes in infants and children.

The maximum and minimum fat intakes that are physiologically tolerable by healthy infants and young children are not well defined. The maximum tolerable fat intake appears to be limited by the minimum requirements of protein, carbohydrates and micronutrients. It is unresolved whether or not there is a minimum metabolic requirement of dietary fat, beyond the requirements of essential fatty acids and lipid soluble vitamins and the effects on energy density and an adequate total energy intake. The first postnatal months of the human infant are characterized by a rapid weight gain and extensive fat deposition. Body fat deposition equals 25% of the total energy intake during the first 2 and 16% during the third and fourth months, respectively. The provision of dietary lipids in amounts at least matching the needs for tissue storage and fat oxidation appears to be of advantage for energy balance and physiological growth. Some reports have associated low fat diets with less than 30% of energy as fat with adverse effects on child growth beyond infancy, but it remains unresolved whether these effects were caused by an associated effect on dietary energy density and total intake of energy and other nutrients. Closely supervised, healthy infants from an affluent population grew normally with a diet providing about 30% of the energy as fat from the seventh month of life onwards, but it is not known to what extent adaptive mechanisms such as a reduction of physical activity may have been required. It is not known whether infants and young children stressed by frequent occurrence of diarrhea and infections may adapt to a 30% fat diet as well or not. No evidence is available for a health benefit of a low total fat intake in infancy. In view of the limited available information, further research is required to define optimal fat intakes in early childhood since this question is of major importance for child health.

Adipose Tissue↗
PubMed1999

Comparison of bolus versus fractionated oral applications of [13C]-linoleic acid in humans.

BACKGROUND: The endogenous conversion of linoleic acid into long-chain polyunsaturated fatty acids is of potential importance for meeting substrate requirements, particularly in young infants. After application of [13C]-linoleic acid, we estimated its conversion to dihomo-gamma-linolenic and arachidonic acids from only two blood samples. DESIGN: Oral tracer doses were given to five healthy adults as a single bolus. In four subjects the tracer was given in nine equal portions over 3 days. Concentration and 13C content of fatty acids from serum phospholipids were analysed by gas chromatography combustion isotope ratio-mass spectrometry. Areas under the tracer-concentration curves were calculated, and fractional transfer and turnover rates estimated from compartmental models. RESULTS: The median fractional turnover of linoleic acid was 93.7% per day (interquartile range 25.3) in the bolus group and 80. 0% per day (6.3) in the fraction group (NS). Fractional conversion of linoleic to dihomo-gamma-linolenic acid was 1.5% (0.9) vs. 2.1% (0.7) (bolus vs. fraction, P < 0.05), and fractional conversion of linoleic to arachidonic acid was 0.3% (0.3) vs. 0.6% (0.3) (bolus vs. fraction, NS). In the fraction group conversion was significantly higher based on areas under the curve. The ratio of tracer concentration in conversion products to linoleic acid 48 h after dosing correlated very well (r >/= 0.94, P < 0.05) with the ratio of areas under the curve. CONCLUSIONS: Using areas under the curve overestimates the conversion, because different residence times are not considered. Estimation of conversion intensity appears possible with only one blood sample obtained after tracer application.

8,11,14-Eicosatrienoic Acid↗