Associations between food portion sizes, insulin resistance, VO2 max and metabolic syndrome in European adolescents: The HELENA study.

BACKGROUND AND AIMS: This study aims to examine the associations of food portion size (PS) with markers of insulin resistance (IR) and clustered of metabolic risk score in European adolescents. METHODS: A total of 495 adolescents (53.5% females) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study were included. The association between PS from food groups and homeostasis model assessment of insulin resistance (HOMA-IR) index, VO2 max, and metabolic risk score was assessed by multilinear regression analysis adjusting for several confounders. Analysis of covariance (ANCOVA) was used to determine the mean differences of food PS from food groups by HOMA-IR cutoff categories by using maternal education as a covariable. RESULTS: Larger PS from vegetables in both gender and milk, yoghurt, and milk beverages in males were associated with higher VO2 max, while larger PS from margarines and vegetable oils were associated with lower VO2 max (p < 0.05). Males who consumed larger PS from fish and fish products; meat substitutes, nuts, and pulses; cakes, pies, and biscuits; and sugar, honey, jams, and chocolate have a higher metabolic risk score (p < 0.05). Males with lower HOMA-IR cutoff values consumed larger PS from vegetables, milk, yoghurt, and milk beverages (p < 0.05). Females with lower HOMA-IR cutoff values consumed larger PS from breakfast cereals, while those with higher HOMA-IR cutoff values consumed larger PS from butter and animal fats (p = 0.018). CONCLUSION: The results show that larger PS from dairy products, cereals, and high energy dense foods are a significant determinant of IR and VO2 max, and larger PS from food with higher content of sugar were associated with higher metabolic risk score.

Branched-chain amino acids: Abundance of their transporters and metabolizing enzymes in adipose tissue, skeletal muscle, and liver of dairy cows at high or normal body condition.

Branched-chain amino acids (BCAA) are major components of milk protein and important precursors for nonessential AA. Thus, the BCAA transport and break-down play a key role in the metabolic adaptation to the high nutrient demands in lactation. However, in monogastrics, increased BCAA levels have been linked with obesity and certain metabolic disorders such as impaired insulin sensitivity. Our objective was to study the effect of over-conditioning at calving on plasma BCAA levels as well as the tissue abundance of the most relevant BCAA transporters and degrading enzymes in dairy cows during late pregnancy and early lactation. Thirty-eight Holstein cows were allocated 15 wk antepartum to either a normal- (NBCS) or over-conditioned (HBCS) group, receiving 6.8 or 7.2 MJ of NEL/kg of DM, respectively, during late lactation to reach the targeted differences in body condition score (BCS) and back fat thickness (BFT; NBCS: BCS <3.5, BFT <1.2 cm; HBCS: BCS >3.75, BFT >1.4 cm) until dry-off. During the dry period and next lactation, cows were fed the same diets, whereby differences in BCS and BFT were maintained: prepartum means were 3.16 ± 0.06 and 1.03 ± 0.07 cm (NBCS) vs. 3.77 ± 0.08 and 1.89 ± 0.11 cm (HBCS), postpartum means were 2.89 ± 0.06 and 0.81 ± 0.05 cm (NBCS) vs. 3.30 ± 0.06 and 1.38 ± 0.08 cm (HBCS). Blood and biopsies from liver, semitendinosus muscle, and subcutaneous adipose tissue (scAT) were sampled at d 49 antepartum, 3, 21, and 84 postpartum. Free BCAA were analyzed and the mRNA abundance of solute carrier family 1 member 5 (SLC1A5), SLC7A5, and SLC38A2 as well as branched-chain aminotransferase 2 (BCAT2), branched-chain α-keto acid dehydrogenase E1α (BCKDHA), and branched-chain α-keto acid dehydrogenase E1ß (BCKDHB) as well as the protein abundance of BCKDHA were assessed. Concentrations of all BCAA changed with time, most markedly in HBCS cows, with a nadir around calving. Apart from Ile, neither individual nor total BCAA differed between groups. The HBCS group had greater BCKDHA mRNA as well as higher prepartum BCKDHA protein abundance in scAT than NBCS cows, pointing to a greater oxidative capacity for the irreversible degradation of BCAA transamination products in scAT of over-conditioned cows. Prepartum hepatic BCKDHA protein abundance was lower in HBCS than in NBCS cows. In both groups, SLC1A5, SLC7A5, and BCAT2 mRNA were most abundant in scAT, whereas SLC38A2 was higher in scAT and muscle compared with liver, and BCKDHA and BCKDHB mRNA were greatest in liver and muscle, respectively. Our results indicate that scAT may be a major site of BCAA uptake and initial catabolism, with the former, however, being independent of BCS and time relative to calving in dairy cows.

Changes in tissue abundance and activity of enzymes related to branched-chain amino acid catabolism in dairy cows during early lactation.

Branched-chain α-keto acid dehydrogenase (BCKDH) complex catalyzes the irreversible oxidative decarboxylation of branched-chain α-keto acids. This reaction is considered as the rate-limiting step in the overall branched-chain amino acid (BCAA) catabolic pathway in mammals. For characterizing the potential enzymatic involvement of liver, skeletal muscle, adipose tissue (AT), and mammary gland (MG) in BCAA metabolism during early lactation, tissue and blood samples were examined on d 1, 42, and 105 after parturition from 25 primiparous Holstein cows. Serum BCAA profiles were analyzed and the mRNA and protein abundance as well as the activity in the different tissues were assessed for the BCAA catabolic enzymes, partly for the branched-chain aminotransferase and completely for BCKDH. Total BCAA concentration in serum was lowest on d 1 after parturition and increased thereafter to a steady level for the duration of the experiment. Pronounced differences between the tissues were observed at all molecular levels. The mRNA abundance of the mitochondrial isoform of branched-chain aminotransferase (BCATm) was greatest in AT as compared with the other tissues studied, indicating that AT might be an important contributor in the initiation of BCAA catabolism in dairy cows. From the different subunits of the BCKDH E1 component, only the mRNA for the ß polypeptide (BCKDHB), not for the α polypeptide (BCKDHA), was elevated in liver. The BCKDHA mRNA abundance was similar across all tissues except muscle, which tended to lower values. Highest BCKDHA protein abundance was observed in both liver and MG, whereas BCKDHB protein was detectable in these tissues but could not be quantified. Adipose tissue and muscle only displayed abundance of the α subunit, with muscle having the lowest BCKDHA protein of all tissues. We found similarities in protein abundance for both BCKDH E1 subunits in liver and MG; however, the corresponding overall BCKDH enzyme activity was 7-fold greater in liver compared with MG, allowing for hepatic oxidation of BCAA transamination products. Reduced BCKDH activity in MG associated with no measurable activity in AT and muscle may favor sparing of BCAA for the synthesis of the different milk components, including nonessential AA. Deviating from previously published data on BCAA net fluxes and isotopic tracer studies in ruminants, our observed results might in part be due to complex counter-regulatory mechanisms during early lactation.

Folate and vitamin B12 concentrations are associated with plasma DHA and EPA fatty acids in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study.

This study aimed to examine the association between vitamin B6, folate and vitamin B12 biomarkers and plasma fatty acids in European adolescents. A subsample from the Healthy Lifestyle in Europe by Nutrition in Adolescence study with valid data on B-vitamins and fatty acid blood parameters, and all the other covariates used in the analyses such as BMI, Diet Quality Index, education of the mother and physical activity assessed by a questionnaire, was selected resulting in 674 cases (43 % males). B-vitamin biomarkers were measured by chromatography and immunoassay and fatty acids by enzymatic analyses. Linear mixed models elucidated the association between B-vitamins and fatty acid blood parameters (changes in fatty acid profiles according to change in 10 units of vitamin B biomarkers). DHA, EPA) and n-3 fatty acids showed positive associations with B-vitamin biomarkers, mainly with those corresponding to folate and vitamin B12. Contrarily, negative associations were found with n-6:n-3 ratio, trans-fatty acids and oleic:stearic ratio. With total homocysteine (tHcy), all the associations found with these parameters were opposite (for instance, an increase of 10 nmol/l in red blood cell folate or holotranscobalamin in females produces an increase of 15·85 µmol/l of EPA (P value <0·01), whereas an increase of 10 nmol/l of tHcy in males produces a decrease of 2·06 µmol/l of DHA (P value <0·05). Positive associations between B-vitamins and specific fatty acids might suggest underlying mechanisms between B-vitamins and CVD and it is worth the attention of public health policies.

Association of heart rate and blood pressure among European adolescents with usual food consumption: The HELENA study.

BACKGROUND AND AIM: In adults, there is some evidence that improving diet reduces blood pressure (BP) and the subsequent risk of cardiovascular diseases (CVDs). However, studies that analyse this association in adolescents are still scarce. The objective of the present study was to examine the associations between heart rate, systolic (SBP), diastolic (DBP) and mean arterial blood pressure (MAP) among European adolescents and usual intake of vegetables, fruits, dairy products, meat, fish, high-sugar foods and savoury snacks. METHODS AND RESULTS: In total, 2283 adolescents from the HELENA-study (12.5-17.5 years old; 1253 girls) were included. Dietary intake was assessed using two computerized 24-hour dietary recalls. Age, sex, body mass index, maternal educational level, physical activity and Tanner stage were considered as confounders. Associations were examined by mixed model analysis stratified by sex. Tests for trend were assessed by tertiles of intake while controlling for the aforementioned confounders. Dairy products and fish intake were negatively associated with BP and heart rate. Significant decreasing trends were observed for heart rate and BP across tertiles of dairy products, fish intake and high-sugar foods intake (p < 0.05). Significant increasing trends were observed for SBP and MAP across tertiles of savoury snack intake (p < 0.05). CONCLUSION: Significant but small inverse associations between fish and dairy products consumption with blood pressure and heart rate have been found in European adolescents. Dietary intervention studies are needed to explore these associations in the context of the modification of several risk factors for the prevention of cardiovascular diseases.

Evaluation of food and nutrient intake assessment using concentration biomarkers in European adolescents from the Healthy Lifestyle in Europe by Nutrition in Adolescence study.

Accurate food and nutrient intake assessment is essential for investigating diet-disease relationships. In the present study, food and nutrient intake assessment among European adolescents using 24 h recalls (mean of two recalls) and a FFQ (separately and the combination of both) were evaluated using concentration biomarkers. Biomarkers included were vitamin C, ß-carotene, DHA+EPA, vitamin B12 (cobalamin and holo-transcobalamin) and folate (erythrocyte folate and plasma folate). For the evaluation of the food intake assessment 390 adolescents were included, while 697 were included for the nutrient intake assessment evaluation. Spearman rank and Pearson correlations, and validity coefficients, which are correlations between intake estimated and habitual true intake, were calculated. Correlations were higher between frequency of food consumption (from the FFQ) and concentration biomarkers than between mean food intake (from the recalls) and concentration biomarkers, especially for DHA+EPA (r 0·35 v. r 0·27). Most correlations were higher among girls than boys. For boys, the highest validity coefficients were found for frequency of fruit consumption (0·88) and for DHA+EPA biomarker (0·71). In girls, the highest validity coefficients were found for fruit consumption frequency (0·76), vegetable consumption frequency (0·74), mean fruit intake (0·90) and DHA+EPA biomarker (0·69). After exclusion of underreporters, correlations slightly improved. Correlations between usual food intakes, adjusted for food consumption frequency, and concentration biomarkers were higher than correlations between mean food intakes and concentration biomarkers. In conclusion, two non-consecutive 24 h recalls in combination with a FFQ seem to be appropriate to rank subjects according to their usual food intake.

Vitamin D status and physical function in nursing home residents: a 1-year observational study.

OBJECTIVE: Low vitamin D blood levels are highly prevalent in elderly people, particularly in nursing home residents (NHR). A relation between vitamin D levels and physical function (PF) is described in several studies in older adults; however, data on NHR are scarce and there is presently no information on the time course of vitamin D levels and PF in this population. The aim of the present study was to describe the 25-hydroxyvitamin D [25(OH)D] status of NHR at baseline (t1) and after 1 year (t2) to examine whether 25(OH)D blood levels are related to PF at t1 and at t2, and whether changes in 25(OH)D levels over 1 year are related to changes in PF. METHODS: All NHR (≥ 65 years) without tube-feeding and severe acute or end-stage disease were asked to participate. At t1 and t2 fasting blood samples were taken for the analysis of 25(OH)D serum levels and PF was estimated by activities of daily living (Barthel ADL) and measured by handgrip strength (HGS) and timed 'up and go' test (TUG). RESULTS: In total, 115 residents, aged 87 (82-93) years (all data in median and 1st-3rd quartile), showed the following values for PF: ADL 50 (20-65) points, HGS 40 (30-50) kPa and TUG 26 (18-31) s. Vitamin D deficiency (< 50 nmol/l) was present in 93.9 % (70.4 % < 25 nmol/l) at t1 and in 71.2 % (57.3 % < 25 nmol/l) at t2. At t1 and at t2 a weak correlation between vitamin D level and PF (Spearman's correlation coefficient t1: ADL r = 0.367, HGS r = 0.313; t2: ADL: r = 0.247; all p < 0.01) was observed. There was no correlation between changes in vitamin D levels over 1 year and changes in PF. CONCLUSIONS: Almost all NHR included in the study showed vitamin D deficiency. 25(OH)D levels were weakly correlated to PF at baseline and at follow-up, and an increase in vitamin D levels was not associated with positive effects on PF in this study.

Sampling and processing of fresh blood samples within a European multicenter nutritional study: evaluation of biomarker stability during transport and storage.

INTRODUCTION: Analysis of several biological markers improves the quality and physiologic comprehension of data obtained in epidemiological nutritional studies. AIM: To develop a methodology that guarantees the centralized analysis and quality assurance of the most relevant blood parameters from fresh blood samples in adolescents in a European multicenter study. MATERIALS AND METHODS: Stability of selected nutrients and biomarkers (vitamins, fatty acids, iron metabolism and immunological parameters) chosen with respect to time and temperature of sample transport and storage was evaluated as part of the pilot study of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) project. RESULTS: Routine biochemistry and iron status parameters included in the HELENA Cross-Sectional Study (CSS) protocol could be analyzed within 24 h from fresh blood samples without any stability problems (coefficient of variation (CV)<5%, P<0.05). However, stability tests for lymphocyte subpopulations, vitamin C and fatty acids showed that they are very unstable at room temperature without any treatment. Therefore, a special handling for these samples was developed. Vitamin C was stabilized with metaphosphoric acid and transported under cooled conditions (CV 4.4%, recovery rate >93%, P>0.05). According to the results, a specific methodology and transport system were developed to collect blood samples at schools in 10 European cities and to send them to the centralized laboratory (IEL, Bonn, Germany). To guarantee good clinical practice, the field workers were instructed in a training workshop and a manual of operation was developed. CONCLUSION: The handling and transport system for fresh blood samples developed for the European multicenter study HELENA is adequate for the final part of the HELENA-CSS and will provide, for the first time, reference values for several biological markers in European adolescents.

Combined calcium and vitamin D supplementation is not superior to calcium supplementation alone in improving disturbed bone metabolism in patients with congestive heart failure.

OBJECTIVES: To clarify the potential role of vitamin D supplementation on bone metabolism in congestive heart failure (CHF) patients with low vitamin D status and insufficient dietary calcium intake. SUBJECTS/METHODS: One hundred and two ambulatory male CHF patients were recruited, of whom the majority was treated with loop diuretics. Nine patients died during follow-up. Additional 14 participants dropped out prematurely because their health status worsened markedly. Five patients had to be excluded due to lack of compliance. A daily vitamin D3 supplement plus 500 mg calcium (CaD group) or a placebo plus 500 mg calcium (Ca group) was given for 9 months. Biochemical parameters of vitamin D and bone metabolism were analyzed at baseline and after 9 months. RESULTS: Median 25-hydroxyvitamin D concentrations increased from 41.7 to 103.0 nmol/l (P < 0.001) in the CaD group and remained constant in the Ca group, while median calcium intake increased above 1200 mg/day in both groups. The percentage of patients with elevated parathyroid hormone levels (> 60 pg/ml), as well as the serum concentration of undercarboxylated osteocalcin, an indicator of osteoporotic fracture risk and the bone resorption marker C-telopeptide fell significantly in both study groups (P < 0.025-0.001). At the end of the study period, biomarkers of bone turnover did not differ between groups. CONCLUSIONS: A vitamin D3 supplement of 50 microg/day has no additional beneficial effects on markers of bone metabolism in CHF patients with low initial 25-hydroxyvitamin D concentrations if an adequate daily calcium intake is guaranteed.

Overweight HIV patients with abdominal fat distribution treated with protease inhibitors are at high risk for abnormalities in glucose metabolism - a reason for glycemic control.

BACKGROUND: In HIV patients, disorders in glucose metabolism seem to be side effects of highly active antiretroviral therapy (HAART) which may be favoured by obesity, abdominal fat accumulation and familial disposition for diabetes mellitus (DM). The aim of our study was to identify patients at high risk for abnormalities in glucose metabolism taking into account HAART, familial disposition for DM and anthropometric parameters. METHODS: Plasma glucose, insulin, c-peptide and insulin resistance (homeostasis model assessment, HOMA) were determined in 44 HIV patients [16 without HAART, 19 with protease inhibitors (PI), 9 without PI (non-PI)] and in 11 healthy subjects. Glucose tolerance was determined by standard procedures. Body mass index (BMI), triceps skin fold thickness and waist circumference were measured and the waist-to-hip-ratio was calculated. Familial disposition for DM was assessed by questionnaire. RESULTS: Impaired fasting glucose was observed in 28% of HAART-treated patients (21% with PI, 7% non-PI), in 13% of HAART-naive but none in healthy controls. 58% of PI, 44% of non-PI, 38% of HAART-naive and none of healthy controls had a HOMA-index > 2.5 which indicates insulin resistance. HAART-treated patients had significantly higher fasting glucose levels (PI: 97 +/- 11 mg/dL, p = 0.048; non-PI: 109 +/- 58 mg/dL, p = 0.009) compared to healthy controls (72 +/- 8 mg/dL). HOMA-Index was higher in PI treated patients (3.74 +/- 3.08) than in HIV negative controls (0.95 +/- 0.28, p = 0.018). The duration of HAART (p = 0.045), overweight and familial disposition for DM (p = 0.017) significantly affected fasting glucose among PI users. Waist circumference affected c-peptide (p = 0.046) concentration in these patients. CONCLUSION: HIV patients on long-term PI therapy with overweight and familial disposition for DM are at high risk to develop abnormalities of glucose metabolism. Thus, measurements of HOMA-Index, BMI and waist circumference should be routinely done especially in PI medicated patients.

Consensus meeting: monosodium glutamate - an update.

OBJECTIVE: Update of the Hohenheim consensus on monosodium glutamate from 1997: Summary and evaluation of recent knowledge with respect to physiology and safety of monosodium glutamate. DESIGN: Experts from a range of relevant disciplines received and considered a series of questions related to aspects of the topic. SETTING: University of Hohenheim, Stuttgart, Germany. METHOD: The experts met and discussed the questions and arrived at a consensus. CONCLUSION: Total intake of glutamate from food in European countries is generally stable and ranged from 5 to 12 g/day (free: ca. 1 g, protein-bound: ca. 10 g, added as flavor: ca. 0.4 g). L-Glutamate (GLU) from all sources is mainly used as energy fuel in enterocytes. A maximum intake of 6.000 [corrected] mg/kg body weight is regarded as safe. The general use of glutamate salts (monosodium-L-glutamate and others) as food additive can, thus, be regarded as harmless for the whole population. Even in unphysiologically high doses GLU will not trespass into fetal circulation. Further research work should, however, be done concerning the effects of high doses of a bolus supply at presence of an impaired blood brain barrier function. In situations with decreased appetite (e.g., elderly persons) palatability can be improved by low dose use of monosodium-L-glutamate.

Fruit and vegetables consumption is associated with higher vitamin intake and blood vitamin status among European adolescents.

BACKGROUND/OBJECTIVES: Current research in adults indicates that fruit and vegetable (FAV) consumption increases serum levels of vitamins C, E and folate of ß-carotene and reduces homocysteine concentrations. The aim of the present study was to examine the association of FAV consumption on vitamin intakes and their impact on blood vitamin concentrations in European adolescents. SUBJECT/METHODS: This multi-center cross-sectional study included 702 (53.7% females) adolescents, aged 12.50-17.49 years, from 10 European cities. Two independent self-administered 24 h dietary recalls were used to estimate the adolescent's diet. The total energy, vitamins and FAV consumption were calculated. Adolescents were categorized into three groups: (i) very low FAV intake (<200 g/day); (ii) low FAV consumption (200-399 g/day) and (iii) adequate FAV consumption (⩾400 g/day). Adolescent's fasted blood samples were taken for their analysis on vitamin concentrations. RESULTS: The main results showed that those adolescents meeting the FAV recommendation, classified as FAV adequate consumers, presented higher intake of energy and some vitamins as B6, total folic acid, C, E and ß-carotene compared with FAV very low consumers (P<0.05). Regarding their blood status, male adolescents who had a very low FAV consumption presented lower plasma folate, RBC folate blood concentrations compared with adequate FAV consumers (P<0.05). Female adequate FAV consumers had higher concentrations of pyridoxal phosphate (PLP), plasma folate, RBC folate, vitamin C, ß-carotene and α-tocopherol compared with very low and low consumers (P<0.05). CONCLUSIONS: Having a FAV dairy intake above 400 g/day is associated with higher vitamin intake and blood vitamin concentrations, especially for antioxidant and B-vitamins concentrations.

Parenteral trace element provision: recent clinical research and practical conclusions.

The aim of this systematic review (PubMed, www.ncbi.nlm.nih.gov/pubmed and Cochrane, www.cochrane.org; last entry 31 December 2014) was to present data from recent clinical studies investigating parenteral trace element provision in adult patients and to draw conclusions for clinical practice. Important physiological functions in human metabolism are known for nine trace elements: selenium, zinc, copper, manganese, chromium, iron, molybdenum, iodine and fluoride. Lack of, or an insufficient supply of, these trace elements in nutrition therapy over a prolonged period is associated with trace element deprivation, which may lead to a deterioration of existing clinical symptoms and/or the development of characteristic malnutrition syndromes. Therefore, all parenteral nutrition prescriptions should include a daily dose of trace elements. To avoid trace element deprivation or imbalances, physiological doses are recommended.

Energy and Protein Intake, Anthropometrics, and Disease Burden in Elderly Home-care Receivers--A Cross-sectional Study in Germany (ErnSIPP Study).

OBJECTIVE: To date, no study has examined the nutritional status and disease burden of elderly home-care receivers living in Germany. Aim of this cross-sectional study was, first, to assess disease burden and nutritional status, denoted in anthropometrics, and, second, to investigate associations between anthropometrics and disease burden. DESIGN: Cross-sectional multi-centre study. SETTING: Home-care receivers living in three urban areas of Germany in 2010. PARTICIPANTS: 353 elderly (>64 years) in home care (128 males aged 79.1 ±7.8 years, 225 females aged 82.0 ±7.5 years). MEASUREMENTS: Nutritional status was assessed by body mass index (BMI), mid upper arm circumference (MUAC) and calf circumference (CC). Medical conditions were assessed in personal interviews. A 3-day prospective nutrition diary was kept. Metric data are reported as mean±SD or median (interquartile range), p<0.05 was considered significant. RESULTS: Most participants were substantially (59%), and 11% severest in need of care. The seniors suffered from 5 (4-7) chronic diseases; dementia, depression, stroke, and respiratory illness were most prevalent (each 20-40%). More than one-third of participants had only moderate or poor appetite, nearly half were unable to eat independently. Chewing problems were reported for 52% of study participants, and more than one quarter of elderly had swallowing problems. Daily mean energy intake was 2017±528 kcal in men (n=123) and 1731±451 kcal in women (n=216; p<0.001). Mean protein intake amounted to 1.0 g/kg body weight. Mean BMI was 28.2±6.2 kg/m² (n=341), 14% of seniors had a BMI <22 kg/m² (including 4% with BMI <20 kg/m²). Critical MUAC (<22 cm) was indicated in 6% of subjects; and CC <31 cm in 11% of men, 21% of women (p<0.05). After adjusting for sex and age, BMI, MUAC and CC were negatively associated with high care level, hospitalization in the previous year, nausea/vomiting, prevalence of dementia, poor appetite, and eating difficulties like dependency, chewing and swallowing problems. CONCLUSION: We recommend to pay special attention to the nutritional status of elderly persons in home-care exhibiting named disease burden.

Effects of insulin and amino acids on leg protein turnover in IDDM patients.

To determine whether the responses of muscle protein metabolism to insulin and amino acids in patients with insulin-dependent diabetes mellitus (IDDM) were different from those in nondiabetic subjects, leg tissue kinetics of [15N]phenylalanine and [1-13C]leucine and its metabolites were measured in eight insulin-withdrawn IDDM patients and eight nondiabetic subjects during basal insulinemia and during infusion of insulin (0.29 nmol.min-1.m-2). The diabetic patients were studied in the absence of amino acids, and both groups were studied during infusion of a mixed-amino acid solution (AA). In the diabetic patients, insulin alone and combined with additional AA reduced leg tissue phenylalanine release by 42 and 41%, respectively (both P less than 0.05), but uptake was unchanged. Leg tissue leucine oxidation was unchanged by insulin alone but was increased (P = 0.012) fourfold during insulin infusion with additional AA. In the nondiabetic subjects, insulin with AA infusion increased leg tissue phenylalanine uptake (45.7 +/- 7.5 to 73.1 +/- 7.3 nmol.min-1.100 g-1, P less than 0.01). Insulin-stimulated glucose uptake in the diabetic patients (1.60 +/- 0.28 mumol.min-1.100 g-1, P = 0.04). These results suggest that, in IDDM patients, 1) infusion of insulin fails to stimulate muscle protein synthesis even when combined with a substantially increased provision of AA, and 2) compared with nondiabetic subjects, muscle protein synthesis as well as glucose uptake exhibit blunted responses to insulin.

Safety and intestinal tolerance of high-dose enteral antioxidants and glutamine peptides after upper gastrointestinal surgery.

OBJECTIVE: Safety and intestinal tolerance of an early high-dose enteral administration of antioxidative vitamins, trace elements, and glutamine dipeptides. DESIGN: open intervention trial. SETTING: Two university teaching hospitals. PATIENTS: A total of 14 patients requiring jejunal feeding (64+/-14 y). INTERVENTION: A measure of 500 ml/day Intestamin (FreseniusKabi: 250 kcal/1.050 kJ, 300 microg selenium, 20 mg zinc, 400 mug chromium, 1500 mg vitamin C, 500 mg vitamin E, 10 mg beta-carotene, 30 g glutamine) for 5 days beginning 6 h after surgery. Parenteral/enteral nutrition was provided to achieve energy target (25 kcal/kg/day). ASSESSMENTS: Intestinal complaints, plasma nutrients, and glutathione. RESULTS: Only minor signs of nausea, hiccups, flatulence (3/14). Plasma micronutrients (except beta-carotene) postoperatively decreased and increased to normal on day 5. Extracellular glutamine remained low (preop: 520+/-94; d1: 357+/-67; d5: 389+/-79 micromol/l); total glutathione decreased (d1: 9.4+/-3.8; d5: 3.6+/-2.5 micromol/l). CONCLUSION: Study feed is well tolerated and metabolically safe representing a valuable tool for targeted pharmaconutrient supply.

Fluid intake of community-living, independent elderly in Germany--a nationwide, representative study.

BACKGROUND: Age-related changes in kidney function and thirst sensation increase the susceptibility for dehydration in the elderly. Adequate fluid intake is the most important prerequisite for fluid homeostasis. Reliable data on fluid intake of older subjects in Germany are lacking. OBJECTIVE: To assess fluid intake from beverages and total fluid intake of independent, community-living elderly people in Germany. DESIGN: From a random sample of 4020 non-institutionalized German elderly, stratified into three age-groups (65-74 y., 75-84 y., 85+ y.), 1372 subjects filled in a prospective, standardised 3-day dietary record (cross-sectional study). Fluid intake by beverages and food was calculated on the basis of the German nutrient data base BLS II.2. RESULTS: Daily median beverage consumption (5. / 95. percentiles) amounted to 1567 (700 / 2967) ml in men and 1400 (600 / 2467) ml in women and thus met the actual recommendation (1310 ml per day). With increasing age beverage intake decreased in both sexes. Consequently, the proportion not meeting the reference value increased with age (33 % vs. 44 % vs. 51 %; p < 0.001). Median total water intake (2387 ml in men, 2224 ml in women) also was higher than the reference value (1990 ml per day) and showed similar differences between sex and age groups as fluid intake by beverages. In one third (28 % of the younger elderly and 41 % of the oldest old) total fluid intake was below the recommendation. CONCLUSION: The majority of independently living elderly without major health problems ingests sufficient amounts of fluid to compensate for fluid losses and to be adequately hydrated. Very old elderly, however, require special attention with respect to adequate supply of fluid.

Compliance of nursing home residents with a nutrient- and energy-dense oral nutritional supplement determines effects on nutritional status.

OBJECTIVES: Administration of oral nutritional supplements (ONS) is an effective strategy to treat and avoid malnutrition, a persisting issue in nursing homes. However, little is known about compliance in the NH population. This study aimed to analyse the effects of compliance of NH residents with a low-volume, nutrient- and energy-dense ONS on nutritional status and to identify residents' characteristics associated with compliance. DESIGN AND SETTING: Randomized, controlled trial in nursing homes. PARTICIPANTS AND INTERVENTION: 87 nursing home residents (87 ± 6y, 91% female) with malnutrition or at risk of malnutrition were randomly allocated to an intervention group (IG) receiving 2 x 125 ml ONS (2.4 kcal/ml)/d for 12 weeks, or the control group (CG) with usual care. MEASUREMENTS: ONS intake was recorded daily and compliance calculated. Low and high compliance were defined as ≤ 30% and ≥ 80% of provided ONS actually consumed, respectively. Body weight (BW), BMI, upper-arm (UAC) and calf-circumference (CC) and MNA-SF were assessed at baseline and after 12 weeks. Associations between compliance and changes of nutritional parameters and residents' characteristics were analysed. RESULTS: Compliance was high in 35.7% and low in 28.6% of the IG (n=42). BW change was significantly higher in subjects with high compliance (median +3.0 (interquartile range +2.1;+3.8) kg, n=15) than in those with low compliance (-0.2 (-2.2;+1.6) kg, n=12) and CG (-0.1 (-1.2; +0.6) kg, n=35; p<0.001), and significantly correlated with compliance in IG (r=0.691; p<0.001). Significant differences and correlations were also identified for BMI, UAC and MNA-SF. High compliance was more often observed in residents with malnutrition (66.7 vs. 27.3%) and chewing difficulties (77.8 vs. 24.2%) than in those without these conditions. Low compliance was more prevalent in residents who were immobile (45.0 vs. 13.6%), depressed (33.3 vs. 6.7%) or had gastrointestinal complaints (50.0 vs. 17.9%) (all p<0.05). CONCLUSIONS: A high compliance of nursing home residents with a low volume, nutrient- and energy dense ONS was related to a significantly improved nutritional status in comparison to low compliance and therefore enhanced the effectiveness of ONS. A higher compliance may be achieved by consideration of different residents' characteristics.

Physiologic fluctuations of serum estradiol levels influence biochemical markers of bone resorption in young women.

We investigated the effect of physiologic variations in sex hormone levels during the menstrual cycle on biomarkers of bone turnover. Blood and 24-h and fasting urine samples were obtained in nine women (age, 25.1+/-3.0 yr) with regular menstrual cycles during the early follicular period (t1), 3 days before ovulation (t2), 3 days after ovulation (t3), at the midluteal period (t4) and again during the early follicular period of the next cycle (t5). All subjects had a calcium intake covering current dietary recommendations (above 1,000 mg/day, standardized food record). Serum calcium, phosphorus, calcitriol, 24-h and 2-h fasting urinary calcium, and phosphorus excretion remained constant during the menstrual cycle. Serum 25-hydroxyvitamin D3 levels decreased slightly from the beginning until the end of the study (P<0.05), indicating low cutaneous vitamin D synthesis during wintertime. The serum levels of sex hormones showed typical monthly variations, with the lowest estradiol (E2) levels at t1 and t5. Fasting 2-h pyridinoline (Pyd) concentrations (a marker of bone resorption) fell from t1 to t3 and rose again at t5 (P<0.01). Similar variations were observed for the resorption marker deoxypyridinoline (Dpd; P<0.05). The amplitude of the two biomarkers was 32% and 33%, respectively. The serum levels of the carboxyterminal propeptide of type I collagen (a marker of bone formation) showed an inverse cyclic pattern, as compared with the pyridinium cross-links. Low concentrations were observed at t1; a rise occurred until t3 and was followed by a decrease until t5 (P<0.05). A similar cyclic pattern was observed for serum PTH levels, with the highest concentrations at t3 (P<0.05). Dpd and Pyd values were significantly correlated with serum E2 levels (r = 0.52; P<0.0001 and r = 0.50; P<0.001, respectively). Neither progesterone nor LH nor FSH was correlated with Pyd or Dpd levels. The data suggest that normal menstrual cycling in young women is associated with monthly fluctuations in bone turnover. This physiological effect of the menstrual cycle is most probably related to variations in serum E2 concentrations.

Determination of glutamine in muscle protein facilitates accurate assessment of proteolysis and de novo synthesis-derived endogenous glutamine production.

BACKGROUND: Results of tracer studies indicate that skeletal muscle contributes to approximately 70% of overall glutamine production in healthy adults; the contribution of de novo synthesis being estimated at approximately 60%. However, measurement of the de novo synthesis rate in muscle tissue requires knowledge of the appearance rate of glutamine in plasma and the quantity of glutamine derived from intracellular proteolysis. Thus, the content of glutamine in muscle protein is a prerequisite for an accurate calculation. OBJECTIVE: The objective of the study was to measure glutamine in muscle protein. DESIGN: Muscle specimens (open biopsies) were obtained from humans (10 men and 4 women), rats (n = 4), cows (n = 4), and pigs (n = 4). Glutamine was assessed via prehydrolysis derivatization, rapid microwave-enhanced acid hydrolysis, and 5-dimethylaminonaphthalene-1-sulfonyl chloride (dansyl chloride) reversed-phase HPLC, and expressed per mg alkali-soluble protein (ASP) and DNA. RESULTS: Glutamine concentrations in muscle cell protein of various species ranged from 41 to 49 microg/mg ASP; the differences were not species related. The combined means (+/-SDs) for the 4 species were 43.6 +/- 4.9 microg/mg ASP and 11.9 +/- 2.0 mg/mg DNA, respectively. In humans, there was no apparent influence of age, sex, or BMI. CONCLUSIONS: Direct and specific measurements of glutamine in intact muscle protein were 50% lower than assumed previously. We used data compiled from earlier studies to recalculate the contributions of proteolysis and de novo synthesis to the endogenous production of glutamine in selected age groups of healthy humans; these contributions remained remarkably constant at approximately 13% and approximately 87%, respectively.